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sciq-3167
|
multiple_choice
|
What part of the brain lies under the cerebrum and behind the brain stem?
|
[
"cerebellum",
"medulla",
"thymus",
"spinal cord"
] |
A
|
Relavent Documents:
Document 0:::
The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the body, processing, integrating, and coordinating the information it receives from the sense organs, and making decisions as to the instructions sent to the rest of the body. The brain is contained in, and protected by, the skull bones of the head.
The cerebrum, the largest part of the human brain, consists of two cerebral hemispheres. Each hemisphere has an inner core composed of white matter, and an outer surface – the cerebral cortex – composed of grey matter. The cortex has an outer layer, the neocortex, and an inner allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four. Each hemisphere is conventionally divided into four lobes – the frontal, temporal, parietal, and occipital lobes. The frontal lobe is associated with executive functions including self-control, planning, reasoning, and abstract thought, while the occipital lobe is dedicated to vision. Within each lobe, cortical areas are associated with specific functions, such as the sensory, motor and association regions. Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum.
The cerebrum is connected by the brainstem to the spinal cord. The brainstem consists of the midbrain, the pons, and the medulla oblongata. The cerebellum is connected to the brainstem by three pairs of nerve tracts called cerebellar peduncles. Within the cerebrum is the ventricular system, consisting of four interconnected ventricles in which cerebrospinal fluid is produced and circulated. Underneath the cerebral cortex
Document 1:::
The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain.
The temporal lobe is involved in processing sensory input into derived meanings for the appropriate retention of visual memory, language comprehension, and emotion association.
Temporal refers to the head's temples.
Structure
The temporal lobe consists of structures that are vital for declarative or long-term memory. Declarative (denotative) or explicit memory is conscious memory divided into semantic memory (facts) and episodic memory (events). Medial temporal lobe structures that are critical for long-term memory include the hippocampus, along with the surrounding hippocampal region consisting of the perirhinal, parahippocampal, and entorhinal neocortical regions. The hippocampus is critical for memory formation, and the surrounding medial temporal cortex is currently theorized to be critical for memory storage. The prefrontal and visual cortices are also involved in explicit memory.
Research has shown that lesions in the hippocampus of monkeys results in limited impairment of function, whereas extensive lesions that include the hippocampus and the medial temporal cortex result in severe impairment.
Function
Visual memories
The temporal lobe communicates with the hippocampus and plays a key role in the formation of explicit long-term memory modulated by the amygdala.
Processing sensory input
Auditory Adjacent areas in the superior, posterior, and lateral parts of the temporal lobes are involved in high-level auditory processing. The temporal lobe is involved in primary auditory perception, such as hearing, and holds the primary auditory cortex. The primary auditory cortex receives sensory information from the ears and secondary areas process the information into meaningful units such as speech and words. The superior temporal gyrus includes an area (wit
Document 2:::
The ovarian cortex is the outer portion of the ovary. The ovarian follicles are located within the ovarian cortex. The ovarian cortex is made up of connective tissue. Ovarian cortex tissue transplant has been performed to treat infertility.
Document 3:::
The human brain anatomical regions are ordered following standard neuroanatomy hierarchies. Functional, connective, and developmental regions are listed in parentheses where appropriate.
Hindbrain (rhombencephalon)
Myelencephalon
Medulla oblongata
Medullary pyramids
Arcuate nucleus
Olivary body
Inferior olivary nucleus
Rostral ventrolateral medulla
Caudal ventrolateral medulla
Solitary nucleus (Nucleus of the solitary tract)
Respiratory center-Respiratory groups
Dorsal respiratory group
Ventral respiratory group or Apneustic centre
Pre-Bötzinger complex
Botzinger complex
Retrotrapezoid nucleus
Nucleus retrofacialis
Nucleus retroambiguus
Nucleus para-ambiguus
Paramedian reticular nucleus
Gigantocellular reticular nucleus
Parafacial zone
Cuneate nucleus
Gracile nucleus
Perihypoglossal nuclei
Intercalated nucleus
Prepositus nucleus
Sublingual nucleus
Area postrema
Medullary cranial nerve nuclei
Inferior salivatory nucleus
Nucleus ambiguus
Dorsal nucleus of vagus nerve
Hypoglossal nucleus
Chemoreceptor trigger zone
Metencephalon
Pons
Pontine nuclei
Pontine cranial nerve nuclei
Chief or pontine nucleus of the trigeminal nerve sensory nucleus (V)
Motor nucleus for the trigeminal nerve (V)
Abducens nucleus (VI)
Facial nerve nucleus (VII)
Vestibulocochlear nuclei (vestibular nuclei and cochlear nuclei) (VIII)
Superior salivatory nucleus
Pontine tegmentum
Pontine micturition center (Barrington's nucleus)
Locus coeruleus
Pedunculopontine nucleus
Laterodorsal tegmental nucleus
Tegmental pontine reticular nucleus
Nucleus incertus
Parabrachial area
Medial parabrachial nucleus
Lateral parabrachial nucleus
Subparabrachial nucleus (Kölliker-Fuse nucleus)
Pontine respiratory group
Superior olivary complex
Medial superior olive
Lateral superior olive
Medial nucleus of the trapezoid body
Paramedian pontine reticular formation
Parvocellular reticular nucleus
Caudal pontine reticular nucleus
Cerebellar peduncles
Superior cerebellar peduncle
Middle cerebellar peduncle
Inferior
Document 4:::
In neuroanatomy, the centrum semiovale, semioval center or centrum ovale is the central area of white matter found underneath the cerebral cortex.
The white matter, located in each hemisphere between the cerebral cortex and nuclei, as a whole has a semioval shape. It consists of cortical projection fibers, association fibers and cortical fibers. It continues ventrally as the corona radiata.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What part of the brain lies under the cerebrum and behind the brain stem?
A. cerebellum
B. medulla
C. thymus
D. spinal cord
Answer:
|
|
sciq-3810
|
multiple_choice
|
Brown algae are important commodities for what?
|
[
"fish",
"reptiles",
"humans",
"parasites"
] |
C
|
Relavent Documents:
Document 0:::
The European Algae Biomass Association (EABA), established on 2 June 2009, is the European association representing both research and industry in the field of algae technologies.
EABA was founded during its inaugural conference on 1–2 June 2009 at Villa La Pietra in Florence. The association is headquartered in Florence, Italy.
History
The first EABA's President, Prof. Dr. Mario Tredici, served a 2-year term since his election on 2 June 2009. The EABA Vice-presidents were Mr. Claudio Rochietta, (Oxem, Italy), Prof. Patrick Sorgeloos (University of Ghent, Belgium) and Mr. Marc Van Aken (SBAE Industries, Belgium). The EABA Executive Director was Mr. Raffaello Garofalo.
EABA had 58 founding members and the EABA reached 79 members in 2011.
The last election occurred on 3 December 2018 in Amsterdam. The EABA's President is Mr. Jean-Paul Cadoret (Algama / France). The EABA Vice-presidents are Prof. Dr. Sammy Boussiba (Ben-Gurion University of the Negev / Israel), Prof. Dr. Gabriel Acien (University of Almeria / Spain) and Dr. Alexandra Mosch (Germany). The EABA General Manager is Dr. Vítor Verdelho (A4F AlgaFuel, S.A. / Portugal) and Prof. Dr. Mario Tredici (University of Florence / Italy) is elected as Honorary President.
Cooperation with other organisations
ART Fuels Forum
European Society of Biochemical Engineering Sciences
Algae Biomass Organization
Document 1:::
The Bachelor of Science in Aquatic Resources and Technology (B.Sc. in AQT) (or Bachelor of Aquatic Resource) is an undergraduate degree that prepares students to pursue careers in the public, private, or non-profit sector in areas such as marine science, fisheries science, aquaculture, aquatic resource technology, food science, management, biotechnology and hydrography. Post-baccalaureate training is available in aquatic resource management and related areas.
The Department of Animal Science and Export Agriculture, at the Uva Wellassa University of Badulla, Sri Lanka, has the largest enrollment of undergraduate majors in Aquatic Resources and Technology, with about 200 students as of 2014.
The Council on Education for Aquatic Resources and Technology includes undergraduate AQT degrees in the accreditation review of Aquatic Resources and Technology programs and schools.
See also
Marine Science
Ministry of Fisheries and Aquatic Resources Development
Document 2:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 3:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 4:::
The SERI microalgae culture collection was a collection from the Department of Energy's Aquatic Species Program cataloged at the Solar Energy Research Institute located in Golden, Colorado. The Aquatic Species Program ended in 1996 after its funding was cut, at which point its microalgae collection was moved to the University of Hawaii. In 1998 the University of Hawaii, partnered with the University of California at Berkeley, received a grant from the National Science Foundation (NSF), for their proposal to develop commercial, medical, and industrial uses of microalgae, as well as new and more efficient techniques for cultivation. This grant was used to form Marine Bioproduct Engineering Center (MarBEC), a facility operating within the University system of Hawaii at Manoa, but connected to corporate interests.
Below is a list of the algal-strains in the microalgae culture collection from the closeout report of the Department of Energy's Aquatic Species Program.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Brown algae are important commodities for what?
A. fish
B. reptiles
C. humans
D. parasites
Answer:
|
|
sciq-2211
|
multiple_choice
|
What kind of rock's makeup is changed by heat and or pressure?
|
[
"metamorphic",
"basaltic",
"igneous",
"tectonic"
] |
A
|
Relavent Documents:
Document 0:::
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects.
Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing rocks. Metamorphic rocks are formed when existing rocks are subjected to such high pressures and temperatures that they are transformed without significant melting.
Humanity has made use of rocks since the earliest humans. This early period, called the Stone Age, saw the development of many stone tools. Stone was then used as a major component in the construction of buildings and early infrastructure. Mining developed to extract rocks from the Earth and obtain the minerals within them, including metals. Modern technology has allowed the development of new man-made rocks and rock-like substances, such as concrete.
Study
Geology is the study of Earth and its components, including the study of rock formations. Petrology is the study of the character and origin of rocks. Mineralogy is the study of the mineral components that create rocks. The study of rocks and their components has contributed to the geological understanding of Earth's history, the archaeological understanding of human history, and the
Document 1:::
The rock cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneous rock such as basalt may break down and dissolve when exposed to the atmosphere, or melt as it is subducted under a continent. Due to the driving forces of the rock cycle, plate tectonics and the water cycle, rocks do not remain in equilibrium and change as they encounter new environments. The rock cycle explains how the three rock types are related to each other, and how processes change from one type to another over time. This cyclical aspect makes rock change a geologic cycle and, on planets containing life, a biogeochemical cycle.
Transition to igneous rock
When rocks are pushed deep under the Earth's surface, they may melt into magma. If the conditions no longer exist for the magma to stay in its liquid state, it cools and solidifies into an igneous rock. A rock that cools within the Earth is called intrusive or plutonic and cools very slowly, producing a coarse-grained texture such as the rock granite. As a result of volcanic activity, magma (which is called lava when it reaches Earth's surface) may cool very rapidly on the Earth's surface exposed to the atmosphere and are called extrusive or volcanic rocks. These rocks are fine-grained and sometimes cool so rapidly that no crystals can form and result in a natural glass, such as obsidian, however the most common fine-grained rock would be known as basalt. Any of the three main types of rocks (igneous, sedimentary, and metamorphic rocks) can melt into magma and cool into igneous rocks.
Secondary changes
Epigenetic change (secondary processes occurring at low temperatures and low pressures) may be arranged under a number of headings, each of which is typical of a group of rocks or rock-forming minerals, though usually more than one of these alt
Document 2:::
The geologic record in stratigraphy, paleontology and other natural sciences refers to the entirety of the layers of rock strata. That is, deposits laid down by volcanism or by deposition of sediment derived from weathering detritus (clays, sands etc.). This includes all its fossil content and the information it yields about the history of the Earth: its past climate, geography, geology and the evolution of life on its surface. According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other. They harden over time to become a solidified (competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events.
Correlating the rock record
At a certain locality on the Earth's surface, the rock column provides a cross section of the natural history in the area during the time covered by the age of the rocks. This is sometimes called the rock history and gives a window into the natural history of the location that spans many geological time units such as ages, epochs, or in some cases even multiple major geologic periods—for the particular geographic region or regions. The geologic record is in no one place entirely complete for where geologic forces one age provide a low-lying region accumulating deposits much like a layer cake, in the next may have uplifted the region, and the same area is instead one that is weathering and being torn down by chemistry, wind, temperature, and water. This is to say that in a given location, the geologic record can be and is quite often interrupted as the ancient local environment was converted by geological forces into new landforms and features. Sediment core data at the mouths of large riverine drainage basins, some of which go deep thoroughly support the law of superposition.
However using broadly occurring deposited layers trapped within differently located rock columns, geologists have pieced together a system of units covering most of the geologic time scale
Document 3:::
In science and engineering the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By high pressure is usually meant pressures of thousands (kilobars) or millions (megabars) of times atmospheric pressure (about 1 bar or 100,000 Pa).
History and overview
Percy Williams Bridgman received a Nobel Prize in 1946 for advancing this area of physics by two magnitudes of pressure (400 MPa to 40 GPa). The list of founding fathers of this field includes also the names of Harry George Drickamer, Tracy Hall, Francis P. Bundy, , and .
It was by applying high pressure as well as high temperature to carbon that man-made diamonds were first produced alongside many other interesting discoveries. Almost any material when subjected to high pressure will compact itself into a denser form, for example, quartz (also called silica or silicon dioxide) will first adopt a denser form known as coesite, then upon application of even higher pressure, form stishovite. These two forms of silica were first discovered by high-pressure experimenters, but then found in nature at the site of a meteor impact.
Chemical bonding is likely to change under high pressure, when the P*V term in the free energy becomes comparable to the energies of typical chemical bonds – i.e. at around 100 GPa. Among the most striking changes are metallization of oxygen at 96 GPa (rendering oxygen a superconductor), and transition of sodium from a nearly-free-electron metal to a transparent insulator at ~200 GPa. At ultimately high compression, however, all materials will metallize.
High-pressure experimentation has led to the discovery of the types of minerals which are believed to exist in the deep mantle of the Earth, such as silicate perovskite, which is thought to make up half of the Earth's bulk, and post-perovskite, which occurs at the core-mantle boundary and explains many anomalies inferred for that regio
Document 4:::
Rock mechanics is a theoretical and applied science of the mechanical behavior of rocks and rock masses.
Compared to geology, it is the branch of mechanics concerned with the response of rock and rock masses to the force fields of their physical environment.
Background
Rock mechanics is part of a much broader subject of geomechanics, which is concerned with the mechanical responses of all geological materials, including soils.
Rock mechanics is concerned with the application of the principles of engineering mechanics to the design of structures built in or on rock. The structure could include many objects such as a drilling well, a mine shaft, a tunnel, a reservoir dam, a repository component, or a building. Rock mechanics is used in many engineering disciplines, but is primarily used in Mining, Civil, Geotechnical, Transportation, and Petroleum Engineering.
Rock mechanics answers questions such as, "is reinforcement necessary for a rock, or will it be able to handle whatever load it is faced with?" It also includes the design of reinforcement systems, such as rock bolting patterns.
Assessing the Project Site
Before any work begins, the construction site must be investigated properly to inform of the geological conditions of the site. Field observations, deep drilling, and geophysical surveys, can all give necessary information to develop a safe construction plan and create a site geological model. The level of investigation conducted at this site depends on factors such as budget, time frame, and expected geological conditions.
The first step of the investigation is the collection of maps and aerial photos to analyze. This can provide information about potential sinkholes, landslides, erosion, etc. Maps can provide information on the rock type of the site, geological structure, and boundaries between bedrock units.
Boreholes
Creating a borehole is a technique that consists of drilling through the ground in various areas at various depths, to get a bett
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of rock's makeup is changed by heat and or pressure?
A. metamorphic
B. basaltic
C. igneous
D. tectonic
Answer:
|
|
ai2_arc-666
|
multiple_choice
|
Four students are investigating the effect of the force of a baseball bat on a ball. They marked the four different points where each of the balls made contact on the bat after each strike by each of the four students. Which of the following describes an error in the experimental design?
|
[
"failure to conduct enough trials",
"not considering the spin of the ball",
"not using balls of different masses",
"failure to define one testable variable"
] |
D
|
Relavent Documents:
Document 0:::
A glossary of terms used in experimental research.
Concerned fields
Statistics
Experimental design
Estimation theory
Glossary
Alias: When the estimate of an effect also includes the influence of one or more other effects (usually high order interactions) the effects are said to be aliased (see confounding). For example, if the estimate of effect D in a four factor experiment actually estimates (D + ABC), then the main effect D is aliased with the 3-way interaction ABC. Note: This causes no difficulty when the higher order interaction is either non-existent or insignificant.
Analysis of variance (ANOVA): A mathematical process for separating the variability of a group of observations into assignable causes and setting up various significance tests.
Balanced design: An experimental design where all cells (i.e. treatment combinations) have the same number of observations.
Blocking: A schedule for conducting treatment combinations in an experimental study such that any effects on the experimental results due to a known change in raw materials, operators, machines, etc., become concentrated in the levels of the blocking variable. Note: the reason for blocking is to isolate a systematic effect and prevent it from obscuring the main effects. Blocking is achieved by restricting randomization.
Center Points: Points at the center value of all factor ranges.
Coding Factor Levels: Transforming the scale of measurement for a factor so that the high value becomes +1 and the low value becomes -1 (see scaling). After coding all factors in a 2-level full factorial experiment, the design matrix has all orthogonal columns. Coding is a simple linear transformation of the original measurement scale. If the "high" value is Xh and the "low" value is XL (in the original scale), then the scaling transformation takes any original X value and converts it to (X − a)/b, where a = (Xh + XL)/2 and b = (Xh−XL)/2. To go back to the original measurement scale, just take the coded value a
Document 1:::
The Design of Experiments is a 1935 book by the English statistician Ronald Fisher about the design of experiments and is considered a foundational work in experimental design. Among other contributions, the book introduced the concept of the null hypothesis in the context of the lady tasting tea experiment. A chapter is devoted to the Latin square.
Chapters
Introduction
The principles of experimentation, illustrated by a psycho-physical experiment
A historical experiment on growth rate
An agricultural experiment in randomized blocks
The Latin square
The factorial design in experimentation
Confounding
Special cases of partial confounding
The increase of precision by concomitant measurements. Statistical Control
The generalization of null hypotheses. Fiducial probability
The measurement of amount of information in general
Quotations regarding the null hypothesis
Fisher introduced the null hypothesis by an example, the now famous Lady tasting tea experiment, as a casual wager. She claimed the ability to determine the means of tea preparation by taste. Fisher proposed an experiment and an analysis to test her claim. She was to be offered 8 cups of tea, 4 prepared by each method, for determination. He proposed the null hypothesis that she possessed no such ability, so she was just guessing. With this assumption, the number of correct guesses (the test statistic) formed a hypergeometric distribution. Fisher calculated that her chance of guessing all cups correctly was 1/70. He was provisionally willing to concede her ability (rejecting the null hypothesis) in this case only. Having an example, Fisher commented:
"...the null hypothesis is never proved or established, but is possibly disproved, in the course of experimentation. Every experiment may be said to exist only in order to give the facts a chance of disproving the null hypothesis."
"...the null hypothesis must be exact, that is free from vagueness and ambiguity, because it must supply the
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 4:::
The barometer question is an example of an incorrectly designed examination question demonstrating functional fixedness that causes a moral dilemma for the examiner. In its classic form, popularized by American test designer professor Alexander Calandra (1911–2006), the question asked the student to "show how it is possible to determine the height of a tall building with the aid of a barometer." The examiner was confident that there was one, and only one, correct answer, which is found by measuring the difference in pressure at the top and bottom of the building and solving for height. Contrary to the examiner's expectations, the student responded with a series of completely different answers. These answers were also correct, yet none of them proved the student's competence in the specific academic field being tested.
The barometer question achieved the status of an urban legend; according to an internet meme, the question was asked at the University of Copenhagen and the student was Niels Bohr. The Kaplan, Inc. ACT preparation textbook describes it as an "MIT legend", and an early form is found in a 1958 American humor book. However, Calandra presented the incident as a real-life, first-person experience that occurred during the Sputnik crisis. Calandra's essay, "Angels on a Pin", was published in 1959 in Pride, a magazine of the American College Public Relations Association. It was reprinted in Current Science in 1964, in Saturday Review in 1968 and included in the 1969 edition of Calandra's The Teaching of Elementary Science and Mathematics. Calandra's essay became a subject of academic discussion. It was frequently reprinted since 1970, making its way into books on subjects ranging from teaching, writing skills, workplace counseling and investment in real estate to chemical industry, computer programming and integrated circuit design.
Calandra's account
A colleague of Calandra posed the barometer question to a student, expecting the correct answer: "the heigh
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Four students are investigating the effect of the force of a baseball bat on a ball. They marked the four different points where each of the balls made contact on the bat after each strike by each of the four students. Which of the following describes an error in the experimental design?
A. failure to conduct enough trials
B. not considering the spin of the ball
C. not using balls of different masses
D. failure to define one testable variable
Answer:
|
|
sciq-1472
|
multiple_choice
|
Blood from the body enters what chamber of the heart before it is pumped to the right ventricle and then to the lungs?
|
[
"left bivalve",
"left atrium",
"left ventricle",
"right atrium"
] |
D
|
Relavent Documents:
Document 0:::
A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles (for example the interventricular septum), while intraventricular means within one ventricle (for example an intraventricular block).
In a four-chambered heart, such as that in humans, there are two ventricles that operate in a double circulatory system: the right ventricle pumps blood into the pulmonary circulation to the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta.
Structure
Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated by the atria to fill the ventricles. Further, the left ventricle has thicker walls than the right because it needs to pump blood to most of the body while the right ventricle fills only the lungs.
On the inner walls of the ventricles are irregular muscular columns called trabeculae carneae which cover all of the inner ventricular surfaces except that of the conus arteriosus, in the right ventricle. There are three types of these muscles. The third type, the papillary muscles, give origin at their apices to the chordae tendinae which attach to the cusps of the tricuspid valve and to the mitral valve.
The mass of the left ventricle, as estimated by magnetic resonance imaging, averages 143 g ± 38.4 g, with a range of 87–224 g.
The right ventricle is equal in size to the left ventricle and contains roughly 85 millilitres (3 imp fl oz; 3 US fl oz) in the adult. Its upper front surface is circled and convex, and forms much of the sternocostal surface of the heart. Its under surface is flattened, forming pa
Document 1:::
The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs. In the lungs the blood is oxygenated and returned to the left atrium to complete the circuit.
The other division of the circulatory system is the systemic circulation that begins with receiving the oxygenated blood from the pulmonary circulation into the left atrium. From the atrium the oxygenated blood enters the left ventricle where it is pumped out to the rest of the body, returning as deoxygenated blood back to the pulmonary circulation.
The blood vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary veins.
A separate circulatory circuit known as the bronchial circulation supplies oxygenated blood to the tissue of the larger airways of the lung.
Structure
De-oxygenated blood leaves the heart, goes to the lungs, and then enters back into the heart. De-oxygenated blood leaves through the right ventricle through the pulmonary artery. From the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve) into the right ventricle. Blood is then pumped from the right ventricle through the pulmonary valve and into the pulmonary artery.
Lungs
The pulmonary arteries carry deoxygenated blood to the lungs, where carbon dioxide is released and oxygen is picked up during respiration. Arteries are further divided into very fine capillaries which are extremely thin-walled. The pulmonary veins return oxygenated blood to the left atrium of the heart.
Veins
Oxygenated blood leaves the lungs through pulmonary veins, which return it to the left part of the heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. From the left ventricle, the blood passes through the aortic valve to the
Document 2:::
The tubular heart or primitive heart tube is the earliest stage of heart development.
From the inflow to the outflow, it consists of sinus venosus, primitive atrium, the primitive ventricle, the bulbus cordis, and truncus arteriosus.
It forms primarily from splanchnic mesoderm. More specifically, they form from endocardial tubes, starting at day 21.
Document 3:::
A heart valve is a one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart valve opens or closes according to differential blood pressure on each side.
The four valves in the mammalian heart are two atrioventricular valves separating the upper atria from the lower ventricles – the mitral valve in the left heart, and the tricuspid valve in the right heart. The other two valves are at the entrance to the arteries leaving the heart these are the semilunar valves – the aortic valve at the aorta, and the pulmonary valve at the pulmonary artery.
The heart also has a coronary sinus valve and an inferior vena cava valve, not discussed here.
Structure
The heart valves and the chambers are lined with endocardium. Heart valves separate the atria from the ventricles, or the ventricles from a blood vessel. Heart valves are situated around the fibrous rings of the cardiac skeleton. The valves incorporate flaps called leaflets or cusps, similar to a duckbill valve or flutter valve, which are pushed open to allow blood flow and which then close together to seal and prevent backflow. The mitral valve has two cusps, whereas the others have three. There are nodules at the tips of the cusps that make the seal tighter.
The pulmonary valve has left, right, and anterior cusps. The aortic valve has left, right, and posterior cusps. The tricuspid valve has anterior, posterior, and septal cusps; and the mitral valve has just anterior and posterior cusps.
The valves of the human heart can be grouped in two sets:
Two atrioventricular valves to prevent backflow of blood from the ventricles into the atria:
Tricuspid valve or right atrioventricular valve, between the right atrium and right ventricle
Mitral valve or bicuspid valve, between the left atrium and left ventricle
Two semilunar valves to prevent the backflow o
Document 4:::
The right atrioventricular orifice (right atrioventricular opening) is the large oval aperture of communication between the right atrium and ventricle in the heart.
Situated at the base of the atrium, it measures about 3.8 to 4 cm. in diameter and is surrounded by a fibrous ring, covered by the lining membrane of the heart; it is considerably larger than the corresponding aperture on the left side, being sufficient to admit the ends of four fingers.
It is guarded by the tricuspid valve.
See also
Left atrioventricular orifice
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Blood from the body enters what chamber of the heart before it is pumped to the right ventricle and then to the lungs?
A. left bivalve
B. left atrium
C. left ventricle
D. right atrium
Answer:
|
|
sciq-4358
|
multiple_choice
|
What is glucose used for the bacteria?
|
[
"energy",
"fuel",
"reproduction",
"food"
] |
D
|
Relavent Documents:
Document 0:::
MicrobeLibrary is a permanent collection of over 1400 original peer-reviewed resources for teaching undergraduate microbiology. It is provided by the American Society for Microbiology, Washington DC, United States.
Contents include curriculum activities; images and animations; reviews of books, websites and other resources; and articles from Focus on Microbiology Education, Microbiology Education and Microbe. Around 40% of the materials are free to educators and students, the remainder require a subscription. the service is suspended with the message to:
"Please check back with us in 2017".
External links
MicrobeLibrary
Microbiology
Document 1:::
The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology
In general the field of microbiology can be divided in the more fundamental branch (pure microbiology) and the applied microbiology (biotechnology). In the more fundamental field the organisms are studied as the subject itself on a deeper (theoretical) level.
Applied microbiology refers to the fields where the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms itself are often not studied as such, but applied to sustain certain processes.
Pure microbiology
Bacteriology: the study of bacteria
Mycology: the study of fungi
Protozoology: the study of protozoa
Phycology/algology: the study of algae
Parasitology: the study of parasites
Immunology: the study of the immune system
Virology: the study of viruses
Nematology: the study of nematodes
Microbial cytology: the study of microscopic and submicroscopic details of microorganisms
Microbial physiology: the study of how the microbial cell functions biochemically. Includes the study of microbial growth, microbial metabolism and microbial cell structure
Microbial pathogenesis: the study of pathogens which happen to be microbes
Microbial ecology: the relationship between microorganisms and their environment
Microbial genetics: the study of how genes are organized and regulated in microbes in relation to their cellular functions Closely related to the field of molecular biology
Cellular microbiology: a discipline bridging microbiology and cell biology
Evolutionary microbiology: the study of the evolution of microbes. This field can be subdivided into:
Micr
Document 2:::
List of Useful Microorganisms Used In preparation Of Food And Beverage
See also
Fermentation (food)
Food microbiology
Document 3:::
Fibrolytic bacteria constitute a group of microorganisms that are able to process complex plant polysaccharides thanks to their capacity to synthesize cellulolytic and hemicellulolytic enzymes. Polysaccharides are present in plant cellular cell walls in a compact fiber form where they are mainly composed of cellulose and hemicellulose.
Fibrolytic enzymes, which are classified as cellulases, can hydrolyze the β (1 ->4) bonds in plant polysaccharides. Cellulase and hemicellulase (also known as xylanase) are the two main representatives of these enzymes.
Biological characteristics
Fibrolytic bacteria use glycolysis and the pentose phosphate pathway as the main metabolic routes to catabolize carbohydrates in order to obtain energy and carbon backbones. They use ammonia as the major and practically exclusive source of nitrogen, and they require several B-vitamins for their development.
They often depend on other microorganisms to obtain some of their nutrients. Although their growth rate is considered slow, it can be enhanced in the presence of considerable amounts of short-chain fatty acids (isobutyric and isovaleric). These compounds are normally generated as a product of the amino acid fermentative activity of other microorganisms.
Because of their habitat conditions, most fibrolytic bacteria are anaerobic.
Cellulolytic communities
Most fibrolytic bacteria are classified as Bacteroidota or Bacillota and include several bacterial species with diverse morphological and physiological characteristics.
They are normally commensal species which have a symbiotic relationship with different insect and mammal species, constituting one of the main components of their gastrointestinal flora. In fact, in herbivores each milliliter of ruminal content can reach about 50 million of bacteria of a great variety of genera and species. .
Given the importance of industrial processing of plant fibers in different fields, the genomic analysis of fibrolytic communities in the gastroi
Document 4:::
Industrial microbiology is a branch of biotechnology that applies microbial sciences to create industrial products in mass quantities, often using microbial cell factories. There are multiple ways to manipulate a microorganism in order to increase maximum product yields. Introduction of mutations into an organism may be accomplished by introducing them to mutagens. Another way to increase production is by gene amplification, this is done by the use of plasmids, and vectors. The plasmids and/ or vectors are used to incorporate multiple copies of a specific gene that would allow more enzymes to be produced that eventually cause more product yield. The manipulation of organisms in order to yield a specific product has many applications to the real world like the production of some antibiotics, vitamins, enzymes, amino acids, solvents, alcohol and daily products. Microorganisms play a big role in the industry, with multiple ways to be used. Medicinally, microbes can be used for creating antibiotics in order to treat infection. Microbes can also be used for the food industry as well. Microbes are very useful in creating some of the mass produced products that are consumed by people. The chemical industry also uses microorganisms in order to synthesize amino acids and organic solvents. Microbes can also be used in an agricultural application for use as a biopesticide instead of using dangerous chemicals and or inoculants to help plant proliferation.
Medical application
The medical application to industrial microbiology is the production of new drugs synthesized in a specific organism for medical purposes. Production of antibiotics is necessary for the treatment of many bacterial infections. Some natural occurring antibiotics and precursors, are produced through a process called fermentation. The microorganisms grow in a liquid media where the population size is controlled in order to yield the greatest amount of product. In this environment nutrient, pH, temperature, an
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is glucose used for the bacteria?
A. energy
B. fuel
C. reproduction
D. food
Answer:
|
|
sciq-3021
|
multiple_choice
|
What to tadpoles develop into?
|
[
"frogs",
"mosquitos",
"snakes",
"toads"
] |
A
|
Relavent Documents:
Document 0:::
The common frog or grass frog (Rana temporaria), also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog, is a semi-aquatic amphibian of the family Ranidae, found throughout much of Europe as far north as Scandinavia and as far east as the Urals, except for most of the Iberian Peninsula, southern Italy, and the southern Balkans. The farthest west it can be found is Ireland. It is also found in Asia, and eastward to Japan. The nominative, and most common, subspecies Rana temporaria temporaria is a largely terrestrial frog native to Europe. It is distributed throughout northern Europe and can be found in Ireland, the Isle of Lewis and as far east as Japan.
Common frogs metamorphose through three distinct developmental life stages — aquatic larva, terrestrial juvenile, and adult. They have corpulent bodies with a rounded snout, webbed feet and long hind legs adapted for swimming in water and hopping on land. Common frogs are often confused with the common toad (Bufo bufo), but frogs can easily be distinguished as they have longer legs, hop, and have a moist skin, whereas toads crawl and have a dry 'warty' skin. The spawn of the two species also differs, in that frog spawn is laid in clumps and toad spawn is laid in long strings.
There are 3 subspecies of the common frog, R. t. temporaria, R. t. honnorati and R. t. palvipalmata. R. t. temporaria is the most common subspecies of this frog.
Description
The adult common frog has a body length of . In addition, its back and flanks vary in colour from olive green to grey-brown, brown, olive brown, grey, yellowish and rufous. However, it can lighten and darken its skin to match its surroundings. Some individuals have more unusual colouration—both black and red individuals have been found in Scotland, and albino frogs have been found with yellow skin and red eyes. During the mating season the male common frog tends to tu
Document 1:::
The western clawed frog (Xenopus tropicalis) is a species of frog in the family Pipidae, also known as tropical clawed frog. It is the only species in the genus Xenopus to have a diploid genome. Its genome has been sequenced, making it a significant model organism for genetics that complements the related species Xenopus laevis (the African clawed frog), a widely used vertebrate model for developmental biology. X. tropicalis also has a number of advantages over X. laevis in research, such as a much shorter generation time (<5 months), smaller size ( body length), and a larger number of eggs per spawn.
It is found in Benin, Burkina Faso, Cameroon, Ivory Coast, Equatorial Guinea, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Nigeria, Senegal, Sierra Leone, Togo, and possibly Mali. Its natural habitats are subtropical or tropical moist lowland forests, moist savanna, rivers, intermittent rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, rural gardens, heavily degraded former forests, water storage areas, ponds, aquaculture ponds, and canals and ditches.
Description
The western clawed frog is a medium-sized species with a somewhat flattened body and a snout-vent length of , females being larger than males. The eyes are bulging and situated high on the head and there is a short tentacle just below each eye. A row of unpigmented dermal tubercles runs along the flank from just behind the eye, and are thought to represent a lateral line organ. The limbs are short and plump, and the fully webbed feet have horny claws. The skin is finely granular. The dorsal surface varies from pale to dark brown and has small grey and black spots. The ventral surface is dull white or yellowish with some dark mottling.
Distribution and habitat
The western clawed frog is an aquatic species and is found in the West African rainforest belt with a range stretching from Senegal to Cameroon and eastern Zaire. It is generally co
Document 2:::
Froggyland is the largest taxidermy frog collection and museum in the world. It islocated in Split, Croatia. It is next to a 4th-century palace built for Diocletian, an emperor of Ancient Rome. The museum is known for its display of 21 dioramas containing 507 different taxidermy frogs posed to appear as if they are participating in human activities.
History
Ferenc Mere was a taxidermist during the 19th and 20th centuries; he was born in 1878 to Hungarian parents and grew up near a pond of frogs. Inspired by the popularity of taxidermy during the 19th century, From 1910 to 1920, Mere would spend time catching, killing, and stuffing Rana escuelenta, a species of frog commonly known as the "edible frog". Mere then arranged the frogs into various scenes depicting human activities, including playing poker, attending school, and performing in a circus. Although Mere initially collected over 1000 of these frogs, only 507 survive.
In 1970, after being discovered in an attic in Serbia, the Froggyland exhibits were bought by the parents of the current owner; they moved the frogs to Split, Croatia, to start the museum. It was eventually passed down to their son, Ivan Medvešek, who owns the museum as of 2021. However, in the same year, he announced plans to sell Froggyland to investors in the United States, citing revenue losses sustained during the COVID-19 pandemic as the reason for the transaction.
The museum has also attracted controversy for Mere's use of stuffed frogs in the exhibits, which critics believe to be animal cruelty.
Maintenance
Every five years, the frogs in the museum are kept preserved with injections of formaldehyde and ammonia; they are also repainted with a layer of varnish.
Document 3:::
Direct development is a concept in biology. It refers to forms of growth to adulthood that do not involve metamorphosis. An animal undergoes direct development if the immature organism resembles a small adult rather than having a distinct larval form. A frog that hatches out of its egg as a small frog undergoes direct development. A frog that hatches out of its egg as a tadpole does not.
Direct development is the opposite of complete metamorphosis. An animal undergoes complete metamorphosis if it becomes a non-moving thing, for example a pupa in a cocoon, between its larval and adult stages.
Examples
Most frogs in the genus Callulina hatch out of their eggs as froglets.
Springtails and mayflies, called ametabolous insects, undergo direct development.
Document 4:::
Batrachology is the branch of zoology concerned with the study of amphibians including frogs and toads, salamanders, newts, and caecilians. It is a sub-discipline of herpetology, which also includes non-avian reptiles (snakes, lizards, amphisbaenids, turtles, terrapins, tortoises, crocodilians, and the tuatara). Batrachologists may study the evolution, ecology, ethology, or anatomy of amphibians.
Amphibians are cold blooded vertebrates largely found in damp habitats although many species have special behavioural adaptations that allow them to live in deserts, trees, underground and in regions with wide seasonal variations in temperature. There are over 7250 species of amphibians.
Notable batrachologists
Jean Marius René Guibé
Gabriel Bibron
Oskar Boettger
George Albert Boulenger
Edward Drinker Cope
François Marie Daudin
Franz Werner
Leszek Berger
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What to tadpoles develop into?
A. frogs
B. mosquitos
C. snakes
D. toads
Answer:
|
|
sciq-6870
|
multiple_choice
|
What is the angiosperm seed surrounded by?
|
[
"uterus",
"ovary",
"cone",
"egg"
] |
B
|
Relavent Documents:
Document 0:::
A seedling is a young sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle (embryonic root), the hypocotyl (embryonic shoot), and the cotyledons (seed leaves). The two classes of flowering plants (angiosperms) are distinguished by their numbers of seed leaves: monocotyledons (monocots) have one blade-shaped cotyledon, whereas dicotyledons (dicots) possess two round cotyledons. Gymnosperms are more varied. For example, pine seedlings have up to eight cotyledons. The seedlings of some flowering plants have no cotyledons at all. These are said to be acotyledons.
The plumule is the part of a seed embryo that develops into the shoot bearing the first true leaves of a plant. In most seeds, for example the sunflower, the plumule is a small conical structure without any leaf structure. Growth of the plumule does not occur until the cotyledons have grown above ground. This is epigeal germination. However, in seeds such as the broad bean, a leaf structure is visible on the plumule in the seed. These seeds develop by the plumule growing up through the soil with the cotyledons remaining below the surface. This is known as hypogeal germination.
Photomorphogenesis and etiolation
Dicot seedlings grown in the light develop short hypocotyls and open cotyledons exposing the epicotyl. This is also referred to as photomorphogenesis. In contrast, seedlings grown in the dark develop long hypocotyls and their cotyledons remain closed around the epicotyl in an apical hook. This is referred to as skotomorphogenesis or etiolation. Etiolated seedlings are yellowish in color as chlorophyll synthesis and chloroplast development depend on light. They will open their cotyledons and turn green when treated with light.
In a natural situation, seedling development starts with skotomorphogenesis while the seedling is growing through the soil and attempting to reach the
Document 1:::
In plant science, the spermosphere is the zone in the soil surrounding a germinating seed. This is a small volume with radius perhaps 1 cm but varying with seed type, the variety of soil microorganisms, the level of soil moisture, and other factors. Within the spermosphere a range of complex interactions take place among the germinating seed, the soil, and the microbiome. Because germination is a brief process, the spermosphere is transient, but the impact of the microbial activity within the spermosphere can have strong and long-lasting effects on the developing plant.
Seeds exude various molecules that influence their surrounding microbial communities, either inhibiting or stimulating their growth. The composition of the exudates varies according to the plant type and such properties of the soil as its pH and moisture content. With these biochemical effects, the spermosphere develops both downward—to form the rhizosphere (upon the emergence of the plant's radicle)—and upward to form the laimosphere, which is the soil surrounding the growing plant stem.
Document 2:::
Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of plants as a main or exclusive food source, in many cases leaving the seeds damaged and not viable. Granivores are found across many families of vertebrates (especially mammals and birds) as well as invertebrates (mainly insects); thus, seed predation occurs in virtually all terrestrial ecosystems. Seed predation is commonly divided into two distinctive temporal categories, pre-dispersal and post-dispersal predation, which affect the fitness of the parental plant and the dispersed offspring (the seed), respectively. Mitigating pre- and post-dispersal predation may involve different strategies. To counter seed predation, plants have evolved both physical defenses (e.g. shape and toughness of the seed coat) and chemical defenses (secondary compounds such as tannins and alkaloids). However, as plants have evolved seed defenses, seed predators have adapted to plant defenses (e.g., ability to detoxify chemical compounds). Thus, many interesting examples of coevolution arise from this dynamic relationship.
Seeds and their defenses
Plant seeds are important sources of nutrition for animals across most ecosystems. Seeds contain food storage organs (e.g., endosperm) that provide nutrients to the developing plant embryo (cotyledon). This makes seeds an attractive food source for animals because they are a highly concentrated and localized nutrient source in relation to other plant parts.
Seeds of many plants have evolved a variety of defenses to deter predation. Seeds are often contained inside protective structures or fruit pulp that encapsulate seeds until they are ripe. Other physical defenses include spines, hairs, fibrous seed coats and hard endosperm. Seeds, especially in arid areas, may have a mucilaginous seed coat that can glue soil to seed hiding it from granivores.
Some seeds have evolved strong anti-herbivore chemical
Document 3:::
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ferns, bacteria, and the growth of the pollen tube from the pollen grain of a seed plant.
Seed plants
Germination is usually the growth of a plant contained within a seed; it results in the formation of the seedling. It is also the process of reactivation of metabolic machinery of the seed resulting in the emergence of radicle and plumule. The seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All fully developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat. Some plants produce varying numbers of seeds that lack embryos; these are empty seeds which never germinate. Dormant seeds are viable seeds that do not germinate because they require specific internal or environmental stimuli to resume growth. Under proper conditions, the seed begins to germinate and the embryo resumes growth, developing into a seedling.
Disturbance of soil can result in vigorous plant growth by exposing seeds already in the soil to changes in environmental factors where germination may have previously been inhibited by depth of the seeds or soil that was too compact. This is often observed at gravesites after a burial.
Seed germination depends on both internal and external conditions. The most important external factors include right temperature, water, oxygen or air and sometimes light or darkness. Various plants require different variables for successful seed germination. Often this depends on the individual seed variety and is closely linked to the ecological conditions of a plant's natural habitat. For some seeds, their future germination response is affected by environmental conditions during seed formation; most ofte
Document 4:::
Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born (or hatches from its egg), it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.
According to plant physiologist A. Carl Leopold, the properties of organization seen in a plant are emergent properties which are more than the sum of the individual parts. "The assembly of these tissues and functions into an integrated multicellular organism yields not only the characteristics of the separate parts and processes but also quite a new set of characteristics which would not have been predictable on the basis of examination of the separate parts."
Growth
A vascular plant begins from a single celled zygote, formed by fertilisation of an egg cell by a sperm cell. From that point, it begins to divide to form a plant embryo through the process of embryogenesis. As this happens, the resulting cells will organize so that one end becomes the first root while the other end forms the tip of the shoot. In seed plants, the embryo will develop one or more "seed leaves" (cotyledons). By the end of embryogenesis, the young plant will have all the parts necessary to begin in its life.
Once the embryo germinates from its seed or parent plant, it begins to produce additional organs (leaves, stems, and roots) through the process of organogenesis. New roots grow from root meristems located at the tip of the root, and new stems and leaves grow from shoot meristems located at the
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the angiosperm seed surrounded by?
A. uterus
B. ovary
C. cone
D. egg
Answer:
|
|
sciq-4899
|
multiple_choice
|
Adaptations that go along with the active, carnivorous lifestyle of sharks are known as?
|
[
"Relative traits",
"similar senses",
"acute parameters",
"acute senses"
] |
D
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Adaptive type – in evolutionary biology – is any population or taxon which have the potential for a particular or total occupation of given free of underutilized home habitats or position in the general economy of nature. In evolutionary sense, the emergence of new adaptive type is usually a result of adaptive radiation certain groups of organisms in which they arise categories that can effectively exploit temporary, or new conditions of the environment.
Such evolutive units with its distinctive – morphological and anatomical, physiological and other characteristics, i.e. genetic and adjustments (feature) have a predisposition for an occupation certain home habitats or position in the general nature economy.
Simply, the adaptive type is one group organisms whose general biological properties represent a key to open the entrance to the observed adaptive zone in the observed natural ecological complex.
Adaptive types are spatially and temporally specific. Since the frames of general biological properties these types of substantially genetic are defined between, in effect the emergence of new adaptive types of the corresponding change in population genetic structure and eternal contradiction between the need for optimal adapted well the conditions of living environment, while maintaining genetic variation for survival in a possible new circumstances.
For example, the specific place in the economy of nature existed millions of years before the appearance of human type. However, just when the process of evolution of primates (order Primates) reached a level that is able to occupy that position, it is open, and then (in leaving world) an unprecedented acceleration increasingly spreading. Culture, in the broadest sense, is a key adaptation of adaptive type type of Homo sapiens the occupation of existing adaptive zone through work, also in the broadest sense of the term.
Document 2:::
Computerized adaptive testing (CAT) is a form of computer-based test that adapts to the examinee's ability level. For this reason, it has also been called tailored testing. In other words, it is a form of computer-administered test in which the next item or set of items selected to be administered depends on the correctness of the test taker's responses to the most recent items administered.
How it works
CAT successively selects questions for the purpose of maximizing the precision of the exam based on what is known about the examinee from previous questions. From the examinee's perspective, the difficulty of the exam seems to tailor itself to their level of ability. For example, if an examinee performs well on an item of intermediate difficulty, they will then be presented with a more difficult question. Or, if they performed poorly, they would be presented with a simpler question. Compared to static tests that nearly everyone has experienced, with a fixed set of items administered to all examinees, computer-adaptive tests require fewer test items to arrive at equally accurate scores.
The basic computer-adaptive testing method is an iterative algorithm with the following steps:
The pool of available items is searched for the optimal item, based on the current estimate of the examinee's ability
The chosen item is presented to the examinee, who then answers it correctly or incorrectly
The ability estimate is updated, based on all prior answers
Steps 1–3 are repeated until a termination criterion is met
Nothing is known about the examinee prior to the administration of the first item, so the algorithm is generally started by selecting an item of medium, or medium-easy, difficulty as the first item.
As a result of adaptive administration, different examinees receive quite different tests. Although examinees are typically administered different tests, their ability scores are comparable to one another (i.e., as if they had received the same test, as is common
Document 3:::
Edward Brinton (January 12, 1924 – January 13, 2010) was a professor of oceanography and research biologist. His particular area of expertise was Euphausiids or krill, small shrimp-like creatures found in all the oceans of the world.
Early life
Brinton was born on January 12, 1924, in Richmond, Indiana to a Quaker couple, Howard Brinton and Anna Shipley Cox Brinton. Much of his childhood was spent on the grounds of Mills College where his mother was Dean of Faculty and his father was a professor. The family later moved to the Pendle Hill Quaker Center for Study and Contemplation, in Pennsylvania where his father and mother became directors.
Academic career
Brinton attended High School at Westtown School in Chester County, Pennsylvania. He studied at Haverford College and graduated in 1949 with a bachelor's degree in biology. He enrolled at Scripps Institution of Oceanography as a graduate student in 1950 and was awarded a Ph.D. in 1957. He continued on as a research biologist in the Marine Life Research Group, part of the CalCOFI program. He soon turned his dissertation into a major publication, The Distribution of Pacific Euphausiids. In this large monograph, he laid out the major biogeographic provinces of the Pacific (and part of the Atlantic), large-scale patterns of pelagic diversity and one of the most rational hypotheses for the mechanism of sympatric, oceanic speciation. In all of these studies the role of physical oceanography and circulation played a prominent part. His work has since been validated by others and continues, to this day, to form the basis for our attempts to understand large-scale pelagic ecology and the role of physics of the movement of water in the regulation of pelagic ecosystems. In addition to these studies he has led in the studies of how climatic variations have led to the large variations in the California Current, and its populations and communities. He has described several new species and, in collaboration with Margaret K
Document 4:::
Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Adaptations that go along with the active, carnivorous lifestyle of sharks are known as?
A. Relative traits
B. similar senses
C. acute parameters
D. acute senses
Answer:
|
|
sciq-10426
|
multiple_choice
|
When zinc metal is mixed with sulfur and heated, what is produced?
|
[
"iron",
"zinc sulfide",
"methane sulfide",
"extraction sulfide"
] |
B
|
Relavent Documents:
Document 0:::
Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.
History
Zinc compounds were probably used by early humans, in processed and unprocessed forms, as a paint or medicinal ointment, but their composition is uncertain. The use of pushpanjan, probably zinc oxide, as a salve for eyes and open wounds, is mentioned in the Indian medical text the Charaka Samhita, thought to date from 500 BC or before. Zinc oxide ointment is also mentioned by the Greek physician Dioscorides (1st century AD). Galen suggested treating ulcerating cancers with zinc oxide, as did Avicenna in his The Canon of Medicine. It is used as an ingredient in products such as baby powder and creams against diaper rashes, calamine cream, anti-dandruff shampoos, and antiseptic ointments.
The Romans produced considerable quantities of brass (an alloy of zinc and copper) as early as 200 BC by a cementation process where copper was reacted with zinc oxide. The zinc oxide is thought to have been produced by heating zinc ore in a shaft furnace. This liberated metallic zinc as a vapor, which then ascended the flue and condensed as the oxide. This process was described by Dioscorides in the 1st century AD. Zinc oxide has also been recovered from zinc mines at Zawar in India, dating from the second half of the first millennium BC.
From the 12th to the 16th century zinc and zinc oxide were recognized and produced in India using a primitive form of the direct synthesis process. From India, zinc manufacture moved to China in the 17th century. In 1743, the first European zinc
Document 1:::
The Department of Social and Decision Sciences (SDS) is an interdisciplinary academic department within the Dietrich College of Humanities and Social Sciences at Carnegie Mellon University. The Department of Social and Decision Sciences is headquartered in Porter Hall in Pittsburgh, Pennsylvania and is led by Department Head Gretchen Chapman. SDS has a world-class reputation for research and education programs in decision-making in public policy, economics, management, and the behavioral social sciences.
History
The Department of Social Sciences was established in 1976, as part of the Dietrich College of Humanities and Social Sciences under Dean John Patrick Crecine with approval from Heinz College Dean Otto Davis, which previously housed the program. The department was staffed by political scientists, sociologists, and economists from within the Dietrich College, the Heinz College, and the Tepper School of Business. In the 1980s, the department was led by Patrick D. Larkey and developed the undergraduate information systems program which became a huge success, eventually being spun off into an independent interdisciplinary program in the Dietrich College. In 1985, Robyn Dawes joined the department and began to re-focus it into its current form and expertise in behavioral decision-making and caused it to be renamed as the Department of Social and Decision Sciences. Carnegie Mellon's Institute for Politics and Strategy was spun off of the department in 2015.
Education
The department runs highly regarded undergraduate Bachelor of Science programs in Decision Science and Policy and Management and a Bachelor of Arts program in Behavioral Economics, Policy, and Organizations as well as minors in Decision Science and Policy and Management. Further, SDS is a partner in various interdisciplinary undergraduate programs such as the Sociology minor, Environmental Policy program, and the Quantitative Social Science Scholars program. At the master's degree level, SDS partner
Document 2:::
Odesa National University of Technologies (ONTU) is a public HEI with the highest level of accreditation. It was established in 1902 and today is a modern innovative scientific center for training of high qualified personnel. ONTU is a multi-profile HEI which includes 4 scientific-educational institutions, 11 faculties and research institute with 15 scientific schools. ONTU has about 6500 students in 21 areas of training, 42 training programs, 10 doctorate and 3 post-doctorate programs, 4 specialized scientific councils for doctorate and post-doctorate theses defense. Educational and research activities of ONTU provides 104 doctors/professors and 388 PhD/associate professors. ONTU cooperates with 50 HEIs from more than 20 countries worldwide, as well as with numerous national and international companies in scientific and training fields. It is a member of international associations: European Universities Association, Eurasian Association of Universities, Black Sea Universities Network, International Council for Open and Distance Education, The Magna Charta Observatory etc.
Before 2021, the university was named the Odesa National Academy of Food Technologies. By order of the Ministry of Education and Science of Ukraine No.918 of August 18, 2021, the Odesa National Academy of Food Technologies was reorganized into the Odesa National Technological University.
Ministry of Justice of Ukraine: Certificate of state registration of the print media series KB No.14344-3315P dated 04.08.2008
The founders of the publication are the Institute of Market Problems and Economic and Environmental Research of the National Academy of Sciences of Ukraine and Odesa National Technological University.
Food technology organizations
Educational institutions established in 1902
Technical universities and colleges in Ukraine
Education in Odesa
Food science institutes
National universities in Ukraine
1902 establishments in the Russian Empire
Research institutes in the Soviet Union
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When zinc metal is mixed with sulfur and heated, what is produced?
A. iron
B. zinc sulfide
C. methane sulfide
D. extraction sulfide
Answer:
|
|
sciq-9163
|
multiple_choice
|
The concentration of hydronium ions in a solution is known as what?
|
[
"acidity",
"akaline",
"base",
"pH value"
] |
A
|
Relavent Documents:
Document 0:::
In chemistry and biochemistry, the Henderson–Hasselbalch equation
relates the pH of a chemical solution of a weak acid to the numerical value of the acid dissociation constant, Ka, of acid and the ratio of the concentrations, of the acid and its conjugate base in an equilibrium.
For example, the acid may be acetic acid
The Henderson–Hasselbalch equation can be used to estimate the pH of a buffer solution by approximating the actual concentration ratio as the ratio of the analytical concentrations of the acid and of a salt, MA.
The equation can also be applied to bases by specifying the protonated form of the base as the acid. For example, with an amine,
Derivation, assumptions and limitations
A simple buffer solution consists of a solution of an acid and a salt of the conjugate base of the acid. For example, the acid may be acetic acid and the salt may be sodium acetate.
The Henderson–Hasselbalch equation relates the pH of a solution containing a mixture of the two components to the acid dissociation constant, Ka of the acid, and the concentrations of the species in solution.
To derive the equation a number of simplifying assumptions have to be made. (pdf)
Assumption 1: The acid, HA, is monobasic and dissociates according to the equations
CA is the analytical concentration of the acid and CH is the concentration the hydrogen ion that has been added to the solution. The self-dissociation of water is ignored. A quantity in square brackets, [X], represents the concentration of the chemical substance X. It is understood that the symbol H+ stands for the hydrated hydronium ion. Ka is an acid dissociation constant.
The Henderson–Hasselbalch equation can be applied to a polybasic acid only if its consecutive pK values differ by at least 3. Phosphoric acid is such an acid.
Assumption 2. The self-ionization of water can be ignored.
This assumption is not, strictly speaking, valid with pH values close to 7, half the value of pKw, the constant for self-ioniz
Document 1:::
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.
Principles of buffering
Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−:
When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increases by less than the amount expected for the quantity of strong acid added.
Similarly, if strong alkali is added to the mixture, the hydrogen ion concentration decreases by less than the amount expected for the quantity of alkali added. In Figure 1, the effect is illustrated by the simulated titration of a weak acid with pKa = 4.7. The relative concentration of undissociated acid is shown in blue, and of its conjugate base in red. The pH changes relatively slowly in the buffer region, pH = pKa ± 1, centered at pH = 4.7, where [HA] = [A−]. The hydrogen ion concentration decreases by less than the amount expected because most of the added hydroxide ion is consumed in the reaction
and only a little is consumed in the neutralization reaction (which is the reaction that results in an increase in pH)
Once the acid is more than 95% deprotonated, the pH rises rapidly because most of the added alkali is consumed in the neutralization reaction.
Buffer capacity
Buffer
Document 2:::
An ICE table or RICE box or RICE chart is a tabular system of keeping track of changing concentrations in an equilibrium reaction. ICE stands for initial, change, equilibrium. It is used in chemistry to keep track of the changes in amount of substance of the reactants and also organize a set of conditions that one wants to solve with. Some sources refer to a RICE table (or box or chart) where the added R stands for the reaction to which the table refers. Others simply call it a concentration table (for the acid–base equilibrium).
Example
To illustrate the processes, consider the case of dissolving a weak acid, HA, in water. The pH can be calculated using an ICE table. Note that in this example, we are assuming that the acid is not very weak, and that the concentration is not very dilute, so that the concentration of [OH−] ions can be neglected. This is equivalent to the assumption that the final pH will be below about 6 or so. See pH calculations for more details.
First write down the equilibrium expression.
HA <=> {A^-} + {H+}
The columns of the table correspond to the three species in equilibrium.
The first row shows the reaction, which some authors label R and some leave blank.
The second row, labeled I, has the initial conditions: the nominal concentration of acid is Ca and it is initially undissociated, so the concentrations of A− and H+ are zero.
The third row, labeled C, specifies the change that occurs during the reaction. When the acid dissociates, its concentration changes by an amount , and the concentrations of A− and H+ both change by an amount . This follows from consideration of mass balance (the total number of each atom/molecule must remain the same) and charge balance (the sum of the electric charges before and after the reaction must be zero).
Note that the coefficients in front of the "x" correlate to the mole ratios of the reactants to the product. For example, if the reaction equation had 2 H+ ions in the product, then the "change"
Document 3:::
The hydration number of a compound is defined as the number of molecules of water bonded to a central ion, often a metal cation. The hydration number is related to the broader concept of solvation number, the number of solvent molecules bonded to a central atom. The hydration number varies with the atom or ion of interest.
In aqueous solution, solutes interact with water molecules to varying degrees. Metal cations form aquo complexes, wherein the oxygen of water bind to the cation. This first coordination sphere is encased in further solvation shells, whereby water bonds to the coordinated water via hydrogen bonding. For charged species, the orientation of water molecules around the solute dependent on its radius and charge, with cations attracting water’s electronegative oxygen and anions attracting the hydrogens. Uncharged compounds such as methane can also be solvated by water and also have a hydration number. Although solvation shells can contain inner and outer shell solvent-solute interactions, the hydration number generally focuses on the inner shell solvent molecules that directly interact with the solute.
A variety of definitions exist for hydration number. One such approach counts the number of water molecules bound to the compound more strongly (by 13.3 kcal/mol or more) than they are bound to other water molecules. Hydration number estimates are not limited to integer values (for instance, estimates for sodium include 4, 4.6, 5.3, 5.5, 5.6, 6, 6.5, and 8), with some of the spread of estimated values being due to differing detection methods.
Determination of hydration number
Hydration numbers can be determined by a variety of experimental methods. These include Raman spectroscopy, neutron and X-ray scattering, luminescence, and NMR. Hydration numbers can change depending on whether the species is locked into a crystall or in solution. The apparent hydration number of a species can vary depending on which experimental method was used. The hydrat
Document 4:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The concentration of hydronium ions in a solution is known as what?
A. acidity
B. akaline
C. base
D. pH value
Answer:
|
|
sciq-9252
|
multiple_choice
|
What do puffer fish produce to protect itself?
|
[
"enzymes",
"venom",
"hormones",
"teeth"
] |
B
|
Relavent Documents:
Document 0:::
Fish anatomy is the study of the form or morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish.
The anatomy of fish is often shaped by the physical characteristics of water, the medium in which fish live. Water is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does. The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always externally visible. The skeleton, which forms the support structure inside the fish, is either made of cartilage (cartilaginous fish) or bone (bony fish). The main skeletal element is the vertebral column, composed of articulating vertebrae which are lightweight yet strong. The ribs attach to the spine and there are no limbs or limb girdles. The main external features of the fish, the fins, are composed of either bony or soft spines called rays which, with the exception of the caudal fins, have no direct connection with the spine. They are supported by the muscles which compose the main part of the trunk.
The heart has two chambers and pumps the blood through the respiratory surfaces of the gills and then around the body in a single circulatory loop. The eyes are adapted for seeing underwater and have only local vision. There is an inner ear but no external or middle ear. Low-frequency vibrations are detected by the lateral line system of sense organs that run along the length of the sides of fish, which responds to nearby movements and to changes in water pressure.
Sharks and rays are basal fish with
Document 1:::
One of the marine ecosystems found in the Virgin Islands are the coral reefs. These coral reefs can be located between the islands of St. Croix, St. Thomas, and St. John. These coral reefs have an area of 297.9 km2, along with other marine habitats that are in between. The way these coral reefs grow are by coral larvae swimming freely and attaching themselves to hard surfaces around the islands and start to develop a skeleton on the outside of their skin to protect themselves from predators but also allow a new place for other coral larvae to attach to and grow on. These corals can form into three different structures; fringing reefs, which are reefs that are close to the shore, barrier reefs, which are reefs that are alongside the shore and is separated by deep water, and an atoll reef which is a coral reef that circles a lagoon or body of water.
Distribution
As stated, the coral reefs such as fringing reefs, deep reefs, patch reefs and spur and groove formation are distributed over three islands in the Virgin Islands which are St. Croix (Salt River Bay National Historical Park and Ecological Preserve, Buck Island Reef National Monument), St. Thomas, and St. John (Virgin Islands Coral Reef National Monument). The coral reefs found offshore of St. Thomas and St. John are distributed patchily around the islands. Additionally, a developed barrier reef system surrounds St. Croix along its eastern and southern shores.
Ecology
The coral reefs as well as hard-bottom habitat accounts for 297.9 km2. The coral reefs are home to diverse species. There are over 40 species of scleractinian corals and three species of Millepora. Live scleractinian species are found throughout the Virgin Islands, but mainly around Buck Island, St. Croix and St. John. More specifically based on a survey from 2001-2006, listed are a total of 215 fishes from St. John and 202 from St. Croix. Four species of sea turtles are found within the Virgin Islands. The coral reefs are impacted by freshwa
Document 2:::
A spongivore is an animal anatomically and physiologically adapted to eating animals of the phylum Porifera, commonly called sea sponges, for the main component of its diet. As a result of their diet, spongivore animals like the hawksbill turtle have developed sharp, narrow bird-like beak that allows them to reach within crevices on the reef to obtain sponges.
Examples
The hawksbill turtle is one of the few animals known to feed primarily on sponges. It is the only known spongivorous reptile. Sponges of various select species constitute up to 95% of the diets of Caribbean hawksbill turtle populations.
Pomacanthus imperator, the emperor angelfish; Lactophrys bicaudalis, the spotted trunkfish; and Stephanolepis hispidus, the planehead filefish are known spongivorous coral reef fish. The rock beauty Holocanthus tricolor is also spongivorous, with sponges making up 96% of their diet.
Certain species of nudibranchs are known to feed selectively on specific species of sponges.
Attacks and counter-attacks
Spongivore offense
The many defenses displayed by sponges means that their spongivores need to learn skills to overcome these defenses to obtain their food. These skills allow spongivores to increase their feeding and use of sponges. Spongivores have three primary strategies for dealing with sponge defenses: choice based on colour, able to handle secondary metabolites and brain development for memory.
Choice based on colour was involved based on which sponge the spongivore would choose to eat. A spongivore would bite small sample of sponges and if they were unharmed that they would continue eating that specific sponge and then move on to another sponge of the same colour.
Spongivores have adapted to be able to handle the secondary metabolites that sponges have. Therefore, spongivores are able to consume a variety of sponges without getting harmed.
Spongivores also have enough brain development to be able to remember the same species of sponge it has eaten in the
Document 3:::
This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
R
S
T
U
V
W
Document 4:::
Cleaner fish are fish that show a specialist feeding strategy by providing a service to other species, referred to as clients, by removing dead skin, ectoparasites, and infected tissue from the surface or gill chambers. This example of cleaning symbiosis represents mutualism and cooperation behaviour, an ecological interaction that benefits both parties involved. However, the cleaner fish may consume mucus or tissue, thus creating a form of parasitism called cheating. The client animals are typically fish of a different species, but can also be aquatic reptiles (sea turtles and marine iguana), mammals (manatees and whales), or octopuses. A wide variety of fish including wrasse, cichlids, catfish, pipefish, lumpsuckers, and gobies display cleaning behaviors across the globe in fresh, brackish, and marine waters but specifically concentrated in the tropics due to high parasite density. Similar behaviour is found in other groups of animals, such as cleaner shrimps.
There are two types of cleaner fish, obligate full time cleaners and facultative part time cleaners where different strategies occur based on resources and local abundance of fish. Cleaning behaviour takes place in pelagic waters as well as designated locations called cleaner stations. Cleaner fish interaction durations and memories of reoccurring clients are influenced by the neuroendocrine system of the fish, involving hormones arginine vasotocin, Isotocin and serotonin.
Conspicuous coloration is a method used by some cleaner fish, where they often display a brilliant blue stripe that spans the length of the body. Other species of fish, called mimics, imitate the behavior and phenotype of cleaner fish to gain access to client fish tissue.
The specialized feeding behaviour of cleaner fish has become a valuable resource in salmon aquaculture in Atlantic Canada, Scotland, Iceland and Norway for prevention of sea lice outbreaks which benefits the economy and environment by minimizing the use of chemical del
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do puffer fish produce to protect itself?
A. enzymes
B. venom
C. hormones
D. teeth
Answer:
|
|
sciq-10105
|
multiple_choice
|
What is it called when a new species arises without geographic separation?
|
[
"sympatric speciation",
"spontaneous evolution",
"Allopatric speciation",
"quantum speciation"
] |
A
|
Relavent Documents:
Document 0:::
The scientific study of speciation — how species evolve to become new species — began around the time of Charles Darwin in the middle of the 19th century. Many naturalists at the time recognized the relationship between biogeography (the way species are distributed) and the evolution of species. The 20th century saw the growth of the field of speciation, with major contributors such as Ernst Mayr researching and documenting species' geographic patterns and relationships. The field grew in prominence with the modern evolutionary synthesis in the early part of that century. Since then, research on speciation has expanded immensely.
The language of speciation has grown more complex. Debate over classification schemes on the mechanisms of speciation and reproductive isolation continue. The 21st century has seen a resurgence in the study of speciation, with new techniques such as molecular phylogenetics and systematics. Speciation has largely been divided into discrete modes that correspond to rates of gene flow between two incipient populations. Current research has driven the development of alternative schemes and the discovery of new processes of speciation.
Early history
Charles Darwin introduced the idea that species could evolve and split into separate lineages, referring to it as specification in his 1859 book On the Origin of Species. It was not until 1906 that the modern term speciation was coined by the biologist Orator F. Cook. Darwin, in his 1859 publication, focused primarily on the changes that can occur within a species, and less on how species may divide into two. It is almost universally accepted that Darwin's book did not directly address its title. Darwin instead saw speciation as occurring by species entering new ecological niches.
Darwin's views
Controversy exists as to whether Charles Darwin recognized a true geographical-based model of speciation in his publication On the Origin of Species. In chapter 11, "Geographical Distribution", Darwin d
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When speciation is not driven by (or strongly correlated with) divergent natural selection, it can be said to be nonecological, so as to distinguish it from the typical definition of ecological speciation: "It is useful to consider ecological speciation as its own form of species formation because it focuses on an explicit mechanism of speciation: namely divergent natural selection. There are numerous ways other than via divergent natural selection in which populations might become genetically differentiated and reproductively isolated." It is likely that many instances of nonecological speciation are allopatric, especially when the organisms in question are poor dispersers (e.g., land snails, salamanders), however sympatric nonecological speciation may also be possible, especially when accompanied by an "instant" (at least in evolutionary time) loss of reproductive compatibility, as when polyploidization happens. Other potential mechanisms for nonecological speciation include mutation-order speciation and changes in chirality in gastropods.
Nonecological speciation might not be accompanied by strong morphological differentiation, so might give rise to cryptic species, however there are some species that are difficult for humans to differentiate that are strongly differentiated with respect to their resource use, and so are likely a result of ecological speciation (e.g., host shifts in parasites or phytophagous insects). When species recognition/sexual selection plays a strong role in maintaining species boundaries, the species generated by nonecological speciation might be straightforward for humans to differentiate, as in some odonates.
See also
Nonadaptive radiation
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Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.
Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information between the two populations leading to reproductive isolation. If the two populations come into contact they will be unable to reproduce—effectively speciating. Other isolating factors such as population dispersal leading to emigration can cause speciation (for instance, the dispersal and isolation of a species on an oceanic island) and is considered a special case of allopatric speciation called peripatric speciation.
Allopatric speciation is typically subdivided into two major models: vicariance and peripatric. Both models differ from one another by virtue of their population sizes and geographic isolating mechanisms. The terms allopatry and vicariance are often used in biogeography to describe the relationship between organisms whose ranges do not significantly overlap but are immediately adjacent to each other—they do not occur together or only occur within a narrow zone of contact. Historically, the language used to refer to modes of speciation directly reflected biogeographical distributions. As such, allopa
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Sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap so that they occur together at least in some places. If these organisms are closely related (e.g. sister species), such a distribution may be the result of sympatric speciation. Etymologically, sympatry is derived from the Greek roots ("together") and ("homeland"). The term was coined by Edward Bagnall Poulton in 1904, who explains the derivation.
Sympatric speciation is one of three traditional geographic modes of speciation. Allopatric speciation is the evolution of species caused by the geographic isolation of two or more populations of a species. In this case, divergence is facilitated by the absence of gene flow. Parapatric speciation is the evolution of geographically adjacent populations into distinct species. In this case, divergence occurs despite limited interbreeding where the two diverging groups come into contact. In sympatric speciation, there is no geographic constraint to interbreeding. These categories are special cases of a continuum from zero (sympatric) to complete (allopatric) spatial segregation of diverging groups.
In multicellular eukaryotic organisms, sympatric speciation is a plausible process that is known to occur, but the frequency with which it occurs is not known.
In bacteria, however, the analogous process (defined as "the origin of new bacterial species that occupy definable ecological niches") might be more common because bacteria are less constrained by the homogenizing effects of sexual reproduction and are prone to comparatively dramatic and rapid genetic change through horizontal gene transfer.
Evidence
Sympatric speciation events are quite common in plants, which are prone to acquiring multiple homologous sets of chromosomes, resulting in polyploidy. The polyp
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Cladogenesis is an evolutionary splitting of a parent species into two distinct species, forming a clade.
This event usually occurs when a few organisms end up in new, often distant areas or when environmental changes cause several extinctions, opening up ecological niches for the survivors and causing population bottlenecks and founder effects changing allele frequencies of diverging populations compared to their ancestral population. The events that cause these species to originally separate from each other over distant areas may still allow both of the species to have equal chances of surviving, reproducing, and even evolving to better suit their environments while still being two distinct species due to subsequent natural selection, mutations and genetic drift.
Cladogenesis is in contrast to anagenesis, in which an ancestral species gradually accumulates change, and eventually, when enough is accumulated, the species is sufficiently distinct and different enough from its original starting form that it can be labeled as a new form - a new species. With anagenesis, the lineage in a phylogenetic tree does not split.
To determine whether a speciation event is cladogenesis or anagenesis, researchers may use simulation, evidence from fossils, molecular evidence from the DNA of different living species, or modelling. It has however been debated whether the distinction between cladogenesis and anagenesis is necessary at all in evolutionary theory.
See also
Anagenesis
Evolutionary biology
Speciation
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is it called when a new species arises without geographic separation?
A. sympatric speciation
B. spontaneous evolution
C. Allopatric speciation
D. quantum speciation
Answer:
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ai2_arc-547
|
multiple_choice
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A new battery claims that it "lasts twice as long as competing batteries under the same loading conditions." Which comparison of the battery with competing batteries would validate this claim?
|
[
"It is twice as large.",
"It contains more electrons.",
"It stores more chemical energy.",
"It destroys less energy when used."
] |
C
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
A battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.
Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current; the original composition of the electrodes can be restored by reverse current. Examples include the lead–acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones.
Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and wristwatches to, at the largest extreme, huge battery banks the size of rooms that provide standby or emergency power for telephone exchanges and computer data centers. Batteries have much lower specific energy (energy per unit mass) than common fuels such as gasoline. In automobiles, this is somewhat offset by the higher efficiency of electric motors in converting electrical energy to mechanical work, compared to combustion engines.
History
Invention
Benjamin Franklin first used the term "battery" in 1749 wh
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A rechargeable battery, storage battery, or secondary cell (formally a type of energy accumulator), is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery, which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells. The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction. Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network. Several different combinations of electrode materials and electrolytes are used, including lead–acid, zinc–air, nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer (Li-ion polymer).
Rechargeable batteries typically initially cost more than disposable batteries but have a much lower total cost of ownership and environmental impact, as they can be recharged inexpensively many times before they need replacing. Some rechargeable battery types are available in the same sizes and voltages as disposable types, and can be used interchangeably with them. Billions of dollars in research are being invested around the world for improving batteries and industry also focuses on building better batteries. Some characteristics of rechargeable battery are given below:
In rechargeable batteries, energy is induced by applying an external source to the chemical substances.
The chemical reaction that occurs in them is reversible.
Internal resistance is comparatively low.
They have a high self-discharge rate comparatively.
They have a bulky and complex design.
They have high resell value.
Applications
Devices which use rechargeable batteries include automobile starters, portable consumer devices, light vehicles (such as motorized wheelchairs, golf carts, e
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Adaptive comparative judgement is a technique borrowed from psychophysics which is able to generate reliable results for educational assessment – as such it is an alternative to traditional exam script marking. In the approach, judges are presented with pairs of student work and are then asked to choose which is better, one or the other. By means of an iterative and adaptive algorithm, a scaled distribution of student work can then be obtained without reference to criteria.
Introduction
Traditional exam script marking began in Cambridge 1792 when, with undergraduate numbers rising, the importance of proper ranking of students was growing. So in 1792 the new Proctor of Examinations, William Farish, introduced marking, a process in which every examiner gives a numerical score to each response by every student, and the overall total mark puts the students in the final rank order. Francis Galton (1869) noted that, in an unidentified year about 1863, the Senior Wrangler scored 7,634 out of a maximum of 17,000, while the Second Wrangler scored 4,123. (The 'Wooden Spoon' scored only 237.)
Prior to 1792, a team of Cambridge examiners convened at 5pm on the last day of examining, reviewed the 19 papers each student had sat – and published their rank order at midnight. Marking solved the problems of numbers and prevented unfair personal bias, and its introduction was a step towards modern objective testing, the format it is best suited to. But the technology of testing that followed, with its major emphasis on reliability and the automatisation of marking, has been an uncomfortable partner for some areas of educational achievement: assessing writing or speaking, and other kinds of performance need something more qualitative and judgemental.
The technique of Adaptive Comparative Judgement is an alternative to marking. It returns to the pre-1792 idea of sorting papers according to their quality, but retains the guarantee of reliability and fairness. It is by far the most rel
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The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A new battery claims that it "lasts twice as long as competing batteries under the same loading conditions." Which comparison of the battery with competing batteries would validate this claim?
A. It is twice as large.
B. It contains more electrons.
C. It stores more chemical energy.
D. It destroys less energy when used.
Answer:
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|
sciq-7604
|
multiple_choice
|
What in saliva protects the lining of the mouth from abrasion and lubricates food for easier swallowing?
|
[
"phloem",
"spores",
"mucus",
"hairs"
] |
C
|
Relavent Documents:
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Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be extracted), enzymes (such as lipase and amylase), antimicrobial agents (such as secretory IgA, and lysozymes).
The enzymes found in saliva are essential in beginning the process of digestion of dietary starches and fats. These enzymes also play a role in breaking down food particles entrapped within dental crevices, thus protecting teeth from bacterial decay. Saliva also performs a lubricating function, wetting food and permitting the initiation of swallowing, and protecting the oral mucosa from drying out.
Various animal species have special uses for saliva that go beyond predigestion. Some swifts use their gummy saliva to build nests. Aerodramus nests form the basis of bird's nest soup.
Cobras, vipers, and certain other members of the venom clade hunt with venomous saliva injected by fangs. Some caterpillars produce silk fiber from silk proteins stored in modified salivary glands (which are unrelated to the vertebrate ones).
Composition
Produced in salivary glands, human saliva comprises 99.5% water, but also contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. Medically, constituents of saliva can noninvasively provide important diagnostic information related to oral and systemic diseases.
Water: 99.5%
Electrolytes:
2–21 mmol/L sodium (lower than blood plasma)
10–36 mmol/L potassium (higher than plasma)
1.2–2.8 mmol/L calcium (similar to plasma)
0.08–0.5 mmol/L magnesium
5–40 mmol/L chloride (lower than plasma)
25 mmol/L bicarbonate (higher than plasma)
1.4–39 mmol/L phosphate
Iodine (mmol/L concentration is usually higher than plasma, but dependent variable according to dietary iodine intake)
Mucus (mucus in saliva mainly consists of mucopolysacchari
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Mucous gland, also known as muciparous glands, are found in several different parts of the body, and they typically stain lighter than serous glands during standard histological preparation. Most are multicellular, but goblet cells are single-celled glands.
Mucous salivary glands
The mucous salivary glands are similar in structure to the buccal and labial glands.
They are found especially at the back part behind the vallate papillae, but are also present at the apex and marginal parts.
In this connection the anterior lingual glands require special notice.
They are situated on the under surface of the apex of the tongue, one on either side of the frenulum, where they are covered by a fascicle of muscular fibers derived from the styloglossus and inferior longitudinal muscles. They produce a glycoprotein, mucin that absorbs water to form a sticky secretion called mucus.
They are from 12 to 25 mm. long, and about 8 mm. broad, and each opens by three or four ducts on the under surface of the apex.
The Weber's glands are an example of muciparous glands located along the tongue.
See also
Mucus
Gland
Exocrine gland
Weber's glands
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The salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous, or seromucous (mixed).
In serous secretions, the main type of protein secreted is alpha-amylase, an enzyme that breaks down starch into maltose and glucose, whereas in mucous secretions, the main protein secreted is mucin, which acts as a lubricant.
In humans, 1200 to 1500 ml of saliva are produced every day. The secretion of saliva (salivation) is mediated by parasympathetic stimulation; acetylcholine is the active neurotransmitter and binds to muscarinic receptors in the glands, leading to increased salivation.
A proposed fourth pair of salivary glands, the tubarial glands, were first identified in 2020. They are named for their location, being positioned in front of and over the torus tubarius. However, this finding from one study is yet to be confirmed.
Structure
The salivary glands are detailed below:
Parotid glands
The two parotid glands are major salivary glands wrapped around the mandibular ramus in humans. These are largest of the salivary glands, secreting saliva to facilitate mastication and swallowing, and amylase to begin the digestion of starches. It is the serous type of gland which secretes alpha-amylase (also known as ptyalin). It enters the oral cavity via the parotid duct. The glands are located posterior to the mandibular ramus and anterior to the mastoid process of the temporal bone. They are clinically relevant in dissections of facial nerve branches while exposing the different lobes, since any iatrogenic lesion will result in either loss of action or strength of muscles involved in facial expression. They produce 20% of the total salivary content in the oral cavity. Mumps is a viral infection, caused by infection in the parotid
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Lingual papillae (: papilla) are small structures on the upper surface of the tongue that give it its characteristic rough texture. The four types of papillae on the human tongue have different structures and are accordingly classified as circumvallate (or vallate), fungiform, filiform, and foliate. All except the filiform papillae are associated with taste buds.
Structure
In living subjects, lingual papillae are more readily seen when the tongue is dry. There are four types of papillae present on the tongue:
Filiform papillae
Filiform papillae are the most numerous of the lingual papillae. They are fine, small, cone-shaped papillae found on the anterior surface of the tongue. They are responsible for giving the tongue its texture and are responsible for the sensation of touch. Unlike the other kinds of papillae, filiform papillae do not contain taste buds. They cover most of the front two-thirds of the tongue's surface.
They appear as very small, conical or cylindrical surface projections, and are arranged in rows which lie parallel to the sulcus terminalis. At the tip of the tongue, these rows become more transverse.
Histologically, they are made up of irregular connective tissue cores with a keratin–containing epithelium which has fine secondary threads. Heavy keratinization of filiform papillae, occurring for instance in cats, gives the tongue a roughness that is characteristic of these animals.
These papillae have a whitish tint, owing to the thickness and density of their epithelium. This epithelium has undergone a peculiar modification as the cells have become cone–like and elongated into dense, overlapping, brush-like threads. They also contain a number of elastic fibers, which render them firmer and more elastic than the other types of papillae. The larger and longer papillae of this group are sometimes termed papillae conicae.
Fungiform papillae
The fungiform papillae are club shaped projections on the tongue, generally red in color. They are foun
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Oral myology (also known as "orofacial myology") is the field of study that involves the evaluation and treatment (known as "orofacial myofunctional therapy") of the oral and facial musculature, including the muscles of the tongue, lips, cheeks, and jaw.
Use
Orofacial myofunctional therapy treatment is most commonly used to retrain oral rest posture, swallowing patterns in the oral phase, and speech.
Tongue thrust and thumb sucking
A major focus of the field of oral myology and treatment of orofacial myofunctional disorders include tongue posture and establishing equilibrium between the tongue, lips and the cheek muscles. Tongue exercise proved to be successful in treating tongue thrust. Tongue exercise alone was reported to be successful in cessation of thumb sucking and treatment of anterior open bite malocclusion. When the tongue rests against the palate it begins to expand the maxilla by applying a slow and consistent force to the lingual (tongue side) surfaces of the teeth. This may aid in the treatment of crooked teeth and under-developed face.
Sleep apnea and snoring
Oral myology plays also an important role in the management of patients with sleep breathing disorders and snoring where oropharyngeal exercises were found to reduce the severity and primary symptoms of obstructive sleep apnea. Poor positioning of the tongue affects breathing and allows a series of events to occur that can affect the orofacial complex. Patients with sleep apnea and other breathing difficulties usually have decreased tone and mobility in the cheek, tongue, lip, and soft palate, and sensory alterations due to a tendency to engage in mouth breathing rather than nasal breathing. In treatment of sleep apnea, oral myology therapy involves a series of exercises designed to improve tongue position and tongue function for a better control of the extrinsic tongue muscles and place the tongue in a ‘‘proper posture during function and at rest.’’
Dysphagia
Disruption of normal swallowi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What in saliva protects the lining of the mouth from abrasion and lubricates food for easier swallowing?
A. phloem
B. spores
C. mucus
D. hairs
Answer:
|
|
scienceQA-2400
|
multiple_choice
|
Select the liquid.
|
[
"pair of dice",
"water droplets",
"spoon",
"chalk"
] |
B
|
Chalk is a solid. You can easily break chalk into pieces. But each piece will still have a size and shape of its own.
Water droplets are a liquid. A liquid takes the shape of any container it is in. If you collect water droplets in a bucket, they will take the shape of the bucket. But the water droplets will still take up the same amount of space.
A spoon is a solid. You can bend a spoon. But it will still have a size and shape of its own.
A pair of dice is a solid. A solid has a size and shape of its own. When you roll a pair of dice, the dice have a shape of their own. They are still cubes when they stop rolling.
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 2:::
A breakthrough curve in adsorption is the course of the effluent adsorptive concentration at the outlet of a fixed bed adsorber. Breakthrough curves are important for adsorptive separation technologies and for the characterization of porous materials.
Importance
Since almost all adsorptive separation processes are dynamic -meaning, that they are running under flow - testing porous materials for those applications for their separation performance has to be tested under flow as well. Since separation processes run with mixtures of different components, measuring several breakthrough curves results in thermodynamic mixture equilibria - mixture sorption isotherms, that are hardly accessible with static manometric sorption characterization. This enables the determination of sorption selectivities in gaseous and liquid phase.
The determination of breakthrough curves is the foundation of many other processes, like the pressure swing adsorption. Within this process, the loading of one adsorber is equivalent to a breakthrough experiment.
Measurement
A fixed bed of porous materials (e.g. activated carbons and zeolites) is pressurized and purged with a carrier gas. After becoming stationary one or more adsorptives are added to the carrier gas, resulting in a step-wise change of the inlet concentration. This is in contrast to chromatographic separation processes, where pulse-wise changes of the inlet concentrations are used. The course of the adsorptive concentrations at the outlet of the fixed bed are monitored.
Results
Integration of the area above the entire breakthrough curve gives the maximum loading of the adsorptive material. Additionally, the duration of the breakthrough experiment until a certain threshold of the adsorptive concentration at the outlet can be measured, which enables the calculation of a technically usable sorption capacity. Up to this time, the quality of the product stream can be maintained. The shape of the breakthrough curves contains informat
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A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a nearly constant volume independent of pressure. It is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape.
The density of a liquid is usually close to that of a solid, and much higher than that of a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids.
A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Unlike a gas, a liquid maintains a fairly constant density and does not disperse to fill every space of a container.
Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is either gas (as interstellar clouds) or plasma (as stars).
Introduction
Liquid is one of the four primary states of matter, with the others being solid, gas and plasma. A liquid is a fluid. Unlike a solid, the molecules in a liquid have a much greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, allowing a liquid to flow while a solid remains rigid.
A liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, and, if placed in a sealed container, will distribute applied pressure evenly to every surface in the container. If liquid is placed in a bag, it can be squeezed into any shape. Unlike a gas, a liquid is nearly incompressible, meaning that it occupies nearly a constant volume over a wide range of pressures; it does not generally expand to fill available space in a containe
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GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the liquid.
A. pair of dice
B. water droplets
C. spoon
D. chalk
Answer:
|
sciq-430
|
multiple_choice
|
The global pattern of precipitation is influenced by movements of what?
|
[
"air masses",
"clouds",
"air valleys",
"pollution masses"
] |
A
|
Relavent Documents:
Document 0:::
The following outline is provided as an overview of and topical guide to the field of Meteorology.
Meteorology The interdisciplinary, scientific study of the Earth's atmosphere with the primary focus being to understand, explain, and forecast weather events. Meteorology, is applied to and employed by a wide variety of diverse fields, including the military, energy production, transport, agriculture, and construction.
Essence of meteorology
Meteorology
Climate – the average and variations of weather in a region over long periods of time.
Meteorology – the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting (in contrast with climatology).
Weather – the set of all the phenomena in a given atmosphere at a given time.
Branches of meteorology
Microscale meteorology – the study of atmospheric phenomena about 1 km or less, smaller than mesoscale, including small and generally fleeting cloud "puffs" and other small cloud features
Mesoscale meteorology – the study of weather systems about 5 kilometers to several hundred kilometers, smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems, skjjoch as sea breezes, squall lines, and mesoscale convective complexes
Synoptic scale meteorology – is a horizontal length scale of the order of 1000 kilometres (about 620 miles) or more
Methods in meteorology
Surface weather analysis – a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations
Weather forecasting
Weather forecasting – the application of science and technology to predict the state of the atmosphere for a future time and a given location
Data collection
Pilot Reports
Weather maps
Weather map
Surface weather analysis
Forecasts and reporting of
Atmospheric pressure
Dew point
High-pressure area
Ice
Black ice
Frost
Low-pressure area
Precipitation
Document 1:::
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. (see also: List of meteorological phenomena)
A
advection
aeroacoustics
aerobiology
aerography (meteorology)
aerology
air parcel (in meteorology)
air quality index (AQI)
airshed (in meteorology)
American Geophysical Union (AGU)
American Meteorological Society (AMS)
anabatic wind
anemometer
annular hurricane
anticyclone (in meteorology)
apparent wind
Atlantic Oceanographic and Meteorological Laboratory (AOML)
Atlantic hurricane season
atmometer
atmosphere
Atmospheric Model Intercomparison Project (AMIP)
Atmospheric Radiation Measurement (ARM)
(atmospheric boundary layer [ABL]) planetary boundary layer (PBL)
atmospheric chemistry
atmospheric circulation
atmospheric convection
atmospheric dispersion modeling
atmospheric electricity
atmospheric icing
atmospheric physics
atmospheric pressure
atmospheric sciences
atmospheric stratification
atmospheric thermodynamics
atmospheric window (see under Threats)
B
ball lightning
balloon (aircraft)
baroclinity
barotropity
barometer ("to measure atmospheric pressure")
berg wind
biometeorology
blizzard
bomb (meteorology)
buoyancy
Bureau of Meteorology (in Australia)
C
Canada Weather Extremes
Canadian Hurricane Centre (CHC)
Cape Verde-type hurricane
capping inversion (in meteorology) (see "severe thunderstorms" in paragraph 5)
carbon cycle
carbon fixation
carbon flux
carbon monoxide (see under Atmospheric presence)
ceiling balloon ("to determine the height of the base of clouds above ground level")
ceilometer ("to determine the height of a cloud base")
celestial coordinate system
celestial equator
celestial horizon (rational horizon)
celestial navigation (astronavigation)
celestial pole
Celsius
Center for Analysis and Prediction of Storms (CAPS) (in Oklahoma in the US)
Center for the Study o
Document 2:::
In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive, dynamical equations which govern atmospheric motions. It can supplement these equations with parameterizations for turbulent diffusion, radiation, moist processes (clouds and precipitation), heat exchange, soil, vegetation, surface water, the kinematic effects of terrain, and convection. Most atmospheric models are numerical, i.e. they discretize equations of motion. They can predict microscale phenomena such as tornadoes and boundary layer eddies, sub-microscale turbulent flow over buildings, as well as synoptic and global flows. The horizontal domain of a model is either global, covering the entire Earth, or regional (limited-area), covering only part of the Earth. The different types of models run are thermotropic, barotropic, hydrostatic, and nonhydrostatic. Some of the model types make assumptions about the atmosphere which lengthens the time steps used and increases computational speed.
Forecasts are computed using mathematical equations for the physics and dynamics of the atmosphere. These equations are nonlinear and are impossible to solve exactly. Therefore, numerical methods obtain approximate solutions. Different models use different solution methods. Global models often use spectral methods for the horizontal dimensions and finite-difference methods for the vertical dimension, while regional models usually use finite-difference methods in all three dimensions. For specific locations, model output statistics use climate information, output from numerical weather prediction, and current surface weather observations to develop statistical relationships which account for model bias and resolution issues.
Types
The main assumption made by the thermotropic model is that while the magnitude of the thermal wind may change, its direction does not change with respect to height, and thus the baroclinicity in the atmosphere can be simulated usi
Document 3:::
A Climate Data Record (CDR) is a specific definition of a climate data series, developed by the Committee on Climate Data Records from NOAA Operational Satellites of the National Research Council at the request of NOAA in the context of satellite records. It is defined as "a time series of measurements of sufficient length, consistency, and continuity to determine climate variability and climate change.".
Such measurements provide an objective basis for the understanding and prediction of climate and its variability, such as global warming.
Interim Climate Data Record (ICDR)
An Interim Climate Data Record (ICDR) is a dataset that has been forward processed, using the baselined CDR algorithm and processing environment but whose consistency and continuity have not been verified. Eventually it will be necessary to perform a new reprocessing of the CDR and ICDR parts together to guarantee consistency, and the new reprocessed data record will replace the old CDR.
Fundamental Climate Data Record (FCDR)
A Fundamental Climate Data Record is a long-term data record of calibrated and quality-controlled data designed to allow the generation of homogeneous products that are accurate and stable enough for climate monitoring.
Examples of CDRs
AVHRR Pathfinder Sea Surface Temperature
GHRSST-PP Reanalysis Project, on the website for Ghrsst-pp
Snow and Ice
NOAA's Climate Data Records homepage
See also
Temperature record
Document 4:::
PERSIANN, "Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks", is a satellite-based precipitation retrieval algorithm that provides near real-time rainfall information. The algorithm uses infrared (IR) satellite data from global geosynchronous satellites as the primary source of precipitation information. Precipitation from IR images is based on statistical relationship between cloud top temperature and precipitation rates. The IR-based precipitation estimates are then calibrated using satellite microwave data available from low Earth orbit satellites (e.g., Tropical Rainfall Measuring Mission Microwave Imager, Special Sensor Microwave Imager, Advanced Microwave Scanning Radiometer‐Earth observing system). The calibration technique relies on an adaptive training algorithm that updates the retrieval parameters when microwave observations become available (approximately at 3 hours intervals).
The PERSIANN satellite precipitation data sets have been validated with ground-based observations and other satellite data products. The PERSIANN data has been used in a wide variety of studies including hydrologic modeling, drought monitoring, soil moisture analysis, and flood forecasting. The PERSIANN data are freely available to the public.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The global pattern of precipitation is influenced by movements of what?
A. air masses
B. clouds
C. air valleys
D. pollution masses
Answer:
|
|
sciq-845
|
multiple_choice
|
What is the name of the type of combustion engine that you would find in a car?
|
[
"internal vapor engine",
"internal oxide engine",
"internal modern engine",
"internal combustion engine"
] |
D
|
Relavent Documents:
Document 0:::
Motronic is the trade name given to a range of digital engine control units developed by Robert Bosch GmbH (commonly known as Bosch) which combined control of fuel injection and ignition in a single unit. By controlling both major systems in a single unit, many aspects of the engine's characteristics (such as power, fuel economy, drivability, and emissions) can be improved.
Motronic 1.x
Motronic M1.x is powered by various i8051 derivatives made by Siemens, usually SAB80C515 or SAB80C535. Code/data is stored in DIL or PLCC EPROM and ranges from 32k to 128k.
1.0
Often known as "Motronic basic", Motronic ML1.x was one of the first digital engine-management systems developed by Bosch. These early Motronic systems integrated the spark timing element with then-existing Jetronic fuel injection technology. It was originally developed and first used in the BMW 7 Series, before being implemented on several Volvo and Porsche engines throughout the 1980s.
The components of the Motronic ML1.x systems for the most part remained unchanged during production, although there are some differences in certain situations. The engine control module (ECM) receives information regarding engine speed, crankshaft angle, coolant temperature and throttle position. An air flow meter also measures the volume of air entering the induction system.
If the engine is naturally aspirated, an air temperature sensor is located in the air flow meter to work out the air mass. However, if the engine is turbocharged, an additional charge air temperature sensor is used to monitor the temperature of the inducted air after it has passed through the turbocharger and intercooler, in order to accurately and dynamically calculate the overall air mass.
Main system characteristics
Fuel delivery, ignition timing, and dwell angle incorporated into the same control unit.
Crank position and engine speed is determined by a pair of sensors reading from the flywheel.
Separate constant idle speed system monitors and re
Document 1:::
A model engine is a small internal combustion engine typically used to power a radio-controlled aircraft, radio-controlled car, radio-controlled boat, free flight, control line aircraft, or ground-running tether car model.
Because of the square–cube law, the behaviour of many engines does not always scale up or down at the same rate as the machine's size; usually at best causing a dramatic loss of power or efficiency, and at worst causing them not to work at all. Methanol and nitromethane are common fuels.
Overview
The fully functional, albeit small, engines vary from the most common single-cylinder two-stroke to the exotic single and multiple-cylinder four-stroke, the latter taking shape in boxer, v-twin, inline and radial form, a few Wankel engine designs are also used. Most model engines run on a blend of methanol, nitromethane, and lubricant (either castor or synthetic oil).
Two-stroke model engines, most often designed since 1970 with Schnuerle porting for best performance, range in typical size from .12 cubic inches (2 cubic centimeters) to 1.2 ci (19.6 cc) and generate between .5 horsepower (370 watts) to 5 hp (3.7 kW), can get as small as .010 ci (.16 cc) and as large as 3-4 ci (49–66 cc). Four-stroke model engines have been made in sizes as small as 0.20 in3 (3.3 cc) for the smallest single-cylinder models, all the way up to 3.05 in3 (50 cc) for the largest size for single-cylinder units, with twin- and multi-cylinder engines on the market being as small as 10 cc for opposed-cylinder twins, while going somewhat larger in size than 50 cc, and even upwards to well above 200 cc for some model boxer opposed-piston, inline and radial engines. While the methanol and nitromethane blended "glow fuel" engines are the most common, many larger (especially above 15 cc/0.90 ci displacement) model engines, both two-stroke and a growing number of four-stroke examples are spark ignition, and are primarily fueled with gasoline — with some examples of both two and four-
Document 2:::
In a reciprocating piston engine, the stroke ratio, defined by either bore/stroke ratio or stroke/bore ratio, is a term to describe the ratio between cylinder bore diameter and piston stroke length. This can be used for either an internal combustion engine, where the fuel is burned within the cylinders of the engine, or external combustion engine, such as a steam engine, where the combustion of the fuel takes place outside the working cylinders of the engine.
A fairly comprehensive yet understandable study of stroke/bore effects was published in Horseless Age, 1916.
Conventions
In a piston engine, there are two different ways of describing the stroke ratio of its cylinders, namely: bore/stroke ratio, and stroke/bore ratio.
Bore/stroke ratio
Bore/stroke is the more commonly used term, with usage in North America, Europe, United Kingdom, Asia, and Australia.
The diameter of the cylinder bore is divided by the length of the piston stroke to give the ratio.
Square, oversquare and undersquare engines
The following terms describe the naming conventions for the configurations of the various bore/stroke ratio:
Square engine
A square engine has equal bore and stroke dimensions, giving a bore/stroke value of exactly 1:1.
Square engine examples
1953 – Ferrari 250 Europa had Lampredi V12 with bore and stroke.
1967 – FIAT 125, 124Sport engine 125A000-90 hp, 125B000-100 hp, 125BC000-110 hp, 1608 ccm, DOHC, bore and stroke.
1970 – Ford 400 had a bore and stroke.
1973 – Kawasaki Z1 and KZ(Z)900 had a bore and stroke.
1973 – British Leyland's Australian division created a 4.4-litre version of the Rover V8 engine, with bore and stroke both measuring 88.9 mm. This engine was exclusively used in the Leyland P76.
1982 - Honda Nighthawk 250 and Honda CMX250C Rebel have a bore and stroke, making it a square engine.
1983 – Mazda FE 2.0L inline four-cylinder engine with a perfectly squared bore and stroke. This engine also features the ideal 1.75:1 rod/stroke ratio.
1
Document 3:::
Engine power is the power that an engine can put out. It can be expressed in power units, most commonly kilowatt, pferdestärke (metric horsepower), or horsepower. In terms of internal combustion engines, the engine power usually describes the rated power, which is a power output that the engine can maintain over a long period of time according to a certain testing method, for example ISO 1585. In general though, an internal combustion engine has a power take-off shaft (the crankshaft), therefore, the rule for shaft power applies to internal combustion engines: Engine power is the product of the engine torque and the crankshaft's angular velocity.
Definition
Power is the product of torque and angular velocity:
Let:
Power in Watt (W)
Torque in Newton-metre (N·m)
Crankshaft speed per Second (s−1)
Angular velocity =
Power is then:
In internal combustion engines, the crankshaft speed is a more common figure than , so we can use instead, which is equivalent to :
Note that is per Second (s−1). If we want to use the common per Minute (min−1) instead, we have to divide by 60:
Usage
Numerical value equations
The approximate numerical value equations for engine power from torque and crankshaft speed are:
International unit system (SI)
Let:
Power in Kilowatt (kW)
Torque in Newton-metre (N·m)
Crankshaft speed per Minute (min−1)
Then:
Technical unit system (MKS)
Power in Pferdestärke (PS)
Torque in Kilopondmetre (kp·m)
Crankshaft speed per Minute (min−1)
Then:
Imperial/U.S. Customary unit system
Power in Horsepower (hp)
Torque in Pound-force foot (lbf·ft)
Crankshaft speed in Revolutions per Minute (rpm)
Then:
Example
A diesel engine produces a torque of 234 N·m at 4200 min−1, which is the engine's rated speed.
Let:
Then:
or using the numerical value equation:
The engine's rated power output is 103 kW.
Units
See also
List of production cars by power output
Bibliography
Document 4:::
Computer science and engineering (CSE) is an academic program at many universities which comprises computer science classes (e.g. data structures and algorithms) and computer engineering classes (e.g computer architecture). There is no clear division in computing between science and engineering, just like in the field of materials science and engineering. CSE is also a term often used in Europe to translate the name of engineering informatics academic programs. It is offered in both undergraduate as well postgraduate with specializations.
Academic courses
Academic programs vary between colleges, but typically include a combination of topics in computer science, computer engineering, and electrical engineering. Undergraduate courses usually include programming, algorithms and data structures, computer architecture, operating systems, computer networks, parallel computing, embedded systems, algorithms design, circuit analysis and electronics, digital logic and processor design, computer graphics, scientific computing, software engineering, database systems, digital signal processing, virtualization, computer simulations and games programming. CSE programs also include core subjects of theoretical computer science such as theory of computation, numerical methods, machine learning, programming theory and paradigms. Modern academic programs also cover emerging computing fields like image processing, data science, robotics, bio-inspired computing, computational biology, autonomic computing and artificial intelligence. Most CSE programs require introductory mathematical knowledge, hence the first year of study is dominated by mathematical courses, primarily discrete mathematics, mathematical analysis, linear algebra, probability, and statistics, as well as the basics of electrical and electronic engineering, physics, and electromagnetism.
Example universities with CSE majors and departments
APJ Abdul Kalam Technological University
American International University-B
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the name of the type of combustion engine that you would find in a car?
A. internal vapor engine
B. internal oxide engine
C. internal modern engine
D. internal combustion engine
Answer:
|
|
scienceQA-10587
|
multiple_choice
|
What do these two changes have in common?
chicken cooking in an oven
bleaching hair
|
[
"Both are chemical changes.",
"Both are only physical changes.",
"Both are caused by cooling.",
"Both are caused by heating."
] |
A
|
Step 1: Think about each change.
Cooking chicken is a chemical change. The heat causes the matter in the chicken to change. Cooked chicken and raw chicken are different types of matter.
Bleaching hair is a chemical change. Hair contains colorful matter called pigment. The bleach reacts with the pigment and turns it into a different type of matter. The new matter gives the hair a lighter color than before.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Cooking is caused by heating. But bleaching hair is not.
Both are caused by cooling.
Neither change is caused by cooling.
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
Test equating traditionally refers to the statistical process of determining comparable scores on different forms of an exam. It can be accomplished using either classical test theory or item response theory.
In item response theory, equating is the process of placing scores from two or more parallel test forms onto a common score scale. The result is that scores from two different test forms can be compared directly, or treated as though they came from the same test form. When the tests are not parallel, the general process is called linking. It is the process of equating the units and origins of two scales on which the abilities of students have been estimated from results on different tests. The process is analogous to equating degrees Fahrenheit with degrees Celsius by converting measurements from one scale to the other. The determination of comparable scores is a by-product of equating that results from equating the scales obtained from test results.
Purpose
Suppose that Dick and Jane both take a test to become licensed in a certain profession. Because the high stakes (you get to practice the profession if you pass the test) may create a temptation to cheat, the organization that oversees the test creates two forms. If we know that Dick scored 60% on form A and Jane scored 70% on form B, do we know for sure which one has a better grasp of the material? What if form A is composed of very difficult items, while form B is relatively easy? Equating analyses are performed to address this very issue, so that scores are as fair as possible.
Equating in item response theory
In item response theory, person "locations" (measures of some quality being assessed by a test) are estimated on an interval scale; i.e., locations are estimated in relation to a unit and origin. It is common in educational assessment to employ tests in order to assess different groups of students with the intention of establishing a common scale by equating the origins, and when appropri
Document 4:::
Computer science and engineering (CSE) is an academic program at many universities which comprises computer science classes (e.g. data structures and algorithms) and computer engineering classes (e.g computer architecture). There is no clear division in computing between science and engineering, just like in the field of materials science and engineering. CSE is also a term often used in Europe to translate the name of engineering informatics academic programs. It is offered in both undergraduate as well postgraduate with specializations.
Academic courses
Academic programs vary between colleges, but typically include a combination of topics in computer science, computer engineering, and electrical engineering. Undergraduate courses usually include programming, algorithms and data structures, computer architecture, operating systems, computer networks, parallel computing, embedded systems, algorithms design, circuit analysis and electronics, digital logic and processor design, computer graphics, scientific computing, software engineering, database systems, digital signal processing, virtualization, computer simulations and games programming. CSE programs also include core subjects of theoretical computer science such as theory of computation, numerical methods, machine learning, programming theory and paradigms. Modern academic programs also cover emerging computing fields like image processing, data science, robotics, bio-inspired computing, computational biology, autonomic computing and artificial intelligence. Most CSE programs require introductory mathematical knowledge, hence the first year of study is dominated by mathematical courses, primarily discrete mathematics, mathematical analysis, linear algebra, probability, and statistics, as well as the basics of electrical and electronic engineering, physics, and electromagnetism.
Example universities with CSE majors and departments
APJ Abdul Kalam Technological University
American International University-B
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
chicken cooking in an oven
bleaching hair
A. Both are chemical changes.
B. Both are only physical changes.
C. Both are caused by cooling.
D. Both are caused by heating.
Answer:
|
sciq-246
|
multiple_choice
|
What planet is a blue green color?
|
[
"Mercury",
"sirius",
"uranus",
"Mars"
] |
C
|
Relavent Documents:
Document 0:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 1:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
Document 2:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 3:::
Green Light, green light, green-light or greenlight may refer to:
Green-colored light, part of the visible spectrum
Arts, entertainment, and media
Films and television
Green Light (1937 film), starring Errol Flynn
Green Light (2002 film), a Turkish film written and directed by Faruk Aksoy
"Green Light" (Breaking Bad), a third-season episode of Breaking Bad
Greenlight, formal approval of a project to move forward
Literature
Green Light, a 1935 novel by Lloyd C. Douglas
"Green Light", the final passage of F. Scott Fitzgerald's novel The Great Gatsby
Greenlights (book), a 2020 book by Matthew McConaughey
Music
Albums
Green Light (Bonnie Raitt album), 1982
Green Light (Cliff Richard album), 1978
The Green Light, a 2009 mixtape by Bow Wow
Songs
"Green Light" (Cliff Richard song) (1979)
"Green Light" (Beyoncé song) (2006)
"Green Light" (John Legend song) (2008)
"Green Light" (Roll Deep song) (2010)
"Green Light" (Lorde song) (2017)
"Green Light" (Valery Leontiev song) (1984)
"Green Light", by the American Breed from Bend Me, Shape Me (1968)
"Green Light", by Girls' Generation from Lion Heart
"Green Light", by Hank Thompson (1954)
"Green Light", by Lil Durk from Love Songs 4 the Streets 2
"Green Light", by R. Kelly from Write Me Back
"Green Light", by Sonic Youth from Evol
"Green Light", by the Bicycles from Oh No, It's Love
"Green Lights", by Aloe Blacc (2011)
"Greenlight" (Pitbull song) (2016)
"Green Lights", by Sarah Jarosz from Undercurrent (2016)
"Green Light", by Kylie Minogue from Tension (2023)
"Greenlight", by 5 Seconds of Summer from 5 Seconds of Summer
"Greenlight", by Enisa Nikaj which represented New York in the American Song Contest
"Greenlights" (song), by Krewella
Computing and technology
Greenlight (Internet service), a fiber-optic Internet service provided by the city of Wilson, North Carolina, US
Greenlight Networks, a fiber-optic Internet service in Rochester, New York, US
Steam Greenlight, a service part of Val
Document 4:::
NASA 360 is a half-hour vodcast developed by NASA in partnership with the National Institute of Aerospace. The show premiered in August 2008. It has aired on more than 450 TV stations across the country, is available on air and cruise lines, and is consistently one of the top-downloaded programs on the NASA.gov website. It is currently in its tenth season.
Description
NASA 360 is one of four programs in NASA's award-winning eClips suite of web-based shows designed to encourage careers in science, technology, engineering, and mathematics. NASA 360 is written, produced, and edited by Timothy J. Allen, Tom Shortridge, and Scott Bednar; Rebecca Jaramillo is the Senior Educator and Project Coordinator for NASA 360, and Harla Sherwood the Principal Investigator - all of the National Institute of Aerospace.
NASA 360 shows how NASA has changed and continues to change life on Earth by examining how technologies developed by or for NASA are being used in everything from space exploration to everyday consumer products. These include lithium ion batteries, medical innovations, sporting equipment, and automotive and aircraft safety and efficiency, among many more.
NASA 360 is shot on-location at NASA centers across the country, as well as at other relevant sites across the globe. The fifth season marked the revitalization of NASA 360 and features new hosts Caleb Kinchlow and Molly McKinney, B-roll, animations, and interviews conducted with NASA researchers, engineers, and astronauts, as well as with outside sources with expertise relevant to the topics being discussed.
The show is produced for a young adult audience, and stylistically this is accomplished through the use of hand-held cameras, quick edits, and numerous transitions, effects, and filters used in post-production.
NASA 360 was originally created in 2006 by producers Kevin Krigsvold and Michael Bibbo. It was hosted by Johnny Alonso and Jennifer Pulley through 2012. Twenty-three episodes were produced during this
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What planet is a blue green color?
A. Mercury
B. sirius
C. uranus
D. Mars
Answer:
|
|
sciq-5688
|
multiple_choice
|
Hormones often regulate what through antagonistic functions?
|
[
"consciousness",
"homeostasis",
"hypothesis",
"breathing"
] |
B
|
Relavent Documents:
Document 0:::
The following is a list of hormones found in Homo sapiens. Spelling is not uniform for many hormones. For example, current North American and international usage uses estrogen and gonadotropin, while British usage retains the Greek digraph in oestrogen and favours the earlier spelling gonadotrophin.
Hormone listing
Steroid
Document 1:::
A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals.
Prominent neurochemicals
Neurotransmitters and neuromodulators
Glutamate is the most common neurotransmitter. Most neurons secrete with glutamate or GABA. Glutamate is excitatory, meaning that the release of glutamate by one cell usually causes adjacent cells to fire an action potential. (Note: Glutamate is chemically identical to the MSG commonly used to flavor food.)
GABA is an example of an inhibitory neurotransmitter.
Monoamine neurotransmitters:
Dopamine is a monoamine neurotransmitter. It plays a key role in the functioning of the limbic system, which is involved in emotional function and control. It also is involved in cognitive processes associated with movement, arousal, executive function, body temperature regulation, and pleasure and reward, and other processes.
Norepinephrine, also known as noradrenaline, is a monoamine neurotransmitter that is involved in arousal, pain perception, executive function, body temperature regulation, and other processes.
Epinephrine, also known as adrenaline, is a monoamine neurotransmitter that plays in fight-or-flight response, increases blood flow to muscles, output of the heart, pupil dilation, and glucose.
Serotonin is a monoamine neurotransmitter that plays a regulatory role in mood, sleep, appetite, body temperature regulation, and other processes.
Histamine is a monoamine neurotransmitter that is involved in arousal, pain, body temperature regulation, and appetite.
Trace amines act as neuromodulators in monoamine neurons via binding to TAAR1.
Acetylcholine assists motor function and is involved in memory.
Nitric oxide functions as a neurotransmitter, despite being a gas. It is not grouped with the other neurotransmitters because it is not released in the same way.
Endocannabinoids act in the endocannabinoid system to control neurotransmitter release
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The following outline is provided as an overview of and topical guide to neuroscience:
Neuroscience is the scientific study of the structure and function of the nervous system. It encompasses the branch of biology that deals with the anatomy, biochemistry, molecular biology, and physiology of neurons and neural circuits. It also encompasses cognition, and human behavior. Neuroscience has multiple concepts that each relate to learning abilities and memory functions. Additionally, the brain is able to transmit signals that cause conscious/unconscious behaviors that are responses verbal or non-verbal. This allows people to communicate with one another.
Branches of neuroscience
Neurophysiology
Neurophysiology is the study of the function (as opposed to structure) of the nervous system.
Brain mapping
Electrophysiology
Extracellular recording
Intracellular recording
Brain stimulation
Electroencephalography
Intermittent rhythmic delta activity
:Category: Neurophysiology
:Category: Neuroendocrinology
:Neuroendocrinology
Neuroanatomy
Neuroanatomy is the study of the anatomy of nervous tissue and neural structures of the nervous system.
Immunostaining
:Category: Neuroanatomy
Neuropharmacology
Neuropharmacology is the study of how drugs affect cellular function in the nervous system.
Drug
Psychoactive drug
Anaesthetic
Narcotic
Behavioral neuroscience
Behavioral neuroscience, also known as biological psychology, biopsychology, or psychobiology, is the application of the principles of biology to the study of mental processes and behavior in human and non-human animals.
Neuroethology
Developmental neuroscience
Developmental neuroscience aims to describe the cellular basis of brain development and to address the underlying mechanisms. The field draws on both neuroscience and developmental biology to provide insight into the cellular and molecular mechanisms by which complex nervous systems develop.
Aging and memory
Cognitive neuroscience
Cognitive ne
Document 3:::
In evolutionary psychology, people often speak of the four Fs which are said to be the four basic and most primal drives (motivations or instincts) that animals (including humans) are evolutionarily adapted to have, follow, and achieve: fighting, fleeing, feeding and mating (the final word beginning with the letter "M" rather than "F" is a reticent allusion to the cruder synonym "fuck").
The list of the four activities appears to have been first introduced in the late 1950s and early 1960s in articles by psychologist Karl H. Pribram, with the fourth entry in the list being known by terms such as "sex" or occasionally "fornicating", although he himself did not use the term "four Fs".
Conventionally, the four Fs were described as adaptations which helped the organism to find food, avoid danger, defend its territory, et cetera. However, in his book The Selfish Gene, Richard Dawkins argued that adaptive traits do not evolve to benefit individual organisms, but to benefit the passing on of genes.
Four Fs and vertebrates
In the case of vertebrates, this list corresponds to the motivational behaviours that drive the activity in the hypothalamus, namely: fighting, fleeing, feeding and sexual functioning. The hypothalamus responds to these motivations by regulating activity in the endocrine system to release hormones to alter the behaviour of the animal. These hormones include epinephrine (adrenaline) to increase blood flow and heart rate for a sufficient fight-or-flight response, and ghrelin, which is commonly described as "the hunger hormone".
In other animals
Species from other phyla than vertebrates, such as arthropods and sponges, do not possess a hypothalamus. Hormones that influence the behaviour of insects are excreted by neurosecretory cells (NCS) in the corpora cardiaca. Sponges, despite not having a neurosystem, do show signs of behaviour in response to external stimuli, but not much is known about neuro-sensory mechanisms in sponges and whether they possess
Document 4:::
The Society for Behavioral Neuroendocrinology is an interdisciplinary scientific organization dedicated to the study of hormonal processes and neuroendocrine systems that regulate behavior.
Publications
SBN publishes the scientific journal Hormones and Behavior.
External links
Neuroscience organizations
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Hormones often regulate what through antagonistic functions?
A. consciousness
B. homeostasis
C. hypothesis
D. breathing
Answer:
|
|
sciq-11170
|
multiple_choice
|
What replicates in the s phase of interphase, resulting in chromosomes composed of two linked sister chromatids?
|
[
"RNA",
"dna",
"hormones",
"protein"
] |
B
|
Relavent Documents:
Document 0:::
Interkinesis or interphase II is a period of rest that cells of some species enter during meiosis between meiosis I and meiosis II. No DNA replication occurs during interkinesis; however, replication does occur during the interphase I stage of meiosis (See meiosis I). During interkinesis, the spindles of the first meiotic division disassembles and the microtubules reassemble into two new spindles for the second meiotic division. Interkinesis follows telophase I; however, many plants skip telophase I and interkinesis, going immediately into prophase II. Each chromosome still consists of two chromatids. In this stage other organelle number may also increase.
Document 1:::
Interphase is the portion of the cell cycle that is not accompanied by visible changes under the microscope, and includes the G1, S and G2 phases. During interphase, the cell grows (G1), replicates its DNA (S) and prepares for mitosis (G2). A cell in interphase is not simply quiescent. The term quiescent (i.e. dormant) would be misleading since a cell in interphase is very busy synthesizing proteins, copying DNA into RNA, engulfing extracellular material, processing signals, to name just a few activities. The cell is quiescent only in the sense of cell division (i.e. the cell is out of the cell cycle, G0). Interphase is the phase of the cell cycle in which a typical cell spends most of its life. Interphase is the 'daily living' or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other "normal" cell functions.
Interphase was formerly called the resting phase. However, interphase does not describe a cell that is merely resting; rather, the cell is living and preparing for later cell division, so the name was changed. A common misconception is that interphase is the first stage of mitosis, but since mitosis is the division of the nucleus, prophase is actually the first stage.
In interphase, the cell gets itself ready for mitosis or meiosis. Somatic cells, or normal diploid cells of the body, go through mitosis in order to reproduce themselves through cell division, whereas diploid germ cells (i.e., primary spermatocytes and primary oocytes) go through meiosis in order to create haploid gametes (i.e., sperm and ova) for the purpose of sexual reproduction.
Stages of interphase
There are three stages of cellular interphase, with each phase ending when a cellular checkpoint checks the accuracy of the stage's completion before proceeding to the next. The stages of interphase are:
G1 (Gap 1), in which the cell grows and functions normally. During this time, a high a
Document 2:::
Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes. However, in contrast to eukaryotic chromosome segregation, replication and segregation are not temporally separated. Instead segregation occurs progressively following replication.
Mitotic chromatid segregation
During mitosis chromosome segregation occurs routinely as a step in cell division (see mitosis diagram). As indicated in the mitosis diagram, mitosis is preceded by a round of DNA replication, so that each chromosome forms two copies called chromatids. These chromatids separate to opposite poles, a process facilitated by a protein complex referred to as cohesin. Upon proper segregation, a complete set of chromatids ends up in each of two nuclei, and when cell division is completed, each DNA copy previously referred to as a chromatid is now called a chromosome.
Meiotic chromosome and chromatid segregation
Chromosome segregation occurs at two separate stages during meiosis called anaphase I and anaphase II (see meiosis diagram). In a diploid cell there are two sets of homologous chromosomes of different parental origin (e.g. a paternal and a maternal set). During the phase of meiosis labeled “interphase s” in the meiosis diagram there is a round of DNA replication, so that each of the chromosomes initially present is now composed of two copies called chromatids. These chromosomes (paired chromatids) then pair with the homologous chromosome (also paired chromatids) present in the same nucleus (see prophase I in the meiosis diagram). The process of alignment of paired homologous chromosomes is called synapsis (see Synapsis). During synapsis, genetic recombination usually occurs. Some of the recombination even
Document 3:::
A kinetochore (, ) is a disc-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis. The term kinetochore was first used in a footnote in a 1934 Cytology book by Lester W. Sharp and commonly accepted in 1936. Sharp's footnote reads: "The convenient term kinetochore (= movement place) has been suggested to the author by J. A. Moore", likely referring to John Alexander Moore who had joined Columbia University as a freshman in 1932.
Monocentric organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles a single, localized kinetochore. Holocentric organisms, such as nematodes and some plants, assemble a kinetochore along the entire length of a chromosome.
Kinetochores start, control, and supervise the striking movements of chromosomes during cell division. During mitosis, which occurs after the amount of DNA is doubled in each chromosome (while maintaining the same number of chromosomes) in S phase, two sister chromatids are held together by a centromere. Each chromatid has its own kinetochore, which face in opposite directions and attach to opposite poles of the mitotic spindle apparatus. Following the transition from metaphase to anaphase, the sister chromatids separate from each other, and the individual kinetochores on each chromatid drive their movement to the spindle poles that will define the two new daughter cells. The kinetochore is therefore essential for the chromosome segregation that is classically associated with mitosis and meiosis.
Structure of Kinetochore
The kinetochore contains two regions:
an inner kinetochore, which is tightly associated with the centromere DNA and assembled in a specialized form of chromatin that persists t
Document 4:::
Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles.
Cohesin loading
Cohesin first associates with the chromosomes during G1 phase. The cohesin ring is composed of two SMC (structural maintenance of chromosomes) proteins and two additional Scc proteins. Cohesin may originally interact with chromosomes via the ATPase domains of the SMC proteins. In yeast, the loading of cohesin on the chromosomes depends on proteins Scc2 and Scc4.
Cohesin interacts with the chromatin at specific loci. High levels of cohesin binding are observed at the centromere. Cohesin is also loaded at cohesin attachment regions (CARs) along the length of the chromosomes. CARs are approximately 500-800 base pair regions spaced at approximately 9 kilobase intervals along the chromosomes. In yeast, CARs tend to be rich in adenine-thymine base pairs. CARs are independent of origins of replication.
Establishment of cohesion
Establishment of cohesion refers to the process by which chromatin-associated cohesin becomes cohesion-competent. Chromatin association of cohesin is not sufficient for cohesion. Cohesin must undergo subsequent modification ("establishment") to be capable of physically holding the sister chromosomes together. Though cohesin can associate with chromatin earlier in the cell cycle, cohesion is established during S phase. Early data suggesting that S phase is crucial to cohesion was based on the fact that after S phase, sister chromatids
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What replicates in the s phase of interphase, resulting in chromosomes composed of two linked sister chromatids?
A. RNA
B. dna
C. hormones
D. protein
Answer:
|
|
sciq-5303
|
multiple_choice
|
How does sap get to the tops of tall trees?
|
[
"through negative pressure",
"via Coriolis forces",
"through pressure from below",
"through suction power"
] |
A
|
Relavent Documents:
Document 0:::
Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice include hat-racking, heading, rounding over, and tipping. Some species of trees are more likely to recover from topping than others. There are alternatives to topping that can help to achieve the same goals without damaging trees.
Purpose
Hundreds of large trees are topped each year, which causes significant stress and future safety issues. It has been shown through survey that the average person's knowledge on tree care is limited.
Another popular misconception is that a topped tree will benefit from increased light penetration. The removal of a large portion of a tree's canopy can have detrimental effects. When a tree is topped, newly formed bark may be susceptible to sun scald. Prolonged exposure can severely damage the bark, thus creating an attractive home for decay-causing organisms. Evidence of decay may be the presence of conks (fungal fruiting structures) on the outer tree bark. The loss of leaves reduces a tree's ability to photosynthesize and produce food. If a large tree is unable to produce enough sugars to feed the roots, it will slowly die from starvation.
Some people have been known to top trees in order to stimulate new growth. When a tree is topped, many adventitious shoots, known as suckers begin to grow from the wound. This is the tree's response to the sudden loss of leaves. Although the tree is able to produce an abundance of suckers, they are susceptible to numerous problems. Firstly, this adventitious growth is succulent and susceptible to attacks by insects such as aphids and caterpillars, and pathogens like fire blight (Rosaceae). Secondly, the branch-stubs that the suckers emerge from are rarely able to form a complete callus. This means that any pathogen that attacks a sucker may enter the tr
Document 1:::
The pressure flow hypothesis, also known as the mass flow hypothesis, is the best-supported theory to explain the movement of sap through the phloem. It was proposed by Ernst Münch, a German plant physiologist in 1930.
A high concentration of organic substances, particularly sugar, inside cells of the phloem at a source, such as a leaf, creates a diffusion gradient (osmotic gradient) that draws water into the cells from the adjacent xylem. This creates turgor pressure, also known as hydrostatic pressure, in the phloem. Movement of phloem sap occurs by bulk flow (mass flow) from sugar sources to sugar sinks. The movement in phloem is bidirectional, whereas, in xylem cells, it is unidirectional (upward). Because of this multi-directional flow, coupled with the fact that sap cannot move with ease between adjacent sieve-tubes, it is not unusual for sap in adjacent sieve-tubes to be flowing in opposite directions.
Sources and sinks
A sugar source is any part of the plant that is producing or releasing sugar.
During the plant's growth period, usually during the spring, storage organs such as the roots are sugar sources, and the plant's many growing areas are sugar sinks.
After the growth period, when the meristems are dormant, the leaves are sources, and storage organs are sinks. Developing seed-bearing organs (such as fruit) are always sinks.
Mechanisms
While movement of water and minerals through the xylem is driven by negative pressures (tension) most of the time, movement through the phloem is driven by positive hydrostatic pressure. This process is termed translocation, and is accomplished by a process called phloem loading and unloading. Cells in a sugar source "load" a sieve-tube element by actively transporting solute molecules into it. This causes water to move into the sieve-tube element by osmosis, creating pressure that pushes the sap down the tube. In sugar sinks, cells actively transport solutes out of the sieve-tube elements, producing the exactly oppos
Document 2:::
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains.
Some animals are exclusively arboreal in habitat, such as the tree snail.
Biomechanics
Arboreal habitats pose numerous mechanical challenges to animals moving in them, which have been solved in diverse ways. These challenges include moving on narrow branches, moving up and down inclines, balancing, crossing gaps, and dealing with obstructions.
Diameter
Moving along narrow surfaces, such as a branch of a tree, can create special difficulties for animals who are not adapted to deal with balancing on small diameter substrates. During locomotion on the ground, the location of the center of mass may swing from side to side. But during arboreal locomotion, this would result in the center of mass moving beyond the edge of the branch, resulting in a tendency to topple over and fall. Not only do some arboreal animals have to be able to move on branches of varying diameter, but they also have to eat on these branches, resulting in the need for the ability to balance while using their hands to feed themselves. This resulted in various types of grasping such as pedal grasping in order to clamp themselves onto small branches for better balance.
Incline
Branches are frequently oriented at an angle to gravity in arboreal habitats, including being vertical, which poses special problems. As an animal moves up an inclined branch, it must fight the force of gravity to raise its body, making the movement more difficult. To get past thi
Document 3:::
{{Automatic taxobox
| fossil_range =
| image = Sequoiafarm Sequoiadendron giganteum.jpg
| image_caption = Sequoiadendron giganteum
| taxon = Sequoioideae
| authority =
| subdivision_ranks = Genera
| subdivision = * Sequoia
Sequoiadendron
Metasequoia
Austrosequoia'
}}
Sequoioideae, commonly referred to as redwoods, is a subfamily of coniferous trees within the family Cupressaceae. It includes the largest and tallest trees in the world. The subfamily achieved its maximum diversity during the Jurassic and Cretaceous periods.
Description
The three redwood subfamily genera are Sequoia from coastal California and Oregon, Sequoiadendron from California's Sierra Nevada, and Metasequoia in China. The redwood species contains the largest and tallest trees in the world. These trees can live for thousands of years. Threats include logging, fire suppression, illegal marijuana cultivation, and burl poaching.
Only two of the genera, Sequoia and Sequoiadendron, are known for massive trees. Trees of Metasequoia, from the single living species Metasequoia glyptostroboides, are deciduous, grow much smaller (although are still large compared to most other trees) and can live in colder climates.
Taxonomy and evolution
Multiple studies of both morphological and molecular characters have strongly supported the assertion that the Sequoioideae are monophyletic. Most modern phylogenies place Sequoia as sister to Sequoiadendron and Metasequoia as the out-group. However, Yang et al. went on to investigate the origin of a peculiar genetic component in Sequoioideae, the polyploidy of Sequoia—and generated a notable exception that calls into question the specifics of this relative consensus.
Cladistic tree
A 2006 paper based on non-molecular evidence suggested the following relationship among extant species:
A 2021 study using molecular evidence found the same relationships among Sequoioideae species, but found Sequoioideae to be the sister group to the Athrotaxidoideae (a superfami
Document 4:::
A bridge graft is a grafting technique used to re-establish the supply of nutrients to the rootstock of a woody perennial when the full thickness of the bark has been removed from part of the trunk.
Damage to the innermost layer of the bark, called the phloem, can interrupt the transport of leave photosynthesised sugars down to the roots. Such wounds are often caused by rabbits or other rodents, stripping the bark away and girdling the tree. The inability to transport sugars from leaves down to the root system causes the root death after the stored nutrient are exhausted, which eventually results in the plant's death.
A bridge graft uses scions to 'bridge' the gap. Each scion is taper cut in order to accommodate the need for matching the cambium layers of the scion with those of the tree to which it is being grafted. It is also vital that the scions be placed so that the end which was closest to their own roots before they were cut is at the bottom of the graft, and the end which was closest to the growing tip is at the top. Incorrect placement (cells in the scion being upside down) will result in its death. Once in place, the graft wounds must be completely sealed, in order to facilitate joining together and prevent infection of the site.
Where one-quarter or less of the trunk circumference has been girdled, it may not be necessary to use this technique. It is also difficult to apply on small caliper tree trunks.
Steps
The Ontario Ministry of Agriculture Factsheet gives details and diagrams for the technique.
However, modern arboriculture suggests that the application of pruning paints and wound dressings can inhibit the trees' natural defences, so a person attempting this technique may try it without the application of wound dressing prior to the graft insertion. Most trees will produce callus tissues to compartmentalize the wounded area. This natural defence is stimulated by environmental factors which may include the presence of the 'f
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How does sap get to the tops of tall trees?
A. through negative pressure
B. via Coriolis forces
C. through pressure from below
D. through suction power
Answer:
|
|
sciq-473
|
multiple_choice
|
What is the difference between the daily high and the daily low?
|
[
"sunrise and sunset",
"tidal change",
"margin of error",
"weather forecast"
] |
B
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 2:::
Single Best Answer (SBA or One Best Answer) is a written examination form of multiple choice questions used extensively in medical education.
Structure
A single question is posed with typically five alternate answers, from which the candidate must choose the best answer. This method avoids the problems of past examinations of a similar form described as Single Correct Answer. The older form can produce confusion where more than one of the possible answers has some validity. The newer form makes it explicit that more than one answer may have elements that are correct, but that one answer will be superior.
Prior to the widespread introduction of SBAs into medical education, the typical form of examination was true-false multiple choice questions. But during the 2000s, educators found that SBAs would be superior.
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The Mathematics Subject Classification (MSC) is an alphanumerical classification scheme that has collaboratively been produced by staff of, and based on the coverage of, the two major mathematical reviewing databases, Mathematical Reviews and Zentralblatt MATH. The MSC is used by many mathematics journals, which ask authors of research papers and expository articles to list subject codes from the Mathematics Subject Classification in their papers. The current version is MSC2020.
Structure
The MSC is a hierarchical scheme, with three levels of structure. A classification can be two, three or five digits long, depending on how many levels of the classification scheme are used.
The first level is represented by a two-digit number, the second by a letter, and the third by another two-digit number. For example:
53 is the classification for differential geometry
53A is the classification for classical differential geometry
53A45 is the classification for vector and tensor analysis
First level
At the top level, 64 mathematical disciplines are labeled with a unique two-digit number. In addition to the typical areas of mathematical research, there are top-level categories for "History and Biography", "Mathematics Education", and for the overlap with different sciences. Physics (i.e. mathematical physics) is particularly well represented in the classification scheme with a number of different categories including:
Fluid mechanics
Quantum mechanics
Geophysics
Optics and electromagnetic theory
All valid MSC classification codes must have at least the first-level identifier.
Second level
The second-level codes are a single letter from the Latin alphabet. These represent specific areas covered by the first-level discipline. The second-level codes vary from discipline to discipline.
For example, for differential geometry, the top-level code is 53, and the second-level codes are:
A for classical differential geometry
B for local differential geometry
C for glo
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The Texas Math and Science Coaches Association or TMSCA is an organization for coaches of academic University Interscholastic League teams in Texas middle schools and high schools, specifically those that compete in mathematics and science-related tests.
Events
There are four events in the TMSCA at both the middle and high school level: Number Sense, General Mathematics, Calculator Applications, and General Science.
Number Sense is an 80-question exam that students are given only 10 minutes to solve. Additionally, no scratch work or paper calculations are allowed. These questions range from simple calculations such as 99+98 to more complicated operations such as 1001×1938. Each calculation is able to be done with a certain trick or shortcut that makes the calculations easier.
The high school exam includes calculus and other difficult topics in the questions also with the same rules applied as to the middle school version.
It is well known that the grading for this event is particularly stringent as errors such as writing over a line or crossing out potential answers are considered as incorrect answers.
General Mathematics is a 50-question exam that students are given only 40 minutes to solve. These problems are usually more challenging than questions on the Number Sense test, and the General Mathematics word problems take more thinking to figure out. Every problem correct is worth 5 points, and for every problem incorrect, 2 points are deducted. Tiebreakers are determined by the person that misses the first problem and by percent accuracy.
Calculator Applications is an 80-question exam that students are given only 30 minutes to solve. This test requires practice on the calculator, knowledge of a few crucial formulas, and much speed and intensity. Memorizing formulas, tips, and tricks will not be enough. In this event, plenty of practice is necessary in order to master the locations of the keys and develop the speed necessary. All correct questions are worth 5
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the difference between the daily high and the daily low?
A. sunrise and sunset
B. tidal change
C. margin of error
D. weather forecast
Answer:
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|
sciq-4607
|
multiple_choice
|
What structure is a larger assembly of several polypeptide chains that are now referred to as subunits of the protein?
|
[
"geological structure",
"digital structure",
"quaternary structure",
"pyramid structure"
] |
C
|
Relavent Documents:
Document 0:::
Proteins are a class of macromolecular organic compounds that are essential to life. They consist of a long polypeptide chain that usually adopts a single stable three-dimensional structure. They fulfill a wide variety of functions including providing structural stability to cells, catalyze chemical reactions that produce or store energy or synthesize other biomolecules including nucleic acids and proteins, transport essential nutrients, or serve other roles such as signal transduction. They are selectively transported to various compartments of the cell or in some cases, secreted from the cell.
This list aims to organize information on how proteins are most often classified: by structure, by function, or by location.
Structure
Proteins may be classified as to their three-dimensional structure (also known a protein fold). The two most widely used classification schemes are:
CATH database
Structural Classification of Proteins database (SCOP)
Both classification schemes are based on a hierarchy of fold types. At the top level are all alpha proteins (domains consisting of alpha helices), all beta proteins (domains consisting of beta sheets), and mixed alpha helix/beta sheet proteins.
While most proteins adopt a single stable fold, a few proteins can rapidly interconvert between one or more folds. These are referred to as metamorphic proteins. Finally other proteins appear not to adopt any stable conformation and are referred to as intrinsically disordered.
Proteins frequently contain two or more domains, each have a different fold separated by intrinsically disordered regions. These are referred to as multi-domain proteins.
Function
Proteins may also be classified based on their celluar function. A widely used classification is PANTHER (protein analysis through evolutionary relationships) classification system.
Structural
Protein#Structural proteins
Catalytic
Enzymes classified according to their Enzyme Commission number (EC). Note that strictly speaki
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Biomolecular structure is the intricate folded, three-dimensional shape that is formed by a molecule of protein, DNA, or RNA, and that is important to its function. The structure of these molecules may be considered at any of several length scales ranging from the level of individual atoms to the relationships among entire protein subunits. This useful distinction among scales is often expressed as a decomposition of molecular structure into four levels: primary, secondary, tertiary, and quaternary. The scaffold for this multiscale organization of the molecule arises at the secondary level, where the fundamental structural elements are the molecule's various hydrogen bonds. This leads to several recognizable domains of protein structure and nucleic acid structure, including such secondary-structure features as alpha helixes and beta sheets for proteins, and hairpin loops, bulges, and internal loops for nucleic acids.
The terms primary, secondary, tertiary, and quaternary structure were introduced by Kaj Ulrik Linderstrøm-Lang in his 1951 Lane Medical Lectures at Stanford University.
Primary structure
The primary structure of a biopolymer is the exact specification of its atomic composition and the chemical bonds connecting those atoms (including stereochemistry). For a typical unbranched, un-crosslinked biopolymer (such as a molecule of a typical intracellular protein, or of DNA or RNA), the primary structure is equivalent to specifying the sequence of its monomeric subunits, such as amino acids or nucleotides.
The primary structure of a protein is reported starting from the amino N-terminus to the carboxyl C-terminus, while the primary structure of DNA or RNA molecule is known as the nucleic acid sequence reported from the 5' end to the 3' end.
The nucleic acid sequence refers to the exact sequence of nucleotides that comprise the whole molecule. Often, the primary structure encodes sequence motifs that are of functional importance. Some examples of such motif
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In structural biology, a protomer is the structural unit of an oligomeric protein. It is the smallest unit composed of at least two different protein chains that form a larger hetero-oligomer by association of two or more copies of this unit.
The term was introduced by Chetverin to make nomenclature in the Na/K-ATPase enzyme unambiguous. This enzyme is composed of two subunits: a large, catalytic α subunit, and a smaller glycoprotein β subunit (plus a proteolipid, called γ-subunit). At the time it was unclear how many of each work together. In addition, when people spoke of a dimer, it was unclear whether they were referring to αβ or to (αβ)2. Chetverin suggested to call αβ a protomer and (αβ)2 a diprotomer.
Protomers usually arrange in cyclic symmetry to form closed point group symmetries.
In chemistry, a so-called protomer is a molecule which displays tautomerism due to position of a proton.
Examples
Hemoglobin is a heterotetramer consisting of four subunits (two α and two β). However, structurally and functionally hemoglobin is described better as (αβ)2, so we call it a dimer of two αβ-protomers, that is, a diprotomer.
Aspartate carbamoyltransferase has a α6β6 subunit composition. The six αβ-protomers are arranged in D3 symmetry.
Viral capsid are often composed of protomers.
Examples in chemistry include tyrosine and 4-aminobenzoic acid. The former may be deprotonated to form the carboxylate and phenoxide anions, and the later may be protonated at the amino or carboxyl groups.
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A supersecondary structure is a compact three-dimensional protein structure of several adjacent elements of a secondary structure that is smaller than a protein domain or a subunit. Supersecondary structures can act as nucleations in the process of protein folding.
Examples
Helix supersecondary structures
Helix hairpin
A helix hairpin, also known as an alpha-alpha hairpin, is composed of two antiparallel alpha helices connected by a loop of two or more residues. True to its name, it resembles a hairpin. A longer loop has a greater number of possible conformations. If short strands connect the helices, then the individual helices will pack together through their hydrophobic residues. The function of a helix hairpin is unknown; however, a four helix bundle is composed of two helix hairpins, which have important ligand binding sites.
Helix corner
A helix corner, also called an alpha-alpha corner, has two alpha helices almost at right angles to each other connected by a short 'loop'. This loop is formed from a hydrophobic residue. The function of a helix corner is unknown.
Helix-loop-helix
The helix-loop-helix structure has two helices connected by a 'loop'. These are fairly common and usually bind ligands. For example, calcium binds with the carboxyl groups of the side chains within the loop region between the helices.
Helix-turn-helix
The helix-turn-helix motif is important for DNA binding and is therefore in many DNA binding proteins.
Beta sheet supersecondary structures
Beta hairpin
A beta hairpin is a common supersecondary motif composed of two anti-parallel beta strands connected by a loop. The structure resembles a hairpin and is often found in globular proteins.
The loop between the beta strands can range anywhere from 2 to 16 residues. However, most loops contain less than seven residues. Residues in beta hairpins with loops of 2, 3, or 4 residues have distinct conformations. However, a wide range of conformations can be seen in longer loops,
Document 4:::
Protein backbone fragment libraries have been used successfully in a variety of structural biology applications, including homology modeling, de novo structure prediction, and structure determination. By reducing the complexity of the search space, these fragment libraries enable more rapid search of conformational space, leading to more efficient and accurate models.
Motivation
Proteins can adopt an exponential number of states when modeled discretely. Typically, a protein's conformations are represented as sets of dihedral angles, bond lengths, and bond angles between all connected atoms. The most common simplification is to assume ideal bond lengths and bond angles. However, this still leaves the phi-psi angles of the backbone, and up to four dihedral angles for each side chain, leading to a worst case complexity of k6*n possible states of the protein, where n is the number of residues and k is the number of discrete states modeled for each dihedral angle. In order to reduce the conformational space, one can use protein fragment libraries rather than explicitly model every phi-psi angle.
Fragments are short segments of the peptide backbone, typically from 5 to 15 residues long, and do not include the side chains. They may specify the location of just the C-alpha atoms if it is a reduced atom representation, or all the backbone heavy atoms (N, C-alpha, C carbonyl, O). Note that side chains are typically not modeled using the fragment library approach. To model discrete states of a side chain, one could use a rotamer library approach.
This approach operates under the assumption that local interactions play a large role in stabilizing the overall protein conformation. In any short sequence, the molecular forces constrain the structure, leading to only a small number of possible conformations, which can be modeled by fragments. Indeed, according to Levinthal's paradox, a protein could not possibly sample all possible conformations within a biologically reasonab
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What structure is a larger assembly of several polypeptide chains that are now referred to as subunits of the protein?
A. geological structure
B. digital structure
C. quaternary structure
D. pyramid structure
Answer:
|
|
sciq-4009
|
multiple_choice
|
What is the term for gases that absorb heat in the atmosphere?
|
[
"sulfuric gases",
"ionic gases",
"thermal gases",
"greenhouse gases"
] |
D
|
Relavent Documents:
Document 0:::
The temperatures of a planet's surface and atmosphere are governed by a delicate balancing of their energy flows. The idealized greenhouse model is based on the fact that certain gases in the Earth's atmosphere, including carbon dioxide and water vapour, are transparent to the high-frequency solar radiation, but are much more opaque to the lower frequency infrared radiation leaving Earth's surface. Thus heat is easily let in, but is partially trapped by these gases as it tries to leave. Rather than get hotter and hotter, Kirchhoff's law of thermal radiation says that the gases of the atmosphere also have to re-emit the infrared energy that they absorb, and they do so, also at long infrared wavelengths, both upwards into space as well as downwards back towards the Earth's surface. In the long-term, the planet's thermal inertia is surmounted and a new thermal equilibrium is reached when all energy arriving on the planet is leaving again at the same rate. In this steady-state model, the greenhouse gases cause the surface of the planet to be warmer than it would be without them, in order for a balanced amount of heat energy to finally be radiated out into space from the top of the atmosphere.
Essential features of this model where first published by Svante Arrhenius in 1896. It has since become a common introductory "textbook model" of the radiative heat transfer physics underlying Earth's energy balance and the greenhouse effect. The planet is idealized by the model as being functionally "layered" with regard to a sequence of simplified energy flows, but dimensionless (i.e. a zero-dimensional model) in terms of its mathematical space. The layers include a surface with constant temperature Ts and an atmospheric layer with constant temperature Ta. For diagrammatic clarity, a gap can be depicted between the atmosphere and the surface. Alternatively, Ts could be interpreted as a temperature representative of the surface and the lower atmosphere, and Ta could be inter
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Volatiles are the group of chemical elements and chemical compounds that can be readily vaporized. In contrast with volatiles, elements and compounds that are not readily vaporized are known as refractory substances.
On planet Earth, the term 'volatiles' often refers to the volatile components of magma. In astrogeology volatiles are investigated in the crust or atmosphere of a planet or moon. Volatiles include nitrogen, carbon dioxide, ammonia, hydrogen, methane, sulfur dioxide, water and others.
Planetary science
Planetary scientists often classify volatiles with exceptionally low melting points, such as hydrogen and helium, as gases, whereas those volatiles with melting points above about 100 K (–173 °C, –280 °F) are referred to as ices. The terms "gas" and "ice" in this context can apply to compounds that may be solids, liquids or gases. Thus, Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants, even though the vast majority of the "gas" and "ice" in their interiors is a hot, highly dense fluid that gets denser as the center of the planet is approached. Inside of Jupiter's orbit, cometary activity is driven by the sublimation of water ice. Supervolatiles such as CO and CO2 have generated cometary activity as far out as .
Igneous petrology
In igneous petrology the term more specifically refers to the volatile components of magma (mostly water vapor and carbon dioxide) that affect the appearance and explosivity of volcanoes. Volatiles in a magma with a high viscosity, generally felsic with a higher silica (SiO2) content, tend to produce eruptions that are explosive eruption. Volatiles in a magma with a low viscosity, generally mafic with a lower silica content, tend to vent as effusive eruption and can give rise to a lava fountain.
Volatiles in magma
Some volcanic eruptions are explosive because of the mixing between water and magma reaching the surface, which releases energy suddenly. However, in some cases, the eruption is caused by vola
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
In atmospheric science, equivalent temperature is the temperature of air in a parcel from which all the water vapor has been extracted by an adiabatic process.
Air contains water vapor that has been evaporated into it from liquid sources (lakes, sea, etc...). The energy needed to do that has been taken from the air. Taking a volume of air at temperature and mixing ratio of , drying it by condensation will restore energy to the airmass. This will depend on the latent heat release as:
where:
: latent heat of evaporation (2400 kJ/kg at 25°C to 2600 kJ/kg at −40°C)
: specific heat at constant pressure for air (≈ 1004 J/(kg·K))
Tables exist for exact values of the last two coefficients.
See also
Wet-bulb temperature
Potential temperature
Atmospheric thermodynamics
Equivalent potential temperature
Bibliography
M Robitzsch, Aequivalenttemperatur und Aequivalentthemometer, Meteorologische Zeitschrift, 1928, pp. 313-315.
M K Yau and R.R. Rogers, Short Course in Cloud Physics, Third Edition, published by Butterworth-Heinemann, January 1, 1989, 304 pages.
J.V. Iribarne and W.L. Godson, Atmospheric Thermodynamics, published by D. Reidel Publishing Company, Dordrecht, Holland, 1973, 222 pages
Atmospheric thermodynamics
Atmospheric temperature
Meteorological quantities
Document 4:::
Thermofluids is a branch of science and engineering encompassing four intersecting fields:
Heat transfer
Thermodynamics
Fluid mechanics
Combustion
The term is a combination of "thermo", referring to heat, and "fluids", which refers to liquids, gases and vapors. Temperature, pressure, equations of state, and transport laws all play an important role in thermofluid problems. Phase transition and chemical reactions may also be important in a thermofluid context. The subject is sometimes also referred to as "thermal fluids".
Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the transfer of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer. Engineers also consider the transfer of mass of differing chemical species, either cold or hot, to achieve heat transfer.
Sections include :
Energy transfer by heat, work and mass
Laws of thermodynamics
Entropy
Refrigeration Techniques
Properties and nature of pure substances
Applications
Engineering : Predicting and analysing the performance of machines
Thermodynamics
Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.
Fluid mechanics
Fluid Mechanics the study of the physical forces at work during fluid flow. Fluid mechanics can be divided into fluid kinematics, the study of fluid motion, and fluid kinetics, the study of the effect of forces on fluid motion. Fluid mechanics can further be divided into fluid statics, the study of fluids at rest, and fluid dynamics, the study of fluids in motion. Some of its more interesting concepts include momentum and reactive forces in fluid flow and fluid machinery theory and performance.
Sections include:
Flu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the term for gases that absorb heat in the atmosphere?
A. sulfuric gases
B. ionic gases
C. thermal gases
D. greenhouse gases
Answer:
|
|
sciq-1934
|
multiple_choice
|
Digestive enzymes secreted in the acidic environment (low ph) of the stomach help break down what?
|
[
"cells",
"molecules",
"particles",
"proteins"
] |
D
|
Relavent Documents:
Document 0:::
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small compounds that the body can use.
In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva. Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work, and electrolytes (Na+, K+, Cl−, HCO−3). About 30% of starch is hydrolyzed into disaccharide in the oral cavity (mouth). After undergoing mastication and starch digestion, the food will be in the form of a small, round slurry mass called a bolus. It will then travel down the esophagus and into the stomach by the action of peristalsis. Gastric juice in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and pepsin. In infants and toddlers, gastric juice also contains rennin to digest milk proteins. As the first two chemicals may damage the stomach wall, mucus and bicarbonates are secreted by the stomach. They provide a slimy layer that acts as a shield against the damag
Document 1:::
The Joan Mott Prize Lecture is a prize lecture awarded annually by The Physiological Society in honour of Joan Mott.
Laureates
Laureates of the award have included:
- Intestinal absorption of sugars and peptides: from textbook to surprises
See also
Physiological Society Annual Review Prize Lecture
Document 2:::
S cells are cells which release secretin, found in the jejunum and duodenum. They are stimulated by a drop in pH to 4 or below in the small intestine's lumen. The released secretin will increase the secretion of bicarbonate (HCO3−) into the lumen, via the pancreas. This is primarily accomplished by an increase in cyclic AMP that activates CFTR to release chloride anions into the lumen. The luminal Cl− is then involved in a bicarbonate transporter protein exchange, in which the chloride is reabsorbed by the cell and HCO3− is secreted into the lumen. S cells are also one of the main producers of cyclosamatin.
Human cells
Digestive system
Document 3:::
Bile (from Latin bilis), or gall, is a yellow-green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, produced continuously by the liver, and stored and concentrated in the gallbladder. After a human eats, this stored bile is discharged into the first section of their small intestine.
Composition
In the human liver, bile is composed of 97–98% water, 0.7% bile salts, 0.2% bilirubin, 0.51% fats (cholesterol, fatty acids, and lecithin), and 200 meq/L inorganic salts. The two main pigments of bile are bilirubin, which is yellow, and its oxidised form biliverdin, which is green. When mixed, they are responsible for the brown color of feces. About of bile is produced per day in adult human beings.
Function
Bile or gall acts to some extent as a surfactant, helping to emulsify the lipids in food. Bile salt anions are hydrophilic on one side and hydrophobic on the other side; consequently, they tend to aggregate around droplets of lipids (triglycerides and phospholipids) to form micelles, with the hydrophobic sides towards the fat and hydrophilic sides facing outwards. The hydrophilic sides are negatively charged, and this charge prevents fat droplets coated with bile from re-aggregating into larger fat particles. Ordinarily, the micelles in the duodenum have a diameter around 1–50 μm in humans.
The dispersion of food fat into micelles provides a greatly increased surface area for the action of the enzyme pancreatic lipase, which digests the triglycerides, and is able to reach the fatty core through gaps between the bile salts. A triglyceride is broken down into two fatty acids and a monoglyceride, which are absorbed by the villi on the intestine walls. After being transferred across the intestinal membrane, the fatty acids reform into triglycerides (), before being absorbed into the lymphatic system through lacteals. Without bile salts, most of the lipids in food wou
Document 4:::
This is a list of articles that describe particular biomolecules or types of biomolecules.
A
For substances with an A- or α- prefix such as
α-amylase, please see the parent page (in this case Amylase).
A23187 (Calcimycin, Calcium Ionophore)
Abamectine
Abietic acid
Acetic acid
Acetylcholine
Actin
Actinomycin D
Adenine
Adenosmeme
Adenosine diphosphate (ADP)
Adenosine monophosphate (AMP)
Adenosine triphosphate (ATP)
Adenylate cyclase
Adiponectin
Adonitol
Adrenaline, epinephrine
Adrenocorticotropic hormone (ACTH)
Aequorin
Aflatoxin
Agar
Alamethicin
Alanine
Albumins
Aldosterone
Aleurone
Alpha-amanitin
Alpha-MSH (Melaninocyte stimulating hormone)
Allantoin
Allethrin
α-Amanatin, see Alpha-amanitin
Amino acid
Amylase (also see α-amylase)
Anabolic steroid
Anandamide (ANA)
Androgen
Anethole
Angiotensinogen
Anisomycin
Antidiuretic hormone (ADH)
Anti-Müllerian hormone (AMH)
Arabinose
Arginine
Argonaute
Ascomycin
Ascorbic acid (vitamin C)
Asparagine
Aspartic acid
Asymmetric dimethylarginine
ATP synthase
Atrial-natriuretic peptide (ANP)
Auxin
Avidin
Azadirachtin A – C35H44O16
B
Bacteriocin
Beauvericin
beta-Hydroxy beta-methylbutyric acid
beta-Hydroxybutyric acid
Bicuculline
Bilirubin
Biopolymer
Biotin (Vitamin H)
Brefeldin A
Brassinolide
Brucine
Butyric acid
C
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Digestive enzymes secreted in the acidic environment (low ph) of the stomach help break down what?
A. cells
B. molecules
C. particles
D. proteins
Answer:
|
|
sciq-601
|
multiple_choice
|
Wings of bats and birds serve the same function. which body part should you study to understand ancestral differences?
|
[
"skull size",
"bones inside wings",
"skin inside wings",
"skin and feathers"
] |
B
|
Relavent Documents:
Document 0:::
Animal science is described as "studying the biology of animals that are under the control of humankind". It can also be described as the production and management of farm animals. Historically, the degree was called animal husbandry and the animals studied were livestock species, like cattle, sheep, pigs, poultry, and horses. Today, courses available look at a broader area, including companion animals, like dogs and cats, and many exotic species. Degrees in Animal Science are offered at a number of colleges and universities. Animal science degrees are often offered at land-grant universities, which will often have on-campus farms to give students hands-on experience with livestock animals.
Education
Professional education in animal science prepares students for careers in areas such as animal breeding, food and fiber production, nutrition, animal agribusiness, animal behavior, and welfare. Courses in a typical Animal Science program may include genetics, microbiology, animal behavior, nutrition, physiology, and reproduction. Courses in support areas, such as genetics, soils, agricultural economics and marketing, legal aspects, and the environment also are offered.
Bachelor degree
At many universities, a Bachelor of Science (BS) degree in Animal Science allows emphasis in certain areas. Typical areas are species-specific or career-specific. Species-specific areas of emphasis prepare students for a career in dairy management, beef management, swine management, sheep or small ruminant management, poultry production, or the horse industry. Other career-specific areas of study include pre-veterinary medicine studies, livestock business and marketing, animal welfare and behavior, animal nutrition science, animal reproduction science, or genetics. Youth programs are also an important part of animal science programs.
Pre-veterinary emphasis
Many schools that offer a degree option in Animal Science also offer a pre-veterinary emphasis such as Iowa State University, th
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Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
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Chickens (Gallus gallus domesticus) and their eggs have been used extensively as research models throughout the history of biology. Today they continue to serve as an important model for normal human biology as well as pathological disease processes.
History
Chicken embryos as a research model
Human fascination with the chicken and its egg are so deeply rooted in history that it is hard to say exactly when avian exploration began. As early as 1400 BCE, ancient Egyptians artificially incubated chicken eggs to propagate their food supply. The developing chicken in the egg first appears in written history after catching the attention of the famous Greek philosopher, Aristotle, around 350 BCE. As Aristotle opened chicken eggs at various time points of incubation, he noted how the organism changed over time. Through his writing of Historia Animalium, he introduced some of the earliest studies of embryology based on his observations of the chicken in the egg.
Aristotle recognized significant similarities between human and chicken development. From his studies of the developing chick, he was able to correctly decipher the role of the placenta and umbilical cord in the human.
Chick research of the 16th century significantly modernized ideas about human physiology. European scientists, including Ulisse Aldrovandi, Volcher Cotier and William Harvey, used the chick to demonstrate tissue differentiation, disproving the widely held belief of the time that organisms are "preformed" in their adult version and only grow larger during development. Distinct tissue areas were recognized that grew and gave rise to specific structures, including the blastoderm, or chick origin. Harvey also closely watched the development of the heart and blood and was the first to note the directional flow of blood between veins and arteries. The relatively large size of the chick as a model organism allowed scientists during this time to make these significant observations without the hel
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A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Wings of bats and birds serve the same function. which body part should you study to understand ancestral differences?
A. skull size
B. bones inside wings
C. skin inside wings
D. skin and feathers
Answer:
|
|
sciq-6599
|
multiple_choice
|
Dissolved oxygen in seawater is critical for sea creatures, but as the oceans warm, oxygen becomes less what?
|
[
"soluble",
"saturated",
"abundant",
"insoluble"
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In freshwater or marine systems apparent oxygen utilization (AOU) is the difference between oxygen gas solubility (i.e. the concentration at saturation) and the measured oxygen concentration in water with the same physical and chemical properties.
General influences
Differences in O2 solubility and measured concentration (AOU) typically occur when biological activity, ocean circulation, or ocean mixing act to change the ambient concentration of oxygen. For example, primary production liberates oxygen and increases its concentration, while respiration consumes it and decreases its concentration.
Consequently, the AOU of a water sample represents the sum of the biological activity that the sample has experienced since it was last in equilibrium with the atmosphere. In shallow water systems (e.g. lakes), the full water column is generally in close contact with the atmosphere, and oxygen concentrations are typically close to saturation, and AOU values are near zero. In deep water systems (e.g. oceans), water can be out of contact with the atmosphere for extremely long periods of time (years, decades, centuries) and large positive AOU values are typical. On occasion, where near-surface primary production has raised oxygen concentrations above saturation, negative AOU values are possible (i.e. oxygen has not been utilized to below saturation concentrations).
O2 trends and AOU in the ocean
O2 concentrations in the ocean have decreased since the 1980s. Part of this decrease is due to increased ocean heat content (OHC) from global warming decreasing O2 solubility. As solubility in surface oceans decreases, O2 out gasses to the atmosphere. Increased AOU is likely also contributing to declining ocean O2 concentrations. Changes in AOU in the ocean could be caused by multiple forcings, such as changes in subduction rates, changes in water mass boundaries, initial O2 from water mass formation, biochemical consumption of O2, or changes in eddy mixing. Based on observations,
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The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
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GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
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Aquatic science is the study of the various bodies of water that make up our planet including oceanic and freshwater environments. Aquatic scientists study the movement of water, the chemistry of water, aquatic organisms, aquatic ecosystems, the movement of materials in and out of aquatic ecosystems, and the use of water by humans, among other things. Aquatic scientists examine current processes as well as historic processes, and the water bodies that they study can range from tiny areas measured in millimeters to full oceans. Moreover, aquatic scientists work in Interdisciplinary groups. For example, a physical oceanographer might work with a biological oceanographer to understand how physical processes, such as tropical cyclones or rip currents, affect organisms in the Atlantic Ocean. Chemists and biologists, on the other hand, might work together to see how the chemical makeup of a certain body of water affects the plants and animals that reside there. Aquatic scientists can work to tackle global problems such as global oceanic change and local problems, such as trying to understand why a drinking water supply in a certain area is polluted.
There are two main fields of study that fall within the field of aquatic science. These fields of study include oceanography and limnology.
Oceanography
Oceanography refers to the study of the physical, chemical, and biological characteristics of oceanic environments. Oceanographers study the history, current condition, and future of the planet's oceans. They also study marine life and ecosystems, ocean circulation, plate tectonics, the geology of the seafloor, and the chemical and physical properties of the ocean.
Oceanography is interdisciplinary. For example, there are biological oceanographers and marine biologists. These scientists specialize in marine organisms. They study how these organisms develop, their relationship with one another, and how they interact and adapt to their environment. Biological oceanographers
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Dissolved oxygen in seawater is critical for sea creatures, but as the oceans warm, oxygen becomes less what?
A. soluble
B. saturated
C. abundant
D. insoluble
Answer:
|
|
sciq-9729
|
multiple_choice
|
What describe the fraction or percentage of a mixture that is made up of a particular substance.
|
[
"atomic weight",
"mole fractions",
"molecular scale",
"solute level"
] |
B
|
Relavent Documents:
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In chemistry, the mass fraction of a substance within a mixture is the ratio (alternatively denoted ) of the mass of that substance to the total mass of the mixture. Expressed as a formula, the mass fraction is:
Because the individual masses of the ingredients of a mixture sum to , their mass fractions sum to unity:
Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (in commercial contexts often called percentage by weight, abbreviated wt.% or % w/w; see mass versus weight). It is one way of expressing the composition of a mixture in a dimensionless size; mole fraction (percentage by moles, mol%) and volume fraction (percentage by volume, vol%) are others.
When the prevalences of interest are those of individual chemical elements, rather than of compounds or other substances, the term mass fraction can also refer to the ratio of the mass of an element to the total mass of a sample. In these contexts an alternative term is mass percent composition. The mass fraction of an element in a compound can be calculated from the compound's empirical formula or its chemical formula.
Terminology
Percent concentration does not refer to this quantity. This improper name persists, especially in elementary textbooks. In biology, the unit "%" is sometimes (incorrectly) used to denote mass concentration, also called mass/volume percentage. A solution with 1g of solute dissolved in a final volume of 100mL of solution would be labeled as "1%" or "1% m/v" (mass/volume). This is incorrect because the unit "%" can only be used for dimensionless quantities. Instead, the concentration should simply be given in units of g/mL. Percent solution or percentage solution are thus terms best reserved for mass percent solutions (m/m, m%, or mass solute/mass total solution after mixing), or volume percent solutions (v/v, v%, or volume solute per volume of total solution after mixing). The very ambiguous terms percent solution and percentage solutions
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In chemistry and fluid mechanics, the volume fraction φi is defined as the volume of a constituent Vi divided by the volume of all constituents of the mixture V prior to mixing:
Being dimensionless, its unit is 1; it is expressed as a number, e.g., 0.18. It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e.g., 18%.
The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients).
The sum of all volume fractions of a mixture is equal to 1:
The volume fraction (percentage by volume, vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
Volume concentration and volume percent
Volume percent is the concentration of a certain solute, measured by volume, in a solution. It has as a denominator the volume of the mixture itself, as usual for expressions of concentration, rather than the total of all the individual components’ volumes prior to mixing:
Volume percent is usually used when the solution is made by mixing two fluids, such as liquids or gases. However, percentages are only additive for ideal gases.
The percentage by volume (vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
In the case of a mixture of ethanol and water, which are miscible in all proportions, the designation of solvent and solute is arbitrary. The volume of such a mixture is slightly less than the sum of the volumes of the components. Thus, by the above definition, the term "40% alcohol by volume" refers to a mixture of 40 volume units of ethanol with enough water to make a final volume of 100 units, rather than a
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Absolute molar mass is a process used to determine the characteristics of molecules.
History
The first absolute measurements of molecular weights (i.e. made without reference to standards) were based on fundamental physical characteristics and their relation to the molar mass. The most useful of these were membrane osmometry and sedimentation.
Another absolute instrumental approach was also possible with the development of light scattering theory by Albert Einstein, Chandrasekhara Venkata Raman, Peter Debye, Bruno H. Zimm, and others. The problem with measurements made using membrane osmometry and sedimentation was that they only characterized the bulk properties of the polymer sample. Moreover, the measurements were excessively time consuming and prone to operator error. In order to gain information about a polydisperse mixture of molar masses, a method for separating the different sizes was developed. This was achieved by the advent of size exclusion chromatography (SEC). SEC is based on the fact that the pores in the packing material of chromatography columns could be made small enough for molecules to become temporarily lodged in their interstitial spaces. As the sample makes its way through a column the smaller molecules spend more time traveling in these void spaces than the larger ones, which have fewer places to "wander". The result is that a sample is separated according to its hydrodynamic volume . As a consequence, the big molecules come out first, and then the small ones follow in the eluent. By choosing a suitable column packing material it is possible to define the resolution of the system. Columns can also be combined in series to increase resolution or the range of sizes studied.
The next step is to convert the time at which the samples eluted into a measurement of molar mass. This is possible because if the molar mass of a standard were known, the time at which this standard eluted should be equal to a specific molar mass. Using multiple
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Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular, of a solute in a solution, in terms of amount of substance per unit volume of solution. In chemistry, the most commonly used unit for molarity is the number of moles per liter, having the unit symbol mol/L or mol/dm3 in SI units. A solution with a concentration of 1 mol/L is said to be 1 molar, commonly designated as 1 M or 1 M. Molarity is often depicted with square brackets around the substance of interest; for example, the molarity of the hydrogen ion is depicted as [H+].
Definition
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase :
Here, is the amount of the solute in moles, is the number of constituent particles present in volume (in litres) of the solution, and is the Avogadro constant, since 2019 defined as exactly . The ratio is the number density .
In thermodynamics the use of molar concentration is often not convenient because the volume of most solutions slightly depends on temperature due to thermal expansion. This problem is usually resolved by introducing temperature correction factors, or by using a temperature-independent measure of concentration such as molality.
The reciprocal quantity represents the dilution (volume) which can appear in Ostwald's law of dilution.
Formality or analytical concentration
If a molecular entity dissociates in solution, the concentration refers to the original chemical formula in solution, the molar concentration is sometimes called formal concentration or formality (FA) or analytical concentration (cA). For example, if a sodium carbonate solution () has a formal concentration of c() = 1 mol/L, the molar concentra
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Baker's percentage is a notation method indicating the proportion of an ingredient relative to the flour used in a recipe when making breads, cakes, muffins, and other baked goods. It is also referred to as baker's math, and may be indicated by a phrase such as based on flour weight. It is sometimes called formula percentage, a phrase that refers to the sum of a set of baker's percentages. Baker's percentage expresses a ratio in percentages of each ingredient's weight to the total flour weight:
For example, in a recipe that calls for 10 pounds of flour and 5 pounds of water, the corresponding baker's percentages are 100% for the flour and 50% for the water. Because these percentages are stated with respect to the weight of flour rather than with respect to the weight of all ingredients, the sum of these percentages always exceeds 100%.
Flour-based recipes are more precisely conceived as baker's percentages, and more accurately measured using weight instead of volume. The uncertainty in using volume measurements follows from the fact that flour settles in storage and therefore does not have a constant density.
Baker's percentages
A yeast-dough formula could call for the following list of ingredients, presented as a series of baker's percentages:
{| class=wikitable style="text-align:center;"
|-
| align=left | flour || 100%
|-
| align=left | water || 60%
|-
| align=left | yeast || 1%
|-
| align=left | salt || 2%
|-
| align=left | oil || 1%
|}
Conversions
There are several common conversions that are used with baker's percentages. Converting baker's percentages to ingredient weights is one. Converting known ingredient weights to baker percentages is another. Conversion to true percentages, or based on total weight, is helpful to calculate unknown ingredient weights from a desired total or formula weight.
Using baker's percentages
To derive the ingredient weights when any weight of flour Wf is chosen:
{| class=wikitable style="text-align:center;"
|-
! align=le
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What describe the fraction or percentage of a mixture that is made up of a particular substance.
A. atomic weight
B. mole fractions
C. molecular scale
D. solute level
Answer:
|
|
sciq-8407
|
multiple_choice
|
Both fluorine and lithium are highly reactive elements because of their number of what?
|
[
"positrons",
"valence electrons",
"shell electrons",
"covalence electrons"
] |
B
|
Relavent Documents:
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In chemistry and physics, valence electrons are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed. In a single covalent bond, a shared pair forms with both atoms in the bond each contributing one valence electron.
The presence of valence electrons can determine the element's chemical properties, such as its valence—whether it may bond with other elements and, if so, how readily and with how many. In this way, a given element's reactivity is highly dependent upon its electronic configuration. For a main-group element, a valence electron can exist only in the outermost electron shell; for a transition metal, a valence electron can also be in an inner shell.
An atom with a closed shell of valence electrons (corresponding to a noble gas configuration) tends to be chemically inert. Atoms with one or two valence electrons more than a closed shell are highly reactive due to the relatively low energy to remove the extra valence electrons to form a positive ion. An atom with one or two electrons fewer than a closed shell is reactive due to its tendency either to gain the missing valence electrons and form a negative ion, or else to share valence electrons and form a covalent bond.
Similar to a core electron, a valence electron has the ability to absorb or release energy in the form of a photon. An energy gain can trigger the electron to move (jump) to an outer shell; this is known as atomic excitation. Or the electron can even break free from its associated atom's shell; this is ionization to form a positive ion. When an electron loses energy (thereby causing a photon to be emitted), then it can move to an inner shell which is not fully occupied.
Overview
Electron configuration
The electrons that determine valence – how an atom reacts chemically – are those with the highest energy.
For a main-group element, the valence electrons are defined as those electrons residing in the e
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In nuclear chemistry, the actinide concept (also known as actinide hypothesis) proposed that the actinides form a second inner transition series homologous to the lanthanides. Its origins stem from observation of lanthanide-like properties in transuranic elements in contrast to the distinct complex chemistry of previously known actinides. Glenn Theodore Seaborg, one of the researchers who synthesized transuranic elements, proposed the actinide concept in 1944 as an explanation for observed deviations and a hypothesis to guide future experiments. It was accepted shortly thereafter, resulting in the placement of a new actinide series comprising elements 89 (actinium) to 103 (lawrencium) below the lanthanides in Dmitri Mendeleev's periodic table of the elements.
Origin
In the late 1930s, the first four actinides (actinium, thorium, protactinium, and uranium) were known. They were believed to form a fourth series of transition metals, characterized by the filling of 6d orbitals, in which thorium, protactinium, and uranium were respective homologs of hafnium, tantalum, and tungsten. This view was widely accepted as chemical investigations of these elements revealed various high oxidation states and characteristics that closely resembled the 5d transition metals. Nevertheless, research into quantum theory by Niels Bohr and subsequent publications proposed that these elements should constitute a 5f series analogous to the lanthanides, with calculations that the first 5f electron should appear in the range from atomic number 90 (thorium) to 99 (einsteinium). Inconsistencies between theoretical models and known chemical properties thus made it difficult to place these elements in the periodic table.
The first appearance of the actinide concept may have been in a 32-column periodic table constructed by Alfred Werner in 1905. Upon determining the arrangement of the lanthanides in the periodic table, he placed thorium as a heavier homolog of cerium, and left spaces for hypot
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In chemistry and physics, the iron group refers to elements that are in some way related to iron; mostly in period (row) 4 of the periodic table. The term has different meanings in different contexts.
In chemistry, the term is largely obsolete, but it often means iron, cobalt, and nickel, also called the iron triad; or, sometimes, other elements that resemble iron in some chemical aspects.
In astrophysics and nuclear physics, the term is still quite common, and it typically means those three plus chromium and manganese—five elements that are exceptionally abundant, both on Earth and elsewhere in the universe, compared to their neighbors in the periodic table. Titanium and vanadium are also produced in Type Ia supernovae.
General chemistry
In chemistry, "iron group" used to refer to iron and the next two elements in the periodic table, namely cobalt and nickel. These three comprised the "iron triad". They are the top elements of groups 8, 9, and 10 of the periodic table; or the top row of "group VIII" in the old (pre-1990) IUPAC system, or of "group VIIIB" in the CAS system. These three metals (and the three of the platinum group, immediately below them) were set aside from the other elements because they have obvious similarities in their chemistry, but are not obviously related to any of the other groups. The iron group and its alloys exhibit ferromagnetism.
The similarities in chemistry were noted as one of Döbereiner's triads and by Adolph Strecker in 1859. Indeed, Newlands' "octaves" (1865) were harshly criticized for separating iron from cobalt and nickel. Mendeleev stressed that groups of "chemically analogous elements" could have similar atomic weights as well as atomic weights which increase by equal increments, both in his original 1869 paper and his 1889 Faraday Lecture.
Analytical chemistry
In the traditional methods of qualitative inorganic analysis, the iron group consists of those cations which
have soluble chlorides; and
are not precipitated
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This is a list of the sizes, shapes, and general characteristics of some common primary and secondary battery types in household, automotive and light industrial use.
The complete nomenclature for a battery specifies size, chemistry, terminal arrangement, and special characteristics. The same physically interchangeable cell size or battery size may have widely different characteristics; physical interchangeability is not the sole factor in substituting a battery.
The full battery designation identifies not only the size, shape and terminal layout of the battery but also the chemistry (and therefore the voltage per cell) and the number of cells in the battery. For example, a CR123 battery is always LiMnO2 ('Lithium') chemistry, in addition to its unique size.
The following tables give the common battery chemistry types for the current common sizes of batteries. See Battery chemistry for a list of other electrochemical systems.
Cylindrical batteries
Rectangular batteries
Camera batteries
As well as other types, digital and film cameras often use specialized primary batteries to produce a compact product. Flashlights and portable electronic devices may also use these types.
Button cells – coin, watch
Lithium cells
Coin-shaped cells are thin compared to their diameter. Polarity is usually stamped on the metal casing.
The IEC prefix "CR" denotes lithium manganese dioxide chemistry. Since LiMnO2 cells produce 3 volts there are no widely available alternative chemistries for a lithium coin battery. The "BR" prefix indicates a round lithium/carbon monofluoride cell. See lithium battery for discussion of the different performance characteristics. One LiMnO2 cell can replace two alkaline or silver-oxide cells.
IEC designation numbers indicate the physical dimensions of the cylindrical cell. Cells less than one centimeter in height are assigned four-digit numbers, where the first two digits are the diameter in millimeters, while the last two digits are the height in
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Superheavy elements, also known as transactinide elements, transactinides, or super-heavy elements, are the chemical elements with atomic number greater than 103. The superheavy elements are those beyond the actinides in the periodic table; the last actinide is lawrencium (atomic number 103). By definition, superheavy elements are also transuranium elements, i.e., having atomic numbers greater than that of uranium (92). Depending on the definition of group 3 adopted by authors, lawrencium may also be included to complete the 6d series.
Glenn T. Seaborg first proposed the actinide concept, which led to the acceptance of the actinide series. He also proposed a transactinide series ranging from element 104 to 121 and a superactinide series approximately spanning elements 122 to 153 (although more recent work suggests the end of the superactinide series to occur at element 157 instead). The transactinide seaborgium was named in his honor.
Superheavy elements are radioactive and have only been obtained synthetically in laboratories. No macroscopic sample of any of these elements have ever been produced. Superheavy elements are all named after physicists and chemists or important locations involved in the synthesis of the elements.
IUPAC defines an element to exist if its lifetime is longer than 10−14 second, which is the time it takes for the atom to form an electron cloud.
The known superheavy elements form part of the 6d and 7p series in the periodic table. Except for rutherfordium and dubnium (and lawrencium if it is included), even the longest-lasting isotopes of superheavy elements have half-lives of minutes or less. The element naming controversy involved elements 102–109. Some of these elements thus used systematic names for many years after their discovery was confirmed. (Usually the systematic names are replaced with permanent names proposed by the discoverers relatively shortly after a discovery has been confirmed.)
Introduction
Synthesis of superheavy nu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Both fluorine and lithium are highly reactive elements because of their number of what?
A. positrons
B. valence electrons
C. shell electrons
D. covalence electrons
Answer:
|
|
scienceQA-11239
|
multiple_choice
|
Select the fish below.
|
[
"great white shark",
"kangaroo",
"tiger salamander",
"Amazon tree boa"
] |
A
|
A kangaroo is a mammal. It has fur and feeds its young milk.
Kangaroos hop to move around. They use their large tails for balance while hopping.
An Amazon tree boa is a reptile. It has scaly, waterproof skin.
Tree boas eat small mammals, birds, lizards, and frogs. Tree boas only need to eat once every few months!
A great white shark is a fish. It lives underwater. It has fins, not limbs.
Great white sharks can live for up to 70 years.
A tiger salamander is an amphibian. It has moist skin and begins its life in water.
Tiger salamanders often live in underground burrows.
|
Relavent Documents:
Document 0:::
Fish intelligence is the resultant of the process of acquiring, storing in memory, retrieving, combining, comparing, and using in new contexts information and conceptual skills" as it applies to fish.
According to Culum Brown from Macquarie University, "Fish are more intelligent than they appear. In many areas, such as memory, their cognitive powers match or exceed those of ‘higher’ vertebrates including non-human primates."
Fish hold records for the relative brain weights of vertebrates. Most vertebrate species have similar brain-to-body mass ratios. The deep sea bathypelagic bony-eared assfish has the smallest ratio of all known vertebrates. At the other extreme, the electrogenic elephantnose fish, an African freshwater fish, has one of the largest brain-to-body weight ratios of all known vertebrates (slightly higher than humans) and the highest brain-to-body oxygen consumption ratio of all known vertebrates (three times that for humans).
Brain
Fish typically have quite small brains relative to body size compared with other vertebrates, typically one-fifteenth the brain mass of a similarly sized bird or mammal. However, some fish have relatively large brains, most notably mormyrids and sharks, which have brains about as massive relative to body weight as birds and marsupials.
The cerebellum of cartilaginous and bony fishes is large and complex. In at least one important respect, it differs in internal structure from the mammalian cerebellum: The fish cerebellum does not contain discrete deep cerebellar nuclei. Instead, the primary targets of Purkinje cells are a distinct type of cell distributed across the cerebellar cortex, a type not seen in mammals. The circuits in the cerebellum are similar across all classes of vertebrates, including fish, reptiles, birds, and mammals. There is also an analogous brain structure in cephalopods with well-developed brains, such as octopuses. This has been taken as evidence that the cerebellum performs functions important to
Document 1:::
The Digital Fish Library (DFL) is a University of California San Diego project funded by the Biological Infrastructure Initiative (DBI) of the National Science Foundation (NSF). The DFL creates 2D and 3D visualizations of the internal and external anatomy of fish obtained with magnetic resonance imaging (MRI) methods and makes these publicly available on the web.
The information core for the Digital Fish Library is generated using high-resolution MRI scanners housed at the Center for functional magnetic resonance imaging (CfMRI) multi-user facility at UC San Diego. These instruments use magnetic fields to take 3D images of animal tissues, allowing researchers to non-invasively see inside them and quantitatively describe their 3D anatomy. Fish specimens are obtained from the Marine Vertebrate Collection at Scripps Institute of Oceanography (SIO) and imaged by staff from UC San Diego's Center for Scientific Computation in Imaging (CSCI).
As of February 2010, the Digital Fish Library contains almost 300 species covering all five classes of fish, 56 of 60 orders, and close to 200 of the 521 fish families as described by Nelson, 2006. DFL imaging has also contributed to a number of published peer-reviewed scientific studies.
Digital Fish Library work has been featured in the media, including two National Geographic documentaries: Magnetic Navigator and Ultimate Shark.
Document 2:::
Fisheries science is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of limnology, oceanography, freshwater biology, marine biology, meteorology, conservation, ecology, population dynamics, economics, statistics, decision analysis, management, and many others in an attempt to provide an integrated picture of fisheries. In some cases new disciplines have emerged, as in the case of bioeconomics and fisheries law. Because fisheries science is such an all-encompassing field, fisheries scientists often use methods from a broad array of academic disciplines. Over the most recent several decades, there have been declines in fish stocks (populations) in many regions along with increasing concern about the impact of intensive fishing on marine and freshwater biodiversity.
Fisheries science is typically taught in a university setting, and can be the focus of an undergraduate, master's or Ph.D. program. Some universities offer fully integrated programs in fisheries science. Graduates of university fisheries programs typically find employment as scientists, fisheries managers of both recreational and commercial fisheries, researchers, aquaculturists, educators, environmental consultants and planners, conservation officers, and many others.
Fisheries research
Because fisheries take place in a diverse set of aquatic environments (i.e., high seas, coastal areas, large and small rivers, and lakes of all sizes), research requires different sampling equipment, tools, and techniques. For example, studying trout populations inhabiting mountain lakes requires a very different set of sampling tools than, say, studying salmon in the high seas. Ocean fisheries research vessels (FRVs) often require platforms which are capable of towing different types of fishing nets, collecting plankton or water samples from a range of depths, and carrying acoustic fish-finding equipment. Fisheries research vessels a
Document 3:::
The Bachelor of Science in Aquatic Resources and Technology (B.Sc. in AQT) (or Bachelor of Aquatic Resource) is an undergraduate degree that prepares students to pursue careers in the public, private, or non-profit sector in areas such as marine science, fisheries science, aquaculture, aquatic resource technology, food science, management, biotechnology and hydrography. Post-baccalaureate training is available in aquatic resource management and related areas.
The Department of Animal Science and Export Agriculture, at the Uva Wellassa University of Badulla, Sri Lanka, has the largest enrollment of undergraduate majors in Aquatic Resources and Technology, with about 200 students as of 2014.
The Council on Education for Aquatic Resources and Technology includes undergraduate AQT degrees in the accreditation review of Aquatic Resources and Technology programs and schools.
See also
Marine Science
Ministry of Fisheries and Aquatic Resources Development
Document 4:::
AquaMaps is a collaborative project with the aim of producing computer-generated (and ultimately, expert reviewed) predicted global distribution maps for marine species on a 0.5 x 0.5 degree grid of the oceans based on data available through online species databases such as FishBase and SeaLifeBase and species occurrence records from OBIS or GBIF and using an environmental envelope model (see niche modelling) in conjunction with expert input. The underlying model represents a modified version of the relative environmental suitability (RES) model developed by Kristin Kaschner to generate global predictions of marine mammal occurrences.
According to the AquaMaps website in August 2013, the project held standardized distribution maps for over 17,300 species of fishes, marine mammals and invertebrates.
The project is also expanding to incorporate freshwater species, with more than 600 biodiversity maps for freshwater fishes of the Americas available as at November 2009. AquaMaps predictions have been validated successfully for a number of species using independent data sets and the model was shown to perform equally well or better than other standard species distribution models, when faced with the currently existing suboptimal input data sets.
In addition to displaying individual maps per species, AquaMaps provides tools to generate species richness maps by higher taxon, plus a spatial search for all species overlapping a specified grid square. There is also the facility to create custom maps for any species via the web by modifying the input parameters and re-running the map generating algorithm in real time, and a variety of other tools including the investigation of effects of climate change on species distributions (see relevant section of the AquaMaps search page).
Coordination
The project is coordinated by Dr Rainer Froese of IFM-GEOMAR and involves contributions from other research institutes including the Evolutionary Biology and Ecology Lab, Albert-Ludwigs
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the fish below.
A. great white shark
B. kangaroo
C. tiger salamander
D. Amazon tree boa
Answer:
|
sciq-7478
|
multiple_choice
|
The average length of a woman’s menstrual cycle is what?
|
[
"19 days",
"16 days",
"28 days",
"5 days"
] |
C
|
Relavent Documents:
Document 0:::
Menarche ( ; ) is the first menstrual cycle, or first menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fertility.
Girls experience menarche at different ages. Having menarche occur between the ages of 9–14 in the West is considered normal. Canadian psychological researcher Niva Piran claims that menarche or the perceived average age of puberty is used in many cultures to separate girls from activity with boys, and to begin transition into womanhood.
The timing of menarche is influenced by female biology, as well as genetic and environmental factors, especially nutritional factors. The mean age of menarche has declined over the last century, but the magnitude of the decline and the factors responsible remain subjects of contention. The worldwide average age of menarche is very difficult to estimate accurately, and it varies significantly by geographical region, race, ethnicity and other characteristics, and occurs mostly during a span of ages from 8 to 16, with a small percentage of girls having menarche by age 10, and the vast majority having it by the time they were 14.
There is a later age of onset in Asian populations compared to the West, but it too is changing with time. For example a Korean study in 2011 showed an overall average age of 12.7, with around 20% before age 12, and more than 90% by age 14. A Chinese study from 2014 published in Acta Paediatrica showed similar results (overall average of age 12.8 in 2005 down to age 12.3 in 2014) and a similar trend in time, but also similar findings about ethnic, cultural, and environmental effects.
The average age of menarche was about 12.7 years in Canada in 2001, and 12.9 in the United Kingdom. A study of girls in Istanbul, Turkey, in 2011 found the median age at menarche to be 12.7 years. In the United States, an analysis of 10,590 women aged 15–44 taken from the 2013–2017 round of th
Document 1:::
Female education in STEM refers to child and adult female representation in the educational fields of science, technology, engineering, and mathematics (STEM). In 2017, 33% of students in STEM fields were women.
The organization UNESCO has stated that this gender disparity is due to discrimination, biases, social norms and expectations that influence the quality of education women receive and the subjects they study. UNESCO also believes that having more women in STEM fields is desirable because it would help bring about sustainable development.
Current status of girls and women in STEM education
Overall trends in STEM education
Gender differences in STEM education participation are already visible in early childhood care and education in science- and math-related play, and become more pronounced at higher levels of education. Girls appear to lose interest in STEM subjects with age, particularly between early and late adolescence. This decreased interest affects participation in advanced studies at the secondary level and in higher education. Female students represent 35% of all students enrolled in STEM-related fields of study at this level globally. Differences are also observed by disciplines, with female enrollment lowest in engineering, manufacturing and construction, natural science, mathematics and statistics and ICT fields. Significant regional and country differences in female representation in STEM studies can be observed, though, suggesting the presence of contextual factors affecting girls’ and women's engagement in these fields. Women leave STEM disciplines in disproportionate numbers during their higher education studies, in their transition to the world of work and even in their career cycle.
Learning achievement in STEM education
Data on gender differences in learning achievement present a complex picture, depending on what is measured (subject, knowledge acquisition against knowledge application), the level of education/age of students, and
Document 2:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
Document 3:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 4:::
Advanced Placement (AP) Statistics (also known as AP Stats) is a college-level high school statistics course offered in the United States through the College Board's Advanced Placement program. This course is equivalent to a one semester, non-calculus-based introductory college statistics course and is normally offered to sophomores, juniors and seniors in high school.
One of the College Board's more recent additions, the AP Statistics exam was first administered in May 1996 to supplement the AP program's math offerings, which had previously consisted of only AP Calculus AB and BC. In the United States, enrollment in AP Statistics classes has increased at a higher rate than in any other AP class.
Students may receive college credit or upper-level college course placement upon passing the three-hour exam ordinarily administered in May. The exam consists of a multiple-choice section and a free-response section that are both 90 minutes long. Each section is weighted equally in determining the students' composite scores.
History
The Advanced Placement program has offered students the opportunity to pursue college-level courses while in high school. Along with the Educational Testing Service, the College Board administered the first AP Statistics exam in May 1997. The course was first taught to students in the 1996-1997 academic year. Prior to that, the only mathematics courses offered in the AP program included AP Calculus AB and BC. Students who didn't have a strong background in college-level math, however, found the AP Calculus program inaccessible and sometimes declined to take a math course in their senior year. Since the number of students required to take statistics in college is almost as large as the number of students required to take calculus, the College Board decided to add an introductory statistics course to the AP program. Since the prerequisites for such a program doesn't require mathematical concepts beyond those typically taught in a second-year al
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The average length of a woman’s menstrual cycle is what?
A. 19 days
B. 16 days
C. 28 days
D. 5 days
Answer:
|
|
sciq-2432
|
multiple_choice
|
What type of reproduction produces offspring from a single parent that share the exact same genetic material as the parent?
|
[
"mutation",
"sexual reproduction",
"asexual reproduction",
"microscopic reproduction"
] |
C
|
Relavent Documents:
Document 0:::
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee.
Human offspring (descendants) are referred to as children (without reference to age, thus one can refer to a parent's "minor children" or "adult children" or "infant children" or "teenage children" depending on their age); male children are sons and female children are daughters (see kinship). Offspring can occur after mating or after artificial insemination.
Overview
Offspring contains many parts and properties that are precise and accurate in what they consist of, and what they define. As the offspring of a new species, also known as a child or f1 generation, consist of genes of the father and the mother, which is also known as the parent generation. Each of these offspring contains numerous genes which have coding for specific tasks and properties. Males and females both contribute equally to the genotypes of their offspring, in which gametes fuse and form. An important aspect of the formation of the parent offspring is the chromosome, which is a structure of DNA which contains many genes.
To focus more on the offspring and how it results in the formation of the f1 generation, is an inheritance called sex linkage, which is a gene located on the sex chromosome, and patterns of this inheritance differ in both male and female. The explanation that proves the theory of the offspring having genes from both parent generations is proven through a process called crossing over, which consists of taking genes from the male chromosomes and genes from the female chromosome, resulting in a process of meiosis occurring, and leading to the splitting of the chromosomes evenly. Depending on which
Document 1:::
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes.
Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such as bacteria and archaea. However, some processes in bacteria, including bacterial conjugation, transformation and transduction, may be considered analogous to sexual reproduction in that they incorporate new genetic information. Some proteins and other features that are key for sexual reproduction may have arisen in bacteria, but sexual reproduction is believed to have developed in an ancient eukaryotic ancestor.
In eukaryotes, diploid precursor cells divide to produce haploid cells in a process called meiosis. In meiosis, DNA is replicated to produce a total of four copies of each chromosome. This is followed by two cell divisions to generate haploid gametes. After the DNA is replicated in meiosis, the homologous chromosomes pair up so that their DNA sequences are aligned with each other. During this period before cell divisions, genetic information is exchanged between homologous chromosomes in genetic recombination. Homologous chromosomes contain highly similar but not identical information, and by exchanging similar but not identical regions, genetic recombination increases genetic diversity among future generations.
During sexual reproduction, two haploid gametes combine into one diploid ce
Document 2:::
In biology and genetics, the germline is the population of a multicellular organism's cells that pass on their genetic material to the progeny (offspring). In other words, they are the cells that form the egg, sperm and the fertilised egg. They are usually differentiated to perform this function and segregated in a specific place away from other bodily cells.
As a rule, this passing-on happens via a process of sexual reproduction; typically it is a process that includes systematic changes to the genetic material, changes that arise during recombination, meiosis and fertilization for example. However, there are many exceptions across multicellular organisms, including processes and concepts such as various forms of apomixis, autogamy, automixis, cloning or parthenogenesis. The cells of the germline are called germ cells. For example, gametes such as a sperm and an egg are germ cells. So are the cells that divide to produce gametes, called gametocytes, the cells that produce those, called gametogonia, and all the way back to the zygote, the cell from which an individual develops.
In sexually reproducing organisms, cells that are not in the germline are called somatic cells. According to this view, mutations, recombinations and other genetic changes in the germline may be passed to offspring, but a change in a somatic cell will not be. This need not apply to somatically reproducing organisms, such as some Porifera and many plants. For example, many varieties of citrus, plants in the Rosaceae and some in the Asteraceae, such as Taraxacum, produce seeds apomictically when somatic diploid cells displace the ovule or early embryo.
In an earlier stage of genetic thinking, there was a clear distinction between germline and somatic cells. For example, August Weismann proposed and pointed out, a germline cell is immortal in the sense that it is part of a lineage that has reproduced indefinitely since the beginning of life and, barring accident, could continue doing so indef
Document 3:::
Extranuclear inheritance or cytoplasmic inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria.
Organelles
Mitochondria are organelles which function to transform energy as a result of cellular respiration. Chloroplasts are organelles which function to produce sugars via photosynthesis in plants and algae. The genes located in mitochondria and chloroplasts are very important for proper cellular function. The mitochondrial DNA and other extranuclear types of DNA replicate independently of the DNA located in the nucleus, which is typically arranged in chromosomes that only replicate one time preceding cellular division. The extranuclear genomes of mitochondria and chloroplasts however replicate independently of cell division. They replicate in response to a cell's increasing energy needs which adjust during that cell's lifespan. Since they replicate independently, genomic recombination of these genomes is rarely found in offspring, contrary to nuclear genomes in which recombination is common.
Mitochondrial diseases are inherited from the mother, not from the father. Mitochondria with their mitochondrial DNA are already present in the egg cell before it gets fertilized by a sperm. In many cases of fertilization, the head of the sperm enters the egg cell; leaving its middle part, with its mitochondria, behind. The mitochondrial DNA of the sperm often remains outside the zygote and gets excluded from inheritance.
Parasites
Extranuclear transmission of viral genomes and symbiotic bacteria is also possible. An example of viral genome transmission is perinatal transmission. This occurs from mother to fetus during the perinatal period, which begins before birth and ends about 1 month after birth. During this time viral material may be passed from mother to child in the bloodst
Document 4:::
Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes, or by mitosis. For example, plants produce gametes through mitosis in gametophytes. The gametophytes grow from haploid spores after sporic meiosis. The existence of a multicellular, haploid phase in the life cycle between meiosis and gametogenesis is also referred to as alternation of generations.
It is the biological process of gametogenesis; cells that are haploid or diploid divide to create other cells. matured haploid gametes. It can take place either through mitosis or meiotic division of diploid gametocytes into different depending on an organism's biological life cycle, gametes. For instance, gametophytes in plants undergo mitosis to produce gametes. Both male and female have different forms.
In animals
Animals produce gametes directly through meiosis from diploid mother cells in organs called gonads (testis in males and ovaries in females). In mammalian germ cell development, sexually dimorphic gametes differentiates into primordial germ cells from pluripotent cells during initial mammalian development. Males and females of a species that reproduce sexually have different forms of gametogenesis:
spermatogenesis (male): Immature germ cells are produced in a man's testes. To mature into sperms, males' immature germ cells, or spermatogonia, go through spermatogenesis during adolescence. Spermatogonia are diploid cells that become larger as they divide through mitosis. These primary spermatocytes. These diploid cells undergo meiotic division to create secondary spermatocytes. These secondary spermatocytes undergo a second meiotic division to produce immature sperms or spermatids. These spermatids undergo spermiogenesis in order to develop into sperm. LH, FSH, GnRH
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of reproduction produces offspring from a single parent that share the exact same genetic material as the parent?
A. mutation
B. sexual reproduction
C. asexual reproduction
D. microscopic reproduction
Answer:
|
|
sciq-6056
|
multiple_choice
|
Where is roughage fermented and digested in pseudo-ruminants?
|
[
"in their cecum",
"in their ileum",
"in their pancreas",
"in their appendix"
] |
A
|
Relavent Documents:
Document 0:::
Pseudoruminant is a classification of animals based on their digestive tract differing from the ruminants. Hippopotami and camels are ungulate mammals with a three-chambered stomach (ruminants have a four-chambered stomach) while equids (horses, asses, zebras) and rhinoceroses are monogastric herbivores.
Anatomy
Like ruminants, some pseudoruminants may use foregut fermentation to break down cellulose in fibrous plant species (while most others are hindgut fermenters with a large cecum). But they have three-chambered stomachs (while others are monogastric) as opposed to ruminant stomachs which have four compartments.
Species
See also
Traditional ruminant
Document 1:::
Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria. The microbial fermentation occurs in the digestive organs that follow the small intestine: the large intestine and cecum. Examples of hindgut fermenters include proboscideans and large odd-toed ungulates such as horses and rhinos, as well as small animals such as rodents, rabbits and koalas. In contrast, foregut fermentation is the form of cellulose digestion seen in ruminants such as cattle which have a four-chambered stomach, as well as in sloths, macropodids, some monkeys, and one bird, the hoatzin.
Cecum
Hindgut fermenters generally have a cecum and large intestine that are much larger and more complex than those of a foregut or midgut fermenter. Research on small cecum fermenters such as flying squirrels, rabbits and lemurs has revealed these mammals to have a GI tract about 10-13 times the length of their body. This is due to the high intake of fiber and other hard to digest compounds that are characteristic to the diet of monogastric herbivores. Unlike in foregut fermenters, the cecum is located after the stomach and small intestine in monogastric animals, which limits the amount of further digestion or absorption that can occur after the food is fermented.
Large intestine
In smaller hindgut fermenters of the order Lagomorpha (rabbits, hares, and pikas), cecotropes formed in the cecum are passed through the large intestine and subsequently reingested to allow another opportunity to absorb nutrients. Cecotropes are surrounded by a layer of mucus which protects them from stomach acid but which does not inhibit nutrient absorption in the small intestine. Coprophagy is also practiced by some rodents, such as the capybara, guinea pig and related species, and by the marsupial common ringtail possum. This process is also beneficial in allowing for restoration of the microflora pop
Document 2:::
Animal science is described as "studying the biology of animals that are under the control of humankind". It can also be described as the production and management of farm animals. Historically, the degree was called animal husbandry and the animals studied were livestock species, like cattle, sheep, pigs, poultry, and horses. Today, courses available look at a broader area, including companion animals, like dogs and cats, and many exotic species. Degrees in Animal Science are offered at a number of colleges and universities. Animal science degrees are often offered at land-grant universities, which will often have on-campus farms to give students hands-on experience with livestock animals.
Education
Professional education in animal science prepares students for careers in areas such as animal breeding, food and fiber production, nutrition, animal agribusiness, animal behavior, and welfare. Courses in a typical Animal Science program may include genetics, microbiology, animal behavior, nutrition, physiology, and reproduction. Courses in support areas, such as genetics, soils, agricultural economics and marketing, legal aspects, and the environment also are offered.
Bachelor degree
At many universities, a Bachelor of Science (BS) degree in Animal Science allows emphasis in certain areas. Typical areas are species-specific or career-specific. Species-specific areas of emphasis prepare students for a career in dairy management, beef management, swine management, sheep or small ruminant management, poultry production, or the horse industry. Other career-specific areas of study include pre-veterinary medicine studies, livestock business and marketing, animal welfare and behavior, animal nutrition science, animal reproduction science, or genetics. Youth programs are also an important part of animal science programs.
Pre-veterinary emphasis
Many schools that offer a degree option in Animal Science also offer a pre-veterinary emphasis such as Iowa State University, th
Document 3:::
Hippology (from Greek: ἵππος, hippos, "horse"; and λόγος, logos, "study") is the study of the horse - a domesticated, one-toed, hoofed mammal belonging to the taxonomic family Equidae.
Today, hippology is the title of an equine veterinary and management knowledge contest that is used in 4-H, Future Farmers of America (FFA), and many horse breed contests. Hippology consists of four phases: horse judging, written examination and slide identification, ID stations, and team problem-solving. Many youths across the United States and in other countries compete in hippology annually, showing their knowledge of all things "horse".
Items covered in the contest may cover any equine subject, including reproduction, training, parasites, dressage, history and origins, anatomy and physiology, driving and harnessing, horse industry, horse management, breeds, genetics, western games, colors, famous horses in history, parts of the saddle, types of bits, gaits, competitions, poisonous plants, and nutrition.
Judging
The judging phase generally includes judging both a halter class and an "under saddle" class (such as western pleasure, hunter under saddle, etc.). The classes involve four horses and contestants are given a judging card to place the horses. Unlike the horse judging competitions, hippology competitors are not expected to give reasons, but only place the classes.
Written examination and slide identification
The written examination is a multiple-choice, 50-question test. The written examination can cover any of the topics and any of the information from the designated sources. The slide identification is composed of 25 slides.
ID stations
The ID station phase includes 10 stations, each with 10 pictures or objects to be identified along with a list of multiple-choice answers. Each station has a theme (anatomy, poisonous plants, tack, etc.). A time limit exists allotting only 2 minutes per station.
Team problem solving
The team problem solving phase requires a team, wi
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Colm P. O'Donnell is an Irish chemist and engineer; he is a professor of biosystems and food engineering at the University College Dublin who is active in the field of process analytical technology (PAT); he is also a head of university School of biosystems and food engineering — as well as a chairperson of the Dairy processing technical committee of International Federation for Process Analysis and Control (IFPAC).
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where is roughage fermented and digested in pseudo-ruminants?
A. in their cecum
B. in their ileum
C. in their pancreas
D. in their appendix
Answer:
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|
sciq-9955
|
multiple_choice
|
What do you call the force identified by a north and south pole?
|
[
"magnetism",
"buoyancy",
"normal force",
"gravity"
] |
A
|
Relavent Documents:
Document 0:::
The south magnetic pole, also known as the magnetic south pole, is the point on Earth's Southern Hemisphere where the geomagnetic field lines are directed perpendicular to the nominal surface. The Geomagnetic South Pole, a related point, is the south pole of an ideal dipole model of the Earth's magnetic field that most closely fits the Earth's actual magnetic field.
For historical reasons, the "end" of a freely hanging magnet that points (roughly) north is itself called the "north pole" of the magnet, and the other end, pointing south, is called the magnet's "south pole". Because opposite poles attract, Earth's south magnetic pole is physically actually a magnetic north pole (see also ).
The south magnetic pole is constantly shifting due to changes in Earth's magnetic field.
As of 2005 it was calculated to lie at , placing it off the coast of Antarctica, between Adélie Land and Wilkes Land. In 2015 it lay at (est). That point lies outside the Antarctic Circle. Due to polar drift, the pole is moving northwest by about per year. Its current distance from the actual Geographic South Pole is approximately . The nearest permanent science station is Dumont d'Urville Station. While the north magnetic pole began wandering very quickly in the mid 1990s, the movement of the south magnetic pole did not show a matching change of speed.
Expeditions
Early unsuccessful attempts to reach the magnetic south pole included those of French explorer Dumont d'Urville (1837–40), American Charles Wilkes (expedition of 1838–42) and Briton James Clark Ross (expedition of 1839 to 1843).
The first calculation of the magnetic inclination to locate the magnetic South Pole was made on 23 January 1838 by the hydrographer , a member of the Dumont d'Urville expedition in Antarctica and Oceania on the corvettes L'Astrolabe and Zélée in 1837–1840, which discovered Adelie Land.
On 16 January 1909 three men (Douglas Mawson, Edgeworth David, and Alistair Mackay) from Sir Ernest Shackleton's Nimrod
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The north magnetic pole, also known as the magnetic north pole, is a point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downward (in other words, if a magnetic compass needle is allowed to rotate in three dimensions, it will point straight down). There is only one location where this occurs, near (but distinct from) the geographic north pole. The geomagnetic north pole is the northern antipodal pole of an ideal dipole model of the Earth's magnetic field, which is the most closely fitting model of Earth's actual magnetic field.
The north magnetic pole moves over time according to magnetic changes and flux lobe elongation in the Earth's outer core. In 2001, it was determined by the Geological Survey of Canada to lie west of Ellesmere Island in northern Canada at . It was situated at in 2005. In 2009, while still situated within the Canadian Arctic at , it was moving toward Russia at between per year. In 2013, the distance between the north magnetic pole and the geographic north pole was approximately . As of 2021, the pole is projected to have moved beyond the Canadian Arctic to .
Its southern hemisphere counterpart is the south magnetic pole. Since Earth's magnetic field is not exactly symmetric, the north and south magnetic poles are not antipodal, meaning that a straight line drawn from one to the other does not pass through the geometric center of Earth.
Earth's north and south magnetic poles are also known as magnetic dip poles, with reference to the vertical "dip" of the magnetic field lines at those points.
Polarity
All magnets have two poles, where lines of magnetic flux enter one pole and emerge from the other pole. By analogy with Earth's magnetic field, these are called the magnet's "north" and "south" poles. The north-seeking pole of a magnet was defined to have the north designation, according to their use in early compasses. Because opposite poles attract, this means that as a physical magne
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Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo.
The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic field (because opposite magnetic poles attract and the north end of a magnet, like a compass needle, points toward Earth's South magnetic field, i.e., the North geomagnetic pole near the Geographic North Pole). As of 2015, the North geomagnetic pole was located on Ellesmere Island, Nunavut, Canada.
While the North and South magnetic poles are usually located near the geographic poles, they slowly and continuously move over geological time scales, but sufficiently slowly for ordinary compasses to remain useful for navigation. However, at irregular intervals averaging several hundred thousand years, Earth's field reverses and the North and South Magnetic Poles respectively, abruptly switch places. These reversals of the geomagnetic poles leave a record in rocks that are of value to paleomagnetists in calculating geomagnetic fields in the past. Such information in turn is helpful in studying the motions of continents and ocean floors in the process of plate tectonics.
The magnetosphere is the regio
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The geomagnetic poles are antipodal points where the axis of a best-fitting dipole intersects the surface of Earth. This theoretical dipole is equivalent to a powerful bar magnet at the center of Earth, and comes closer than any other point dipole model to describing the magnetic field observed at Earth's surface. In contrast, the magnetic poles of the actual Earth are not antipodal; that is, the line on which they lie does not pass through Earth's center.
Owing to motion of fluid in the Earth's outer core, the actual magnetic poles are constantly moving (secular variation). However, over thousands of years, their direction averages to the Earth's rotation axis. On the order of once every half a million years, the poles reverse (i.e., north switches place with south) although the time frame of this switching can be anywhere from every 10 thousand years to every 50 million years. The poles also swing in an oval of around in diameter daily due to solar wind deflecting the magnetic field.
Although the geomagnetic pole is only theoretical and cannot be located directly, it arguably is of more practical relevance than the magnetic (dip) pole. This is because the poles describe a great deal about the Earth's magnetic field, determining for example where auroras can be observed. The dipole model of the Earth's magnetic field consists of the location of geomagnetic poles and the dipole moment, which describes the strength of the field.
Definition
As a first-order approximation, the Earth's magnetic field can be modeled as a simple dipole (like a bar magnet), tilted about 9.6° with respect to the Earth's rotation axis (which defines the Geographic North and Geographic South Poles) and centered at the Earth's center. The North and South Geomagnetic Poles are the antipodal points where the axis of this theoretical dipole intersects the Earth's surface. Thus, unlike the actual magnetic poles, the geomagnetic poles always have an equal degree of latitude and supplementary de
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As described by the third of Newton's laws of motion of classical mechanics, all forces occur in pairs such that if one object exerts a force on another object, then the second object exerts an equal and opposite reaction force on the first. The third law is also more generally stated as: "To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts." The attribution of which of the two forces is the action and which is the reaction is arbitrary. Either of the two can be considered the action, while the other is its associated reaction.
Examples
Interaction with ground
When something is exerting force on the ground, the ground will push back with equal force in the opposite direction. In certain fields of applied physics, such as biomechanics, this force by the ground is called 'ground reaction force'; the force by the object on the ground is viewed as the 'action'.
When someone wants to jump, he or she exerts additional downward force on the ground ('action'). Simultaneously, the ground exerts upward force on the person ('reaction'). If this upward force is greater than the person's weight, this will result in upward acceleration. When these forces are perpendicular to the ground, they are also called a normal force.
Likewise, the spinning wheels of a vehicle attempt to slide backward across the ground. If the ground is not too slippery, this results in a pair of friction forces: the 'action' by the wheel on the ground in backward direction, and the 'reaction' by the ground on the wheel in forward direction. This forward force propels the vehicle.
Gravitational forces
The Earth, among other planets, orbits the Sun because the Sun exerts a gravitational pull that acts as a centripetal force, holding the Earth to it, which would otherwise go shooting off into space. If the Sun's pull is considered an action, then Earth simultaneously exerts a reaction as a gravi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do you call the force identified by a north and south pole?
A. magnetism
B. buoyancy
C. normal force
D. gravity
Answer:
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sciq-10742
|
multiple_choice
|
The posterior pituitary is an extension of what anatomical structure?
|
[
"frontal lobe",
"hippocampus",
"brain stem",
"hypothalamus"
] |
D
|
Relavent Documents:
Document 0:::
The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain.
The temporal lobe is involved in processing sensory input into derived meanings for the appropriate retention of visual memory, language comprehension, and emotion association.
Temporal refers to the head's temples.
Structure
The temporal lobe consists of structures that are vital for declarative or long-term memory. Declarative (denotative) or explicit memory is conscious memory divided into semantic memory (facts) and episodic memory (events). Medial temporal lobe structures that are critical for long-term memory include the hippocampus, along with the surrounding hippocampal region consisting of the perirhinal, parahippocampal, and entorhinal neocortical regions. The hippocampus is critical for memory formation, and the surrounding medial temporal cortex is currently theorized to be critical for memory storage. The prefrontal and visual cortices are also involved in explicit memory.
Research has shown that lesions in the hippocampus of monkeys results in limited impairment of function, whereas extensive lesions that include the hippocampus and the medial temporal cortex result in severe impairment.
Function
Visual memories
The temporal lobe communicates with the hippocampus and plays a key role in the formation of explicit long-term memory modulated by the amygdala.
Processing sensory input
Auditory Adjacent areas in the superior, posterior, and lateral parts of the temporal lobes are involved in high-level auditory processing. The temporal lobe is involved in primary auditory perception, such as hearing, and holds the primary auditory cortex. The primary auditory cortex receives sensory information from the ears and secondary areas process the information into meaningful units such as speech and words. The superior temporal gyrus includes an area (wit
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The human brain anatomical regions are ordered following standard neuroanatomy hierarchies. Functional, connective, and developmental regions are listed in parentheses where appropriate.
Hindbrain (rhombencephalon)
Myelencephalon
Medulla oblongata
Medullary pyramids
Arcuate nucleus
Olivary body
Inferior olivary nucleus
Rostral ventrolateral medulla
Caudal ventrolateral medulla
Solitary nucleus (Nucleus of the solitary tract)
Respiratory center-Respiratory groups
Dorsal respiratory group
Ventral respiratory group or Apneustic centre
Pre-Bötzinger complex
Botzinger complex
Retrotrapezoid nucleus
Nucleus retrofacialis
Nucleus retroambiguus
Nucleus para-ambiguus
Paramedian reticular nucleus
Gigantocellular reticular nucleus
Parafacial zone
Cuneate nucleus
Gracile nucleus
Perihypoglossal nuclei
Intercalated nucleus
Prepositus nucleus
Sublingual nucleus
Area postrema
Medullary cranial nerve nuclei
Inferior salivatory nucleus
Nucleus ambiguus
Dorsal nucleus of vagus nerve
Hypoglossal nucleus
Chemoreceptor trigger zone
Metencephalon
Pons
Pontine nuclei
Pontine cranial nerve nuclei
Chief or pontine nucleus of the trigeminal nerve sensory nucleus (V)
Motor nucleus for the trigeminal nerve (V)
Abducens nucleus (VI)
Facial nerve nucleus (VII)
Vestibulocochlear nuclei (vestibular nuclei and cochlear nuclei) (VIII)
Superior salivatory nucleus
Pontine tegmentum
Pontine micturition center (Barrington's nucleus)
Locus coeruleus
Pedunculopontine nucleus
Laterodorsal tegmental nucleus
Tegmental pontine reticular nucleus
Nucleus incertus
Parabrachial area
Medial parabrachial nucleus
Lateral parabrachial nucleus
Subparabrachial nucleus (Kölliker-Fuse nucleus)
Pontine respiratory group
Superior olivary complex
Medial superior olive
Lateral superior olive
Medial nucleus of the trapezoid body
Paramedian pontine reticular formation
Parvocellular reticular nucleus
Caudal pontine reticular nucleus
Cerebellar peduncles
Superior cerebellar peduncle
Middle cerebellar peduncle
Inferior
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This article describes anatomical terminology that is used to describe the central and peripheral nervous systems - including the brain, brainstem, spinal cord, and nerves.
Anatomical terminology in neuroanatomy
Neuroanatomy, like other aspects of anatomy, uses specific terminology to describe anatomical structures. This terminology helps ensure that a structure is described accurately, with minimal ambiguity. Terms also help ensure that structures are described consistently, depending on their structure or function. Terms are often derived from Latin and Greek, and like other areas of anatomy are generally standardised based on internationally accepted lexicons such as Terminologia Anatomica.
To help with consistency, humans and other species are assumed when described to be in standard anatomical position, with the body standing erect and facing observer, arms at sides, palms forward.
Location
Anatomical terms of location depend on the location and species that is being described.
To understand the terms used for anatomical localisation, consider an animal with a straight CNS, such as a fish or lizard. In such animals the terms "rostral", "caudal", "ventral" and "dorsal" mean respectively towards the rostrum, towards the tail, towards the belly and towards the back. For a full discussion of those terms, see anatomical terms of location.
For many purposes of anatomical description, positions and directions are relative to the standard anatomical planes and axes. Such reference to the anatomical planes and axes is called the stereotactic approach.
Standard terms used throughout anatomy include anterior / posterior for the front and back of a structure, superior / inferior for above and below, medial / lateral for structures close to and away from the midline respectively, and proximal / distal for structures close to and far away from a set point.
Some terms are used more commonly in neuroanatomy, particularly:
Rostral and caudal: In animals with linear ne
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Lateral accessory lobes, or LALs are paired, symmetrical, systems of synaptic neuropils that exist in the brains of insects and other arthropods. Lateral accessory lobes are located inferiorly and laterally from ellipsoid body, anteriorly and laterally from the bulb. In the frontal section of the arthropod brain the LALs are projected as two triangles, called lateral triangles. The LALs have roughly pyramidal shape.
Anatomy
The LALs are located behind the antennal lobes and in front of the ventral nervous complex. The two LALs, left and right, are interconnected by the commissure of lateral accessory lobes.
Synonyms
Lateral accessory lobes are synonymous with the ventral part of the inferior dorsofrontal protocerebrum of the arthropod brain.
Physiology and function
There is some evidence that lateral accessory lobes take part in the sensory processing and integration in the arthropod brain.
Proposed homology of the arthropod LAL and the thalamus of the chordates
In 2013, one author published a controversial article equating some parts of arthropod central complex with the basal ganglia of chordates, and the LALs of the arthropods with the nigro-receptive part of the thalamus of chordates. The proposed homology was based on the anatomical analogy in the location of those structures in the brain, on the analogous physiological functions of those structures, and, more importantly, on the patterns of gene expression during embryogenesis and later stages of ontogenesis of those structures.
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The following diagram is provided as an overview of and topical guide to the human nervous system:
Human nervous system – the part of the human body that coordinates a person's voluntary and involuntary actions and transmits signals between different parts of the body. The human nervous system consists of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are long fibers that connect the CNS to every other part of the body. The PNS includes motor neurons, mediating voluntary movement; the autonomic nervous system, comprising the sympathetic nervous system and the parasympathetic nervous system and regulating involuntary functions; and the enteric nervous system, a semi-independent part of the nervous system whose function is to control the gastrointestinal system.
Evolution of the human nervous system
Evolution of nervous systems
Evolution of human intelligence
Evolution of the human brain
Paleoneurology
Some branches of science that study the human nervous system
Neuroscience
Neurology
Paleoneurology
Central nervous system
The central nervous system (CNS) is the largest part of the nervous system and includes the brain and spinal cord.
Spinal cord
Brain
Brain – center of the nervous system.
Outline of the human brain
List of regions of the human brain
Principal regions of the vertebrate brain:
Peripheral nervous system
Peripheral nervous system (PNS) – nervous system structures that do not lie within the CNS.
Sensory system
A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception.
List of sensory systems
Sensory neuron
Perception
Visual system
Auditory system
Somatosensory system
Vestibular system
Olfactory system
Taste
Pain
Components of the nervous system
Neuron
I
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The posterior pituitary is an extension of what anatomical structure?
A. frontal lobe
B. hippocampus
C. brain stem
D. hypothalamus
Answer:
|
|
sciq-10849
|
multiple_choice
|
What is needed by all known forms of life?
|
[
"warmth",
"air",
"water",
"nitrogen"
] |
C
|
Relavent Documents:
Document 0:::
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments.
Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations. Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the scientific method to make observations, pose questions, generate hypotheses, perform experiments, and form conclusions about the world around them.
Life on Earth, which emerged more than 3.7 billion years ago, is immensely diverse. Biologists have sought to study and classify the various forms of life, from prokaryotic organisms such as archaea and bacteria to eukaryotic organisms such as protists, fungi, plants, and animals. These various organisms contribute to the biodiversity of an ecosystem, where they play specialized roles in the cycling of nutrients and energy through their biophysical environment.
History
The earliest of roots of science, which included medicine, can be traced to ancient Egypt and Mesopotamia in around 3000 to 1200 BCE. Their contributions shaped ancient Greek natural philosophy. Ancient Greek philosophers such as Aristotle (384–322 BCE) contributed extensively to the development of biological knowledge. He explored biological causation and the diversity of life. His successor, Theophrastus, began the scienti
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GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 2:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 3:::
The Seven Pillars of Life are the essential principles of life described by Daniel E. Koshland in 2002 in order to create a universal definition of life. One stated goal of this universal definition is to aid in understanding and identifying artificial and extraterrestrial life. The seven pillars are Program, Improvisation, Compartmentalization, Energy, Regeneration, Adaptability, and Seclusion. These can be abbreviated as PICERAS.
The Seven Pillars
Program
Koshland defines "Program" as an "organized plan that describes both the ingredients themselves and the kinetics of the interactions among ingredients as the living system persists through time." In natural life as it is known on Earth, the program operates through the mechanisms of nucleic acids and amino acids, but the concept of program can apply to other imagined or undiscovered mechanisms.
Improvisation
"Improvisation" refers to the living system's ability to change its program in response to the larger environment in which it exists. An example of improvisation on earth is natural selection.
Compartmentalization
"Compartmentalization" refers to the separation of spaces in the living system that allow for separate environments for necessary chemical processes. Compartmentalization is necessary to protect the concentration of the ingredients for a reaction from outside environments.
Energy
Because living systems involve net movement in terms of chemical movement or body movement, and lose energy in those movements through entropy, energy is required for a living system to exist. The main source of energy on Earth is the sun, but other sources of energy exist for life on Earth, such as hydrogen gas or methane, used in chemosynthesis.
Regeneration
"Regeneration" in a living system refers to the general compensation for losses and degradation in the various components and processes in the system. This covers the thermodynamic loss in chemical reactions, the wear and tear of larger parts, and the large
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Planetary habitability is the measure of a planet's or a natural satellite's potential to develop and maintain environments hospitable to life. Life may be generated directly on a planet or satellite endogenously or be transferred to it from another body, through a hypothetical process known as panspermia. Environments do not need to contain life to be considered habitable nor are accepted habitable zones (HZ) the only areas in which life might arise.
As the existence of life beyond Earth is unknown, planetary habitability is largely an extrapolation of conditions on Earth and the characteristics of the Sun and Solar System which appear favorable to life's flourishing. Of particular interest are those factors that have sustained complex, multicellular organisms on Earth and not just simpler, unicellular creatures. Research and theory in this regard is a component of a number of natural sciences, such as astronomy, planetary science and the emerging discipline of astrobiology.
An absolute requirement for life is an energy source, and the notion of planetary habitability implies that many other geophysical, geochemical, and astrophysical criteria must be met before an astronomical body can support life. In its astrobiology roadmap, NASA has defined the principal habitability criteria as "extended regions of liquid water, conditions favorable for the assembly of complex organic molecules, and energy sources to sustain metabolism". In August 2018, researchers reported that water worlds could support life.
Habitability indicators and biosignatures must be interpreted within a planetary and environmental context. In determining the habitability potential of a body, studies focus on its bulk composition, orbital properties, atmosphere, and potential chemical interactions. Stellar characteristics of importance include mass and luminosity, stable variability, and high metallicity. Rocky, wet terrestrial-type planets and moons with the potential for Earth-like chemistry ar
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is needed by all known forms of life?
A. warmth
B. air
C. water
D. nitrogen
Answer:
|
|
sciq-1230
|
multiple_choice
|
What will happen if the gas particles inside an inflated balloon suddenly stop moving?
|
[
"balloon inflates",
"balloon bursts",
"balloon falls",
"balloon deflates"
] |
D
|
Relavent Documents:
Document 0:::
A balloon pops when the material that makes up its surface tears or shreds, creating a hole. Normally, there is a balance of the balloon skin's elastic tension in which every point on the balloon's surface is being pulled by the material surrounding it. However, if a hole is made on the balloon's surface, the force becomes imbalanced, since there is no longer any force exerted by the center of the hole on the material at its edge. As a result, the balloon's surface at the edge of the hole pulls away, making it bigger; the high pressure air can then escape through the hole and the balloon pops. A balloon can be popped by either physical or chemical actions. Limpanuparb et al. use popping a balloon as a demonstration to teach about physical and chemical hazards in laboratory safety.
Physical
A pin or needle is frequently used to pop a balloon. As the needle or pin creates a hole on the balloon surface, the balloon pops. However, if tape is placed on the part where the hole is created, the balloon will not pop since the tape helps reinforce the elastic tension in that area, preventing the edges of the hole pulling away from the center. Likewise, the thick spots of the balloon at the top and the bottom can be pierced by a needle, pin, or even skewer without the balloon popping.
Chemical
Organic solvent
Applying an organic solvent such as toluene onto a balloon's surface can pop it, since the solvent can partially dissolve the material making up the balloon's surface.
cis-1,4-polyisoprene (solid) + organic solvent → cis-1,4-polyisoprene (partly dissolved)
Baby oil can also be applied to water balloons to pop them.
Orange peel
Orange peel contains a compound called limonene which is a hydrocarbon compound similar to the rubber that can be used to make balloons. Based on "like dissolves like" principle, rubber balloons can be dissolved by limonene, popping the balloon. If the balloon is vulcanized (hardened with sulfur), the balloon will not pop.
Gallery
See a
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The two-balloon experiment is an experiment involving interconnected balloons. It is used in physics classes as a demonstration of elasticity.
Two identical balloons are inflated to different diameters and connected by means of a tube. The flow of air through the tube is controlled by a valve or clamp. The clamp is then released, allowing air to flow between the balloons. For many starting conditions, the smaller balloon then gets smaller and the balloon with the larger diameter inflates even more. This result is surprising, since most people assume that the two balloons will have equal sizes after exchanging air.
The behavior of the balloons in the two-balloon experiment was first explained theoretically by David Merritt and Fred Weinhaus in 1978.
Theoretical pressure curve
The key to understanding the behavior of the balloons is understanding how the pressure inside a balloon varies with the balloon's diameter. The simplest way to do this is to imagine that the balloon is made up of a large number of small rubber patches, and to analyze how the size of a patch is affected by the force acting on it.
The Karan–Guth stress-strain relation for a parallelepiped of ideal rubber can be written
Here, fi is the externally applied force in the i'''th direction, Li is a linear dimension, k is Boltzmann's constant,K is a constant related to the number of possible network configurations of the sample, T is the absolute temperature,Li0 is an unstretched dimension, p is the internal (hydrostatic) pressure, and V is the volume of the sample. Thus, the force consists of two parts: the first one (caused by the polymer network) gives a tendency to contract, while the second gives a tendency to expand.
Suppose that the balloon is composed of many such interconnected patches, which deform in a similar way as the balloon expands. Because rubber strongly resists volume changes, the volume V can be considered constant. This allows the stress-strain relation to be written
where
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
A thermogravitational cycle is a reversible thermodynamic cycle using the gravitational works of weight and buoyancy to respectively compress and expand a working fluid.
Theoretical framework
Consider a column filled with a transporting medium and a balloon filled with a working fluid. Due to the hydrostatic pressure of the transporting medium, the pressure inside the column increases along the z axis (see figure). Initially, the balloon is inflated by the working fluid at temperature TC and pressure P0 and located on top of the column. A thermogravitational cycle is decomposed into four ideal steps:
1→2: Descent of the balloon towards the bottom of the column. The working fluid undergoes adiabatic compression with its temperature increasing and its pressure reaching value Ph at the bottom (Ph>P0).
2→3: While the ballon lays at the bottom, the working fluid receives heat from the hot source at temperature TH and undergoes isobaric expansion at pressure Ph.
3→4: The balloon rises towards the column top. The working fluid undergoes adiabatic expansion with a drop in temperature and reaches pressure P0 after expansion when the balloon is on top.
4→1: Once arrived on top, the working fluid supplies heat to the cold source at temperature TC while undergoing isobaric compression at pressure P0.
For a thermogravitational cycle to occur, the balloon has to be denser than the transporting medium during 1→2 step and less dense during 3→4 step. If these conditions are not naturally satisfied by the working fluid, a weight can be attached to the balloon to increase its effective mass density.
Applications and examples
An experimental device working according to thermogravitational cycle principle was developed in a laboratory of the University of Bordeaux and patented in France. Such thermogravitational electric generator is based on inflation and deflation cycles of an elastic bag made of nitrile elastomer cut from a glove finger. The bag is filled with a volatile
Document 4:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What will happen if the gas particles inside an inflated balloon suddenly stop moving?
A. balloon inflates
B. balloon bursts
C. balloon falls
D. balloon deflates
Answer:
|
|
sciq-7504
|
multiple_choice
|
Which season is moist, causing the most thunderstorms?
|
[
"autumn",
"winter",
"spring",
"summer"
] |
D
|
Relavent Documents:
Document 0:::
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. (see also: List of meteorological phenomena)
A
advection
aeroacoustics
aerobiology
aerography (meteorology)
aerology
air parcel (in meteorology)
air quality index (AQI)
airshed (in meteorology)
American Geophysical Union (AGU)
American Meteorological Society (AMS)
anabatic wind
anemometer
annular hurricane
anticyclone (in meteorology)
apparent wind
Atlantic Oceanographic and Meteorological Laboratory (AOML)
Atlantic hurricane season
atmometer
atmosphere
Atmospheric Model Intercomparison Project (AMIP)
Atmospheric Radiation Measurement (ARM)
(atmospheric boundary layer [ABL]) planetary boundary layer (PBL)
atmospheric chemistry
atmospheric circulation
atmospheric convection
atmospheric dispersion modeling
atmospheric electricity
atmospheric icing
atmospheric physics
atmospheric pressure
atmospheric sciences
atmospheric stratification
atmospheric thermodynamics
atmospheric window (see under Threats)
B
ball lightning
balloon (aircraft)
baroclinity
barotropity
barometer ("to measure atmospheric pressure")
berg wind
biometeorology
blizzard
bomb (meteorology)
buoyancy
Bureau of Meteorology (in Australia)
C
Canada Weather Extremes
Canadian Hurricane Centre (CHC)
Cape Verde-type hurricane
capping inversion (in meteorology) (see "severe thunderstorms" in paragraph 5)
carbon cycle
carbon fixation
carbon flux
carbon monoxide (see under Atmospheric presence)
ceiling balloon ("to determine the height of the base of clouds above ground level")
ceilometer ("to determine the height of a cloud base")
celestial coordinate system
celestial equator
celestial horizon (rational horizon)
celestial navigation (astronavigation)
celestial pole
Celsius
Center for Analysis and Prediction of Storms (CAPS) (in Oklahoma in the US)
Center for the Study o
Document 1:::
The following outline is provided as an overview of and topical guide to the field of Meteorology.
Meteorology The interdisciplinary, scientific study of the Earth's atmosphere with the primary focus being to understand, explain, and forecast weather events. Meteorology, is applied to and employed by a wide variety of diverse fields, including the military, energy production, transport, agriculture, and construction.
Essence of meteorology
Meteorology
Climate – the average and variations of weather in a region over long periods of time.
Meteorology – the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting (in contrast with climatology).
Weather – the set of all the phenomena in a given atmosphere at a given time.
Branches of meteorology
Microscale meteorology – the study of atmospheric phenomena about 1 km or less, smaller than mesoscale, including small and generally fleeting cloud "puffs" and other small cloud features
Mesoscale meteorology – the study of weather systems about 5 kilometers to several hundred kilometers, smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems, skjjoch as sea breezes, squall lines, and mesoscale convective complexes
Synoptic scale meteorology – is a horizontal length scale of the order of 1000 kilometres (about 620 miles) or more
Methods in meteorology
Surface weather analysis – a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations
Weather forecasting
Weather forecasting – the application of science and technology to predict the state of the atmosphere for a future time and a given location
Data collection
Pilot Reports
Weather maps
Weather map
Surface weather analysis
Forecasts and reporting of
Atmospheric pressure
Dew point
High-pressure area
Ice
Black ice
Frost
Low-pressure area
Precipitation
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
PERSIANN, "Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks", is a satellite-based precipitation retrieval algorithm that provides near real-time rainfall information. The algorithm uses infrared (IR) satellite data from global geosynchronous satellites as the primary source of precipitation information. Precipitation from IR images is based on statistical relationship between cloud top temperature and precipitation rates. The IR-based precipitation estimates are then calibrated using satellite microwave data available from low Earth orbit satellites (e.g., Tropical Rainfall Measuring Mission Microwave Imager, Special Sensor Microwave Imager, Advanced Microwave Scanning Radiometer‐Earth observing system). The calibration technique relies on an adaptive training algorithm that updates the retrieval parameters when microwave observations become available (approximately at 3 hours intervals).
The PERSIANN satellite precipitation data sets have been validated with ground-based observations and other satellite data products. The PERSIANN data has been used in a wide variety of studies including hydrologic modeling, drought monitoring, soil moisture analysis, and flood forecasting. The PERSIANN data are freely available to the public.
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which season is moist, causing the most thunderstorms?
A. autumn
B. winter
C. spring
D. summer
Answer:
|
|
sciq-1364
|
multiple_choice
|
What occurs in a formerly inhabited area that was disturbed?
|
[
"natural selection",
"mass extinction",
"secondary succession",
"spontaneous mutation"
] |
C
|
Relavent Documents:
Document 0:::
Urban evolution refers to the heritable genetic changes of populations in response to urban development and anthropogenic activities in urban areas. Urban evolution can be caused by mutation, genetic drift, gene flow, or evolution by natural selection. Biologists have observed evolutionary change in numerous species compared to their rural counterparts on a relatively short timescale.
Strong selection pressures due to urbanization play a big role in this process. The changed environmental conditions lead to selection and adaptive changes in city-dwelling plants and animals. Also, there is a significant change in species composition between rural and urban ecosystems.
Shared aspects of cities worldwide also give ample opportunity for scientists to study the specific evolutionary responses in these rapidly changed landscapes independently. How certain organisms (are able to) adapt to urban environments while others cannot, gives a live perspective on rapid evolution.
Urbanization
With urban growth, the urban-rural gradient has seen a large shift in distribution of humans, moving from low density to very high in the last millennia. This has brought a large change to environments as well as societies.
Urbanization transforms natural habitats to completely altered living spaces that sustain large human populations. Increasing congregation of humans accompanies the expansion of infrastructure, industry and housing. Natural vegetation and soil are mostly replaced or covered by dense grey materials. Urbanized areas continue to expand both in size and number globally; in 2018, the United Nations estimated that 68% of people globally will live in ever-larger urban areas by 2050.
Urban evolution selective agents
Urbanization intensifies diverse stressors spatiotemporally such that they can act in concert to cause rapid evolutionary consequences such as extinction, maladaptation, or adaptation. Three factors have come to the forefront as the main evolutionary influencer
Document 1:::
Ian Gordon Simmons (born 22 January 1937) is a British geographer. He retired as Professor of Geography from the University of Durham in 2001. He has made significant contributions to environmental history and prehistoric archaeology.
Background
Simmons grew up in East London and then East Lincolnshire until the age of 12. He studied physical geography (BSc) and holds a PhD from the University of London (early 1960s) on the vegetation history of Dartmoor. He began university lecturing in his early 20s and was Lecturer and then Reader in Geography at the University of Durham from 1962 to 1977, then Professor of Geography at the University of Bristol from 1977 to 1981 before returning to a Chair in Geography at Durham, where he worked until retiring in 2001.
In 1972–73, he taught biogeography for a year at York University, Canada and has held other appointments including Visiting Scholar, St. John's College, University of Oxford in the 1990s. Previously, he had been an ACLS postdoctoral fellow at the University of California, Berkeley.
Scholarship
His research includes the study of the later Mesolithic and early Neolithic in their environmental setting on English uplands, where he has demonstrated the role of these early human communities in initiating some of Britain's characteristic landscape elements. His work also encompasses the long-term effects of human manipulation of the natural environment and its consequences for resource use and environmental change. This line of work resulted in his last three books, which looked at environmental history on three nested scales: the moorlands of England and Wales, Great Britain, and the Globe. Each dealt with the last 10,000 years and tried to encompassboth conventional science-based data with the insights of the social sciences and humanities.
Simmons has authored several books on environmental thought and culture over the ages as well as contemporary resource management and environmental problems. Since retireme
Document 2:::
The history of life on Earth is closely associated with environmental change on multiple spatial and temporal scales. Climate change is a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates. These changes have a broad range of observed effects that are synonymous with the term. Climate change is any significant long term change in the expected pattern, whether due to natural variability or as a result of human activity. Predicting the effects that climate change will have on plant biodiversity can be achieved using various models, however bioclimatic models are most commonly used.
Environmental conditions play a key role in defining the function and geographic distributions of plants, in combination with other factors, thereby modifying patterns of biodiversity. Changes in long term environmental conditions that can be collectively coined climate change are known to have had enormous impacts on current plant diversity patterns; further impacts are expected in the future. It is predicted that climate change will remain one of the major drivers of biodiversity patterns in the future. Climate change is thought to be one of several factors causing the currently ongoing human-triggered mass extinction, which is changing the distribution and abundance of many plants.
Palaeo context
The Earth has experienced a constantly changing climate in the time since plants first evolved. In comparison to the present day, this history has seen Earth as cooler, warmer, drier and wetter, and (carbon dioxide) concentrations have been both higher and lower. These changes have been reflected by constantly shifting vegetation, for example forest communities dominating most areas in interglacial periods, and herbaceous communities dominating during glacial periods. It has been shown through fossil records that past climatic change has been a major driver of the processes of speciation and extinction. The best known example
Document 3:::
The Institute for Biodiversity and Ecosystem Dynamics (IBED) is one of the ten research institutes of the Faculty of Science of the Universiteit van Amsterdam. IBED employs more than 100 researchers, with PhD students and Postdocs forming a majority, and 30 supporting staff. The total annual budget is around 10 m€, of which more than 40 per cent comes from external grants and contracts. The main output consist of publications in peer reviewed journals and books (on average 220 per year). Each year around 15 PhD students defend their thesis and obtain their degree from the Universiteit van Amsterdam. The institute is managed by a general director appointed by the Dean of the Faculty for a period of five years, assisted by a business manager.
Mission statement
The mission of the Institute for Biodiversity and Ecosystem Dynamics is to increase our insights in the functioning and biodiversity of ecosystems in all their complexity. Knowledge of the interactions between living organisms and processes in their physical and chemical environment is essential for a better understanding of the dynamics of ecosystems at different temporal and spatial scales.
Organization of IBED Research
IBED research is organized in the following three themes:
Theme I: Biodiversity and Evolution
The main question of Theme I research is how patterns in biodiversity can be explained from underlying processes: speciation and extinction, dispersal and the (dis)appearance of geographical barriers, reproductive isolation and hybridisation of taxa. Modern reconstructions of the history of life on earth rely heavily on analyses of DNA data that contain the footprints of the past. Research related to human-made effects on biodiversity includes the identification of endangered biodiversity hotspots affected by global change, potential risks of an escape of transgenes from crops to wild species, and the consequences of habitat fragmentation for the viability and genetic diversity of populations and
Document 4:::
A natural phenomenon is an observable event which is not man-made. Examples include: sunrise, weather, fog, thunder, tornadoes; biological processes, decomposition, germination; physical processes, wave propagation, erosion; tidal flow, and natural disasters such as electromagnetic pulses, volcanic eruptions, hurricanes and earthquakes.
History
Over many intervals of time, natural phenomena have been observed by a series of countless events as a feature created by nature.
Physical phenomena
The act of:
Freezing
Boiling
Gravity
Magnetism
Gallery
Chemical phenomena
Oxidation
Fire
Rusting
Biological phenomena
Metabolism
Catabolism
Anabolism
Decomposition – by which organic substances are broken down into a much simpler form of matter
Fermentation – converts sugar to acids, gases and/or alcohol.
Growth
Birth
Death
Population decrease
Gallery
Astronomical phenomena
Supernova
Gamma ray bursts
Quasars
Blazars
Pulsars
Cosmic microwave background radiation.
Geological phenomena
Mineralogic phenomena
Lithologic phenomena
Rock types
Igneous rock
Igneous formation processes
Sedimentary rock
Sedimentary formation processes (sedimentation)
Quicksand
Metamorphic rock
Endogenic phenomena
Plate tectonics
Continental drift
Earthquake
Oceanic trench
Phenomena associated with igneous activity
Geysers and hot springs
Bradyseism
Volcanic eruption
Earth's magnetic field
Exogenic phenomena
Slope phenomena
Slump
Landslide
Weathering phenomena
Erosion
Glacial and peri-glacial phenomena
Glaciation
Moraines
Hanging valleys
Atmospheric phenomena
Impact phenomena
Impact crater
Coupled endogenic-exogenic phenomena
Orogeny
Drainage development
Stream capture
Gallery
Meteorological phenomena
Violent meteorological phenomena are called storms. Regular, cyclical phenomena include seasons and atmospheric circulation. climate change is often semi-regular.
Atmospheric optical phenomena
Oceanographic
Oceanographic phenomena inc
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What occurs in a formerly inhabited area that was disturbed?
A. natural selection
B. mass extinction
C. secondary succession
D. spontaneous mutation
Answer:
|
|
sciq-8559
|
multiple_choice
|
What is the addition of oxygen to a molecule or the removal of hydrogen from a molecule called?
|
[
"oxidation",
"ionization",
"precipitation",
"evaporation"
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applications for this science is in studying the thermodynamics and kinetics of reactions. For example, one application is in studying the thermodynamics of the solvation of ions. Ions with small solvation spheres of 1, 2, 3... solvent molecules can be studied in the gas phase and then extrapolated to bulk solution.
Theory
Transition state theory
Transition state theory is the theory of the rates of elementary reactions which assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated complexes.
RRKM theory
RRKM theory is used to compute simple estimates of the unimolecular ion decomposition reaction rates from a few characteristics of the potential energy surface.
Gas phase ion formation
The process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions can occur in the gas phase. These processes are an important component of gas phase ion chemistry.
Associative ionization
Associative ionization is a gas phase reaction in which two atoms or molecules interact to form a single product ion.
where species A with excess internal energy (indicated by the asterisk) interacts with B to form the ion AB+.
One or both of the interacting species may have excess internal energy.
Charge-exchange ionization
Charge-exchange ionization (also called charge-transfer ionization) is a gas phase reaction between an ion and a neutral species
in which the charge of the ion is transferred to the neutral.
Chemical ionization
In chemical ionization, ions are produced through the reaction of ions of a reagent gas with other species. Some common reagent gases include: methane, ammonia, and isobutane.
Chemi-ionization
Chemi-ionization can
Document 2:::
Classification
Oxidoreductases are classified as EC 1 in the EC number classification of enzymes. Oxidoreductases can be further classified into 21 subclasses:
EC 1.1 includes oxidoreductases that act on the CH-OH group of donors (alcohol oxidoreductases such as methanol dehydrogenase)
EC 1.2 includes oxidoreductases that act on the aldehyde or oxo group of donors
EC 1.3 includes oxidoreductases that act on the CH-CH group of donors (CH-CH oxidore
Document 3:::
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually utilizes NADP+ or NAD+ as cofactors. Transmembrane oxidoreductases create electron transport chains in bacteria, chloroplasts and mitochondria, including respiratory complexes I, II and III. Some others can associate with biological membranes as peripheral membrane proteins or be anchored to the membranes through a single transmembrane helix.
Reactions
For example, an enzyme that catalyzed this reaction would be an oxidoreductase:
A– + B → A + B–
In this example, A is the reductant (electron donor) and B is the oxidant (electron acceptor).
In biochemical reactions, the redox reactions are sometimes more difficult to see, such as this reaction from glycolysis:
Pi + glyceraldehyde-3-phosphate + NAD+ → NADH + H+ + 1,3-bisphosphoglycerate
In this reaction, NAD+ is the oxidant (electron acceptor), and glyceraldehyde-3-phosphate is the reductant (electron donor).
Nomenclature
Proper names of oxidoreductases are formed as "donor:acceptor oxidoreductase"; however, other names are much more common. The common name is "donor dehydrogenase" when possible, such as glyceraldehyde-3-phosphate dehydrogenase for the second reaction above. Common names are also sometimes formed as "acceptor reductase", such as NAD+ reductase. "Donor oxidase" is a special case where O2 is the acceptor.
Document 4:::
Hydrogen–deuterium exchange (also called H–D or H/D exchange) is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium source, without any catalyst. The use of acid, base or metal catalysts, coupled with conditions of increased temperature and pressure, can facilitate the exchange of non-exchangeable hydrogen atoms, so long as the substrate is robust to the conditions and reagents employed. This often results in perdeuteration: hydrogen-deuterium exchange of all non-exchangeable hydrogen atoms in a molecule.
An example of exchangeable protons which are commonly examined in this way are the protons of the amides in the backbone of a protein. The method gives information about the solvent accessibility of various parts of the molecule, and thus the tertiary structure of the protein. The theoretical framework for understanding hydrogen exchange in proteins was first described by Kaj Ulrik Linderstrøm-Lang and he was the first to apply H/D exchange to study proteins.
Exchange reaction
In protic solution exchangeable protons such as those in hydroxyl or amine group exchange protons with the solvent. If D2O is solvent, deuterons will be incorporated at these positions. The exchange reaction can be followed using a variety of methods (see Detection). Since this exchange is an equilibrium reaction, the molar amount of deuterium should be high compared to the exchangeable protons of the substrate. For instance, deuterium is added to a protein in H2O by diluting the H2O solution with D2O (e.g. tenfold). Usually exchange is performed at physiological pH (7.0–8.0) where proteins are in their most native ensemble of conformational states.
The H/D exchange reaction can also be catalysed, by acid, base or metal catalysts such as platinum. For the backbone amide hydrogen atoms of p
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the addition of oxygen to a molecule or the removal of hydrogen from a molecule called?
A. oxidation
B. ionization
C. precipitation
D. evaporation
Answer:
|
|
ai2_arc-486
|
multiple_choice
|
A student is standing on a skateboard that is not moving. The total mass of the student and the skateboard is 50 kilograms. The student throws a ball with a mass of 2 kilograms forward at 5 m/s. Assuming the skateboard wheels are frictionless, how will the student and the skateboard move?
|
[
"forward at 0.4 m/s",
"forward at 5 m/s",
"backward at 0.2 m/s",
"backward at 5 m/s"
] |
D
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Advanced Placement (AP) Physics C: Mechanics (also known as AP Mechanics) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester calculus-based university course in mechanics. The content of Physics C: Mechanics overlaps with that of AP Physics 1, but Physics 1 is algebra-based, while Physics C is calculus-based. Physics C: Mechanics may be combined with its electricity and magnetism counterpart to form a year-long course that prepares for both exams.
Course content
Intended to be equivalent to an introductory college course in mechanics for physics or engineering majors, the course modules are:
Kinematics
Newton's laws of motion
Work, energy and power
Systems of particles and linear momentum
Circular motion and rotation
Oscillations and gravitation.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a Calculus I class.
This course is often compared to AP Physics 1: Algebra Based for its similar course material involving kinematics, work, motion, forces, rotation, and oscillations. However, AP Physics 1: Algebra Based lacks concepts found in Calculus I, like derivatives or integrals.
This course may be combined with AP Physics C: Electricity and Magnetism to make a unified Physics C course that prepares for both exams.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Mechanics is separate from the AP examination for AP Physics C: Electricity and Magnetism. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday aftern
Document 2:::
There are four Advanced Placement (AP) Physics courses administered by the College Board as part of its Advanced Placement program: the algebra-based Physics 1 and Physics 2 and the calculus-based Physics C: Mechanics and Physics C: Electricity and Magnetism. All are intended to be at the college level. Each AP Physics course has an exam for which high-performing students may receive credit toward their college coursework.
AP Physics 1 and 2
AP Physics 1 and AP Physics 2 were introduced in 2015, replacing AP Physics B. The courses were designed to emphasize critical thinking and reasoning as well as learning through inquiry. They are algebra-based and do not require any calculus knowledge.
AP Physics 1
AP Physics 1 covers Newtonian mechanics, including:
Unit 1: Kinematics
Unit 2: Dynamics
Unit 3: Circular Motion and Gravitation
Unit 4: Energy
Unit 5: Momentum
Unit 6: Simple Harmonic Motion
Unit 7: Torque and Rotational Motion
Until 2020, the course also covered topics in electricity (including Coulomb's Law and resistive DC circuits), mechanical waves, and sound. These units were removed because they are included in AP Physics 2.
AP Physics 2
AP Physics 2 covers the following topics:
Unit 1: Fluids
Unit 2: Thermodynamics
Unit 3: Electric Force, Field, and Potential
Unit 4: Electric Circuits
Unit 5: Magnetism and Electromagnetic Induction
Unit 6: Geometric and Physical Optics
Unit 7: Quantum, Atomic, and Nuclear Physics
AP Physics C
From 1969 to 1972, AP Physics C was a single course with a single exam that covered all standard introductory university physics topics, including mechanics, fluids, electricity and magnetism, optics, and modern physics. In 1973, the College Board split the course into AP Physics C: Mechanics and AP Physics C: Electricity and Magnetism. The exam was also split into two separate 90-minute tests, each equivalent to a semester-length calculus-based college course. Until 2006, both exams could be taken for a single
Document 3:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 4:::
Advanced Placement (AP) Physics 1 is a year-long introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester algebra-based university course in mechanics. Along with AP Physics 2, the first AP Physics 1 exam was administered in 2015.
In its first five years, AP Physics 1 covered forces and motion, conservation laws, waves, and electricity. As of 2021, AP Physics 1 includes mechanics topics only.
History
The heavily computational AP Physics B course served for four decades as the College Board's algebra-based offering. As part of the College Board's redesign of science courses, AP Physics B was discontinued; therefore, AP Physics 1 and 2 were created with guidance from the National Research Council and the National Science Foundation. The course covers material of a first-semester university undergraduate physics course offered at American universities that use best practices of physics pedagogy. The first AP Physics 1 classes had begun in the 2014–2015 school year, with the first AP exams administered in May 2015.
Curriculum
AP Physics 1 is an algebra-based, introductory college-level physics course that includes mechanics topics such as motion, force, momentum, energy, harmonic motion, and rotation; The College Board published a curriculum framework that includes seven big ideas on which the AP Physics 1 and 2 courses are based, along with "enduring understandings" students are expected to acquire within each of the big ideas.:
Questions for the exam are constructed with direct reference to items in the curriculum framework. Student understanding of each topic is tested with reference to multiple skills—that is, questions require students to use quantitative, semi-quantitative, qualitative, and experimental reasoning in each content area.
Exam
Science Practices Assessed
Multiple Choice and Free Response Sections of the AP® Physics 1 exam are also assessed on scientific prac
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A student is standing on a skateboard that is not moving. The total mass of the student and the skateboard is 50 kilograms. The student throws a ball with a mass of 2 kilograms forward at 5 m/s. Assuming the skateboard wheels are frictionless, how will the student and the skateboard move?
A. forward at 0.4 m/s
B. forward at 5 m/s
C. backward at 0.2 m/s
D. backward at 5 m/s
Answer:
|
|
ai2_arc-427
|
multiple_choice
|
A bowling ball with a mass of 8.0 kg rolls down a bowling lane at 2.0 m/s. What is the momentum of the bowling ball?
|
[
"4.0 kg x m/s",
"6.0 kg x m/s",
"10.0 kg x m/s",
"16.0 kg x m/s"
] |
D
|
Relavent Documents:
Document 0:::
Advanced Placement (AP) Physics C: Mechanics (also known as AP Mechanics) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester calculus-based university course in mechanics. The content of Physics C: Mechanics overlaps with that of AP Physics 1, but Physics 1 is algebra-based, while Physics C is calculus-based. Physics C: Mechanics may be combined with its electricity and magnetism counterpart to form a year-long course that prepares for both exams.
Course content
Intended to be equivalent to an introductory college course in mechanics for physics or engineering majors, the course modules are:
Kinematics
Newton's laws of motion
Work, energy and power
Systems of particles and linear momentum
Circular motion and rotation
Oscillations and gravitation.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a Calculus I class.
This course is often compared to AP Physics 1: Algebra Based for its similar course material involving kinematics, work, motion, forces, rotation, and oscillations. However, AP Physics 1: Algebra Based lacks concepts found in Calculus I, like derivatives or integrals.
This course may be combined with AP Physics C: Electricity and Magnetism to make a unified Physics C course that prepares for both exams.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Mechanics is separate from the AP examination for AP Physics C: Electricity and Magnetism. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday aftern
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 3:::
Advanced Placement (AP) Physics B was a physics course administered by the College Board as part of its Advanced Placement program. It was equivalent to a year-long introductory university course covering Newtonian mechanics, electromagnetism, fluid mechanics, thermal physics, waves, optics, and modern physics. The course was algebra-based and heavily computational; in 2015, it was replaced by the more concept-focused AP Physics 1 and AP Physics 2.
Exam
The exam consisted of a 70 MCQ section, followed by a 6-7 FRQ section. Each section was 90 minutes and was worth 50% of the final score. The MCQ section banned calculators, while the FRQ allowed calculators and a list of common formulas. Overall, the exam was configured to approximately cover a set percentage of each of the five target categories:
Purpose
According to the College Board web site, the Physics B course provided "a foundation in physics for students in the life sciences, a pre medical career path, and some applied sciences, as well as other fields not directly related to science."
Discontinuation
Starting in the 2014–2015 school year, AP Physics B was no longer offered, and AP Physics 1 and AP Physics 2 took its place. Like AP Physics B, both are algebra-based, and both are designed to be taught as year-long courses.
Grade distribution
The grade distributions for the Physics B scores from 2010 until its discontinuation in 2014 are as follows:
Document 4:::
There are four Advanced Placement (AP) Physics courses administered by the College Board as part of its Advanced Placement program: the algebra-based Physics 1 and Physics 2 and the calculus-based Physics C: Mechanics and Physics C: Electricity and Magnetism. All are intended to be at the college level. Each AP Physics course has an exam for which high-performing students may receive credit toward their college coursework.
AP Physics 1 and 2
AP Physics 1 and AP Physics 2 were introduced in 2015, replacing AP Physics B. The courses were designed to emphasize critical thinking and reasoning as well as learning through inquiry. They are algebra-based and do not require any calculus knowledge.
AP Physics 1
AP Physics 1 covers Newtonian mechanics, including:
Unit 1: Kinematics
Unit 2: Dynamics
Unit 3: Circular Motion and Gravitation
Unit 4: Energy
Unit 5: Momentum
Unit 6: Simple Harmonic Motion
Unit 7: Torque and Rotational Motion
Until 2020, the course also covered topics in electricity (including Coulomb's Law and resistive DC circuits), mechanical waves, and sound. These units were removed because they are included in AP Physics 2.
AP Physics 2
AP Physics 2 covers the following topics:
Unit 1: Fluids
Unit 2: Thermodynamics
Unit 3: Electric Force, Field, and Potential
Unit 4: Electric Circuits
Unit 5: Magnetism and Electromagnetic Induction
Unit 6: Geometric and Physical Optics
Unit 7: Quantum, Atomic, and Nuclear Physics
AP Physics C
From 1969 to 1972, AP Physics C was a single course with a single exam that covered all standard introductory university physics topics, including mechanics, fluids, electricity and magnetism, optics, and modern physics. In 1973, the College Board split the course into AP Physics C: Mechanics and AP Physics C: Electricity and Magnetism. The exam was also split into two separate 90-minute tests, each equivalent to a semester-length calculus-based college course. Until 2006, both exams could be taken for a single
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A bowling ball with a mass of 8.0 kg rolls down a bowling lane at 2.0 m/s. What is the momentum of the bowling ball?
A. 4.0 kg x m/s
B. 6.0 kg x m/s
C. 10.0 kg x m/s
D. 16.0 kg x m/s
Answer:
|
|
sciq-1855
|
multiple_choice
|
What kind of muscle is responsible for hollow organs contracting?
|
[
"micro muscle",
"smooth muscle",
"tough muscle",
"rough muscle"
] |
B
|
Relavent Documents:
Document 0:::
Anatomical terminology is used to uniquely describe aspects of skeletal muscle, cardiac muscle, and smooth muscle such as their actions, structure, size, and location.
Types
There are three types of muscle tissue in the body: skeletal, smooth, and cardiac.
Skeletal muscle
Skeletal muscle, or "voluntary muscle", is a striated muscle tissue that primarily joins to bone with tendons. Skeletal muscle enables movement of bones, and maintains posture. The widest part of a muscle that pulls on the tendons is known as the belly.
Muscle slip
A muscle slip is a slip of muscle that can either be an anatomical variant, or a branching of a muscle as in rib connections of the serratus anterior muscle.
Smooth muscle
Smooth muscle is involuntary and found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and feces in the former and urine in the latter. Other places smooth muscle can be found are within the uterus, where it helps facilitate birth, and the eye, where the pupillary sphincter controls pupil size.
Cardiac muscle
Cardiac muscle is specific to the heart. It is also involuntary in its movement, and is additionally self-excitatory, contracting without outside stimuli.
Actions of skeletal muscle
As well as anatomical terms of motion, which describe the motion made by a muscle, unique terminology is used to describe the action of a set of muscles.
Agonists and antagonists
Agonist muscles and antagonist muscles are muscles that cause or inhibit a movement.
Agonist muscles are also called prime movers since they produce most of the force, and control of an action. Agonists cause a movement to occur through their own activation. For example, the triceps brachii contracts, producing a shortening (concentric) contraction, during the up phase of a push-up (elbow extension). During the down phase of a push-up, th
Document 1:::
Myology is the study of the muscular system, including the study of the structure, function and diseases of muscle. The muscular system consists of skeletal muscle, which contracts to move or position parts of the body (e.g., the bones that articulate at joints), smooth and cardiac muscle that propels, expels or controls the flow of fluids and contained substance.
See also
Myotomy
Oral myology
Document 2:::
Vertebrates
Tendon cells, or tenocytes, are elongated fibroblast type cells. The cytoplasm is stretched between the collagen fibres of the tendon. They have a central cell nucleus with a prominent nucleolus. Tendon cells have a well-developed rough endoplasmic reticulum and they are responsible for synthesis and turnover of tendon fibres and ground substance.
Invertebrates
Tendon cells form a connecting epithelial layer between the muscle and shell in molluscs. In gastropods, for example, the retractor muscles connect to the shell via tendon cells. Muscle cells are attached to the collagenous myo-tendon space via hemidesmosomes. The myo-tendon space is then attached to the base of the tendon cells via basal hemidesmosomes, while apical hemidesmosomes, which sit atop microvilli, attach the tendon cells to a thin layer of collagen. This is in turn attached to the shell via organic fibres which insert into the shell. Molluscan tendon cells appear columnar and contain a large basal cell nucleus. The cytoplasm is filled with granular endoplasmic reticulum and sparse golgi. Dense bundles of microfilaments run the length of the cell connecting the basal to the apical hemidesmosomes.
See also
List of human cell types derived from the germ layers
List of distinct cell types in the adult human body
Document 3:::
Instruments used in Anatomy dissections are as follows:
Instrument list
Image gallery
Document 4:::
In an isotonic contraction, tension remains the same, whilst the muscle's length changes. Isotonic contractions differ from isokinetic contractions in that in isokinetic contractions the muscle speed remains constant. While superficially identical, as the muscle's force changes via the length-tension relationship during a contraction, an isotonic contraction will keep force constant while velocity changes, but an isokinetic contraction will keep velocity constant while force changes. A near isotonic contraction is known as Auxotonic contraction.
There are two types of isotonic contractions: (1) concentric and (2) eccentric. In a concentric contraction, the muscle tension rises to meet the resistance, then remains the same as the muscle shortens. In eccentric, the muscle lengthens due to the resistance being greater than the force the muscle is producing.
Concentric
This type is typical of most exercise. The external force on the muscle is less than the force the muscle is generating - a shortening contraction. The effect is not visible during the classic biceps curl, which is in fact auxotonic because the resistance (torque due to the weight being lifted) does not remain the same through the exercise. Tension is highest at a parallel to the floor level, and eases off above and below this point. Therefore, tension changes as well as muscle length.
Eccentric
There are two main features to note regarding eccentric contractions. First, the absolute tensions achieved can be very high relative to the muscle's maximum tetanic tension generating capacity (you can set down a much heavier object than you can lift). Second, the absolute tension is relatively independent of lengthening velocity.
Muscle injury and soreness are selectively associated with eccentric contraction. Muscle strengthening using exercises that involve eccentric contractions is lower than using concentric exercises. However because higher levels of tension are easier to attain during exercises th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of muscle is responsible for hollow organs contracting?
A. micro muscle
B. smooth muscle
C. tough muscle
D. rough muscle
Answer:
|
|
sciq-1993
|
multiple_choice
|
What are bacteria and archaea examples of?
|
[
"prokaryotes",
"fungi",
"eukaryotes",
"plants"
] |
A
|
Relavent Documents:
Document 0:::
Archaea ( ; : archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use.
Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. It is unknown if these are able to produce endospores.
Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of Haloquadratum walsbyi. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes involved in transcription and translation. Other aspects of archaeal biochemistry are unique, such as their reliance on ether lipids in their cell membranes, including archaeols. Archaea use more diverse energy sources than eukaryotes, ranging from organic compounds such as sugars, to ammonia, metal ions or even hydrogen gas. The salt-tolerant Haloarchaea use sunlight as an energy source, and other species of archaea fix carbon (autotrophy), but unlike plants and cyanobacteria, no known species of archaea does both. Archaea reproduce asexually by binary fission, fragmentation, or budding; unlike bacteria, no known species of Archaea form endospores.
The first observed archaea were extremophiles, living in extreme environments such as hot springs and salt lakes with no other organisms. Improved molecular detection tools led to the discovery of archaea in almost every habitat, including soil, oceans, and marshlands. Archaea are particularly numerous in the oceans, and
Document 1:::
Microbiology () is the scientific study of microorganisms, those being of unicellular (single-celled), multicellular (consisting of complex cells), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, protistology, mycology, immunology, and parasitology.
Eukaryotic microorganisms possess membrane-bound organelles and include fungi and protists, whereas prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and include Bacteria and Archaea. Microbiologists traditionally relied on culture, staining, and microscopy for the isolation and identification of microorganisms. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means. With the emergence of biotechnology, Microbiologists currently rely on molecular biology tools such as DNA sequence-based identification, for example, the 16S rRNA gene sequence used for bacterial identification.
Viruses have been variably classified as organisms, as they have been considered either as very simple microorganisms or very complex molecules. Prions, never considered as microorganisms, have been investigated by virologists, however, as the clinical effects traced to them were originally presumed due to chronic viral infections, virologists took a search—discovering "infectious proteins".
The existence of microorganisms was predicted many centuries before they were first observed, for example by the Jains in India and by Marcus Terentius Varro in ancient Rome. The first recorded microscope observation was of the fruiting bodies of moulds, by Robert Hooke in 1666, but the Jesuit priest Athanasius Kircher was likely the first to see microbes, which he mentioned observing in milk and putrid material in 1658. Antonie van Leeuwenhoek is considered a father of microbiology as he observed and experimented with microscopic organisms in the 1670s, us
Document 2:::
The bacterium, despite its simplicity, contains a well-developed cell structure which is responsible for some of its unique biological structures and pathogenicity. Many structural features are unique to bacteria and are not found among archaea or eukaryotes. Because of the simplicity of bacteria relative to larger organisms and the ease with which they can be manipulated experimentally, the cell structure of bacteria has been well studied, revealing many biochemical principles that have been subsequently applied to other organisms.
Cell morphology
Perhaps the most elemental structural property of bacteria is their morphology (shape). Typical examples include:
coccus (circle or spherical)
bacillus (rod-like)
coccobacillus (between a sphere and a rod)
spiral (corkscrew-like)
filamentous (elongated)
Cell shape is generally characteristic of a given bacterial species, but can vary depending on growth conditions. Some bacteria have complex life cycles involving the production of stalks and appendages (e.g. Caulobacter) and some produce elaborate structures bearing reproductive spores (e.g. Myxococcus, Streptomyces). Bacteria generally form distinctive cell morphologies when examined by light microscopy and distinct colony morphologies when grown on Petri plates.
Perhaps the most obvious structural characteristic of bacteria is (with some exceptions) their small size. For example, Escherichia coli cells, an "average" sized bacterium, are about 2 µm (micrometres) long and 0.5 µm in diameter, with a cell volume of 0.6–0.7 μm3. This corresponds to a wet mass of about 1 picogram (pg), assuming that the cell consists mostly of water. The dry mass of a single cell can be estimated as 23% of the wet mass, amounting to 0.2 pg. About half of the dry mass of a bacterial cell consists of carbon, and also about half of it can be attributed to proteins. Therefore, a typical fully grown 1-liter culture of Escherichia coli (at an optical density of 1.0, corresponding to c. 109
Document 3:::
Bergey's Manual of Systematic Bacteriology is the main resource for determining the identity of prokaryotic organisms, emphasizing bacterial species, using every characterizing aspect.
The manual was published subsequent to the Bergey's Manual of Determinative Bacteriology, though the latter is still published as a guide for identifying unknown bacteria. First published in 1923 by David Hendricks Bergey, it is used to classify bacteria based on their structural and functional attributes by arranging them into specific familial orders. However, this process has become more empirical in recent years.
The Taxonomic Outline of Bacteria and Archaea is a derived publication indexing taxon names from version two of the manual. It used to be available for free from the Bergey's manual trust website until September 2018. Michigan State University provides an alternative version that indexes NamesforLife records.
The five-volume BMSB is officially replaced by Bergey's Manual of Systematics of Archaea and Bacteria (BMSAB), a continuously-updated online book, since 2015.
Organization
The change in volume set to "Systematic Bacteriology" came in a new contract in 1980, whereupon the new style included "relationships between organisms" and had "expanded scope" overall. This new style was picked up for a four-volume set that first began publishing in 1984. The information in the volumes was separated as:
Volume 1 included information on all types of Gram-negative bacteria that were considered to have "medical and industrial importance." Volume 2 included information on all types of Gram-positive bacteria. Volume 3 deals with all of the remaining, slightly different Gram-negative bacteria, along with the Archaea. Volume 4 has information on filamentous actinomycetes and other, similar bacteria.
The current volumes differ drastically from previous volumes in that many higher taxa are not defined in terms of phenotype, but solely on 16S phylogeny, as is the case of the classes
Document 4:::
The following outline is provided as an overview of and topical guide to life forms:
A life form (also spelled life-form or lifeform) is an entity that is living, such as plants (flora), animals (fauna), and fungi (funga). It is estimated that more than 99% of all species that ever existed on Earth, amounting to over five billion species, are extinct.
Earth is the only celestial body known to harbor life forms. No form of extraterrestrial life has been discovered yet.
Archaea
Archaea – a domain of single-celled microorganisms, morphologically similar to bacteria, but they possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably the enzymes involved in transcription and translation. Many archaea are extremophiles, which means living in harsh environments, such as hot springs and salt lakes, but they have since been found in a broad range of habitats.
Thermoproteota – a phylum of the Archaea kingdom. Initially
Thermoprotei
Sulfolobales – grow in terrestrial volcanic hot springs with optimum growth occurring
Euryarchaeota – In the taxonomy of microorganisms
Haloarchaea
Halobacteriales – in taxonomy, the Halobacteriales are an order of the Halobacteria, found in water saturated or nearly saturated with salt.
Methanobacteria
Methanobacteriales – information including symptoms, causes, diseases, symptoms, treatments, and other medical and health issues.
Methanococci
Methanococcales aka Methanocaldococcus jannaschii – thermophilic methanogenic archaea, meaning that it thrives at high temperatures and produces methane
Methanomicrobia
Methanosarcinales – In taxonomy, the Methanosarcinales are an order of the Methanomicrobia
Methanopyri
Methanopyrales – In taxonomy, the Methanopyrales are an order of the methanopyri.
Thermococci
Thermococcales
Thermoplasmata
Thermoplasmatales – An order of aerobic, thermophilic archaea, in the kingdom
Halophiles – organisms that thrive in high salt concentrations
Ko
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are bacteria and archaea examples of?
A. prokaryotes
B. fungi
C. eukaryotes
D. plants
Answer:
|
|
sciq-6781
|
multiple_choice
|
What often occurs on steep slopes in dry climates?
|
[
"landslides",
"tsunamis",
"volcanoes",
"earthquakes"
] |
A
|
Relavent Documents:
Document 0:::
Vegetation and slope stability are interrelated by the ability of the plant life growing on slopes to both promote and hinder the stability of the slope. The relationship is a complex combination of the type of soil, the rainfall regime, the plant species present, the slope aspect, and the steepness of the slope. Knowledge of the underlying slope stability as a function of the soil type, its age, horizon development, compaction, and other impacts is a major underlying aspect of understanding how vegetation can alter the stability of the slope. There are four major ways in which vegetation influences slope stability: wind throwing, the removal of water, mass of vegetation (surcharge), and mechanical reinforcement of roots.
Wind throwing
Wind throw is the toppling of a tree due to the force of the wind, this exposes the root plate and adjacent soil beneath the tree and influences slope stability. Wind throw is factor when considering one tree on a slope, however it is of lesser importance when considering general slope stability for a body of trees as the wind forces involved represent a smaller percentage of the potential disturbing forces and the trees which are in the centre of the group will be sheltered by those on the outside.
Removal of water
Vegetation influences slope stability by removing water through transpiration. Transpiration is the vaporisation of liquid water contained in plant tissue and the vapour removal to the air. Water is drawn up from the roots and transported through the plant up to the leaves.
The major effect of transpiration is the reduction of soil pore water pressures which counteracts the loss of strength which occurs through wetting, this is most readily seen as a loss of moisture around trees. However it is not easy to rely on tree and shrub roots to remove water from slopes and consequently help ensure slope stability. The ability to transpire in wet conditions is severely reduced and therefore any increase in soil strength
Document 1:::
The Géotechnique lecture is an biennial lecture on the topic of soil mechanics, organised by the British Geotechnical Association named after its major scientific journal Géotechnique.
This should not be confused with the annual BGA Rankine Lecture.
List of Géotechnique Lecturers
See also
Named lectures
Rankine Lecture
Terzaghi Lecture
External links
ICE Géotechnique journal
British Geotechnical Association
Document 2:::
The Q-slope method for rock slope engineering and rock mass classification is developed by Barton and Bar. It expresses the quality of the rock mass for slope stability using the Q-slope value, from which long-term stable, reinforcement-free slope angles can be derived.
The Q-slope value can be determined with:
Q-slope utilizes similar parameters to the Q-system which has been used for over 40 years in the design of ground support for tunnels and underground excavations. The first four parameters, RQD (rock quality designation), Jn (joint set number), Jr (joint roughness number) and Ja (joint alteration number) are the same as in the Q-system. However, the frictional resistance pair Jr and Ja can apply, when needed, to individual sides of a potentially unstable wedges. Simply applied orientation factors (0), like (Jr/Ja)1x0.7 for set J1 and (Jr/Ja)2x0.9 for set J2, provide estimates of overall whole-wedge frictional resistance reduction, if appropriate. The Q-system term Jw is replaced with Jwice, and takes into account a wider range of environmental conditions appropriate to rock slopes, which are exposed to the environment indefinitely. The conditions include the extremes of erosive intense rainfall, ice wedging, as may seasonally occur at opposite ends of the rock-type and regional spectrum. There are also slope-relevant SRF (strength reduction factor) categories.
Multiplication of these terms results in the Q-slope value, which can range between 0.001 (exceptionally poor) to 1000 (exceptionally good) for different rock masses.
A simple formula for the steepest slope angle (β), in degrees, not requiring reinforcement or support is given by:
Q-slope is intended for use in reinforcement-free site access road cuts, roads or railway cuttings, or individual benches in open cast mines. It is based on over 500 case studies in slopes ranging from 35 to 90 degrees in fresh hard rock slopes as well as weak, weathered and saprolitic rock slopes. Q-slope has also been a
Document 3:::
Quick clay, also known as Leda clay and Champlain Sea clay in Canada, is any of several distinctively sensitive glaciomarine clays found in Canada, Norway, Russia, Sweden, Finland, the United States and other locations around the world. The clay is so unstable that when a mass of quick clay is subjected to sufficient stress, the material behavior may drastically change from that of a particulate material to that of a watery fluid. Landslides occur because of the sudden soil liquefaction caused by external sollicitations such as vibrations induced by an earthquake, or massive rainfalls.
Quick clay main deposits
Quick clay is found only in countries close to the north pole, such as Russia; Canada; Norway; Sweden; and Finland; and in Alaska, United States; since they were glaciated during the Pleistocene epoch. In Canada, the clay is associated primarily with the Pleistocene-era Champlain Sea, in the modern Ottawa Valley, the St. Lawrence Valley, and the Saguenay River regions.
Quick clay has been the underlying cause of many deadly landslides. In Canada alone, it has been associated with more than 250 mapped landslides. Some of these are ancient, and may have been triggered by earthquakes.
Clay colloids stability
Quick clay has a remolded strength which is much less than its strength upon initial loading. This is caused by its highly unstable clay particle structure.
Quick clay is originally deposited in a marine environment. Clay mineral particles are always negatively charged because of the presence of permanent negative charges and pH dependent charges at their surface. Because of the need to respect electro-neutrality and a net zero electrical charge balance, these negative electrical charges are always compensated by the positive charges born by cations (such as Na+) adsorbed onto the surface of the clay, or present in the clay pore water. Exchangeable cations are present in the clay minerals interlayers and on the external basal planes of clay platelets. Ca
Document 4:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What often occurs on steep slopes in dry climates?
A. landslides
B. tsunamis
C. volcanoes
D. earthquakes
Answer:
|
|
sciq-5736
|
multiple_choice
|
Which group of metals in the periodic table include elements such as sodium and potassium?
|
[
"alkali metals",
"actinides",
"lanthanides",
"igneous metals"
] |
A
|
Relavent Documents:
Document 0:::
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals. There is no standard definition of a metalloid and no complete agreement on which elements are metalloids. Despite the lack of specificity, the term remains in use in the literature of chemistry.
The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. Five elements are less frequently so classified: carbon, aluminium, selenium, polonium and astatine. On a standard periodic table, all eleven elements are in a diagonal region of the p-block extending from boron at the upper left to astatine at lower right. Some periodic tables include a dividing line between metals and nonmetals, and the metalloids may be found close to this line.
Typical metalloids have a metallic appearance, but they are brittle and only fair conductors of electricity. Chemically, they behave mostly as nonmetals. They can form alloys with metals. Most of their other physical properties and chemical properties are intermediate in nature. Metalloids are usually too brittle to have any structural uses. They and their compounds are used in alloys, biological agents, catalysts, flame retardants, glasses, optical storage and optoelectronics, pyrotechnics, semiconductors, and electronics.
The electrical properties of silicon and germanium enabled the establishment of the semiconductor industry in the 1950s and the development of solid-state electronics from the early 1960s.
The term metalloid originally referred to nonmetals. Its more recent meaning, as a category of elements with intermediate or hybrid properties, became widespread in 1940–1960. Metalloids are sometimes called semimetals, a practice that has been discouraged, as the term semimetal has a different meaning in physics than in chemistry. In physics, it refers to a specific kind of electronic band structure of a substance. In this context, only
Document 1:::
Nonmetals show more variability in their properties than do metals. Metalloids are included here since they behave predominately as chemically weak nonmetals.
Physically, they nearly all exist as diatomic or monatomic gases, or polyatomic solids having more substantial (open-packed) forms and relatively small atomic radii, unlike metals, which are nearly all solid and close-packed, and mostly have larger atomic radii. If solid, they have a submetallic appearance (with the exception of sulfur) and are brittle, as opposed to metals, which are lustrous, and generally ductile or malleable; they usually have lower densities than metals; are mostly poorer conductors of heat and electricity; and tend to have significantly lower melting points and boiling points than those of most metals.
Chemically, the nonmetals mostly have higher ionisation energies, higher electron affinities (nitrogen and the noble gases have negative electron affinities) and higher electronegativity values than metals noting that, in general, the higher an element's ionisation energy, electron affinity, and electronegativity, the more nonmetallic that element is. Nonmetals, including (to a limited extent) xenon and probably radon, usually exist as anions or oxyanions in aqueous solution; they generally form ionic or covalent compounds when combined with metals (unlike metals, which mostly form alloys with other metals); and have acidic oxides whereas the common oxides of nearly all metals are basic.
Properties
Abbreviations used in this section are: AR Allred-Rochow; CN coordination number; and MH Moh's hardness
Group 1
Hydrogen is a colourless, odourless, and comparatively unreactive diatomic gas with a density of 8.988 × 10−5 g/cm3 and is about 14 times lighter than air. It condenses to a colourless liquid −252.879 °C and freezes into an ice- or snow-like solid at −259.16 °C. The solid form has a hexagonal crystalline structure and is soft and easily crushed. Hydrogen is an insulator in all of
Document 2:::
can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties. All metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metals; and have at least one basic oxide. Metalloids are metallic-looking brittle solids that are either semiconductors or exist in semiconducting forms, and have amphoteric or weakly acidic oxides. Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides. Most or some elements in each category share a range of other properties; a few elements have properties that are either anomalous given their category, or otherwise extraordinary.
Properties
Metals
Metals appear lustrous (beneath any patina); form mixtures (alloys) when combined with other metals; tend to lose or share electrons when they react with other substances; and each forms at least one predominantly basic oxide.
Most metals are silvery looking, high density, relatively soft and easily deformed solids with good electrical and thermal conductivity, closely packed structures, low ionisation energies and electronegativities, and are found naturally in combined states.
Some metals appear coloured (Cu, Cs, Au), have low densities (e.g. Be, Al) or very high melting points (e.g. W, Nb), are liquids at or near room temperature (e.g. Hg, Ga), are brittle (e.g. Os, Bi), not easily machined (e.g. Ti, Re), or are noble (hard to oxidise, e.g. Au, Pt), or have nonmetallic structures (Mn and Ga are structurally analogous to, respectively, white P and I).
Metals comprise the large majority of the elements, and can be subdivided into several different categories. From left to right in the periodic table, these categories include the highly reactive alkali metals; the less-reactive alkaline earth metals, lanthanides, and radioactive actinides; the archetypal tran
Document 3:::
A nonmetal is a chemical element that mostly lacks metallic properties. Seventeen elements are generally considered nonmetals, though some authors recognize more or fewer depending on the properties considered most representative of metallic or nonmetallic character. Some borderline elements further complicate the situation.
Nonmetals tend to have low density and high electronegativity (the ability of an atom in a molecule to attract electrons to itself). They range from colorless gases like hydrogen to shiny solids like the graphite form of carbon. Nonmetals are often poor conductors of heat and electricity, and when solid tend to be brittle or crumbly. In contrast, metals are good conductors and most are pliable. While compounds of metals tend to be basic, those of nonmetals tend to be acidic.
The two lightest nonmetals, hydrogen and helium, together make up about 98% of the observable ordinary matter in the universe by mass. Five nonmetallic elements—hydrogen, carbon, nitrogen, oxygen, and silicon—make up the overwhelming majority of the Earth's crust, atmosphere, oceans and biosphere.
The distinct properties of nonmetallic elements allow for specific uses that metals often cannot achieve. Elements like hydrogen, oxygen, carbon, and nitrogen are essential building blocks for life itself. Moreover, nonmetallic elements are integral to industries such as electronics, energy storage, agriculture, and chemical production.
Most nonmetallic elements were not identified until the 18th and 19th centuries. While a distinction between metals and other minerals had existed since antiquity, a basic classification of chemical elements as metallic or nonmetallic emerged only in the late 18th century. Since then nigh on two dozen properties have been suggested as single criteria for distinguishing nonmetals from metals.
Definition and applicable elements
Properties mentioned hereafter refer to the elements in their most stable forms in ambient conditions unless otherwise
Document 4:::
The purpose of this annotated list is to provide a chronological, consolidated list of nonmetal monographs, which could enable the interested reader to further trace classification approaches in this area. Those marked with a ▲ classify the following 14 elements as nonmetals: H, N; O, S; the stable halogens; and the noble gases.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which group of metals in the periodic table include elements such as sodium and potassium?
A. alkali metals
B. actinides
C. lanthanides
D. igneous metals
Answer:
|
|
sciq-9560
|
multiple_choice
|
What runs through the penis and opens to the outside at the tip of the penis?
|
[
"fallopian tube",
"vas deferens",
"prostate gland",
"the urethra"
] |
D
|
Relavent Documents:
Document 0:::
In human anatomy, the penis (; : penises or penes; from the Latin pēnis, initially "tail") is an external male intromittent organ that additionally serves as the urinary duct. The main parts are the root (radix); the body (corpus); and the epithelium of the penis including the shaft skin and the foreskin (prepuce) covering the glans penis. The body of the penis is made up of three columns of tissue: two corpora cavernosa on the dorsal side and corpus spongiosum between them on the ventral side. The human male urethra passes through the prostate gland, where it is joined by the ejaculatory duct, and then through the penis. The urethra traverses the corpus spongiosum, and its opening, the meatus (), lies on the tip of the glans penis. It is a passage both for urination and ejaculation of semen.
An erection is the stiffening expansion and orthogonal reorientation of the penis, which occurs during sexual arousal. Erections can occur in non-sexual situations; spontaneous non-sexual erections frequently occur during adolescence and sleep. In its flaccid state the penis is smaller, gives to pressure, and the glans is covered by the foreskin. In its fully erect state, the shaft becomes rigid and the glans becomes engorged but not rigid. An erect penis may be straight or curved and may point at an upward angle, a downward angle, or straight ahead. , the average erect human penis is long and has a circumference of . Neither age nor size of the flaccid penis accurately predicts erectile length. There are several common body modifications to the penis, including circumcision and piercings.
Anatomy
Parts
Root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the crus of penis, one on either side of the bulb. It lies within the superficial perineal pouch. The crus of penis is attached to the pubic arch.
Body of the penis (corpus): The pendulous part of the penis. It has two surfaces: dorsal (posterosuperior in the erect penis),
Document 1:::
The corona of glans penis (or, directly from the Latin, the corona glandis penis) or penis crown refers to the rounded projecting border or flare that forms at the base of the glans in human males. The corona overhangs a mucosal surface, known as the neck of the penis, which separates the shaft and the glans. The deep retro-glandular coronal sulcus forms between the corona and the neck of the penis. The two sides of the corona merge on the ventral midline forming the septum glandis. The circumference of the corona is richly innervated and is described as a highly erogenous area of the glans.
Anatomy
Development
During the embryonic development of the male fetus, a thickening on the epidermis appears around the base of the developing glans. The thickening separates from the glans creating the preputial fold and the preputial lamina on its ventral surface. The lamina expands outwards over the epithelium of the glans and also backwards forming an ingrowing fold at the base of the glans that will become the coronal sulcus.
Vascularization
The corona and the neck are highly vascularized areas of the penis. The axial and dorsal penile arteries merge together at the neck before entering the glans. Branches of the dorsal artery of the penis curve around the distal shaft to enter the frenulum and the glans from its ventral surface. Small venous tributaries deriving from the corona drain the glans forming a venous retro-coronal plexus before merging with the dorsal veins.
Innervation
The circumference and the underside of the corona are densely innervated by several types of nerve terminals, including genital corpuscles and free nerve endings, and are considered by males a highly erogenous zone of their penis. The area is reported to be particularly responsive to stimulation and a source of distinct sexual pleasure.
Penile papules
In some males, small skin-colored bumps, known as pearly penile papules, may appear at the circumference of the corona. Their appearance m
Document 2:::
The two crura of penis (one crus on each side) constitute the root of penis along with the bulb of penis. The two crura flank the bulb - one to each side of the bulb. Each crus is attached at the angle between the perineal membrane and ischiopubic ramus. The deep artery of the penis enters the anterior portion of the crus. Distally, each crus transitions into either corpus spongiosum of the body of penis.
Anatomy
Each crus represents the tapering, posterior fourth of each corpora cavernosa penis; the two corpora cavernosa are situated alongside each other along the length of the body of penis while the two crura diverge laterally in the root of penis before attaching firmly onto either ischial ramus at their proximal end.
Each crus begins proximally as a blunt-pointed process in anterior to the tuberosity of the ischium, along the perineal surface of the conjoined (ischiopubic) ramus.
Just proximal to the convergence of the two crura, they come into contact with the bulb of (corpus cavernosum of) penis.
Additional images
See also
Crus of clitoris
Document 3:::
The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body, and within the pelvis.
The main male sex organs are the penis and the scrotum which contains the testicles that produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body; the fertilized ovum (zygote) develops into a fetus, which is later born as an infant.
The corresponding system in females is the female reproductive system.
External genital organs
Penis
The penis is an intromittent organ with a long shaft, an enlarged bulbous-shaped tip called the glans and its foreskin for protection. Inside the penis is the urethra, which is used to ejaculate semen and to excrete urine. Both substances exit through the meatus.
When the male becomes sexually aroused, the penis becomes erect and ready for sexual activity. Erection occurs because sinuses within the erectile tissue of the penis become filled with blood. The arteries of the penis are dilated while the veins are compressed so that blood flows into the erectile cartilage under pressure. The penis is supplied by the pudendal artery.
Scrotum
The scrotum is a sac of skin that hangs behind the penis. It holds and protects the testicles. It also contains numerous nerves and blood vessels. During times of lower temperatures, the cremaster muscle contracts and pulls the scrotum closer to the body, while the dartos muscle gives it a wrinkled appearance; when the temperature increases, the cremaster and dartos muscles relax to bring down the scrotum away from the body and remove the wrinkles respectively.
The scrotum remains connected with the abdomen or pelvic cavity through the inguinal canal. (The spermatic cord, formed from spermatic artery, vein and nerve bound together with connective tissue passes into the testis through inguinal canal.)
Internal genital organs
Testicles
The testicles have two
Document 4:::
This list of related male and female reproductive organs shows how the male and female reproductive organs and the development of the reproductive system are related, sharing a common developmental path. This makes them biological homologues. These organs differentiate into the respective sex organs in males and females.
List
Internal organs
External organs
The external genitalia of both males and females have similar origins. They arise from the genital tubercle that forms anterior to the cloacal folds (proliferating mesenchymal cells around the cloacal membrane). The caudal aspect of the cloacal folds further subdivides into the posterior anal folds and the anterior urethral folds. Bilateral to the urethral fold, genital swellings (tubercles) become prominent. These structures are the future scrotum and labia majora in males and females, respectively.
The genital tubercles of an eight-week-old embryo of either sex are identical. They both have a glans area, which will go on to form the glans clitoridis (females) or glans penis (males), a urogenital fold and groove, and an anal tubercle. At around ten weeks, the external genitalia are still similar. At the base of the glans, there is a groove known as the coronal sulcus or corona glandis. It is the site of attachment of the future prepuce. Just anterior to the anal tubercle, the caudal end of the left and right urethral folds fuse to form the urethral raphe. The lateral part of the genital tubercle (called the lateral tubercle) grows longitudinally and is about the same length in either sex.
Human physiology
The male external genitalia include the penis and the scrotum. The female external genitalia include the clitoris, the labia, and the vaginal opening, which are collectively called the vulva. External genitalia vary widely in external appearance among different people.
One difference between the glans penis and the glans clitoridis is that the glans clitoridis packs nerve endings into a volume only about
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What runs through the penis and opens to the outside at the tip of the penis?
A. fallopian tube
B. vas deferens
C. prostate gland
D. the urethra
Answer:
|
|
sciq-8923
|
multiple_choice
|
Human population is growing exponentially and humans have increased what normally limiting factor through technology, urbanization, and harnessing the energy of fossil fuels?
|
[
"habitat loss",
"zero population growth",
"mass extinction",
"carrying capacity"
] |
D
|
Relavent Documents:
Document 0:::
The Limits to Growth (LTG) is a 1972 report that discussed the possibility of exponential economic and population growth with finite supply of resources, studied by computer simulation. The study used the World3 computer model to simulate the consequence of interactions between the Earth and human systems. The model was based on the work of Jay Forrester of MIT, as described in his book World Dynamics.
Commissioned by the Club of Rome, the findings of the study were first presented at international gatherings in Moscow and Rio de Janeiro in the summer of 1971. The report's authors are Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III, representing a team of 17 researchers.
The report's findings suggest that in the absence of significant alterations in resource utilization, it is highly likely that there would be an abrupt and unmanageable decrease in both population and industrial capacity. Despite facing severe criticism and scrutiny upon its initial release, subsequent research aimed at verifying its predictions consistently supports the notion that there have been inadequate modifications made since 1972 to substantially alter its essence.
Since its publication, some 30 million copies of the book in 30 languages have been purchased. It continues to generate debate and has been the subject of several subsequent publications.
Beyond the Limits and The Limits to Growth: The 30-Year Update were published in 1992 and 2004 respectively, in 2012, a 40-year forecast from Jørgen Randers, one of the book's original authors, was published as 2052: A Global Forecast for the Next Forty Years, and in 2022 two of the original Limits to Growth authors, Dennis Meadows and Jørgen Randers, joined 19 other contributors to produce Limits and Beyond.
Purpose
In commissioning the MIT team to undertake the project that resulted in LTG, the Club of Rome had three objectives:
Gain insights into the limits of our world system and the constraints it put
Document 1:::
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as the environment's maximal load, which in population ecology corresponds to the population equilibrium, when the number of deaths in a population equals the number of births (as well as immigration and emigration). The effect of carrying capacity on population dynamics is modelled with a logistic function. Carrying capacity is applied to the maximum population an environment can support in ecology, agriculture and fisheries. The term carrying capacity has been applied to a few different processes in the past before finally being applied to population limits in the 1950s. The notion of carrying capacity for humans is covered by the notion of sustainable population.
At the global scale, scientific data indicates that humans are living beyond the carrying capacity of planet Earth and that this cannot continue indefinitely. This scientific evidence comes from many sources worldwide. It was presented in detail in the Millennium Ecosystem Assessment of 2005, a collaborative effort involving more than 1,360 experts worldwide. More recent, detailed accounts are provided by ecological footprint accounting, and interdisciplinary research on planetary boundaries to safe human use of the biosphere. The Sixth Assessment Report on Climate Change from the IPCC and the First Assessment Report on Biodiversity and Ecosystem Services by the IPBES, large international summaries of the state of scientific knowledge regarding climate disruption and biodiversity loss, also support this view.
An early detailed examination of global limits was published in the 1972 book Limits to Growth, which has prompted follow-up commentary and analysis. A 2012 review in Nature by 22 international researchers expressed concerns that the Earth may be "approaching
Document 2:::
The InterAcademy Panel Statement on Population Growth is an international scientist consensus document discussing and demanding a halt of the population expansion. This was the first worldwide joint statement of academies of sciences, and their cooperative InterAcademy Panel on International Issues. It was signed by 58 member academies and began as follows.
Let 1994 be remembered as the year when the people of the world decided to act together for the benefit of future generations.
Background
Between October 24 and October 27, 1993, an international "scientist's top summit" was held in New Delhi, India, with representatives from academies of sciences from all over the world. This grew out of two previous meetings, one joint meeting by the British Royal Society and the United States National Academy of Sciences, and one international meeting organised by the Royal Swedish Academy of Sciences. The scientists discussed the environmental and social welfare problems for the world population, and found them closely linked to the population expansion.
In the year 1950, there were approximately 2.5 billion (2,500 million) humans alive in this world. By 1960, the number had reached 3 billion, and by 1975 was at 4 billion. The 5 billion mark was reached around 1987, and in 1993, at the New Delhi meeting, academics estimated the population to be 5.5 billion. For some time, world food production had been able to roughly match population growth, meaning that starvation was a regional and distributional problem, rather than one based on a total shortage of food. The scientists noted that increased food production on land and on sea in the previous decade was less than the population increase over the same period. Moreover, by increased food production and otherwise, the population growth was contributing to a loss of biodiversity, deforestation and loss of topsoil, and shortages of water and fuel. The academics noted that the complex relationships between population size and
Document 3:::
Biodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, depending on whether the environmental degradation that leads to the loss is reversible through ecological restoration/ecological resilience or effectively permanent (e.g. through land loss). The current global extinction (frequently called the sixth mass extinction or Anthropocene extinction), has resulted in a biodiversity crisis being driven by human activities which push beyond the planetary boundaries and so far has proven irreversible.
The main direct threats to conservation (and thus causes for biodiversity loss) fall in eleven categories: Residential and commercial development; farming activities; energy production and mining; transportation and service corridors; biological resource usages; human intrusions and activities that alter, destroy, disturb habitats and species from exhibiting natural behaviors; natural system modification; invasive and problematic species, pathogens and genes; pollution; catastrophic geological events, climate change, and so on.
Numerous scientists and the IPBES Global Assessment Report on Biodiversity and Ecosystem Services assert that human population growth and overconsumption are the primary factors in this decline. However other scientists have criticized this, saying that loss of habitat is caused mainly by "the growth of commodities for export" and that population has very little to do with overall consumption, due to country wealth disparities.
Climate change is another threat to global biodiversity. For example, coral reefs – which are biodiversity hotspots – will be lost within the century if global warming continues at the current rate. However, habitat destruction e.g. for the expansion of agriculture, is currently the more significant driver of contemporary biodiversity lo
Document 4:::
The human climate niche is the ensemble of climate conditions that have sustained human life and human activities, like agriculture, on the globe for the last millennia. The human climate niche is estimated by calculating the human population density with respect to mean annual temperature. The human population distribution as a function of mean annual temperature is bimodal and results in two modes; one at 15 °C and another one at ~20 to 25 °C. Crops and livestock required for sustaining the human population are also limited to the similar niche conditions. Given the rise in mean global temperatures, the human population is projected to experience climate conditions beyond the human climate niche. Some projections show that considering temperature and demographic changes, 2.0 and 3.7 billion people will live in out of the niche by 2030 and 2090, respectively.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Human population is growing exponentially and humans have increased what normally limiting factor through technology, urbanization, and harnessing the energy of fossil fuels?
A. habitat loss
B. zero population growth
C. mass extinction
D. carrying capacity
Answer:
|
|
ai2_arc-766
|
multiple_choice
|
How does the tilt of Earth’s axis and its rotation affect the weather?
|
[
"The tilt of Earth allows Earth to absorb all of the Sun’s radiation as it rotates.",
"The tilt allows certain latitudes of Earth to be heated at a greater rate while Earth rotates.",
"The tilt of Earth allows Earth to rotate fast enough to allow surface cooling to occur at night.",
"The tilt allows energy to be evenly distributed throughout the atmosphere while Earth rotates."
] |
B
|
Relavent Documents:
Document 0:::
In earth science, global surface temperature (GST; sometimes referred to as global mean surface temperature, GMST, or global average surface temperature) is calculated by averaging the temperatures over sea and land. Periods of global cooling and global warming have alternated throughout Earth's history.
Series of reliable global temperature measurements began in the 1850—1880 time frame. Through 1940, the average annual temperature increased, but was relatively stable between 1940 and 1975. Since 1975, it has increased by roughly 0.15 °C to 0.20 °C per decade, to at least 1.1 °C (1.9 °F) above 1880 levels. The current annual GMST is about , though monthly temperatures can vary almost above or below this figure.
Sea levels have risen and fallen sharply during Earth's 4.6 billion year history. However, recent global sea level rise, driven by increasing global surface temperatures, has increased over the average rate of the past two to three thousand years. The continuation or acceleration of this trend will cause significant changes in the world's coastlines.
Background
In the 1860s, physicist John Tyndall recognized the Earth's natural greenhouse effect and suggested that slight changes in the atmospheric composition could bring about climatic variations. In 1896, a seminal paper by Swedish scientist Svante Arrhenius first predicted that changes in the levels of carbon dioxide in the atmosphere could substantially alter the surface temperature through the greenhouse effect.
Changes in global temperatures over the past century provide evidence for the effects of increasing greenhouse gasses. When the climate system reacts to such changes, climate change follows. Measurement of the GST(global surface temperature) is one of the many lines of evidence supporting the scientific consensus on climate change, which is that humans are causing warming of Earth's climate system.
Warming oceans
With the Earth's temperature increasing, the ocean has absorbed much of th
Document 1:::
Polar motion of the Earth is the motion of the Earth's rotational axis relative to its crust. This is measured with respect to a reference frame in which the solid Earth is fixed (a so-called Earth-centered, Earth-fixed or ECEF reference frame). This variation is a few meters on the surface of the Earth.
Analysis
Polar motion is defined relative to a conventionally defined reference axis, the CIO (Conventional International Origin), being the pole's average location over the year 1900. It consists of three major components: a free oscillation called Chandler wobble with a period of about 435 days, an annual oscillation, and an irregular drift in the direction of the 80th meridian west, which has lately been less extremely west.
Causes
The slow drift, about 20 m since 1900, is partly due to motions in the Earth's core and mantle, and partly to the redistribution of water mass as the Greenland ice sheet melts, and to isostatic rebound, i.e. the slow rise of land that was formerly burdened with ice sheets or glaciers. The drift is roughly along the 80th meridian west. Since about 2000, the pole has found a less extreme drift, which is roughly along the central meridian. This less dramatically westward drift of motion is attributed to the global scale mass transport between the oceans and the continents.
Major earthquakes cause abrupt polar motion by altering the volume distribution of the Earth's solid mass. These shifts are quite small in magnitude relative to the long-term core/mantle and isostatic rebound components of polar motion.
Principle
In the absence of external torques, the vector of the angular momentum M of a rotating system remains constant and is directed toward a fixed point in space. If the earth were perfectly symmetrical and rigid, M would remain aligned with its axis of symmetry, which would also be its axis of rotation. In the case of the Earth, it is almost identical with its axis of rotation, with the discrepancy due to shifts of mass on the
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Sun path, sometimes also called day arc, refers to the daily and seasonal arc-like path that the Sun appears to follow across the sky as the Earth rotates and orbits the Sun. The Sun's path affects the length of daytime experienced and amount of daylight received along a certain latitude during a given season.
The relative position of the Sun is a major factor in the heat gain of buildings and in the performance of solar energy systems. Accurate location-specific knowledge of sun path and climatic conditions is essential for economic decisions about solar collector area, orientation, landscaping, summer shading, and the cost-effective use of solar trackers.
Angles
Effect of the Earth's axial tilt
Sun paths at any latitude and any time of the year can be determined from basic geometry. The Earth's axis of rotation tilts about 23.5 degrees, relative to the plane of Earth's orbit around the Sun. As the Earth orbits the Sun, this creates the 47° declination difference between the solstice sun paths, as well as the hemisphere-specific difference between summer and winter.
In the Northern Hemisphere, the winter sun (November, December, January) rises in the southeast, transits the celestial meridian at a low angle in the south (more than 43° above the southern horizon in the tropics), and then sets in the southwest. It is on the south (equator) side of the house all day long. A vertical window facing south (equator side) is effective for capturing solar thermal energy. For comparison, the winter sun in the Southern Hemisphere (May, June, July) rises in the northeast, peaks out at a low angle in the north (more than halfway up from the horizon in the tropics), and then sets in the northwest. There, the north-facing window would let in plenty of solar thermal energy to the house.
In the Northern Hemisphere in summer (May, June, July), the Sun rises in the northeast, peaks out slightly south of overhead point (lower in the south at higher latitude), and then sets in t
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This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. (see also: List of meteorological phenomena)
A
advection
aeroacoustics
aerobiology
aerography (meteorology)
aerology
air parcel (in meteorology)
air quality index (AQI)
airshed (in meteorology)
American Geophysical Union (AGU)
American Meteorological Society (AMS)
anabatic wind
anemometer
annular hurricane
anticyclone (in meteorology)
apparent wind
Atlantic Oceanographic and Meteorological Laboratory (AOML)
Atlantic hurricane season
atmometer
atmosphere
Atmospheric Model Intercomparison Project (AMIP)
Atmospheric Radiation Measurement (ARM)
(atmospheric boundary layer [ABL]) planetary boundary layer (PBL)
atmospheric chemistry
atmospheric circulation
atmospheric convection
atmospheric dispersion modeling
atmospheric electricity
atmospheric icing
atmospheric physics
atmospheric pressure
atmospheric sciences
atmospheric stratification
atmospheric thermodynamics
atmospheric window (see under Threats)
B
ball lightning
balloon (aircraft)
baroclinity
barotropity
barometer ("to measure atmospheric pressure")
berg wind
biometeorology
blizzard
bomb (meteorology)
buoyancy
Bureau of Meteorology (in Australia)
C
Canada Weather Extremes
Canadian Hurricane Centre (CHC)
Cape Verde-type hurricane
capping inversion (in meteorology) (see "severe thunderstorms" in paragraph 5)
carbon cycle
carbon fixation
carbon flux
carbon monoxide (see under Atmospheric presence)
ceiling balloon ("to determine the height of the base of clouds above ground level")
ceilometer ("to determine the height of a cloud base")
celestial coordinate system
celestial equator
celestial horizon (rational horizon)
celestial navigation (astronavigation)
celestial pole
Celsius
Center for Analysis and Prediction of Storms (CAPS) (in Oklahoma in the US)
Center for the Study o
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Upper-atmospheric models are simulations of the Earth's atmosphere between 20 and 100 km (65,000 and 328,000 feet) that comprises the stratosphere, mesosphere, and the lower thermosphere. Whereas most climate models simulate a region of the Earth's atmosphere from the surface to the stratopause, there also exist numerical models which simulate the wind, temperature and composition of the Earth's tenuous upper atmosphere, from the mesosphere to the exosphere, including the ionosphere. This region is affected strongly by the 11 year Solar cycle through variations in solar UV/EUV/Xray radiation and solar wind leading to high latitude particle precipitation and aurora. It has been proposed that these phenomena may have an effect on the lower atmosphere, and should therefore be included in simulations of climate change. For this reason there has been a drive in recent years to create whole atmosphere models to investigate whether or not this is the case.
Jet stream perturbation model
A jet stream perturbation model is employed by Weather Logistics UK, which simulates the diversion of the air streams in the upper atmosphere. North Atlantic air flow modelling is simulated by combining a monthly jet stream climatology input calculated at 20 to 30°W, with different blocking high patterns. The jet stream input is generated by thermal wind balance calculations at 316mbars (6 to 9 km aloft) in the mid-latitude range from 40 to 60°N. Long term blocking patterns are determined by the weather forecaster, who identifies the likely position and strength of North Atlantic Highs from synoptic charts, the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO) patterns. The model is based on the knowledge that low pressure systems at the surface are steered by the fast ribbons (jet streams) of air in the upper atmosphere. The jet stream - blocking interaction model simulation examines the sea surface temperature field using data from NOAA tracked along the ocean on a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How does the tilt of Earth’s axis and its rotation affect the weather?
A. The tilt of Earth allows Earth to absorb all of the Sun’s radiation as it rotates.
B. The tilt allows certain latitudes of Earth to be heated at a greater rate while Earth rotates.
C. The tilt of Earth allows Earth to rotate fast enough to allow surface cooling to occur at night.
D. The tilt allows energy to be evenly distributed throughout the atmosphere while Earth rotates.
Answer:
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sciq-9572
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multiple_choice
|
Chemical elements and water are recycled through what cycle?
|
[
"biogenic",
"evaporation",
"biogeochemical",
"dynamical"
] |
C
|
Relavent Documents:
Document 0:::
A biogeochemical cycle, or more generally a cycle of matter, is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is transformed and cycled by living organisms and through various geological forms and reservoirs, including the atmosphere, the soil and the oceans. It can be thought of as the pathway by which a chemical substance cycles (is turned over or moves through) the biotic compartment and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, lithosphere and hydrosphere.
For example, in the carbon cycle, atmospheric carbon dioxide is absorbed by plants through photosynthesis, which converts it into organic compounds that are used by organisms for energy and growth. Carbon is then released back into the atmosphere through respiration and decomposition. Additionally, carbon is stored in fossil fuels and is released into the atmosphere through human activities such as burning fossil fuels. In the nitrogen cycle, atmospheric nitrogen gas is converted by plants into usable forms such as ammonia and nitrates through the process of nitrogen fixation. These compounds can be used by other organisms, and nitrogen is returned to the atmosphere through denitrification and other processes. In the water cycle, the universal solvent water evaporates from land and oceans to form clouds in the atmosphere, and then precipitates back to different parts of the planet. Precipitation can seep into the ground and become part of groundwater systems used by plants and other organisms, or can runoff the surface to form lakes and rivers. Subterranean water can then seep into the ocean along with river discharges, rich with dissolved and particulate organic matter and other nutrients.
There are bio
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The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water (salt water) and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, transpiration, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation.
The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment. These heat exchanges influence climate.
The evaporative phase of the cycle purifies water, causing salts and other solids picked up during the cycle to be left behind, and then the condensation phase in the atmosphere replenishes the land with freshwater. The flow of liquid water and ice transports minerals across the globe. It is also involved in reshaping the geological features of the Earth, through processes including erosion and sedimentation. The water cycle is also essential for the maintenance of most life and ecosystems on the planet.
Description
Overall process
The water cycle is powered from the energy emitted by the sun. This energy heats water in the ocean and seas. Water evaporates as water vapor into the air. Some ice and snow sublimates directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the soil. Th
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A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygen cycle, among others that continually recycle along with other mineral nutrients into productive ecological nutrition.
Overview
The nutrient cycle is nature's recycling system. All forms of recycling have feedback loops that use energy in the process of putting material resources back into use. Recycling in ecology is regulated to a large extent during the process of decomposition. Ecosystems employ biodiversity in the food webs that recycle natural materials, such as mineral nutrients, which includes water. Recycling in natural systems is one of the many ecosystem services that sustain and contribute to the well-being of human societies.
There is much overlap between the terms for the biogeochemical cycle and nutrient cycle. Most textbooks integrate the two and seem to treat them as synonymous terms. However, the terms often appear independently. Nutrient cycle is more often used in direct reference to the idea of an intra-system cycle, where an ecosystem functions as a unit. From a practical point, it does not make sense to assess a terrestrial ecosystem by considering the full column of air above it as well as the great depths of Earth below it. While an ecosystem often has no clear boundary, as a working model it is practical to consider the functional community where the bulk of matter and energy transfer occurs. Nutrient cycling occurs in ecosystems that participate in the "larger biogeochemical cycles of the earth through a system of inputs and outputs."
Complete and closed loop
Ecosystems are capable of complete recycling. Complete recycling means that 100% of the waste material can be reconstituted inde
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Marine biogeochemical cycles are biogeochemical cycles that occur within marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. These biogeochemical cycles are the pathways chemical substances and elements move through within the marine environment. In addition, substances and elements can be imported into or exported from the marine environment. These imports and exports can occur as exchanges with the atmosphere above, the ocean floor below, or as runoff from the land.
There are biogeochemical cycles for the elements calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, and sulfur; molecular cycles for water and silica; macroscopic cycles such as the rock cycle; as well as human-induced cycles for synthetic compounds such as polychlorinated biphenyl (PCB). In some cycles there are reservoirs where a substance can be stored for a long time. The cycling of these elements is interconnected.
Marine organisms, and particularly marine microorganisms are crucial for the functioning of many of these cycles. The forces driving biogeochemical cycles include metabolic processes within organisms, geological processes involving the earth's mantle, as well as chemical reactions among the substances themselves, which is why these are called biogeochemical cycles. While chemical substances can be broken down and recombined, the chemical elements themselves can be neither created nor destroyed by these forces, so apart from some losses to and gains from outer space, elements are recycled or stored (sequestered) somewhere on or within the planet.
Overview
Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the many transfers between trophic levels. However, the matter that makes up living organisms is conserved and recycled. The six most common elements associated with organic molecules—carbon, nitrogen, hydrogen, oxy
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The carbon cycle is that part of the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycle. Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone. The carbon cycle comprises a sequence of events that are key to making Earth capable of sustaining life. It describes the movement of carbon as it is recycled and reused throughout the biosphere, as well as long-term processes of carbon sequestration (storage) to and release from carbon sinks.
To describe the dynamics of the carbon cycle, a distinction can be made between the fast and slow carbon cycle. The fast carbon cycle is also referred to as the biological carbon cycle. Fast carbon cycles can complete within years, moving substances from atmosphere to biosphere, then back to the atmosphere. Slow or geological cycles (also called deep carbon cycle) can take millions of years to complete, moving substances through the Earth's crust between rocks, soil, ocean and atmosphere.
Human activities have disturbed the fast carbon cycle for many centuries by modifying land use, and moreover with the recent industrial-scale mining of fossil carbon (coal, petroleum, and gas extraction, and cement manufacture) from the geosphere. Carbon dioxide in the atmosphere had increased nearly 52% over pre-industrial levels by 2020, forcing greater atmospheric and Earth surface heating by the Sun. The increased carbon dioxide has also caused a reduction in the ocean's pH value and is fundamentally altering marine chemistry. The majority of fossil carbon has been extracted over just the past half century, and rates continue to rise rapidly, contributing to human-caused climate change.
Main compartments
The carbon cycle was first described by Antoine Lavoisier and Joseph Priestley, and popularised by Humphry Davy. The g
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Chemical elements and water are recycled through what cycle?
A. biogenic
B. evaporation
C. biogeochemical
D. dynamical
Answer:
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sciq-7522
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multiple_choice
|
Overpopulation takes place when the number of organisms in an area exceeds what?
|
[
"predators",
"consumers",
"biome size",
"carrying capacity"
] |
D
|
Relavent Documents:
Document 0:::
Overpopulation or overabundance is a phenomenon in which a species' population becomes larger than the carrying capacity of its environment. This may be caused by increased birth rates, lowered mortality rates, reduced predation or large scale migration, leading to an overabundant species and other animals in the ecosystem competing for food, space, and resources. The animals in an overpopulated area may then be forced to migrate to areas not typically inhabited, or die off without access to necessary resources.
Judgements regarding overpopulation always involve both facts and values. Animals often are judged overpopulated when their numbers cause impacts that people find dangerous, damaging, expensive, or otherwise harmful. Societies may be judged overpopulated when their human numbers cause impacts that degrade ecosystem services, decrease human health and well-being, or crowd other species out of existence.
Background
In ecology, overpopulation is a concept used primarily in wildlife management. Typically, an overpopulation causes the entire population of the species in question to become weaker, as no single individual is able to find enough food or shelter. As such, overpopulation is thus characterized by an increase in the diseases and parasite-load which live upon the species in question, as the entire population is weaker. Other characteristics of overpopulation are lower fecundity, adverse effects on the environment (soil, vegetation or fauna) and lower average body weights. Especially the worldwide increase of deer populations, which usually show irruptive growth, is proving to be of ecological concern. Ironically, where ecologists were preoccupied with conserving or augmenting deer populations only a century ago, the focus has now shifted in the direct opposite, and ecologists are now more concerned with limiting the populations of such animals.
Supplemental feeding of charismatic species or interesting game species is a major problem in causing overp
Document 1:::
A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system. The limiting factor is in a pyramid shape of organisms going up from the producers to consumers and so on. A factor not limiting over a certain domain of starting conditions may yet be limiting over another domain of starting conditions, including that of the factor.
Overview
The identification of a factor as limiting is possible only in distinction to one or more other factors that are non-limiting. Disciplines differ in their use of the term as to whether they allow the simultaneous existence of more than one limiting factor which (may then be called "co-limiting"), but they all require the existence of at least one non-limiting factor when the terms are used. There are several different possible scenarios of limitation when more than one factor is present. The first scenario, called single limitation occurs when only one factor, the one with maximum demand, limits the System. Serial co-limitation is when one factor has no direct limiting effects on the system, but must be present to increase the limitation of a second factor. A third scenario, independent limitation, occurs when two factors both have limiting effects on the system but work through different mechanisms. Another scenario, synergistic limitation, occurs when both factors contribute to the same limitation mechanism, but in different ways.
In 1905 Frederick Blackman articulated the role of limiting factors as follows: "When a process is conditioned as to its rapidity by several separate factors the rate of the process is limited by the pace of the slowest factor." In terms of the magnitude of a function, he wrote, "When the magnitude of a function is limited by one of a set of possible factors, increase of that factor, and of that one alone, will be found to bring about an increase of the magnitude of the function."
Ecology
In population ecology, a regulating factor, al
Document 2:::
In biology, overabundant species refers to an excessive number of individuals and occurs when the normal population density has been exceeded. Increase in animal populations is influenced by a variety of factors, some of which include habitat destruction or augmentation by human activity, the introduction of invasive species and the reintroduction of threatened species to protected reserves.
Population overabundance can have a negative impact on the environment, and in some cases on the public as well. There are various methods through which populations can be controlled such as hunting, contraception, chemical controls, disease and genetic modification. Overabundant species is an important area of research as it can potentially impact the biodiversity of ecosystems.
Most research studies have examined negative impacts of overabundant species, whereas very few have documented or performed an in-depth examination on positive impacts. As a result, this article focuses on the negative impact of overabundant species.
Definitions
When referring to animals as “overabundant”, various definitions apply. The following classes explore the different associations with overabundance:
The inconvenience of animals in a certain region or area that threatens human livelihood, for example the tropics are considered to contain an overabundant population of the Anopheles mosquito which carries the malaria parasite.
The population density of a preferred species has been reduced by another species population which is then considered as overabundant, for example predator populations of lions and hyenas reducing zebra and wildebeest numbers.
A species population within a specific habitat exceeds the carrying capacity, for example national parks reducing herbivore populations to maintain and manage habitat equilibrium.
The entire equilibrium consisting of animal and plant organisations is already out of balance, for example existing populations colonising new habitat.
Out of all
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Biodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, depending on whether the environmental degradation that leads to the loss is reversible through ecological restoration/ecological resilience or effectively permanent (e.g. through land loss). The current global extinction (frequently called the sixth mass extinction or Anthropocene extinction), has resulted in a biodiversity crisis being driven by human activities which push beyond the planetary boundaries and so far has proven irreversible.
The main direct threats to conservation (and thus causes for biodiversity loss) fall in eleven categories: Residential and commercial development; farming activities; energy production and mining; transportation and service corridors; biological resource usages; human intrusions and activities that alter, destroy, disturb habitats and species from exhibiting natural behaviors; natural system modification; invasive and problematic species, pathogens and genes; pollution; catastrophic geological events, climate change, and so on.
Numerous scientists and the IPBES Global Assessment Report on Biodiversity and Ecosystem Services assert that human population growth and overconsumption are the primary factors in this decline. However other scientists have criticized this, saying that loss of habitat is caused mainly by "the growth of commodities for export" and that population has very little to do with overall consumption, due to country wealth disparities.
Climate change is another threat to global biodiversity. For example, coral reefs – which are biodiversity hotspots – will be lost within the century if global warming continues at the current rate. However, habitat destruction e.g. for the expansion of agriculture, is currently the more significant driver of contemporary biodiversity lo
Document 4:::
Urban evolution refers to the heritable genetic changes of populations in response to urban development and anthropogenic activities in urban areas. Urban evolution can be caused by mutation, genetic drift, gene flow, or evolution by natural selection. Biologists have observed evolutionary change in numerous species compared to their rural counterparts on a relatively short timescale.
Strong selection pressures due to urbanization play a big role in this process. The changed environmental conditions lead to selection and adaptive changes in city-dwelling plants and animals. Also, there is a significant change in species composition between rural and urban ecosystems.
Shared aspects of cities worldwide also give ample opportunity for scientists to study the specific evolutionary responses in these rapidly changed landscapes independently. How certain organisms (are able to) adapt to urban environments while others cannot, gives a live perspective on rapid evolution.
Urbanization
With urban growth, the urban-rural gradient has seen a large shift in distribution of humans, moving from low density to very high in the last millennia. This has brought a large change to environments as well as societies.
Urbanization transforms natural habitats to completely altered living spaces that sustain large human populations. Increasing congregation of humans accompanies the expansion of infrastructure, industry and housing. Natural vegetation and soil are mostly replaced or covered by dense grey materials. Urbanized areas continue to expand both in size and number globally; in 2018, the United Nations estimated that 68% of people globally will live in ever-larger urban areas by 2050.
Urban evolution selective agents
Urbanization intensifies diverse stressors spatiotemporally such that they can act in concert to cause rapid evolutionary consequences such as extinction, maladaptation, or adaptation. Three factors have come to the forefront as the main evolutionary influencer
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Overpopulation takes place when the number of organisms in an area exceeds what?
A. predators
B. consumers
C. biome size
D. carrying capacity
Answer:
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|
sciq-8832
|
multiple_choice
|
Body plans do provide a succinct way to compare and contrast what?
|
[
"distinctive animal features",
"degenerative animal features",
"key animal features",
"missing animal features"
] |
C
|
Relavent Documents:
Document 0:::
A body plan, (), or ground plan is a set of morphological features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many.
This term, usually applied to animals, envisages a "blueprint" encompassing aspects such as symmetry, layers, segmentation, nerve, limb, and gut disposition. Evolutionary developmental biology seeks to explain the origins of diverse body plans.
Body plans have historically been considered to have evolved in a flash in the Ediacaran biota; filling the Cambrian explosion with the results, and a more nuanced understanding of animal evolution suggests gradual development of body plans throughout the early Palaeozoic. Recent studies in animals and plants started to investigate whether evolutionary constraints on body plan structures can explain the presence of developmental constraints during embryogenesis such as the phenomenon referred to as phylotypic stage.
History
Among the pioneering zoologists, Linnaeus identified two body plans outside the vertebrates; Cuvier identified three; and Haeckel had four, as well as the Protista with eight more, for a total of twelve. For comparison, the number of phyla recognised by modern zoologists has risen to 36.
Linnaeus, 1735
In his 1735 book Systema Naturæ, Swedish botanist Linnaeus grouped the animals into quadrupeds, birds, "amphibians" (including tortoises, lizards and snakes), fish, "insects" (Insecta, in which he included arachnids, crustaceans and centipedes) and "worms" (Vermes). Linnaeus's Vermes included effectively all other groups of animals, not only tapeworms, earthworms and leeches but molluscs, sea urchins and starfish, jellyfish, squid and cuttlefish.
Cuvier, 1817
In his 1817 work, Le Règne Animal, French zoologist Georges Cuvier combined evidence from comparative anatomy and palaeontology to divide the animal kingdom into four body plans. Taking the central nervous system as the main organ system which controlled all the othe
Document 1:::
Animal science is described as "studying the biology of animals that are under the control of humankind". It can also be described as the production and management of farm animals. Historically, the degree was called animal husbandry and the animals studied were livestock species, like cattle, sheep, pigs, poultry, and horses. Today, courses available look at a broader area, including companion animals, like dogs and cats, and many exotic species. Degrees in Animal Science are offered at a number of colleges and universities. Animal science degrees are often offered at land-grant universities, which will often have on-campus farms to give students hands-on experience with livestock animals.
Education
Professional education in animal science prepares students for careers in areas such as animal breeding, food and fiber production, nutrition, animal agribusiness, animal behavior, and welfare. Courses in a typical Animal Science program may include genetics, microbiology, animal behavior, nutrition, physiology, and reproduction. Courses in support areas, such as genetics, soils, agricultural economics and marketing, legal aspects, and the environment also are offered.
Bachelor degree
At many universities, a Bachelor of Science (BS) degree in Animal Science allows emphasis in certain areas. Typical areas are species-specific or career-specific. Species-specific areas of emphasis prepare students for a career in dairy management, beef management, swine management, sheep or small ruminant management, poultry production, or the horse industry. Other career-specific areas of study include pre-veterinary medicine studies, livestock business and marketing, animal welfare and behavior, animal nutrition science, animal reproduction science, or genetics. Youth programs are also an important part of animal science programs.
Pre-veterinary emphasis
Many schools that offer a degree option in Animal Science also offer a pre-veterinary emphasis such as Iowa State University, th
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Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
Document 3:::
The Visible Human Project is an effort to create a detailed data set of cross-sectional photographs of the human body, in order to facilitate anatomy visualization applications. It is used as a tool for the progression of medical findings, in which these findings link anatomy to its audiences. A male and a female cadaver were cut into thin slices, which were then photographed and digitized. The project is run by the U.S. National Library of Medicine (NLM) under the direction of Michael J. Ackerman. Planning began in 1986; the data set of the male was completed in November 1994 and the one of the female in November 1995. The project can be viewed today at the NLM in Bethesda, Maryland. There are currently efforts to repeat this project with higher resolution images but only with parts of the body instead of a cadaver.
Data
The male cadaver was encased and frozen in a gelatin and water mixture in order to stabilize the specimen for cutting. The specimen was then "cut" in the axial plane at 1-millimeter intervals. Each of the resulting 1,871 "slices" was photographed in both analog and digital, yielding 15 gigabytes of data. In 2000, the photos were rescanned at a higher resolution, yielding more than 65 gigabytes. The female cadaver was cut into slices at 0.33-millimeter intervals, resulting in some 40 gigabytes of data.
The term "cut" is a bit of a misnomer, yet it is used to describe the process of grinding away the top surface of a specimen at regular intervals. The term "slice", also a misnomer, refers to the revealed surface of the specimen to be photographed; the process of grinding the surface away is entirely destructive to the specimen and leaves no usable or preservable "slice" of the cadaver.
The data are supplemented by axial sections of the whole body obtained by computed tomography, axial sections of the head and neck obtained by magnetic resonance imaging (MRI), and coronal sections of the rest of the body also obtained by MRI.
The scanning,
Document 4:::
The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organs and then organ systems. They ensure homeostasis and the viability of the human body.
It comprises a head, hair, neck, torso (which includes the thorax and abdomen), arms and hands, legs and feet.
The study of the human body includes anatomy, physiology, histology and embryology. The body varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis, with safe levels of substances such as sugar and oxygen in the blood.
The body is studied by health professionals, physiologists, anatomists, and artists to assist them in their work.
Composition
The human body is composed of elements including hydrogen, oxygen, carbon, calcium and phosphorus. These elements reside in trillions of cells and non-cellular components of the body.
The adult male body is about 60% water for a total water content of some . This is made up of about of extracellular fluid including about of blood plasma and about of interstitial fluid, and about of fluid inside cells. The content, acidity and composition of the water inside and outside cells is carefully maintained. The main electrolytes in body water outside cells are sodium and chloride, whereas within cells it is potassium and other phosphates.
Cells
The body contains trillions of cells, the fundamental unit of life. At maturity, there are roughly 3037trillion cells in the body, an estimate arrived at by totaling the cell numbers of all the organs of the body and cell types. The body is also host to about the same number of non-human cells as well as multicellular organisms which reside in the gastrointestinal tract and on the skin. Not all parts of the body are made from cells. Cells sit in an extracellular matrix that consists of proteins such as collagen,
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Body plans do provide a succinct way to compare and contrast what?
A. distinctive animal features
B. degenerative animal features
C. key animal features
D. missing animal features
Answer:
|
|
sciq-5065
|
multiple_choice
|
What harmful light does ozone reduce in the upper atmospheres?
|
[
"infrared light",
"visible light",
"ultraviolet light",
"specific light"
] |
C
|
Relavent Documents:
Document 0:::
The ozone–oxygen cycle is the process by which ozone is continually regenerated in Earth's stratosphere, converting ultraviolet radiation (UV) into heat. In 1930 Sydney Chapman resolved the chemistry involved. The process is commonly called the Chapman cycle by atmospheric scientists.
Most of the ozone production occurs in the tropical upper stratosphere and mesosphere. The total mass of ozone produced per day over the globe is about 400 million metric tons. The global mass of ozone is relatively constant at about 3 billion metric tons, meaning the Sun produces about 12% of the ozone layer each day.
Photochemistry
The Chapman cycle describes the main reactions that naturally determine, to first approximation, the concentration of ozone in the stratosphere. It includes four processes - and a fifth, less important one - all involving oxygen atoms and molecules, and UV radiation:
Creation
An oxygen molecule is split (photolyzed) by higher frequency UV light (top end of UV-B, UV-C and above) into two oxygen atoms (see figure):
1. oxygen photodissociation: O2 + ℎν(<242 nm) → 2 O
Each oxygen atom may then combine with an oxygen molecule to form an ozone molecule:
2. ozone creation: O + O2 + A → O3 + A
where A denotes an additional molecule or atom, such as N2 or O2, required to maintain the conservation of energy and momentum in the reaction. Any excess energy is produced as kinetic energy.
The ozone–oxygen cycle
The ozone molecules formed by the reaction (above) absorb radiation with an appropriate wavelength between UV-C and UV-B. The triatomic ozone molecule becomes diatomic molecular oxygen, plus a free oxygen atom (see figure):
3. ozone photodissociation: O3 + ℎν(240–310 nm) → O2 + O
The atomic oxygen produced may react with another oxygen molecule to reform ozone via the ozone creation reaction (reaction 2 above).
These two reactions thus form the ozone–oxygen cycle, wherein the chemical energy released by ozone creation becomes molecular kinetic energy. The n
Document 1:::
The Dobson unit (DU) is a unit of measurement of the amount of a trace gas in a vertical column through the Earth's atmosphere. It originated, and continues to be primarily used in respect to, atmospheric ozone, whose total column amount, usually termed "total ozone", and sometimes "column abundance", is dominated by the high concentrations of ozone in the stratospheric ozone layer.
The Dobson unit is defined as the thickness (in units of 10 μm) of that layer of pure gas which would be formed by the total column amount at standard conditions for temperature and pressure (STP). This is sometimes referred to as a 'milli-atmo-centimeter'. A typical column amount of 300 DU of atmospheric ozone therefore would form a 3 mm layer of pure gas at the surface of the Earth if its temperature and pressure conformed to STP.
The Dobson unit is named after Gordon Dobson, a researcher at the University of Oxford who in the 1920s built the first instrument to measure total ozone from the ground, making use of a double prism monochromator to measure the differential absorption of different bands of solar ultraviolet radiation by the ozone layer. This instrument, called the Dobson ozone spectrophotometer, has formed the backbone of the global network for monitoring atmospheric ozone and was the source of the discovery in 1984 of the Antarctic ozone hole.
Ozone
NASA uses a baseline value of 220 DU for ozone. This was chosen as the starting point for observations of the Antarctic ozone hole, since values of less than 220 Dobson units were not found before 1979. Also, from direct measurements over Antarctica, a column ozone level of less than 220 Dobson units is a result of the ozone loss from chlorine and bromine compounds.
Sulfur dioxide
In addition, Dobson units are often used to describe total column densities of sulfur dioxide, which occurs in the atmosphere in small amounts due to the combustion of fossil fuels, from biological processes releasing dimethyl sulfide, or by natura
Document 2:::
The Electro-Optical Systems Atmospheric Effects Library (EOSAEL) was developed in 1979 by the U.S. Army Atmospheric Sciences Laboratory, which later became a part of the U.S. Army Research Laboratory. EOSAEL was a library of theoretical, semi-empirical, and empirical computer models that described various aspects of atmospheric effects in battlefield environments. As of 1999, EOSAEL consisted of 22 models.
Background
EOSAEL was focused on weather effects and how weather impacts military technology. The battlefield environment includes many sources of aerosols and particulates, including chemical/biological agents, smoke, dust, and chaff. Weather in these environments impacts the functions of military technology, specifically electro-optical devices used for target acquisition. A need for standard tools to facilitate system performance analyses and weather impact decision aids led to development of standard algorithms for modeling efforts, which became a part of EOSAEL.
Description
The EOSAEL modules provide transmittance and radiance calculations through gases, natural aerosols, battlefield aerosols, smoke, haze, fog, and clouds for bandpass and laser propagation. Its operating system is Microsoft Windows 3.1, a graphical display operating system which gives a common interface to hardware. EOSAEL models provide the visible and near-infrared (0.2-2.0 ]dm), mid-infrared (3.0-5.0 urn), far-infrared (8.0-12.0 ym), and millimeter wave (10–350 GHz) regions of the spectrum, plus 53 laser lines.
Document 3:::
The infrared atmospheric window refers to a region of the Infrared spectrum where there is relatively little absorption of terrestrial thermal radiation by atmospheric gases. The window plays an important role in the atmospheric greenhouse effect by maintaining the balance between incoming solar radiation and outgoing IR to space. In the Earth's atmosphere this window is roughly the region between 8 and 14 μm although it can be narrowed or closed at times and places of high humidity because of the strong absorption in the water vapor continuum or because of blocking by clouds. It covers a substantial part of the spectrum from surface thermal emission which starts at roughly 5 μm. Principally it is a large gap in the absorption spectrum of water vapor. Carbon dioxide plays an important role in setting the boundary at the long wavelength end. Ozone partly blocks transmission in the middle of the window.
The importance of the infrared atmospheric window in the atmospheric energy balance was discovered by George Simpson in 1928, based on G. Hettner's 1918 laboratory studies of the gap in the absorption spectrum of water vapor. In those days, computers were not available, and Simpson notes that he used approximations; he writes about the need for this in order to calculate outgoing IR radiation: "There is no hope of getting an exact solution; but by making suitable simplifying assumptions . . . ." Nowadays, accurate line-by-line computations are possible, and careful studies of the spectroscopy of infrared atmospheric gases have been published.
Mechanisms in the infrared atmospheric window
The principal natural greenhouse gases in order of their importance are water vapor , carbon dioxide , ozone , methane and nitrous oxide . The concentration of the least common of these, , is about 400 ppbV. Other gases which contribute to the greenhouse effect are present at pptV levels. These include the chlorofluorocarbons (CFCs), halons and hydrofluorocarbons (HFC and HCFCs). A
Document 4:::
In infrared astronomy, the M band is an atmospheric transmission window centred on 4.7 micrometres (in the mid-infrared).
Electromagnetic spectrum
Infrared imaging
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What harmful light does ozone reduce in the upper atmospheres?
A. infrared light
B. visible light
C. ultraviolet light
D. specific light
Answer:
|
|
sciq-10299
|
multiple_choice
|
What is a mixture of potassium nitrate, sulfur, and charcoal?
|
[
"gasoline",
"gunpowder",
"cyanide",
"TNT"
] |
B
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
Nitrous acid (molecular formula ) is a weak and monoprotic acid known only in solution, in the gas phase and in the form of nitrite () salts. Nitrous acid is used to make diazonium salts from amines. The resulting diazonium salts are reagents in azo coupling reactions to give azo dyes.
Structure
In the gas phase, the planar nitrous acid molecule can adopt both a syn and an anti form. The anti form predominates at room temperature, and IR measurements indicate it is more stable by around 2.3 kJ/mol.
Preparation
Nitrous acid is usually generated by acidification of aqueous solutions of sodium nitrite with a mineral acid. The acidification is usually conducted at ice temperatures, and the HNO2 is consumed in situ. Free nitrous acid is unstable and decomposes rapidly.
Nitrous acid can also be produced by dissolving dinitrogen trioxide in water according to the equation
N2O3 + H2O → 2 HNO2
Reactions
Nitrous acid is the main chemphore in the Liebermann reagent, used to spot-test for alkaloids.
Decomposition
Gaseous nitrous acid, which is rarely encountered, decomposes into nitrogen dioxide, nitric oxide, and water:
2 HNO2 → NO2 + NO + H2O
Nitrogen dioxide disproportionates into nitric acid and nitrous acid in aqueous solution:
2 NO2 + H2O → HNO3 + HNO2
In warm or concentrated solutions, the overall reaction amounts to production of nitric acid, water, and nitric oxide:
3 HNO2 → HNO3 + 2 NO + H2O
The nitric oxide can subsequently be re-oxidized by air to nitric acid, making the overall reaction:
2 HNO2 + O2 → 2 HNO3
Reduction
With I− and Fe2+ ions, NO is formed:
2 HNO2 + 2 KI + 2 H2SO4 → I2 + 2 NO + 2 H2O + 2 K2SO4
2 HNO2 + 2 FeSO4 + 2 H2SO4 → Fe2(SO4)3 + 2 NO + 2 H2O + K2SO4
With Sn2+ ions, N2O is formed:
Document 4:::
Computer science and engineering (CSE) is an academic program at many universities which comprises computer science classes (e.g. data structures and algorithms) and computer engineering classes (e.g computer architecture). There is no clear division in computing between science and engineering, just like in the field of materials science and engineering. CSE is also a term often used in Europe to translate the name of engineering informatics academic programs. It is offered in both undergraduate as well postgraduate with specializations.
Academic courses
Academic programs vary between colleges, but typically include a combination of topics in computer science, computer engineering, and electrical engineering. Undergraduate courses usually include programming, algorithms and data structures, computer architecture, operating systems, computer networks, parallel computing, embedded systems, algorithms design, circuit analysis and electronics, digital logic and processor design, computer graphics, scientific computing, software engineering, database systems, digital signal processing, virtualization, computer simulations and games programming. CSE programs also include core subjects of theoretical computer science such as theory of computation, numerical methods, machine learning, programming theory and paradigms. Modern academic programs also cover emerging computing fields like image processing, data science, robotics, bio-inspired computing, computational biology, autonomic computing and artificial intelligence. Most CSE programs require introductory mathematical knowledge, hence the first year of study is dominated by mathematical courses, primarily discrete mathematics, mathematical analysis, linear algebra, probability, and statistics, as well as the basics of electrical and electronic engineering, physics, and electromagnetism.
Example universities with CSE majors and departments
APJ Abdul Kalam Technological University
American International University-B
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a mixture of potassium nitrate, sulfur, and charcoal?
A. gasoline
B. gunpowder
C. cyanide
D. TNT
Answer:
|
|
sciq-2780
|
multiple_choice
|
What are the active transport mechanisms by which molecules enter and leave the cell inside vesicles?
|
[
"oxidation and exocytosis",
"dielectric and exocytosis",
"endocytosis and exocytosis",
"endocytosis and oxidation"
] |
C
|
Relavent Documents:
Document 0:::
Transcellular transport involves the transportation of solutes by a cell through a cell. Transcellular transport can occur in three different ways active transport, passive transport, and transcytosis.
Active Transport
Main article: Active transport
Active transport is the process of moving molecules from an area of low concentrations to an area of high concentration. There are two types of active transport, primary active transport and secondary active transport. Primary active transport uses adenosine triphosphate (ATP) to move specific molecules and solutes against its concentration gradient. Examples of molecules that follow this process are potassium K+, sodium Na+, and calcium Ca2+. A place in the human body where this occurs is in the intestines with the uptake of glucose. Secondary active transport is when one solute moves down the electrochemical gradient to produce enough energy to force the transport of another solute from low concentration to high concentration. An example of where this occurs is in the movement of glucose within the proximal convoluted tubule (PCT).
Passive Transport
Main article: Passive transport
Passive transport is the process of moving molecules from an area of high concentration to an area of low concentration without expelling any energy. There are two types of passive transport, passive diffusion and facilitated diffusion. Passive diffusion is the unassisted movement of molecules from high concentration to low concentration across a permeable membrane. One example of passive diffusion is the gas exchange that occurs between the oxygen in the blood and the carbon dioxide present in the lungs. Facilitated diffusion is the movement of polar molecules down the concentration gradient with the assistance of membrane proteins. Since the molecules associated with facilitated diffusion are polar, they are repelled by the hydrophobic sections of permeable membrane, therefore they need to be assisted by the membrane proteins. Both t
Document 1:::
Exocytosis () is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell (exo- + cytosis). As an active transport mechanism, exocytosis requires the use of energy to transport material. Exocytosis and its counterpart, endocytosis, are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. Exocytosis is the process by which a large amount of molecules are released; thus it is a form of bulk transport. Exocytosis occurs via secretory portals at the cell plasma membrane called porosomes. Porosomes are permanent cup-shaped lipoprotein structure at the cell plasma membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell.
In exocytosis, membrane-bound secretory vesicles are carried to the cell membrane, where they dock and fuse at porosomes and their contents (i.e., water-soluble molecules) are secreted into the extracellular environment. This secretion is possible because the vesicle transiently fuses with the plasma membrane. In the context of neurotransmission, neurotransmitters are typically released from synaptic vesicles into the synaptic cleft via exocytosis; however, neurotransmitters can also be released via reverse transport through membrane transport proteins.
Exocytosis is also a mechanism by which cells are able to insert membrane proteins (such as ion channels and cell surface receptors), lipids, and other components into the cell membrane. Vesicles containing these membrane components fully fuse with and become part of the outer cell membrane.
History
The term was proposed by De Duve in 1963.
Types
In eukaryotes there are two types of exocytosis:
1) Ca2+ triggered non-constitutive (i.e., regulated exocytosis) and
2) non-Ca2+ triggered constitutive (i.e., non-regulated).
Ca2+ triggered non-const
Document 2:::
Intracellular transport is the movement of vesicles and substances within a cell. Intracellular transport is required for maintaining homeostasis within the cell by responding to physiological signals. Proteins synthesized in the cytosol are distributed to their respective organelles, according to their specific amino acid’s sorting sequence. Eukaryotic cells transport packets of components to particular intracellular locations by attaching them to molecular motors that haul them along microtubules and actin filaments. Since intracellular transport heavily relies on microtubules for movement, the components of the cytoskeleton play a vital role in trafficking vesicles between organelles and the plasma membrane by providing mechanical support. Through this pathway, it is possible to facilitate the movement of essential molecules such as membrane‐bounded vesicles and organelles, mRNA, and chromosomes.
Intracellular transport is unique to eukaryotic cells because they possess organelles enclosed in membranes that need to be mediated for exchange of cargo to take place. Conversely, in prokaryotic cells, there is no need for this specialized transport mechanism because there are no membranous organelles and compartments to traffic between. Prokaryotes are able to subsist by allowing materials to enter the cell via simple diffusion. Intracellular transport is more specialized than diffusion; it is a multifaceted process which utilizes transport vesicles. Transport vesicles are small structures within the cell consisting of a fluid enclosed by a lipid bilayer that hold cargo. These vesicles will typically execute cargo loading and vesicle budding, vesicle transport, the binding of the vesicle to a target membrane and the fusion of the vesicle membranes to target membrane. To ensure that these vesicles embark in the right direction and to further organize the cell, special motor proteins attach to cargo-filled vesicles and carry them along the cytoskeleton. For example, th
Document 3:::
Passive transport is a type of membrane transport that does not require energy to move substances across cell membranes. Instead of using cellular energy, like active transport, passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes. Fundamentally, substances follow Fick's first law, and move from an area of high concentration to an area of low concentration because this movement increases the entropy of the overall system. The rate of passive transport depends on the permeability of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane lipids and proteins. The four main kinds of passive transport are simple diffusion, facilitated diffusion, filtration, and/or osmosis.
Passive transport follows Fick's first law.
Diffusion
Diffusion is the net movement of material from an area of high concentration to an area with lower concentration. The difference of concentration between the two areas is often termed as the concentration gradient, and diffusion will continue until this gradient has been eliminated. Since diffusion moves materials from an area of higher concentration to an area of lower concentration, it is described as moving solutes "down the concentration gradient" (compared with active transport, which often moves material from area of low concentration to area of higher concentration, and therefore referred to as moving the material "against the concentration gradient").
However, in many cases (e.g. passive drug transport) the driving force of passive transport can not be simplified to the concentration gradient. If there are different solutions at the two sides of the membrane with different equilibrium solubility of the drug, the difference in the degree of saturation is the driving force of passive membrane transport. It is also true for supersaturated solutions which are more and more important owing to the spreading of the application of amorph
Document 4:::
In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. The regulation of passage through the membrane is due to selective membrane permeability – a characteristic of biological membranes which allows them to separate substances of distinct chemical nature. In other words, they can be permeable to certain substances but not to others.
The movements of most solutes through the membrane are mediated by membrane transport proteins which are specialized to varying degrees in the transport of specific molecules. As the diversity and physiology of the distinct cells is highly related to their capacities to attract different external elements, it is postulated that there is a group of specific transport proteins for each cell type and for every specific physiological stage. This differential expression is regulated through the differential transcription of the genes coding for these proteins and its translation, for instance, through genetic-molecular mechanisms, but also at the cell biology level: the production of these proteins can be activated by cellular signaling pathways, at the biochemical level, or even by being situated in cytoplasmic vesicles. The cell membrane regulates the transport of materials entering and exiting the cell.
Background
Thermodynamically the flow of substances from one compartment to another can occur in the direction of a concentration or electrochemical gradient or against it. If the exchange of substances occurs in the direction of the gradient, that is, in the direction of decreasing potential, there is no requirement for an input of energy from outside the system; if, however, the transport is against the gradient, it will require the input of energy, metabolic energy in this case.
For example, a classic chemical mechanism for separation that does
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the active transport mechanisms by which molecules enter and leave the cell inside vesicles?
A. oxidation and exocytosis
B. dielectric and exocytosis
C. endocytosis and exocytosis
D. endocytosis and oxidation
Answer:
|
|
sciq-3044
|
multiple_choice
|
What kind of volcanic eruptions are less deadly?
|
[
"non-explosive",
"serial eruptions",
"non-dormant",
"explosive"
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Explosive volcanic eruptions affect the global climate in several ways.
Lowering sea surface temperature
One main impact of volcanoes is the injection of sulfur-bearing gases into the stratosphere, which oxidize to form sulfate aerosols. Stratospheric sulfur aerosols spread around the globe by the atmospheric circulation, producing surface cooling by scattering solar radiation back to space. This cooling effect on the ocean surface usually lasts for several years as the lifetime of sulfate aerosols is about 2–3 years. However, in the subsurface ocean the cooling signal may persist for a longer time and may have impacts on some decadal variabilities, such as the Atlantic meridional overturning circulation (AMOC).
Volcanic aerosols from huge volcanoes (VEI>=5) directly reduce global mean sea surface temperature (SST) by approximately 0.2-0.3 °C, milder than global total surface temperature drop, which is ~0.3 to 0.5 °C, according to both global temperature records and model simulations. It usually takes several years to be back to normal.
Decreasing ocean heat content
The volcanic cooling signals in ocean heat content can persist for much longer time (decadal or mutil-decadal time scale), far beyond the duration of volcanic forcing.
Several studies have revealed that Krakatau’s effect in the heat content can be as long as one-century. Relaxation time of the effects of recent volcanoes is generally shorter than those before the 1950s. For example, the recovery time of ocean heat content of Pinatubo, which caused comparable radiative forcing to Krakatau, seems to be much shorter. This is because Pinatubo happened under a warm and non-stationary background with increasing greenhouse gas forcing. However, its signal still could penetrate down to ~1000 m deep.
A 2022 study on environmental impacts of volcanic eruptions showed that in the eastern equatorial of the pacific, after the volcano erupts, some low-latitude volcano trends to warmer. But some highlatitude vol
Document 2:::
Maui Nui is a modern geologists' name given to a prehistoric Hawaiian island and the corresponding modern biogeographic region. Maui Nui is composed of four modern islands: Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe. Administratively, the four modern islands comprise Maui County (and a tiny part of Molokaʻi called Kalawao County). Long after the breakup of Maui Nui, the four modern islands retained plant and animal life similar to each other. Thus, Maui Nui is not only a prehistoric island but also a modern biogeographic region.
Geology
Maui Nui formed and broke up during the Pleistocene Epoch, which lasted from about 2.58 million to 11,700 years ago.
Maui Nui is built from seven shield volcanoes. The three oldest are Penguin Bank, West Molokaʻi, and East Molokaʻi, which probably range from slightly over to slightly less than 2 million years old. The four younger volcanoes are Lāna‘i, West Maui, Kaho‘olawe, and Haleakalā, which probably formed between 1.5 and 2 million years ago.
At its prime 1.2 million years ago, Maui Nui was , 50% larger than today's Hawaiʻi Island. The island of Maui Nui included four modern islands (Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe) and landmass west of Molokaʻi called Penguin Bank, which is now completely submerged.
Maui Nui broke up as rising sea levels flooded the connections between the volcanoes. The breakup was complex because global sea levels rose and fell intermittently during the Quaternary glaciation. About 600,000 years ago, the connection between Molokaʻi and the island of Lāna‘i/Maui/Kahoʻolawe became intermittent. About 400,000 years ago, the connection between Lāna‘i and Maui/Kahoʻolawe also became intermittent. The connection between Maui and Kahoʻolawe was permanently broken between 200,000 and 150,000 years ago. Maui, Lāna‘i, and Molokaʻi were connected intermittently thereafter, most recently about 18,000 years ago during the Last Glacial Maximum.
Today, the sea floor between these four islands is relatively shallow
Document 3:::
Martian geysers (or jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions.
Martian geysers are distinct from geysers on Earth, which are typically associated with hydrothermal activity. These are unlike any terrestrial geological phenomenon. The reflectance (albedo), shapes and unusual spider appearance of these features have stimulated a variety of hypotheses about their origin, ranging from differences in frosting reflectance, to explanations involving biological processes. However, all current geophysical models assume some sort of jet or geyser-like activity on Mars. Their characteristics, and the process of their formation, are still a matter of debate.
These features are unique to the south polar region of Mars in an area informally called the 'cryptic region', at latitudes 60° to 80° south and longitudes 150°W to 310°W; this 1 meter deep carbon dioxide (CO2) ice transition area—between the scarps of the thick polar ice layer and the permafrost—is where clusters of the apparent geyser systems are located.
The seasonal frosting and defrosting of carbon dioxide ice results in the appearance of a number of features, such dark dune spots with spider-like rilles or channels below the ice, where spider-like radial channels are carved between the ground and the carbon dioxide ice, giving it an appearance of spider webs, then, pressure accumulating in their interior ejects gas and dark basaltic sand or dust, which is deposited on the ice surface and thus, forming dark dune spots. This process is rapid, observed happening in the space of a few days, weeks or months, a growth rate rather unusual in geology – especially for Mars. However, it would seem that multiple years would be required to carve the larger spider-like channels. There is no direct data on these features othe
Document 4:::
The mid-24th century BCE climate anomaly is the period, between 2354–2345 BCE, of consistently, reduced annual temperatures that are reconstructed from consecutive abnormally narrow, Irish oak tree rings. These tree rings are indicative of a period of catastrophically reduced growth in Irish trees during that period. This range of dates also matches the transition from the Neolithic to the Bronze Age in the British Isles and a period of widespread societal collapse in the Near East. It has been proposed that this anomalous downturn in the climate might have been the result of comet debris suspended in the atmosphere.
In 1997, Marie-Agnès Courty proposed that a natural disaster involving wildfires, floods, and an air blast of over 100 megatons power occurred about 2350 BCE. This proposal is based on unusual "dust" deposits which have been reported from archaeological sites in Mesopotamia that are a few hundred kilometres from each other. In later papers, Courty subsequently revised the date of this event from 2350 BCE to 2000 BCE.
Based only upon the analysis of satellite imagery, Umm al Binni lake in southern Iraq has been suggested as a possible extraterrestrial impact crater and possible cause of this natural disaster. More recent sources have argued for a formation of the lake through the subsidence of the underlying basement fault blocks. Baillie and McAneney's 2015 discussion of this climate anomaly discusses its abnormally narrow Irish tree rings and the anomalous dust deposits of Courty. However, this paper lacks any mention of Umm al Binni lake.
See also
4.2-kiloyear event, c. 2200 BCE
Great Flood (China), c. 2300 BCE
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of volcanic eruptions are less deadly?
A. non-explosive
B. serial eruptions
C. non-dormant
D. explosive
Answer:
|
|
sciq-3487
|
multiple_choice
|
What term refers to the conditions of the atmosphere from day to day?
|
[
"temperture",
"weather",
"climate",
"humidity"
] |
B
|
Relavent Documents:
Document 0:::
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. (see also: List of meteorological phenomena)
A
advection
aeroacoustics
aerobiology
aerography (meteorology)
aerology
air parcel (in meteorology)
air quality index (AQI)
airshed (in meteorology)
American Geophysical Union (AGU)
American Meteorological Society (AMS)
anabatic wind
anemometer
annular hurricane
anticyclone (in meteorology)
apparent wind
Atlantic Oceanographic and Meteorological Laboratory (AOML)
Atlantic hurricane season
atmometer
atmosphere
Atmospheric Model Intercomparison Project (AMIP)
Atmospheric Radiation Measurement (ARM)
(atmospheric boundary layer [ABL]) planetary boundary layer (PBL)
atmospheric chemistry
atmospheric circulation
atmospheric convection
atmospheric dispersion modeling
atmospheric electricity
atmospheric icing
atmospheric physics
atmospheric pressure
atmospheric sciences
atmospheric stratification
atmospheric thermodynamics
atmospheric window (see under Threats)
B
ball lightning
balloon (aircraft)
baroclinity
barotropity
barometer ("to measure atmospheric pressure")
berg wind
biometeorology
blizzard
bomb (meteorology)
buoyancy
Bureau of Meteorology (in Australia)
C
Canada Weather Extremes
Canadian Hurricane Centre (CHC)
Cape Verde-type hurricane
capping inversion (in meteorology) (see "severe thunderstorms" in paragraph 5)
carbon cycle
carbon fixation
carbon flux
carbon monoxide (see under Atmospheric presence)
ceiling balloon ("to determine the height of the base of clouds above ground level")
ceilometer ("to determine the height of a cloud base")
celestial coordinate system
celestial equator
celestial horizon (rational horizon)
celestial navigation (astronavigation)
celestial pole
Celsius
Center for Analysis and Prediction of Storms (CAPS) (in Oklahoma in the US)
Center for the Study o
Document 1:::
The following outline is provided as an overview of and topical guide to the field of Meteorology.
Meteorology The interdisciplinary, scientific study of the Earth's atmosphere with the primary focus being to understand, explain, and forecast weather events. Meteorology, is applied to and employed by a wide variety of diverse fields, including the military, energy production, transport, agriculture, and construction.
Essence of meteorology
Meteorology
Climate – the average and variations of weather in a region over long periods of time.
Meteorology – the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting (in contrast with climatology).
Weather – the set of all the phenomena in a given atmosphere at a given time.
Branches of meteorology
Microscale meteorology – the study of atmospheric phenomena about 1 km or less, smaller than mesoscale, including small and generally fleeting cloud "puffs" and other small cloud features
Mesoscale meteorology – the study of weather systems about 5 kilometers to several hundred kilometers, smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems, skjjoch as sea breezes, squall lines, and mesoscale convective complexes
Synoptic scale meteorology – is a horizontal length scale of the order of 1000 kilometres (about 620 miles) or more
Methods in meteorology
Surface weather analysis – a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations
Weather forecasting
Weather forecasting – the application of science and technology to predict the state of the atmosphere for a future time and a given location
Data collection
Pilot Reports
Weather maps
Weather map
Surface weather analysis
Forecasts and reporting of
Atmospheric pressure
Dew point
High-pressure area
Ice
Black ice
Frost
Low-pressure area
Precipitation
Document 2:::
The term standard day is used throughout meteorology, aviation, and other sciences and disciplines as a way of defining certain properties of the atmosphere in a manner which allows those who use our atmosphere to effectively calculate and communicate its properties at any given time. For example, a temperature deviation of +8 °C means that the air at any given altitude is 8 °C (14 °F) warmer than what standard day conditions and the measurement altitude would predict, and would indicate a higher density altitude. These variations are extremely important to both meteorologists and aviators, as they strongly determine the different properties of the atmosphere.
For example, on a cool day, an airliner might have no problem safely departing a medium length runway, but on a warmer day, the density altitude might be higher, require a higher ground speed and true airspeed prior to liftoff, which would require more acceleration, a longer runway, and a reduced climb rate after liftoff. The pilot may choose to reduce the gross weight of the aircraft by carrying less fuel or reducing the amount/weight of the cargo, or even reducing the number of passengers (usually the last option). Not carrying sufficient fuel to complete the flight to the destination, the pilot would plan an intermediate fuel stop, which would likely delay the final destination arrival time. In meteorology, departure from standard day conditions is what gives rise to all weather phenomena, including thunderstorms, fronts, clouds, even the heating and cooling of our planet.
Standard day parameters
For Pilots: At sea level, Altimeter:29.92 in/Hg at
The "standard day" model of the atmosphere is defined at sea level, with certain present conditions such as temperature and pressure. But other factors, such as humidity, further alter the nature of the atmosphere, and are also defined under standard day conditions:
Density (ρ): 1.225 kg/m3 (0.00237 slug/ft3)
Pressure (p): 101.325 kPa (14.7 lb/ in2)
Document 3:::
A temperature gradient is a physical quantity that describes in which direction and at what rate the temperature changes the most rapidly around a particular location. The temperature gradient is a dimensional quantity expressed in units of degrees (on a particular temperature scale) per unit length. The SI unit is kelvin per meter (K/m).
Temperature gradients in the atmosphere are important in the atmospheric sciences (meteorology, climatology and related fields).
Mathematical description
Assuming that the temperature T is an intensive quantity, i.e., a single-valued, continuous and differentiable function of three-dimensional space (often called a scalar field), i.e., that
where x, y and z are the coordinates of the location of interest, then the temperature gradient is the vector quantity defined as
Physical processes
Climatology
On a global and annual basis, the dynamics of the atmosphere (and the oceans) can be understood as attempting to reduce the large difference of temperature between the poles and the equator by redistributing warm and cold air and water, known as Earth's heat engine.
Meteorology
Differences in air temperature between different locations are critical in weather forecasting and climate. The absorption of solar light at or near the planetary surface increases the temperature gradient and may result in convection (a major process of cloud formation, often associated with precipitation).
Meteorological fronts are regions where the horizontal temperature gradient may reach relatively high values, as these are boundaries between air masses with rather distinct properties.
Clearly, the temperature gradient may change substantially in time, as a result of diurnal or seasonal heating and cooling for instance. This most likely happens during an inversion. For instance, during the day the temperature at ground level may be cold while it's warmer up in the atmosphere. As the day shifts over to night the temperature might drop rapidly while
Document 4:::
Biometeorology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or shorter (in contrast with bioclimatology).
Examples of relevant processes
Weather events influence biological processes on short time scales. For instance, as the Sun rises above the horizon in the morning, light levels become sufficient for the process of photosynthesis to take place in plant leaves. Later on, during the day, air temperature and humidity may induce the partial or total closure of the stomata, a typical response of many plants to limit the loss of water through transpiration. More generally, the daily evolution of meteorological variables controls the circadian rhythm of plants and animals alike.
Living organisms, for their part, can collectively affect weather patterns. The rate of evapotranspiration of forests, or of any large vegetated area for that matter, contributes to the release of water vapor in the atmosphere. This local, relatively fast and continuous process may contribute significantly to the persistence of precipitations in a given area. As another example, the wilting of plants results in definite changes in leaf angle distribution and therefore modifies the rates of reflection, transmission and absorption of solar light in these plants. That, in turn, changes the albedo of the ecosystem as well as the relative importance of the sensible and latent heat fluxes from the surface to the atmosphere. For an example in oceanography, consider the release of dimethyl sulfide by biological activity in sea water and its impact on atmospheric aerosols.
Human biometeorology
The methods and measurements traditionally used in biometeorology are not different when applied to study the interactions between human bodies and the atmosphere, but some aspects or applications may have been explored more extensively. For instance, wind chill has been investigated to determine th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term refers to the conditions of the atmosphere from day to day?
A. temperture
B. weather
C. climate
D. humidity
Answer:
|
|
sciq-5324
|
multiple_choice
|
The accumulation of what cells begin the development of the vertebral column and thoracic cage?
|
[
"mesenchyme cells",
"hindbrain cells",
"semiosis cells",
"False cells"
] |
A
|
Relavent Documents:
Document 0:::
This is a list of cells in humans derived from the three embryonic germ layers – ectoderm, mesoderm, and endoderm.
Cells derived from ectoderm
Surface ectoderm
Skin
Trichocyte
Keratinocyte
Anterior pituitary
Gonadotrope
Corticotrope
Thyrotrope
Somatotrope
Lactotroph
Tooth enamel
Ameloblast
Neural crest
Peripheral nervous system
Neuron
Glia
Schwann cell
Satellite glial cell
Neuroendocrine system
Chromaffin cell
Glomus cell
Skin
Melanocyte
Nevus cell
Merkel cell
Teeth
Odontoblast
Cementoblast
Eyes
Corneal keratocyte
Neural tube
Central nervous system
Neuron
Glia
Astrocyte
Ependymocytes
Muller glia (retina)
Oligodendrocyte
Oligodendrocyte progenitor cell
Pituicyte (posterior pituitary)
Pineal gland
Pinealocyte
Cells derived from mesoderm
Paraxial mesoderm
Mesenchymal stem cell
Osteochondroprogenitor cell
Bone (Osteoblast → Osteocyte)
Cartilage (Chondroblast → Chondrocyte)
Myofibroblast
Fat
Lipoblast → Adipocyte
Muscle
Myoblast → Myocyte
Myosatellite cell
Tendon cell
Cardiac muscle cell
Other
Fibroblast → Fibrocyte
Other
Digestive system
Interstitial cell of Cajal
Intermediate mesoderm
Renal stem cell
Angioblast → Endothelial cell
Mesangial cell
Intraglomerular
Extraglomerular
Juxtaglomerular cell
Macula densa cell
Stromal cell → Interstitial cell → Telocytes
Simple epithelial cell → Podocyte
Kidney proximal tubule brush border cell
Reproductive system
Sertoli cell
Leydig cell
Granulosa cell
Peg cell
Germ cells (which migrate here primordially)
spermatozoon
ovum
Lateral plate mesoderm
Hematopoietic stem cell
Lymphoid
Lymphoblast
see lymphocytes
Myeloid
CFU-GEMM
see myeloid cells
Circulatory system
Endothelial progenitor cell
Endothelial colony forming cell
Endothelial stem cell
Angioblast/Mesoangioblast
Pericyte
Mural cell
Document 1:::
The progress zone is a layer of mesodermal cells immediately beneath the apical ectodermal ridge in the developing limb bud. The fate of the mesodermal cells is thought to be patterned by the length of time spent in the progress zone during limb outgrowth. However, some recent evidence using microinjected embryos suggests that the cells are prespecified early in limb bud development.
The progress zone acts as positional information to tell which cells to develop into the limb. If cells spend a very short time in this area as they receive signals from the apical ectodermal ridge, then more proximal limb structures are not able to develop even if distal ones can.
Document 2:::
Vertebrates
Tendon cells, or tenocytes, are elongated fibroblast type cells. The cytoplasm is stretched between the collagen fibres of the tendon. They have a central cell nucleus with a prominent nucleolus. Tendon cells have a well-developed rough endoplasmic reticulum and they are responsible for synthesis and turnover of tendon fibres and ground substance.
Invertebrates
Tendon cells form a connecting epithelial layer between the muscle and shell in molluscs. In gastropods, for example, the retractor muscles connect to the shell via tendon cells. Muscle cells are attached to the collagenous myo-tendon space via hemidesmosomes. The myo-tendon space is then attached to the base of the tendon cells via basal hemidesmosomes, while apical hemidesmosomes, which sit atop microvilli, attach the tendon cells to a thin layer of collagen. This is in turn attached to the shell via organic fibres which insert into the shell. Molluscan tendon cells appear columnar and contain a large basal cell nucleus. The cytoplasm is filled with granular endoplasmic reticulum and sparse golgi. Dense bundles of microfilaments run the length of the cell connecting the basal to the apical hemidesmosomes.
See also
List of human cell types derived from the germ layers
List of distinct cell types in the adult human body
Document 3:::
Paraxial mesoderm, also known as presomitic or somitic mesoderm, is the area of mesoderm in the neurulating embryo that flanks and forms simultaneously with the neural tube. The cells of this region give rise to somites, blocks of tissue running along both sides of the neural tube, which form muscle and the tissues of the back, including connective tissue and the dermis.
Formation and somitogenesis
The paraxial and other regions of the mesoderm are thought to be specified by bone morphogenetic proteins (BMPs) along an axis spanning from the center to the sides of the body. Members of the fibroblast growth factor family also play an important role, as does the Wnt pathway. In particular, Noggin, a downstream target of the Wnt pathway, antagonizes BMP signaling, forming boundaries where antagonists meet and limiting this signaling to a particular region of the mesoderm. Together, these pathways provide the initial specification of the paraxial mesoderm and maintain this identity.
This specification process has now been fully recapitulated in vitro with the formation of paraxial mesoderm progenitors from pluripotent stem cells, using a directed differentiation approach.
The tissue undergoes convergent extension as the primitive streak regresses, or as the embryo gastrulates. The notochord extends from the base of the head to the tail; with it extend thick bands of paraxial mesoderm.
As the primitive streak continues to regress, somites form from the paraxial mesoderm by "budding off" rostrally.
In certain model systems, it has been shown that the daughter cells of stem cell-like progenitor cells which come from the primitive streak or site of gastrulation migrate out and localize in the posterior paraxial mesoderm. As the primitive streak regresses and somites bud off anteriorly, new cells derived from these stem-cell like precursors constantly enter the posterior end of the paraxial mesoderm.
Derived tissues
Many kinds of tissue derive from the segmented paraxi
Document 4:::
Stem Cells is a peer-review scientific journal of cell biology. It was established as The International Journal of Cell Cloning in 1983, acquiring its current title in 1993.
The journal is published by AlphaMed Press, and is currently edited by Jan Nolta (University of California). Stem Cells currently has an impact factor of 6.277.
Abstracting and indexing
The journal is abstracted and indexed in the following bibliographic databases:
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The accumulation of what cells begin the development of the vertebral column and thoracic cage?
A. mesenchyme cells
B. hindbrain cells
C. semiosis cells
D. False cells
Answer:
|
|
sciq-3687
|
multiple_choice
|
What type of mapping is critical for identifying the location of genes that cause genetic diseases?
|
[
"interaction mapping",
"diagnostic mapping",
"linkage mapping",
"chemical mapping"
] |
C
|
Relavent Documents:
Document 0:::
Gene mapping or genome mapping describes the methods used to identify the location of a gene on a chromosome and the distances between genes. Gene mapping can also describe the distances between different sites within a gene.
The essence of all genome mapping is to place a collection of molecular markers onto their respective positions on the genome. Molecular markers come in all forms. Genes can be viewed as one special type of genetic markers in the construction of genome maps, and mapped the same way as any other markers. In some areas of study, gene mapping contributes to the creation of new recombinants within an organism.
Gene maps help describe the spatial arrangement of genes on a chromosome. Genes are designated to a specific location on a chromosome known as the locus and can be used as molecular markers to find the distance between other genes on a chromosome. Maps provide researchers with the opportunity to predict the inheritance patterns of specific traits, which can eventually lead to a better understanding of disease-linked traits.
The genetic basis to gene maps is to provide an outline that can potentially help researchers carry out DNA sequencing. A gene map helps point out the relative positions of genes and allows researchers to locate regions of interest in the genome. Genes can then be identified quickly and sequenced quickly.
Two approaches to generating gene maps (gene mapping) include physical mapping and genetic mapping. Physical mapping utilizes molecular biology techniques to inspect chromosomes. These techniques consequently allow researchers to observe chromosomes directly so that a map may be constructed with relative gene positions. Genetic mapping on the other hand uses genetic techniques to indirectly find association between genes. Techniques can include cross-breeding (hybrid) experiments and examining pedigrees. These technique allow for maps to be constructed so that relative positions of genes and other important sequences
Document 1:::
In genetics, a morbid map is a chart or diagram of diseases and the chromosomal location of genes the diseases are associated with. A morbid map exists as an appendix of the Online Mendelian Inheritance in Man (OMIM) knowledgebase, listing chromosomes and the genes mapped to specific sites on those chromosomes, and this format most clearly reveals the relationship between gene and phenotype.
Document 2:::
The Personal Genetics Education Project (pgEd) aims to engage and inform a worldwide audience about the benefits of knowing one's genome as well as the ethical, legal and social issues (ELSI) and dimensions of personal genetics. pgEd was founded in 2006, is housed in the Department of Genetics at Harvard Medical School and is directed by Ting Wu, a professor in that department. It employs a variety of strategies for reaching general audiences, including generating online curricular materials, leading discussions in classrooms, workshops, and conferences, developing a mobile educational game (Map-Ed), holding an annual conference geared toward accelerating awareness (GETed), and working with the world of entertainment to improve accuracy and outreach.
Online curricular materials and professional development for teachers
pgEd develops tools for teachers and general audiences that examine the potential benefits and risks of personalized genome analysis. These include freely accessible, interactive lesson plans that tackle issues such as genetic testing of minors, reproductive genetics, complex human traits and genetics, and the history of eugenics. pgEd also engages educators at conferences as well as organizes professional development workshops. All of pgEd's materials are freely available online.
Map-Ed, a mobile quiz
In 2013, pgEd created a mobile educational quiz called Map-Ed. Map-Ed invites players to work their way through five questions that address key concepts in genetics and then pin themselves on a world map. Within weeks of its launch, Map-Ed gained over 1,000 pins around the world, spanning across all 7 continents. Translations and new maps linked to questions on topics broadly related to genetics are in development.
GETed conference
pgEd hosts the annual GETed conference, a meeting that brings together experts from across the United States and beyond in education, research, health, entertainment, and policy to develop strategies for acceleratin
Document 3:::
In genetics, association mapping, also known as "linkage disequilibrium mapping", is a method of mapping quantitative trait loci (QTLs) that takes advantage of historic linkage disequilibrium to link phenotypes (observable characteristics) to genotypes (the genetic constitution of organisms), uncovering genetic associations.
Theory
Association mapping is based on the idea that traits that have entered a population only recently will still be linked to the surrounding genetic sequence of the original evolutionary ancestor, or in other words, will more often be found within a given haplotype, than outside of it. It is most often performed by scanning the entire genome for significant associations between a panel of single nucleotide polymorphisms (SNPs) (which, in many cases are spotted onto glass slides to create "SNP chips") and a particular phenotype. These associations must then be independently verified in order to show that they either (a) contribute to the trait of interest directly, or (b) are linked to/ in linkage disequilibrium with a quantitative trait locus (QTL) that contributes to the trait of interest.
Association mapping seeks to identify specific functional genetic variants (loci, alleles) linked to phenotypic differences in a trait to facilitate detection of trait causing DNA sequence polymorphisms and selection of genotypes that closely resemble the phenotype. In order to identify these functional variants, it requires high throughput markers like SNPs.
Use
The advantage of association mapping is that it can map quantitative traits with high resolution in a way that is statistically very powerful. Association mapping, however, also requires extensive knowledge of SNPs within the genome of the organism of interest, and is therefore difficult to perform in species that have not been well studied or do not have well-annotated genomes. Association mapping has been most widely applied to the study of human disease, specifically in the form of a genom
Document 4:::
Genetics (from Ancient Greek , “genite” and that from , “origin”), a discipline of biology, is the science of heredity and variation in living organisms.
Articles (arranged alphabetically) related to genetics include:
#
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of mapping is critical for identifying the location of genes that cause genetic diseases?
A. interaction mapping
B. diagnostic mapping
C. linkage mapping
D. chemical mapping
Answer:
|
|
sciq-6675
|
multiple_choice
|
Water is a polar compound, so its molecules are attracted to each other and form what kind of bonds?
|
[
"carbon",
"helium",
"hydrogen",
"mixed"
] |
C
|
Relavent Documents:
Document 0:::
In chemistry, the carbon-hydrogen bond ( bond) is a chemical bond between carbon and hydrogen atoms that can be found in many organic compounds. This bond is a covalent, single bond, meaning that carbon shares its outer valence electrons with up to four hydrogens. This completes both of their outer shells, making them stable.
Carbon–hydrogen bonds have a bond length of about 1.09 Å (1.09 × 10−10 m) and a bond energy of about 413 kJ/mol (see table below). Using Pauling's scale—C (2.55) and H (2.2)—the electronegativity difference between these two atoms is 0.35. Because of this small difference in electronegativities, the bond is generally regarded as being non-polar. In structural formulas of molecules, the hydrogen atoms are often omitted. Compound classes consisting solely of bonds and bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as hydrocarbons.
In October 2016, astronomers reported that the very basic chemical ingredients of life—the carbon-hydrogen molecule (CH, or methylidyne radical), the carbon-hydrogen positive ion () and the carbon ion ()—are the result, in large part, of ultraviolet light from stars, rather than in other ways, such as the result of turbulent events related to supernovae and young stars, as thought earlier.
Bond length
The length of the carbon-hydrogen bond varies slightly with the hybridisation of the carbon atom. A bond between a hydrogen atom and an sp2 hybridised carbon atom is about 0.6% shorter than between hydrogen and sp3 hybridised carbon. A bond between hydrogen and sp hybridised carbon is shorter still, about 3% shorter than sp3 C-H. This trend is illustrated by the molecular geometry of ethane, ethylene and acetylene.
Reactions
The C−H bond in general is very strong, so it is relatively unreactive. In several compound classes, collectively called carbon acids, the C−H bond can be sufficiently acidic for proton removal. Unactivated C−H bonds are found in alkanes and are no
Document 1:::
Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons. It often, but not always, involves some chemical bonding.
In some cases, the associations can be quite strong—for example, the protein streptavidin and the vitamin biotin have a dissociation constant (reflecting the ratio between bound and free biotin) on the order of 10−14—and so the reactions are effectively irreversible. The result of molecular binding is sometimes the formation of a molecular complex in which the attractive forces holding the components together are generally non-covalent, and thus are normally energetically weaker than covalent bonds.
Molecular binding occurs in biological complexes (e.g., between pairs or sets of proteins, or between a protein and a small molecule ligand it binds) and also in abiologic chemical systems, e.g. as in cases of coordination polymers and coordination networks such as metal-organic frameworks.
Types
Molecular binding can be classified into the following types:
Non-covalent – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
Reversible covalent – a chemical bond is formed, however the free energy difference separating the noncovalently-bonded reactants from bonded product is near equilibrium and the activation barrier is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
Irreversible covalent – a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such that the reverse reaction does not take place.
Bound molecules are sometimes called a "molecular complex"—the term generally refers to non-covalent associations. Non-covalent interactions can effectively become irreversible; for example, tight binding inhibitors of enzymes
Document 2:::
Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe (behind molecular hydrogen and carbon monoxide).
Water molecules form hydrogen bonds with each other and are strongly polar. This polarity allows it to dissociate ions in salts and bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a relatively high boiling point of 100 °C for its molar mass, and a high heat capacity.
Water is amphoteric, meaning that it can exhibit properties of an acid or a base, depending on the pH of the solution that it is in; it readily produces both and ions. Related to its amphoteric character, it undergoes self-ionization. The product of the activities, or approximately, the concentrations of and is a constant, so their respective concentrations are inversely proportional to each other.
Physical properties
Water is the chemical substance with chemical formula ; one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. Water is a tasteless, odorless liquid at ambient temperature and pressure. Liquid water has weak absorption bands at wavelengths of around 750 nm which cause it to appear to have a blue color. This can easily be observed in a water-filled bath or wash-basin whose lining is white. Large ice crystals, as in glaciers, also appear blue.
Under standard conditions, water is primarily a liquid, unlike other analogous hydrides of the oxygen family, which are generally gaseou
Document 3:::
A chemical bonding model is a theoretical model used to explain atomic bonding structure, molecular geometry, properties, and reactivity of physical matter. This can refer to:
VSEPR theory, a model of molecular geometry.
Valence bond theory, which describes molecular electronic structure with localized bonds and lone pairs.
Molecular orbital theory, which describes molecular electronic structure with delocalized molecular orbitals.
Crystal field theory, an electrostatic model for transition metal complexes.
Ligand field theory, the application of molecular orbital theory to transition metal complexes.
Chemical bonding
Document 4:::
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.
In contrast, hydrophobes are not attracted to water and may seem to be repelled by it. Hygroscopics are attracted to water, but are not dissolved by water.
Molecules
A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more thermodynamically favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in other polar solvents.
Hydrophilic molecules (and portions of molecules) can be contrasted with hydrophobic molecules (and portions of molecules). In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiphilic molecules is the lipids that comprise the cell membrane. Another example is soap, which has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both water and oil.
Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively. Some hydrophilic substances do not dissolve. This type of mixture is called a colloid.
An approximate rule of thumb for hydrophilicity of organic compounds is that solubility of a molecule in water is more than 1 mass % if there is at least one neutral hydrophile group per 5 carbons, or at least one electrically charged hydrophile group per 7 carbons.
Hydrophilic substances (ex: salts) can seem to attract water out of the air. Sugar is also hydrophilic, and like salt is sometimes used to draw water out of foods. Sugar sprinkled on cut fruit will "draw out the water" through hydrophilia, making the fruit mushy and wet, as in a common strawberry compote recipe.
Chemicals
Liquid hydrophilic chemicals complexed with solid chemicals can be used to optimize solubility of hydrophobic chemical
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Water is a polar compound, so its molecules are attracted to each other and form what kind of bonds?
A. carbon
B. helium
C. hydrogen
D. mixed
Answer:
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|
ai2_arc-235
|
multiple_choice
|
Which statement describes how muscles work to allow a person to extend an arm from a curled position by straightening the elbow?
|
[
"Both the biceps and triceps contract.",
"Both the biceps and the triceps relax.",
"The triceps contract and the biceps relax.",
"The biceps contract and the triceps relax."
] |
C
|
Relavent Documents:
Document 0:::
In an isotonic contraction, tension remains the same, whilst the muscle's length changes. Isotonic contractions differ from isokinetic contractions in that in isokinetic contractions the muscle speed remains constant. While superficially identical, as the muscle's force changes via the length-tension relationship during a contraction, an isotonic contraction will keep force constant while velocity changes, but an isokinetic contraction will keep velocity constant while force changes. A near isotonic contraction is known as Auxotonic contraction.
There are two types of isotonic contractions: (1) concentric and (2) eccentric. In a concentric contraction, the muscle tension rises to meet the resistance, then remains the same as the muscle shortens. In eccentric, the muscle lengthens due to the resistance being greater than the force the muscle is producing.
Concentric
This type is typical of most exercise. The external force on the muscle is less than the force the muscle is generating - a shortening contraction. The effect is not visible during the classic biceps curl, which is in fact auxotonic because the resistance (torque due to the weight being lifted) does not remain the same through the exercise. Tension is highest at a parallel to the floor level, and eases off above and below this point. Therefore, tension changes as well as muscle length.
Eccentric
There are two main features to note regarding eccentric contractions. First, the absolute tensions achieved can be very high relative to the muscle's maximum tetanic tension generating capacity (you can set down a much heavier object than you can lift). Second, the absolute tension is relatively independent of lengthening velocity.
Muscle injury and soreness are selectively associated with eccentric contraction. Muscle strengthening using exercises that involve eccentric contractions is lower than using concentric exercises. However because higher levels of tension are easier to attain during exercises th
Document 1:::
Reciprocal inhibition describes the relaxation of muscles on one side of a joint to accommodate contraction on the other side. In some allied health disciplines, this is known as reflexive antagonism. The central nervous system sends a message to the agonist muscle to contract. The tension in the antagonist muscle is activated by impulses from motor neurons, causing it to relax.
Mechanics
Joints are controlled by two opposing sets of muscles called extensors and flexors, that work in synchrony for smooth movement. When a muscle spindle is stretched, the stretch reflex is activated, and the opposing muscle group must be inhibited to prevent it from working against the contraction of the homonymous muscle. This inhibition is accomplished by the actions of an inhibitor interneuron in the spinal cord.
The afferent of the muscle spindle bifurcates in the spinal cord. One branch innervates the alpha motor neuron that causes the homonymous muscle to contract, producing the reflex. The other branch innervates the inhibitory interneuron, which then innervates the alpha motor neuron that synapses onto the opposing muscle. Because the interneuron is inhibitory, it prevents the opposing alpha motor neuron from firing, thereby reducing the contraction of the opposing muscle. Without this reciprocal inhibition, both groups of muscles might contract simultaneously and work against each other.
If opposing muscles were to contract at the same time, a muscle tear can occur. This may occur during physical activities such as running, during which opposing muscles engage and disengage sequentially to produce coordinated movement. Reciprocal inhibition facilitates ease of movement and is a safeguard against injury. However, if a "misfiring" of motor neurons occurs, causing simultaneous contraction of opposing muscles, a tear can occur. For example, if the quadriceps femoris and hamstring contract simultaneously at a high intensity, the stronger muscle (traditionally the quadriceps)
Document 2:::
A stretch-shortening cycle (SSC) is an active stretch (eccentric contraction) of a muscle followed by an immediate shortening (concentric contraction) of that same muscle.
Research studies
The increased performance benefit associated with muscle contractions that take place during SSCs has been the focus of much research in order to determine the true nature of this enhancement. At present, there is some debate as to where and how this performance enhancement takes place. It has been postulated that elastic structures in series with the contractile component can store energy like a spring after being forcibly stretched. Since the length of the tendon increases due to the active stretch phase, if the series elastic component acts as a spring, it would therefore be storing more potential energy. This energy would be released as the tendon shortened. Thus, the recoil of the tendon during the shortening phase of the movement would result in a more efficient movement than one in which no energy had been stored. This research is further supported by Roberts et al.
However, other studies have found that removing portions of these series-elastic components (by way of tendon length reduction) had little effect on muscle performance.
Studies on turkeys have, nevertheless, shown that during SSC, a performance enhancement associated with elastic energy storage still takes place but it is thought that the aponeurosis could be a major source of energy storage (Roleveld et al., 1994).
The contractile component itself has also been associated with the ability to increase contractile performance through muscle potentiation
while other studies have found that this ability is quite limited and unable to account for such enhancements (Lensel and Goubel, 1987, Lensel-Corbeil and Goubel, 1990; Ettema and Huijing, 1989).
Community agreement
The results of these often contradictory studies have been associated with improved efficiencies for human or animal movements such as counter
Document 3:::
Optomyography (OMG) was proposed in 2015 as a technique that could be used to monitor muscular activity. It is possible to use OMG for the same applications where Electromyography (EMG) and Mechanomyography (MMG) are used. However, OMG offers superior signal-to-noise ratio and improved robustness against the disturbing factors and limitations of EMG and MMG.
The basic principle of OMG is to use active near-infra-red optical sensors to measure the variations in the measured signals that are reflected from the surface of the skin while activating the muscles below and around the skin spot where the photoelectric sensor is focusing to measure the signals reflected from this spot.
Applications
A glasses based optomyography device was patented for measuring facial expressions and emotional responses particularly for mental health monitoring . Generating proper control signals is the most important task to be able to control any kind of a prosthesis, computer game or any other system which contains a human-computer interaction unit or module. For this purpose, surface-Electromyographic (s-EMG) and Mechanomyographic (MMG) signals are measured during muscular activities and used, not only for monitoring and assessing these activities, but also to help in providing efficient rehabilitation treatment for patients with disabilities as well as in constructing and controlling sophisticated prostheses for various types of amputees and disabilities. However, while the existing s-EMG and MMG based systems have compelling benefits, many engineering challenges still remain unsolved, especially with regard to the sensory control system.
Document 4:::
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus.
Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs via neural pathways in the nervous system called reflex arcs. A stimulus initiates a neural signal, which is carried to a synapse. The signal is then transferred across the synapse to a motor neuron, which evokes a target response. These neural signals do not always travel to the brain, so many reflexes are an automatic response to a stimulus that does not receive or need conscious thought.
Many reflexes are fine-tuned to increase organism survival and self-defense. This is observed in reflexes such as the startle reflex, which provides an automatic response to an unexpected stimulus, and the feline righting reflex, which reorients a cat's body when falling to ensure safe landing. The simplest type of reflex, a short-latency reflex, has a single synapse, or junction, in the signaling pathway. Long-latency reflexes produce nerve signals that are transduced across multiple synapses before generating the reflex response.
Types of human reflexes
Myotatic reflexes
The myotatic or muscle stretch reflexes (sometimes known as deep tendon reflexes) provide information on the integrity of the central nervous system and peripheral nervous system. This information can be detected using electromyography (EMG). Generally, decreased reflexes indicate a peripheral problem, and lively or exaggerated reflexes a central one. A stretch reflex is the contraction of a muscle in response to its lengthwise stretch.
Biceps reflex (C5, C6)
Brachioradialis reflex (C5, C6, C7)
Extensor digitorum reflex (C6, C7)
Triceps reflex (C6, C7, C8)
Patellar reflex or knee-jerk reflex (L2, L3, L4)
Ankle jerk reflex (Achilles reflex) (S1, S2)
While the reflexes above are stimulated mechanically, the term H-reflex refers to the analogous reflex stimulated
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which statement describes how muscles work to allow a person to extend an arm from a curled position by straightening the elbow?
A. Both the biceps and triceps contract.
B. Both the biceps and the triceps relax.
C. The triceps contract and the biceps relax.
D. The biceps contract and the triceps relax.
Answer:
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|
sciq-940
|
multiple_choice
|
Lying with their mouths open, a behavior called gaping, probably serves what function for crocodiles?
|
[
"digesting",
"sleeping",
"cooling down",
"eating"
] |
C
|
Relavent Documents:
Document 0:::
Structures built by non-human animals, often called animal architecture, are common in many species. Examples of animal structures include termite mounds, ant hills, wasp and beehives, burrow complexes, beaver dams, elaborate nests of birds, and webs of spiders.
Often, these structures incorporate sophisticated features such as temperature regulation, traps, bait, ventilation, special-purpose chambers and many other features. They may be created by individuals or complex societies of social animals with different forms carrying out specialized roles. These constructions may arise from complex building behaviour of animals such as in the case of night-time nests for chimpanzees, from inbuilt neural responses, which feature prominently in the construction of bird songs, or triggered by hormone release as in the case of domestic sows, or as emergent properties from simple instinctive responses and interactions, as exhibited by termites, or combinations of these. The process of building such structures may involve learning and communication, and in some cases, even aesthetics. Tool use may also be involved in building structures by animals.
Building behaviour is common in many non-human mammals, birds, insects and arachnids. It is also seen in a few species of fish, reptiles, amphibians, molluscs, urochordates, crustaceans, annelids and some other arthropods. It is virtually absent from all the other animal phyla.
Functions
Animals create structures primarily for three reasons:
to create protected habitats, i.e. homes.
to catch prey and for foraging, i.e. traps.
for communication between members of the species (intra-specific communication), i.e. display.
Animals primarily build habitat for protection from extreme temperatures and from predation. Constructed structures raise physical problems which need to be resolved, such as humidity control or ventilation, which increases the complexity of the structure. Over time, through evolution, animals use shelters for ot
Document 1:::
A cnidariologist is a zoologist specializing in Cnidaria, a group of freshwater and marine aquatic animals that include the sea anemones, corals, and jellyfish.
Examples
Edward Thomas Browne (1866-1937)
Henry Bryant Bigelow (1879-1967)
Randolph Kirkpatrick (1863–1950)
Kamakichi Kishinouye (1867-1929)
Paul Lassenius Kramp (1887-1975)
Alfred G. Mayer (1868-1922)
See also
Document 2:::
The Tinbergen Lecture is an academic prize lecture awarded by the Association for the Study of Animal Behaviour (ASAB).
Lecturers
1974 W.H. Thorpe
1975 G.P. Baerends
1976 J. Maynard Smith
1977 F. Huber
1978 R.A. Hinde
1979 J. Bowlby
1980 W.D. Hamilton
1981 S.J. Gould
1982 H. Kummer
1983 Jörg-Peter Ewert
1984 Frank A. Beach
1985 Peter Marler
1986 Jürgen Aschoff
1987 Aubrey Manning
1988 Stephen T. Emlen
1989 P.P.G. Bateson
1990 J.D. Delius
1991 John R. Krebs
1992 E. Curio
1993 Linda Partridge
1994 Fernando Nottebohm
1995 G.A. Parker
1996 Serge Daan
1997 N.B. Davies
1998 Michael Land
1999 Bert Hölldobler
2000 Richard Dawkins
2001 Felicity Huntingford
2002 Marian Dawkins
2003 Tim Clutton-Brock
2004 Tim Birkhead
2005 P.K. McGregor
2006 Pat Monaghan
2007 M. Kirkpatrick
2008 Peter Slater
2009
2010 Laurent Keller
2011 Cancelled
2012 A Cockburn
2013 Marlene Zuk
2014 Innes Cuthill
2015 Nina Wedell
2016 Alex Kacelnik
2017 Christine Nicol
2018 Bart Kempenaers
2019 Rebecca Kilner
2020 Lars Chittka
Document 3:::
Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
Document 4:::
Gaping is a common form of behavior in the animal kingdom, in which an animal opens its mouth widely and displays the interior of its mouth, for any of various purposes. This may be a form of deimatic behaviour, colloquially known as a startle display or threat display, as it enlarges the appearance of the animal, and for those with teeth it shows the threat that these represent. Animals may also use gaping as part of a courtship display, or to otherwise communicate with each other. Some animals have evolved features which make gaping behavior more visually effective. For example, "[i]n many species of reptile, the oral mucosa may be a bright color that serves to distract the predator". Gaping is part of the shark agonistic display, and is also found in snakes such as the cottonmouth, and in birds ranging from seagulls to puffins to roosters.
A number of species of bird use a gaping, open beak in their fear and threat displays. Some augment the display by hissing or breathing heavily, while others clap their beaks. In birds, the muscles that depress the lower mandible are usually weak, but certain birds have well-developed digastric muscles that aid in gaping actions. In most birds, these muscles are relatively small as compared to the jaw muscles of similarly sized mammals. Both male and female puffins use gaping as a prominent part of their threat display, with "a range of intensities" based on the situation, and with puffins engaging in territorial gape contests, where they mirror each other until one gives up and leaves, or an actual fight occurs.
Some animals are named for their tendency to use gaping as a threat display, or for the features that become apparent when making such a display. For example, the cottonmouth is so named because the white lining of its mouth is visible when gaping. Other snakes, such as the Western Massasauga, have been observed to engage in gaping behavior which "appears to be unrelated to any threat".
Gallery of images
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Lying with their mouths open, a behavior called gaping, probably serves what function for crocodiles?
A. digesting
B. sleeping
C. cooling down
D. eating
Answer:
|
|
sciq-5969
|
multiple_choice
|
What makes viral stis more dangerous than other types?
|
[
"they are more contagious",
"they are more severe",
"they are incurable",
"they are larger"
] |
C
|
Relavent Documents:
Document 0:::
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs), are infections that are commonly spread by sexual activity, especially vaginal intercourse, anal sex and oral sex. The most prevalent STIs may be carried by a significant fraction of the human population.
Document 1:::
Those involved in the care of athletes should be alert to the possibility of getting an infectious disease for the following reasons:
There is the chance, or even the expectation, of contact or collision with another player, or the playing surface, which may be a mat or artificial turf.
The opportunities for skin breaks, obvious or subtle, are present and compromise skin defenses.
Young people congregate in dormitories, locker rooms, showers, etc.
There is the possibility of sharing personal toilet articles.
Equipment, gloves and pads and protective gear, is difficult to sanitize and can become contaminated.
However, in many cases, the chance of infection can be reduced by relatively simple measures.
Herpes gladiatorum
Wrestlers use mats which are abrasive and the potential for a true contagion (Latin contagion-, contagio, from contingere to have contact with) is very real. The herpes simplex virus, type I, is very infectious and large outbreaks have been documented. A major epidemic threatened the 2007 Minnesota high school wrestling season, but was largely contained by instituting an eight-day isolation period during which time competition was suspended. Practices, such as 'weight cutting', which can at least theoretically reduce immunity, might potentiate the risk. In non-epidemic circumstances, herpes gladiatorum affects about 3% of high school wrestlers and 8% of collegiate wrestlers. There is the potential for prevention of infection, or at least containment, with antiviral agents which are effective in reducing the spread to other athletes when given to those who are herpes positive, or who have recurrent herpes gladiatorum.
The NCAA specifies that a wrestler must:
- be free of systemic symptoms (fever, malaise, etc.).
- have developed no new blisters for 72 hours before the examination.
- have no moist lesions; all lesions must be dried and have progressed to a FIRM ADHERENT CRUST.
- have been on appropriate systemic antiviral therapy for at lea
Document 2:::
Optimal virulence is a concept relating to the ecology of hosts and parasites. One definition of virulence is the host's parasite-induced loss of fitness. The parasite's fitness is determined by its success in transmitting offspring to other hosts. For about 100 years, the consensus was that virulence decreased and parasitic relationships evolved toward symbiosis. This was even called the law of declining virulence despite being a hypothesis, not even a theory. It has been challenged since the 1980s and has been disproved.
A pathogen that is too restrained will lose out in competition to a more aggressive strain that diverts more host resources to its own reproduction. However, the host, being the parasite's resource and habitat in a way, suffers from this higher virulence. This might induce faster host death, and act against the parasite's fitness by reducing probability to encounter another host (killing the host too fast to allow for transmission). Thus, there is a natural force providing pressure on the parasite to "self-limit" virulence.
The idea is, then, that there exists an equilibrium point of virulence, where parasite's fitness is highest. Any movement on the virulence axis, towards higher or lower virulence, will result in lower fitness for the parasite, and thus will be selected against.
Mode of transmission
Paul W. Ewald has explored the relationship between virulence and mode of transmission. He came to the conclusion that virulence tends to remain especially high in waterborne and vector-borne infections, such as cholera and dengue. Cholera is spread through sewage and dengue through mosquitos. In the case of respiratory infections, the pathogen depends on an ambulatory host to survive. It must spare the host long enough to find a new host. Water- or vector-borne transmission circumvents the need for a mobile host. Ewald is convinced that the crowding of field hospitals and trench warfare provided an easy route to transmission that evolved the
Document 3:::
Freshers' flu is a name commonly given to a battery of illnesses contracted by new students (freshers) during the first few weeks at a university, and colleges of further education in some form; common symptoms include fever, sore throat, severe headache, coughing and general discomfort. The illnesses may or may not include actual flu and is often simply a bad cold.
Causes
The most likely cause is the convergence of large numbers of people arriving from all over the world; this is a particularly elevated risk due to the COVID-19 pandemic. The poor diet and heavy consumption of alcohol during freshers' week is also reported as a cause for many of the illnesses contracted during this time. "Stress, which may be induced by tiredness, combined with a poor diet, late nights and too much alcohol, can weaken the immune system and be a recipe for ill health. All this can make students and staff working with the students more susceptible to infections within their first weeks of term." In addition to this, nearly all university academic years in the UK commence around the end of September or beginning of October, which "marks the start of the annual flu season". The increased susceptibility to illness from late nights, heavy alcohol consumption and stress peaks 2–4 weeks after arrival at university and happens to coincide with the seasonal surge in the outbreaks of colds and flu in the Northern Hemisphere.
Other effects
As well as the usual viral effects, freshers' flu can also have some psychological effects. These effects arise where the stress of leaving home and other consequences of being independent, not to mention various levels of homesickness and the attempts at making new friends, can further weaken the immune system, increasing susceptibility to illness.
See also
Freshman 15
Document 4:::
An infection rate (or incident rate) is the probability or risk of an infection in a population. It is used to measure the frequency of occurrence of new instances of infection within a population during a specific time period.
The number of infections equals the cases identified in the study or observed. An example would be HIV infection during a specific time period in the defined population. The population at risk are the cases appearing in the population during the same time period. An example would be all the people in a city during a specific time period. The constant, or K is assigned a value of 100 to represent a percentage. An example would be to find the percentage of people in a city who are infected with HIV: 6,000 cases in March divided by the population of a city (one million) multiplied by the constant (K) would give an infection rate of 0.6%.
Calculating the infection rate is used to analyze trends for the purpose of infection and disease control. An online infection rate calculator has been developed by the Centers for Disease Control and Prevention that allows the determination of the Streptococcal A infection rate in a population.
Clinical applications
Health care facilities routinely track their infection rates according to the guidelines issued by the Joint Commission. The healthcare-associated infection (HAI) rates measure infection of patients in a particular hospital. This allows rates to compared with other hospitals. These infections can often be prevented when healthcare facilities follow guidelines for safe care. To get payment from Medicare, hospitals are required to report data about some infections to the Centers for Disease Control and Prevention's (CDC's) National Healthcare Safety Network (NHSN). Hospitals currently submit information on central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), MRSA Bacteremia, and C. difficile laboratory-i
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What makes viral stis more dangerous than other types?
A. they are more contagious
B. they are more severe
C. they are incurable
D. they are larger
Answer:
|
|
sciq-9816
|
multiple_choice
|
The epidermis is made of which closely packed cells?
|
[
"cancer cells",
"epithelial cells",
"nerve cells",
"muscle cells"
] |
B
|
Relavent Documents:
Document 0:::
In mammals, trichocytes are the specialized epithelial cells from which the highly mechanically resilient tissues hair and nails are formed. They can be identified by the fact that they express "hard", "trichocyte" or "hair" keratin proteins. These are modified keratins containing large amounts of the amino acid cysteine, which facilitates chemical cross-linking of these proteins to form the tough material from which hair and nail is composed. These cells give rise to non-hair non-keratinized IRSC (inner root sheath cell) as well.
See also
List of human cell types derived from the germ layers
List of distinct cell types in the adult human body
Document 1:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 2:::
In biology, the extracellular matrix (ECM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM.
The animal extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i.e., in the intercellular spaces). Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. Basement membranes are sheet-like depositions of ECM on which various epithelial cells rest. Each type of connective tissue in animals has a type of ECM: collagen fibers and bone mineral comprise the ECM of bone tissue; reticular fibers and ground substance comprise the ECM of loose connective tissue; and blood plasma is the ECM of blood.
The plant ECM includes cell wall components, like cellulose, in addition to more complex signaling molecules. Some single-celled organisms adopt multicellular biofilms in which the cells are embedded in an ECM composed primarily of extracellular polymeric substances (EPS).
Structure
Components of the ECM are produced intracellularly by resident cells and secreted into the ECM via exocytosis. Once secreted, they then aggregate with the existing matrix. The ECM is composed of an interlocking mesh of fibrous proteins and glycosaminoglycans (GAGs).
Proteoglycans
Glycosaminoglycans (GAGs) are carbohydrate polymers and mostly attached to extracellular matrix proteins to form proteoglycans (hyaluronic acid is a notable exception; see below). Proteoglycans have a net negative charge that attracts positively charged sod
Document 3:::
In zoology, the epidermis is an epithelium (sheet of cells) that covers the body of a eumetazoan (animal more complex than a sponge). Eumetazoa have a cavity lined with a similar epithelium, the gastrodermis, which forms a boundary with the epidermis at the mouth.
Sponges have no epithelium, and therefore no epidermis or gastrodermis. The epidermis of a more complex invertebrate is just one layer deep, and may be protected by a non-cellular cuticle. The epidermis of a higher vertebrate has many layers, and the outer layers are reinforced with keratin and then die.
Document 4:::
Epithelium or epithelial tissue is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves.
There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or compound, either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epithelial cells. Functions of epithelial cells include diffusion, filtration, secretion, selective absorption, germination, and transcellular transport. Compound epithelium has protective functions.
Epithelial layers contain no blood vessels (avascular), so they must receive nourishment via diffusion of substances from the underlying connective tissue, through the basement membrane. Cell junctions are especially abundant in epithelial tissues.
Classification
Simple epithelium
Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where absorption and filtration occur. The thinness of the epithelial barrier facilitates these processes.
In general, epithelial tissues are classified by the number of their layers and by the shape and function of the cells.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The epidermis is made of which closely packed cells?
A. cancer cells
B. epithelial cells
C. nerve cells
D. muscle cells
Answer:
|
|
sciq-4148
|
multiple_choice
|
What is the amount of solute that can dissolve in a given amount of solvent at a given temperature?
|
[
"permeability",
"solubility",
"humidity",
"viscosity"
] |
B
|
Relavent Documents:
Document 0:::
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be "miscible in all proportions" (or just "miscible").
The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations, and a solid or liquid can be "dissolved" in a gas only by passing into the gaseous state first.
The solubility mainly depends on the composition of solute and solvent (including their pH and the presence of other dissolved substances) as well as on temperature and pressure. The dependency can often be explained in terms of interactions between the particles (atoms, molecules, or ions) of the two substances, and of thermodynamic concepts such as enthalpy and entropy.
Under certain conditions, the concentration of the solute can exceed its usual solubility limit. The result is a supersaturated solution, which is metastable and will rapidly exclude the excess solute if a suitable nucleation site appears.
The concept of solubility does not apply when there is an irreversible chemical reaction between the two substances, such as the reaction of calcium hydroxide with hydrochloric acid; even though one might say, informally, that one "dissolved" the other. The solubility is also not the same as the rate of solution, which is how fast a solid solute dissolves in a liquid solvent. This property de
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In chemistry, solvent effects are the influence of a solvent on chemical reactivity or molecular associations. Solvents can have an effect on solubility, stability and reaction rates and choosing the appropriate solvent allows for thermodynamic and kinetic control over a chemical reaction.
A solute dissolves in a solvent when solvent-solute interactions are more favorable than solute-solute interaction.
Effects on stability
Different solvents can affect the equilibrium constant of a reaction by differential stabilization of the reactant or product. The equilibrium is shifted in the direction of the substance that is preferentially stabilized.
Stabilization of the reactant or product can occur through any of the different non-covalent interactions with the solvent such as H-bonding, dipole-dipole interactions, van der Waals interactions etc.
Acid-base equilibria
The ionization equilibrium of an acid or a base is affected by a solvent change. The effect of the solvent is not only because of its acidity or basicity but also because of its dielectric constant and its ability to preferentially solvate and thus stabilize certain species in acid-base equilibria. A change in the solvating ability or dielectric constant can thus influence the acidity or basicity.
In the table above, it can be seen that water is the most polar-solvent, followed by DMSO, and then acetonitrile. Consider the following acid dissociation equilibrium:
HA A− + H+
Water, being the most polar-solvent listed above, stabilizes the ionized species to a greater extent than does DMSO or Acetonitrile. Ionization - and, thus, acidity - would be greatest in water and lesser in DMSO and Acetonitrile, as seen in the table below, which shows pKa values at 25 °C for acetonitrile (ACN) and dimethyl sulfoxide (DMSO) and water.
Keto–enol equilibria
Many carbonyl compounds exhibit keto–enol tautomerism. This effect is especially pronounced in 1,3-dicarbonyl compounds that can form hydrogen-bonded enols. The e
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Hansen solubility parameters were developed by Charles M. Hansen in his Ph.D thesis in 1967 as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that like dissolves like where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
Specifically, each molecule is given three Hansen parameters, each generally measured in MPa0.5:
The energy from dispersion forces between molecules
The energy from dipolar intermolecular forces between molecules
The energy from hydrogen bonds between molecules.
These three parameters can be treated as co-ordinates for a point in three dimensions also known as the Hansen space. The nearer two molecules are in this three-dimensional space, the more likely they are to dissolve into each other. To determine if the parameters of two molecules (usually a solvent and a polymer) are within range, a value called interaction radius () is given to the substance being dissolved. This value determines the radius of the sphere in Hansen space and its center is the three Hansen parameters. To calculate the distance () between Hansen parameters in Hansen space the following formula is used:
Combining this with the interaction radius gives the relative energy difference (RED) of the system:
If the molecules are alike and will dissolve
If the system will partially dissolve
If the system will not dissolve
Uses
Historically Hansen solubility parameters (HSP) have been used in industries such as paints and coatings where understanding and controlling solvent–polymer interactions was vital. Over the years their use has been extended widely to applications such as:
Environmental stress cracking of polymers
Controlled dispersion of pigments, such as carbon black
Understanding of solubility/dispersion properties of carbon nanotubes, buckyballs and quantum dots
Adhesion to polymers
Permeation of solvents and chemicals through plastics to understand i
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Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L (pronounced "osmolar"), in the same way that the molarity of a solution is expressed as "M" (pronounced "molar"). Whereas molarity measures the number of moles of solute per unit volume of solution, osmolarity measures the number of osmoles of solute particles per unit volume of solution. This value allows the measurement of the osmotic pressure of a solution and the determination of how the solvent will diffuse across a semipermeable membrane (osmosis) separating two solutions of different osmotic concentration.
Unit
The unit of osmotic concentration is the osmole. This is a non-SI unit of measurement that defines the number of moles of solute that contribute to the osmotic pressure of a solution. A milliosmole (mOsm) is 1/1,000 of an osmole. A microosmole (μOsm) (also spelled micro-osmole) is 1/1,000,000 of an osmole.
Types of solutes
Osmolarity is distinct from molarity because it measures osmoles of solute particles rather than moles of solute. The distinction arises because some compounds can dissociate in solution, whereas others cannot.
Ionic compounds, such as salts, can dissociate in solution into their constituent ions, so there is not a one-to-one relationship between the molarity and the osmolarity of a solution. For example, sodium chloride (NaCl) dissociates into Na+ and Cl− ions. Thus, for every 1 mole of NaCl in solution, there are 2 osmoles of solute particles (i.e., a 1 mol/L NaCl solution is a 2 osmol/L NaCl solution). Both sodium and chloride ions affect the osmotic pressure of the solution.
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In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid, but it can also be applied to liquids and gases dissolved in a liquid. A supersaturated solution is in a metastable state; it may return to equilibrium by separation of the excess of solute from the solution, by dilution of the solution by adding solvent, or by increasing the solubility of the solute in the solvent.
History
Early studies of the phenomenon were conducted with sodium sulfate, also known as Glauber's Salt because, unusually, the solubility of this salt in water may decrease with increasing temperature. Early studies have been summarised by Tomlinson. It was shown that the crystallization of a supersaturated solution does not simply come from its agitation, (the previous belief) but from solid matter entering and acting as a "starting" site for crystals to form, now called "seeds". Expanding upon this, Gay-Lussac brought attention to the kinematics of salt ions and the characteristics of the container having an impact on the supersaturation state. He was also able to expand upon the number of salts with which a supersaturated solution can be obtained. Later Henri Löwel came to the conclusion that both nuclei of the solution and the walls of the container have a catalyzing effect on the solution that cause crystallization. Explaining and providing a model for this phenomenon has been a task taken on by more recent research. Désiré Gernez contributed to this research by discovering that nuclei must be of the same salt that is being crystallized in order to promote crystallization.
Occurrence and examples
Solid precipitate, liquid solvent
A solution of a chemical compound in a liquid will become supersaturated when the temperature of the saturated solution is changed. In most cases solubility decreases wit
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the amount of solute that can dissolve in a given amount of solvent at a given temperature?
A. permeability
B. solubility
C. humidity
D. viscosity
Answer:
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sciq-1451
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multiple_choice
|
What celestial bodies are classified by color and temperature, ranging from blue to red and hottest to coolest?
|
[
"planets",
"galaxies",
"astroids",
"stars"
] |
D
|
Relavent Documents:
Document 0:::
A color–color diagram is a means of comparing the colors of an astronomical object at different wavelengths. Astronomers typically observe at narrow bands around certain wavelengths, and objects observed will have different brightnesses in each band. The difference in brightness between two bands is referred to as color. On color–color diagrams, the color defined by two wavelength bands is plotted on the horizontal axis, and the color defined by another brightness difference will be plotted on the vertical axis.
Background
Although stars are not perfect blackbodies, to first order the spectra of light emitted by stars conforms closely to a black-body radiation curve, also referred to sometimes as a thermal radiation curve. The overall shape of a black-body curve is uniquely determined by its temperature, and the wavelength of peak intensity is inversely proportional to temperature, a relation known as Wien's Displacement Law. Thus, observation of a stellar spectrum allows determination of its effective temperature. Obtaining complete spectra for stars through spectrometry is much more involved than simple photometry in a few bands. Thus by comparing the magnitude of the star in multiple different color indices, the effective temperature of the star can still be determined, as magnitude differences between each color will be unique for that temperature. As such, color-color diagrams can be used as a means of representing the stellar population, much like a Hertzsprung–Russell diagram, and stars of different spectral classes will inhabit different parts of the diagram. This feature leads to applications within various wavelength bands.
In the stellar locus, stars tend to align in a more or less straight feature. If stars were perfect black bodies, the stellar locus would be a pure straight line indeed. The divergences with the straight line are due to the absorptions and emission lines in the stellar spectra. These divergences can be more or less evident depending
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Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are." Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.
In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; and the origin and ultimate fate of the universe. Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.
History
Astronomy is an ancient science, long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthl
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An asteroid spectral type is assigned to asteroids based on their reflectance spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classifications.
Taxonomic systems
In 1975, astronomers Clark R. Chapman, David Morrison, and Ben Zellner developed a simple taxonomic system for asteroids based on color, albedo, and spectral shape. The three categories were labelled "C" for dark carbonaceous objects, "S" for stony (silicaceous) objects, and "U" for those that did not fit into either C or S. This basic division of asteroid spectra has since been expanded and clarified. A number of classification schemes are currently in existence, and while they strive to retain some mutual consistency, quite a few asteroids are sorted into different classes depending on the particular scheme. This is due to the use of different criteria for each approach. The two most widely used classifications are described below:
Overview of Tholen and SMASS
S3OS2 classification
The Small Solar System Objects Spectroscopic Survey (S3OS2 or S3OS2, also known as the Lazzaro classification) observed 820 asteroids, using the former ESO 1.52-metre telescope at La Silla Observatory during 1996–2001. This survey applied both the Tholen and Bus–Binzel (SMASS) taxonomy to the observed objects, many of which had previously not been classified. For the Tholen-like classification, the survey introduced a new "Caa-type", which shows a broad absorption band associated indicating an aqueous alteration of the body's surface. The Caa class corresponds to Tholen's C-type and to the SMASS hydrated Ch-type (inclu
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A red dwarf is the smallest and coolest kind of star on the main sequence. Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighborhood of the Sun. However, as a result of their low luminosity, individual red dwarfs cannot be easily observed. From Earth, not one star that fits the stricter definitions of a red dwarf is visible to the naked eye. Proxima Centauri, the nearest star to the Sun, is a red dwarf, as are fifty of the sixty nearest stars. According to some estimates, red dwarfs make up three-quarters of the stars in the Milky Way.
The coolest red dwarfs near the Sun have a surface temperature of about and the smallest have radii about 9% that of the Sun, with masses about 7.5% that of the Sun. These red dwarfs have spectral types of L0 to L2. There is some overlap with the properties of brown dwarfs, since the most massive brown dwarfs at lower metallicity can be as hot as and have late M spectral types.
Definitions and usage of the term "red dwarf" vary on how inclusive they are on the hotter and more massive end. One definition is synonymous with stellar M dwarfs (M-type main sequence stars), yielding a maximum temperature of and . One includes all stellar M-type main-sequence and all K-type main-sequence stars (K dwarf), yielding a maximum temperature of and . Some definitions include any stellar M dwarf and part of the K dwarf classification. Other definitions are also in use. Many of the coolest, lowest mass M dwarfs are expected to be brown dwarfs, not true stars, and so those would be excluded from any definition of red dwarf.
Stellar models indicate that red dwarfs less than are fully convective. Hence, the helium produced by the thermonuclear fusion of hydrogen is constantly remixed throughout the star, avoiding helium buildup at the core, thereby prolonging the period of fusion. Low-mass red dwarfs therefore develop very slowly, maintaining a constant luminosity and spectral type for trillions of years,
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In astronomy, a spectral atlas is a collection of spectra of one or more objects, intended as a reference work for comparison with spectra of other objects. Several different types of collections are titled spectral atlases: those intended for spectral classification, for key reference, or as a collection of spectra of a general type of object.
In any spectral atlas, generally all the spectra have been taken with the same equipment, or with very similar instruments at different locations, to provide data as uniform as possible in its spectral resolution, wavelength coverage, noise characteristics, etc.
Types
For spectral classification
When assigning a spectral classification, a spectral atlas is a collection of standard spectra of stars with known spectral types, against which a spectrum of an unknown star is compared. It is analogous to an identification key in biology. Originally, such atlases included reproductions of the monochrome spectra as recorded on photographic plates, as in the original Morgan-Keenan-Kellman atlas and other atlases. These atlases include identifications and notations for use of those spectral features to be used as discriminators between close spectral types. With very large surveys of the sky which include automated assignment of spectral classification from the digital spectra data, graphical atlases have been supplanted by libraries of spectra of standard stars which often can be downloaded from VizieR and other sources.
For key reference
A spectral atlas can be a very high-quality spectrum of a key reference object, often made with very high spectral resolution, generally presented in large-format graphical form as a line chart (but normally strictly without markers at specific data points) of intensity or relative intensity (which for a star whose spectrum is dominated by absorption lines runs from zero to a normalized continuum) as a function of wavelength. Such spectral atlases have been made several times for the Sun (e
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What celestial bodies are classified by color and temperature, ranging from blue to red and hottest to coolest?
A. planets
B. galaxies
C. astroids
D. stars
Answer:
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|
sciq-9388
|
multiple_choice
|
Shivering and adipose tissue called brown fat are used by mammals in particular to produce what?
|
[
"nutrition",
"blood",
"heat",
"energy"
] |
C
|
Relavent Documents:
Document 0:::
An energy budget is a balance sheet of energy income against expenditure. It is studied in the field of Energetics which deals with the study of energy transfer and transformation from one form to another. Calorie is the basic unit of measurement. An organism in a laboratory experiment is an open thermodynamic system, exchanging energy with its surroundings in three ways - heat, work and the potential energy of biochemical compounds.
Organisms use ingested food resources (C=consumption) as building blocks in the synthesis of tissues (P=production) and as fuel in the metabolic process that power this synthesis and other physiological processes (R=respiratory loss). Some of the resources are lost as waste products (F=faecal loss, U=urinary loss). All these aspects of metabolism can be represented in energy units. The basic model of energy budget may be shown as:
P = C - R - U - F or
P = C - (R + U + F) or
C = P + R + U + F
All the aspects of metabolism can be represented in energy units (e.g. joules (J);1 calorie = 4.2 kJ).
Energy used for metabolism will be
R = C - (F + U + P)
Energy used in the maintenance will be
R + F + U = C - P
Endothermy and ectothermy
Energy budget allocation varies for endotherms and ectotherms. Ectotherms rely on the environment as a heat source while endotherms maintain their body temperature through the regulation of metabolic processes. The heat produced in association with metabolic processes facilitates the active lifestyles of endotherms and their ability to travel far distances over a range of temperatures in the search for food. Ectotherms are limited by the ambient temperature of the environment around them but the lack of substantial metabolic heat production accounts for an energetically inexpensive metabolic rate. The energy demands for ectotherms are generally one tenth of that required for endotherms.
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Animal nutrition focuses on the dietary nutrients needs of animals, primarily those in agriculture and food production, but also in zoos, aquariums, and wildlife management.
Constituents of diet
Macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and lipids from which cell membranes and some signaling molecules are built) and energy. Some of the structural material can be used to generate energy internally, though the net energy depends on such factors as absorption and digestive effort, which vary substantially from instance to instance. Vitamins, minerals, fiber, and water do not provide energy, but are required for other reasons. A third class dietary material, fiber (i.e., non-digestible material such as cellulose), seems also to be required, for both mechanical and biochemical reasons, though the exact reasons remain unclear.
Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple monosaccharides (glucose, fructose, galactose) to complex polysaccharides (starch). Fats are triglycerides, made of assorted fatty acid monomers bound to glycerol backbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body. Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are nitrogen-containing amino acids. Essential amino acids cannot be made by the animal. Some of the amino acids are convertible (with the expenditure of energy) to glucose and can be used for energy production just as ordinary glucose. By breaking down existing protein, some glucose can be produced internally; the remaining amino acids are discarded, primarily as urea in urine. This occurs normally only during prolonged starvation.
Other dietary substances found in plant foods (phytochemicals, polyphenols) are not identified as essential nutrients but appear to impact healt
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The term human equivalent is used in a number of different contexts. This term can refer to human equivalents of various comparisons of animate and inanimate things.
Animal models in chemistry and medicine
Animal models are used to learn more about a disease, its diagnosis and its treatment, with animal models predicting human toxicity in up to 71% of cases. The human equivalent dose (HED) or human equivalent concentration (HEC) is the quantity of a chemical that, when administered to humans, produces an effect equal to that produced in test animals by a smaller dose. Calculating the HED is a step in carrying out a clinical trial of a pharmaceutical drug.
Human energy usage and conversion
The concept of human-equivalent energy (H-e) assists in understanding of energy flows in physical and biological systems by expressing energy units in human terms: it provides a “feel” for the use of a given amount of energy by expressing it in terms of the relative quantity of energy needed for human metabolism, assuming an average human energy expenditure of 12,500 kJ per day and a basal metabolic rate of 80 watts. A light bulb running at 100 watts is running at 1.25 human equivalents (100/80), i.e. 1.25 H-e. On the other hand, a human may generate as much as 1,000 watts for a task lasting a few minutes, or even more for a task of a few seconds' duration, while climbing a flight of stairs may represent work at a rate of about 200 watts.
Animal attributes expressed in terms of human equivalents
Cat and dog years
The ages of domestic cats and dogs are often referred to in terms of "cat years" or "dog years", representing a conversion to human-equivalent years. One formula for cat years is based on a cat reaching maturity in approximately 1 year, which could be seen as 16 in human terms, then adding about 4 years for every year the cat ages. A 5-year-old cat would then be (5 − 1) × 4 + 16 = 32 "cat years" (i.e. human-equivalent years), and a 10-year-old cat (10 − 1) × 4 + 16 =
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Thermogenin (called uncoupling protein by its discoverers and now known as uncoupling protein 1, or UCP1) is a mitochondrial carrier protein found in brown adipose tissue (BAT). It is used to generate heat by non-shivering thermogenesis, and makes a quantitatively important contribution to countering heat loss in babies which would otherwise occur due to their high surface area-volume ratio.
Mechanism
UCP1 belongs to the UCP family which are transmembrane proteins that decrease the proton gradient generated in oxidative phosphorylation. They do this by increasing the permeability of the inner mitochondrial membrane, allowing protons that have been pumped into the intermembrane space to return to the mitochondrial matrix and hence dissipating the proton gradient. UCP1-mediated heat generation in brown fat uncouples the respiratory chain, allowing for fast substrate oxidation with a low rate of ATP production. UCP1 is related to other mitochondrial metabolite transporters such as the adenine nucleotide translocator, a proton channel in the mitochondrial inner membrane that permits the translocation of protons from the mitochondrial intermembrane space to the mitochondrial matrix. UCP1 is restricted to brown adipose tissue, where it provides a mechanism for the enormous heat-generating capacity of the tissue.
UCP1 is activated in the brown fat cell by fatty acids and inhibited by nucleotides. Fatty acids are released by the following signaling cascade: Sympathetic nervous system terminals release Norepinephrine onto a Beta-3 adrenergic receptor on the plasma membrane. This activates adenylyl cyclase, which catalyses the conversion of ATP to cyclic AMP (cAMP). cAMP activates protein kinase A, causing its active C subunits to be freed from its regulatory R subunits. Active protein kinase A, in turn, phosphorylates triacylglycerol lipase, thereby activating it. The lipase converts triacylglycerols into free fatty acids, which activate UCP1, overriding the inhibition ca
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Field metabolic rate (FMR) refers to a measurement of the metabolic rate of a free-living animal.
Method
Measurement of the Field metabolic rate is made using the doubly labeled water method, although alternative techniques, such as monitoring heart rates, can also be used. The advantages and disadvantages of the alternative approaches have been reviewed by Butler, et al. Several summary reviews have been published.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Shivering and adipose tissue called brown fat are used by mammals in particular to produce what?
A. nutrition
B. blood
C. heat
D. energy
Answer:
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|
sciq-5541
|
multiple_choice
|
What term is used to describe the process of removing wastes and excess water from the body?
|
[
"aeration",
"excretion",
"diffusion",
"digestion"
] |
B
|
Relavent Documents:
Document 0:::
The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body. The dual function of excretory systems is the elimination of the waste products of metabolism and to drain the body of used up and broken down components in a liquid and gaseous state. In humans and other amniotes (mammals, birds and reptiles) most of these substances leave the body as urine and to some degree exhalation, mammals also expel them through sweating.
Only the organs specifically used for the excretion are considered a part of the excretory system. In the narrow sense, the term refers to the urinary system. However, as excretion involves several functions that are only superficially related, it is not usually used in more formal classifications of anatomy or function.
As most healthy functioning organs produce metabolic and other wastes, the entire organism depends on the function of the system. Breaking down of one of more of the systems is a serious health condition, for example kidney failure.
Systems
Urinary system
The kidneys are large, bean-shaped organs which are present on each side of the vertebral column in the abdominal cavity. Humans have two kidneys and each kidney is supplied with blood from the renal artery. The kidneys remove from the blood the nitrogenous wastes such as urea, as well as salts and excess water, and excrete them in the form of urine. This is done with the help of millions of nephrons present in the kidney. The filtrated blood is carried away from the kidneys by the renal vein (or kidney vein). The urine from the kidney is collected by the ureter (or excretory tubes), one from each kidney, and is passed to the urinary bladder. The urinary bladder collects and stores the urine until urination. The urine collected in the bladder is passed into the external environment from the body through an opening called
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Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.
The wet process is usually done in the manufactured assembly of interlacing fibers, filaments and yarns, having a substantial surface (planar) area in relation to its thickness, and adequate mechanical strength to give it a cohesive structure. In other words, the wet process is done on manufactured fiber, yarn and fabric.
All of these stages require an aqueous medium which is created by water. A massive amount of water is required in these processes per day. It is estimated that, on an average, almost 50–100 liters of water is used to process only 1 kilogram of textile goods, depending on the process engineering and applications. Water can be of various qualities and attributes. Not all water can be used in the textile processes; it must have some certain properties, quality, color and attributes of being used. This is the reason why water is a prime concern in wet processing engineering.
Water
Water consumption and discharge of wastewater are the two major concerns. The textile industry uses a large amount of water in its varied processes especially in wet operations such as pre-treatment, dyeing, and printing. Water is required as a solvent of various dyes and chemicals and it is used in washing or rinsing baths in different steps. Water consumption depends upon the application methods, processes, dyestuffs, equipment/machines and technology which may vary mill to mill and material composition. Longer processing sequences, processing of extra dark colors and reprocessing lead
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Drinking is the act of ingesting water or other liquids into the body through the mouth, proboscis, or elsewhere. Humans drink by swallowing, completed by peristalsis in the esophagus. The physiological processes of drinking vary widely among other animals.
Most animals drink water to maintain bodily hydration, although many can survive on the water gained from their food. Water is required for many physiological processes. Both inadequate and (less commonly) excessive water intake are associated with health problems.
Methods of drinking
In humans
When a liquid enters a human mouth, the swallowing process is completed by peristalsis which delivers the liquid through the esophagus to the stomach; much of the activity is abetted by gravity. The liquid may be poured from the hands or drinkware may be used as vessels. Drinking can also be performed by acts of inhalation, typically when imbibing hot liquids or drinking from a spoon. Infants employ a method of suction wherein the lips are pressed tight around a source, as in breastfeeding: a combination of breath and tongue movement creates a vacuum which draws in liquid.
In other land mammals
By necessity, terrestrial animals in captivity become accustomed to drinking water, but most free-roaming animals stay hydrated through the fluids and moisture in fresh food, and learn to actively seek foods with high fluid content. When conditions impel them to drink from bodies of water, the methods and motions differ greatly among species.
Cats, canines, and ruminants all lower the neck and lap in water with their powerful tongues. Cats and canines lap up water with the tongue in a spoon-like shape. Canines lap water by scooping it into their mouth with a tongue which has taken the shape of a ladle. However, with cats, only the tip of their tongue (which is smooth) touches the water, and then the cat quickly pulls its tongue back into its mouth which soon closes; this results in a column of liquid being pulled into the ca
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Metabolic wastes or excrements are substances left over from metabolic processes (such as cellular respiration) which cannot be used by the organism (they are surplus or toxic), and must therefore be excreted. This includes nitrogen compounds, water, CO2, phosphates, sulphates, etc. Animals treat these compounds as excretes. Plants have metabolic pathways which transforms some of them (primarily the oxygen compounds) into useful substances..
All the metabolic wastes are excreted in a form of water solutes through the excretory organs (nephridia, Malpighian tubules, kidneys), with the exception of CO2, which is excreted together with the water vapor throughout the lungs. The elimination of these compounds enables the chemical homeostasis of the organism.
Nitrogen wastes
The nitrogen compounds through which excess nitrogen is eliminated from organisms are called nitrogenous wastes () or nitrogen wastes. They are ammonia, urea, uric acid, and creatinine. All of these substances are produced from protein metabolism. In many animals, the urine is the main route of excretion for such wastes; in some, it is the feces.
Ammonotelism
Ammonotelism is the excretion of ammonia and ammonium ions. Ammonia (NH3) forms with the oxidation of amino groups.(-NH2), which are removed from the proteins when they convert into carbohydrates. It is a very toxic substance to tissues and extremely soluble in water. Only one nitrogen atom is removed with it. A lot of water is needed for the excretion of ammonia, about 0.5 L of water is needed per 1 g of nitrogen to maintain ammonia levels in the excretory fluid below the level in body fluids to prevent toxicity. Thus, the marine organisms excrete ammonia directly into the water and are called ammonotelic. Ammonotelic animals include crustaceans, platyhelminths, cnidarians, poriferans, echinoderms, and other aquatic invertebrates.
Ureotelism
The excretion of urea is called ureotelism. Land animals, mainly amphibians and mammals, convert
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Evapotranspiration (ET) is the combined processes which move water from the Earth's surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in agricultural irrigation and water resource management.
Definition of evapotranspiration
Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evapotranspiration are:
Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, solar radiation and wind speed.
Transpiration: the movement of water from root systems, through a plant, and exit into the air as water vapor. This exit occurs through stomata in the plant. Rate of transpiration can be influenced by factors including plant type, soil type, weather conditions and water content, and also cultivation practices.
Evapotranspiration is typically measured in millimeters of water (i.e. volume of water moved per unit area of the Earth's surface) in a set unit of time. Globally, it is estimated that on average between three-fifths and three-quarters of land precipitation is returned to the atmosphere via evapotranspiration.
Evapotranspiration does not, in general, account for other mechanisms which are involved in returning water to the atmosphere, though some of these, such as snow and ice sublimation in regions of high elevation or high latitude, can make a large contribution to atmospheric moisture even under standard conditions.
Factors that impact evapotranspiration levels
Primary factors
Because evaporation and transpiration
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term is used to describe the process of removing wastes and excess water from the body?
A. aeration
B. excretion
C. diffusion
D. digestion
Answer:
|
|
sciq-6167
|
multiple_choice
|
Exposure to toxins is most damaging during weeks 4 through 8 of the embryonic stage due to development of what during this period?
|
[
"organs",
"pain",
"faith",
"samples"
] |
A
|
Relavent Documents:
Document 0:::
Fetal pigs are unborn pigs used in elementary as well as advanced biology classes as objects for dissection. Pigs, as a mammalian species, provide a good specimen for the study of physiological systems and processes due to the similarities between many pig and human organs.
Use in biology labs
Along with frogs and earthworms, fetal pigs are among the most common animals used in classroom dissection. There are several reasons for this, the main reason being that pigs, like humans, are mammals. Shared traits include common hair, mammary glands, live birth, similar organ systems, metabolic levels, and basic body form. They also allow for the study of fetal circulation, which differs from that of an adult. Secondly, fetal pigs are easy to obtain because they are by-products of the pork industry. Fetal pigs are the unborn piglets of sows that were killed by the meat-packing industry. These pigs are not bred and killed for this purpose, but are extracted from the deceased sow’s uterus. Fetal pigs not used in classroom dissections are often used in fertilizer or simply discarded. Thirdly, fetal pigs are cheap, which is an essential component for dissection use by schools. They can be ordered for about $30 at biological product companies. Fourthly, fetal pigs are easy to dissect because of their soft tissue and incompletely developed bones that are still made of cartilage. In addition, they are relatively large with well-developed organs that are easily visible. As long as the pork industry exists, fetal pigs will be relatively abundant, making them the prime choice for classroom dissections.
Alternatives
Several peer-reviewed comparative studies have concluded that the educational outcomes of students who are taught basic and advanced biomedical concepts and skills using non-animal methods are equivalent or superior to those of their peers who use animal-based laboratories such as animal dissection.
A systematic review concluded that students taught using non-animal m
Document 1:::
Ecotoxicity, the subject of study in the field of ecotoxicology (a portmanteau of ecology and toxicology), refers to the biological, chemical or physical stressors that affect ecosystems. Such stressors could occur in the natural environment at densities, concentrations, or levels high enough to disrupt natural biochemical and physiological behavior and interactions. This ultimately affects all living organisms that comprise an ecosystem.
Ecotoxicology has been defined as a branch of toxicology that focuses on the study of toxic effects, caused by natural or synthetic pollutants. These pollutants affect animals (including humans), vegetation, and microbes, in an intrinsic way.
Acute vs. chronic ecotoxicity
According to Barrie Peake in their paper “Impact of Pharmaceuticals on the Environment.”, The ecotoxicity of chemicals can be described based on the amount of exposure to any hazardous materials. There are two categories of ecotoxicity founded off of this description: acute toxins and chronic toxins (Peake, 2016). Acute ecotoxicity refers to the detrimental effects resulting from a hazardous exposure for no more than 15 days. Acute ecotoxicity is the direct result from the interaction of a chemical hazard with cell membranes of an organism (Peake, 2016). This interaction often leads to cell or tissue damage or death. Chronic ecotoxicity on the other hand are the detrimental effects resulting from a hazardous exposure of 15 days, to possibly years (Peake, 2016). Chronic ecotoxicity is often associated with “particular drug–receptor actions that initiate a particular pharmacological response in an aquatic or terrestrial organism.” (Peake, 2016). Due to this interaction, chronic ecotoxicity is usually not lethal in the way that acute ecotoxicity is. However, chronic ecotoxicity decreases cellular biochemical functions. This often results in alterations to psychological or behavioral responses of the organism to environmental stimuli (Peake, 2016).
Common environ
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Prenatal perception is the study of the extent of somatosensory and other types of perception during pregnancy. In practical terms, this means the study of fetuses; none of the accepted indicators of perception are present in embryos. Studies in the field inform the abortion debate, along with certain related pieces of legislation in countries affected by that debate. As of 2022, there is no scientific consensus on whether a fetus can feel pain.
Prenatal hearing
Numerous studies have found evidence indicating a fetus's ability to respond to auditory stimuli. The earliest fetal response to a sound stimulus has been observed at 16 weeks' gestational age, while the auditory system is fully functional at 25–29 weeks' gestation. At 33–41 weeks' gestation, the fetus is able to distinguish its mother's voice from others.
Prenatal pain
The hypothesis that human fetuses are capable of perceiving pain in the first trimester has little support, although fetuses at 14 weeks may respond to touch. A multidisciplinary systematic review from 2005 found limited evidence that thalamocortical pathways begin to function "around 29 to 30 weeks' gestational age", only after which a fetus is capable of feeling pain.
In March 2010, the Royal College of Obstetricians and Gynecologists submitted a report, concluding that "Current research shows that the sensory structures are not developed or specialized enough to respond to pain in a fetus of less than 24 weeks",
The report specifically identified the anterior cingulate as the area of the cerebral cortex responsible for pain processing. The anterior cingulate is part of the cerebral cortex, which begins to develop in the fetus at week 26. A co-author of that report revisited the evidence in 2020, specifically the functionality of the thalamic projections into the cortical subplate, and posited "an immediate and unreflective pain experience...from as early as 12 weeks."
There is a consensus among developmental neurobiologists that the
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Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus. This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications. The human embryo or fetus is relatively susceptible to impact from adverse conditions within the mother's environment. Substandard fetal conditions often cause various degrees of developmental delays, both physical and mental, for the growing baby. Although some variables do occur as a result of genetic conditions pertaining to the father, a great many are directly brought about from environmental toxins that the mother is exposed to.
Various toxins pose a significant hazard to fetuses during development. A 2011 study found that virtually all US pregnant women carry multiple chemicals, including some banned since the 1970s, in their bodies. Researchers detected polychlorinated biphenyls, organochlorine pesticides, perfluorinated compounds, phenols, polybrominated diphenyl ethers, phthalates, polycyclic aromatic hydrocarbons, perchlorate PBDEs, compounds used as flame retardants, and dichlorodiphenyltrichloroethane (DDT), a pesticide banned in the United States in 1972, in the bodies of 99 to 100 percent of the pregnant women they tested. Among other environmental estrogens, Bisphenol A (BPA) was identified in 96 percent of the women surveyed. Several of the chemicals were at the same concentrations that have been associated with negative effects in children from other studies and it is thought that exposure to multiple chemicals can have a greater impact than exposure to only one substance.
Effects
Environmental toxicants can be described separately by what effects they have, such as structural abnormalities, altered growth, functional deficiencies, congenital neoplasia, or even death for the fetus.
Preterm birth
One in ten US babies is born preterm and a
Document 4:::
Early pregnancy loss is a medical term that when referring to humans can variously be used to mean:
Death of an embryo or fetus during the first trimester. This can happen by implantation failure, miscarriage, embryo resorption, early fetal resorption or vanishing twin syndrome.
Death of an embryo or fetus before 20 weeks gestation, as in all pregnancy loss before it becomes considered stillbirth.
Causes of early pregnancy loss
Pregnancy loss, in many cases, occurs for unknown reasons, often involving random chromosome issues during conception. Miscarriage is not caused by everyday activities like working, exercising, or having sex. Even falls or blows are rarely to blame. Research on the effects of alcohol, tobacco, and caffeine on miscarriage is inconclusive, so it's not something you could have prevented. It's crucial not to blame yourself for a miscarriage, as it's not the result of anything you did or didn't do.
Symptoms of early pregnancy loss
The most prevalent indication of pregnancy loss is vaginal bleeding. In the later stages of pregnancy, a woman experiencing a stillbirth may cease to sense fetal movements. However, it's important to note that each type of pregnancy loss presents distinct symptoms, so it's essential to consult your healthcare provider for a proper diagnosis.
See also
Pregnancy with abortive outcome
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Exposure to toxins is most damaging during weeks 4 through 8 of the embryonic stage due to development of what during this period?
A. organs
B. pain
C. faith
D. samples
Answer:
|
|
scienceQA-3285
|
multiple_choice
|
What do these two changes have in common?
burning a candle
mixing glue and laundry powder to create putty
|
[
"Both are caused by heating.",
"Both are only physical changes.",
"Both are chemical changes.",
"Both are caused by cooling."
] |
C
|
Step 1: Think about each change.
Burning a candle is a chemical change. Both the wick and the melted wax burn. They react with oxygen in the air and turn into soot, carbon dioxide, and water.
Mixing glue and laundry powder to create putty is a chemical change. The putty is a different type of matter that was not there before the change.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Burning is caused by heating. But mixing glue and laundry powder to create putty is not.
Both are caused by cooling.
Neither change is caused by cooling.
|
Relavent Documents:
Document 0:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
Thermofluids is a branch of science and engineering encompassing four intersecting fields:
Heat transfer
Thermodynamics
Fluid mechanics
Combustion
The term is a combination of "thermo", referring to heat, and "fluids", which refers to liquids, gases and vapors. Temperature, pressure, equations of state, and transport laws all play an important role in thermofluid problems. Phase transition and chemical reactions may also be important in a thermofluid context. The subject is sometimes also referred to as "thermal fluids".
Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the transfer of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer. Engineers also consider the transfer of mass of differing chemical species, either cold or hot, to achieve heat transfer.
Sections include :
Energy transfer by heat, work and mass
Laws of thermodynamics
Entropy
Refrigeration Techniques
Properties and nature of pure substances
Applications
Engineering : Predicting and analysing the performance of machines
Thermodynamics
Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.
Fluid mechanics
Fluid Mechanics the study of the physical forces at work during fluid flow. Fluid mechanics can be divided into fluid kinematics, the study of fluid motion, and fluid kinetics, the study of the effect of forces on fluid motion. Fluid mechanics can further be divided into fluid statics, the study of fluids at rest, and fluid dynamics, the study of fluids in motion. Some of its more interesting concepts include momentum and reactive forces in fluid flow and fluid machinery theory and performance.
Sections include:
Flu
Document 3:::
In physics, a dynamical system is said to be mixing if the phase space of the system becomes strongly intertwined, according to at least one of several mathematical definitions. For example, a measure-preserving transformation T is said to be strong mixing if
whenever A and B are any measurable sets and μ is the associated measure. Other definitions are possible, including weak mixing and topological mixing.
The mathematical definition of mixing is meant to capture the notion of physical mixing. A canonical example is the Cuba libre: suppose one is adding rum (the set A) to a glass of cola. After stirring the glass, the bottom half of the glass (the set B) will contain rum, and it will be in equal proportion as it is elsewhere in the glass. The mixing is uniform: no matter which region B one looks at, some of A will be in that region. A far more detailed, but still informal description of mixing can be found in the article on mixing (mathematics).
Every mixing transformation is ergodic, but there are ergodic transformations which are not mixing.
Physical mixing
The mixing of gases or liquids is a complex physical process, governed by a convective diffusion equation that may involve non-Fickian diffusion as in spinodal decomposition. The convective portion of the governing equation contains fluid motion terms that are governed by the Navier–Stokes equations. When fluid properties such as viscosity depend on composition, the governing equations may be coupled. There may also be temperature effects. It is not clear that fluid mixing processes are mixing in the mathematical sense.
Small rigid objects (such as rocks) are sometimes mixed in a rotating drum or tumbler. The 1969 Selective Service draft lottery was carried out by mixing plastic capsules which contained a slip of paper (marked with a day of the year).
See also
Miscibility
Document 4:::
A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame.
The degree of flammability in air depends largely upon the volatility of the material - this is related to its composition-specific vapour pressure, which is temperature dependent. The quantity of vapour produced can be enhanced by increasing the surface area of the material forming a mist or dust. Take wood as an example. Finely divided wood dust can undergo explosive flames and produce a blast wave. A piece of paper (made from wood) catches on fire quite easily. A heavy oak desk is much harder to ignite, even though the wood fibre is the same in all three materials.
Common sense (and indeed scientific consensus until the mid-1700s) would seem to suggest that material "disappears" when burned, as only the ash is left. In fact, there is an increase in weight because the flammable material reacts (or combines) chemically with oxygen, which also has mass. The original mass of flammable material and the mass of the oxygen required for flames equals the mass of the flame products (ash, water, carbon dioxide, and other gases). Antoine Lavoisier, one of the pioneers in these early insights, stated that Nothing is lost, nothing is created, everything is transformed, which would later be known as the law of conservation of mass. Lavoisier used the experimental fact that some metals gained mass when they burned to support his ideas.
Definitions
Historically, flammable, inflammable and combustible meant capable of burning. The word "inflammable" came through French from the Latin inflammāre = "to set fire to", where the Latin preposition "in-" means "in" as in "indoctrinate", rather than "not" as in "invisible" and "ineligible".
The word "inflammable" may be er
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
burning a candle
mixing glue and laundry powder to create putty
A. Both are caused by heating.
B. Both are only physical changes.
C. Both are chemical changes.
D. Both are caused by cooling.
Answer:
|
sciq-1524
|
multiple_choice
|
For a star to form, what force pulls gas and dust into the center of the nebula?
|
[
"motion",
"gravity",
"centrifugal force",
"weight"
] |
B
|
Relavent Documents:
Document 0:::
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars referred as star clusters or stellar associations.
Stellar nurseries
Interstellar clouds
Spiral galaxies like the Milky Way contain stars, stellar remnants, and a diffuse interstellar medium (ISM) of gas and dust. The interstellar medium consists of 104 to 106 particles per cm3, and is typically composed of roughly 70% hydrogen, 28% helium, and 1.5% heavier elements by mass. The trace amounts of heavier elements were and are produced within stars via stellar nucleosynthesis and ejected as the stars pass beyond the end of their main sequence lifetime. Higher density regions of the interstellar medium form clouds, or diffuse nebulae, where star formation takes place. In contrast to spiral galaxies, elliptical galaxies lose the cold component of its interstellar medium within roughly a billion years, which hinders the galaxy from forming diffuse nebulae except through mergers with other galaxies.
In the dense nebulae where stars are produced, much of the hydrogen is in the molecular (H2) form, so these nebulae are called molecular clouds. The Herschel Space Observatory has revealed that filaments, or elongated dense gas structures, are truly ubiquitous in molecular clouds and central to the star formation process. They fr
Document 1:::
The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting the Sun which clumped up together to form the planets. The theory was developed by Immanuel Kant and published in his Universal Natural History and Theory of the Heavens (1755) and then modified in 1796 by Pierre Laplace. Originally applied to the Solar System, the process of planetary system formation is now thought to be at work throughout the universe. The widely accepted modern variant of the nebular theory is the solar nebular disk model (SNDM) or solar nebular model. It offered explanations for a variety of properties of the Solar System, including the nearly circular and coplanar orbits of the planets, and their motion in the same direction as the Sun's rotation. Some elements of the original nebular theory are echoed in modern theories of planetary formation, but most elements have been superseded.
According to the nebular theory, stars form in massive and dense clouds of molecular hydrogen—giant molecular clouds (GMC). These clouds are gravitationally unstable, and matter coalesces within them to smaller denser clumps, which then rotate, collapse, and form stars. Star formation is a complex process, which always produces a gaseous protoplanetary disk (proplyd) around the young star. This may give birth to planets in certain circumstances, which are not well known. Thus the formation of planetary systems is thought to be a natural result of star formation. A Sun-like star usually takes approximately 1 million years to form, with the protoplanetary disk evolving into a planetary system over the next 10–100 million years.
The protoplanetary disk is an accretion disk that feeds the central star. Initially very hot, the disk later cools in what is known as the T Tauri star stage; here, formation of small dust grains ma
Document 2:::
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are." Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.
In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; and the origin and ultimate fate of the universe. Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.
History
Astronomy is an ancient science, long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthl
Document 3:::
Cosmic wind is a powerful cosmic stream of charged particles that can push interstellar dust clouds of low density into intergalactic space. Although it easily pushes low density gas and dust clouds, it cannot easily push high density clouds. As the cosmic winds start to push the clouds, they start to separate and start looking like taffy being pulled apart. It has a primary composition of photons ejected from large stars and sometimes thermal energy from exploding stars. It can be caused by orbital motion of gas in the cluster of a galaxy, or can be ejected from a black hole. Because new stars and planets form from gases, the cosmic winds that push the gases away are preventing new stars from forming and are ultimately playing a role in galaxy evolution.
Description
These winds come from the thermal expansion of galactic halos in O and B stars and are further increased by cosmic rays, which shoot out and help push gas out of the halo and disk of its galaxy. In these supernovae, these winds are a result of the conversion of the supernova's thermal energy into kinetic energy which is also further increased by cosmic rays. It is a combination of these hot and cooling flows that cause cosmic wind. In smaller stars, such as the sun, the wind comes from the sun's corona and is referred to as solar wind.
Observation
The presence of cosmic wind in the vicinity of a black hole can be noted through the meticulous inspection of absorption line features in the spectra of the accretion disk surrounding said black hole. These features are commonly seen through X-ray telescopes such as the Chandra X-ray Observatory, NuSTAR, and NICER. Before 2007, this was only theorized to occur but several physicists including an astrophysicist named Andrew Robinson analyzed the accretion disk of galaxy that is about 3 billion light years away from the Milky Way. They used the William Herschel Telescope to observe this galaxy, and they noticed that the light surrounding the accretion disk wa
Document 4:::
A protoplanetary nebula or preplanetary nebula (PPN, plural PPNe) is an astronomical object which is at the short-lived episode during a star's rapid evolution between the late asymptotic giant branch (LAGB) phase and the subsequent planetary nebula (PN) phase. A PPN emits strongly in infrared radiation, and is a kind of reflection nebula. It is the second-from-the-last high-luminosity evolution phase in the life cycle of intermediate-mass stars (1–8 ).
Naming
The name protoplanetary nebula is an unfortunate choice due to the possibility of confusion with the same term being sometimes employed when discussing the unrelated concept of protoplanetary disks. The name protoplanetary nebula is a consequence of the older term planetary nebula, which was chosen due to early astronomers looking through telescopes and finding a similarity in appearance of planetary nebula to the gas giants such as Neptune and Uranus. To avoid any possible confusion, suggested employing a new term preplanetary nebula which does not overlap with any other disciplines of astronomy. They are often referred to as post-AGB stars, although that category also includes stars that will never ionize their ejected matter.
Evolution
Beginning
During the late asymptotic giant branch (LAGB) phase, when mass loss reduces the hydrogen envelope's mass to around 10−2 for a core mass of 0.60 , a star will begin to evolve towards the blue side of the Hertzsprung–Russell diagram. When the hydrogen envelope has been further reduced to around 10−3 , the envelope will have been so disrupted that it is believed further significant mass loss is not possible. At this point, the effective temperature of the star, T*, will be around 5,000 K and it is defined to be the end of the LAGB and the beginning of the PPN.
Protoplanetary nebula phase
During the ensuing protoplanetary nebula phase, the central star's effective temperature will continue rising as a result of the envelope's mass loss as a consequence o
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
For a star to form, what force pulls gas and dust into the center of the nebula?
A. motion
B. gravity
C. centrifugal force
D. weight
Answer:
|
|
sciq-377
|
multiple_choice
|
What astronomical phenomenon, formed of split asteroids or planetary rocks, provides clues about our solar system?
|
[
"stars",
"comets",
"meteorites",
"galaxies"
] |
C
|
Relavent Documents:
Document 0:::
This article is a list of notable unsolved problems in astronomy. Some of these problems are theoretical, meaning that existing theories may be incapable of explaining certain observed phenomena or experimental results. Others are experimental, meaning that experiments necessary to test proposed theory or investigate a phenomenon in greater detail have not yet been performed. Some pertain to unique events or occurrences that have not repeated themselves and whose causes remain unclear.
Planetary astronomy
Our solar system
Orbiting bodies and rotation:
Are there any non-dwarf planets beyond Neptune?
Why do extreme trans-Neptunian objects have elongated orbits?
Rotation rate of Saturn:
Why does the magnetosphere of Saturn rotate at a rate close to that at which the planet's clouds rotate?
What is the rotation rate of Saturn's deep interior?
Satellite geomorphology:
What is the origin of the chain of high mountains that closely follows the equator of Saturn's moon, Iapetus?
Are the mountains the remnant of hot and fast-rotating young Iapetus?
Are the mountains the result of material (either from the rings of Saturn or its own ring) that over time collected upon the surface?
Extra-solar
How common are Solar System-like planetary systems? Some observed planetary systems contain Super-Earths and Hot Jupiters that orbit very close to their stars. Systems with Jupiter-like planets in Jupiter-like orbits appear to be rare. There are several possibilities why Jupiter-like orbits are rare, including that data is lacking or the grand tack hypothesis.
Stellar astronomy and astrophysics
Solar cycle:
How does the Sun generate its periodically reversing large-scale magnetic field?
How do other Sol-like stars generate their magnetic fields, and what are the similarities and differences between stellar activity cycles and that of the Sun?
What caused the Maunder Minimum and other grand minima, and how does the solar cycle recover from a minimum state?
Coronal heat
Document 1:::
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are." Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.
In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; and the origin and ultimate fate of the universe. Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.
History
Astronomy is an ancient science, long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthl
Document 2:::
Cosmic dustalso called extraterrestrial dust, space dust, or star dustis dust that occurs in outer space or has fallen onto Earth. Most cosmic dust particles measure between a few molecules and , such as micrometeoroids. Larger particles are called meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (as in the zodiacal cloud), and circumplanetary dust (as in a planetary ring). There are several methods to obtain space dust measurement.
In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, planetary dust (like from Mars), asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach Earth's surface every year, with most grains having a mass between 10−16 kg (0.1 pg) and 10−4 kg (0.1 g). The density of the dust cloud through which the Earth is traveling is approximately 10−6 dust grains/m3.
Cosmic dust contains some complex organic compounds (amorphous organic solids with a mixed aromatic–aliphatic structure) that could be created naturally, and rapidly, by stars. A smaller fraction of dust in space is "stardust" consisting of larger refractory minerals that condensed as matter left by stars.
Interstellar dust particles were collected by the Stardust spacecraft and samples were returned to Earth in 2006.
Study and importance
Cosmic dust was once solely an annoyance to astronomers, as it obscures objects they wished to observe. When infrared astronomy began, the dust particles were observed to be significant and vital components of astrophysical processes. Their analysis can reveal information about phenomena like the formation of the Solar System. For example, cosmic dust can drive the mass loss when a star is nearing the end of its life, play a part in the early stages of star formation, and form planets. In the Solar System,
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An asteroid spectral type is assigned to asteroids based on their reflectance spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classifications.
Taxonomic systems
In 1975, astronomers Clark R. Chapman, David Morrison, and Ben Zellner developed a simple taxonomic system for asteroids based on color, albedo, and spectral shape. The three categories were labelled "C" for dark carbonaceous objects, "S" for stony (silicaceous) objects, and "U" for those that did not fit into either C or S. This basic division of asteroid spectra has since been expanded and clarified. A number of classification schemes are currently in existence, and while they strive to retain some mutual consistency, quite a few asteroids are sorted into different classes depending on the particular scheme. This is due to the use of different criteria for each approach. The two most widely used classifications are described below:
Overview of Tholen and SMASS
S3OS2 classification
The Small Solar System Objects Spectroscopic Survey (S3OS2 or S3OS2, also known as the Lazzaro classification) observed 820 asteroids, using the former ESO 1.52-metre telescope at La Silla Observatory during 1996–2001. This survey applied both the Tholen and Bus–Binzel (SMASS) taxonomy to the observed objects, many of which had previously not been classified. For the Tholen-like classification, the survey introduced a new "Caa-type", which shows a broad absorption band associated indicating an aqueous alteration of the body's surface. The Caa class corresponds to Tholen's C-type and to the SMASS hydrated Ch-type (inclu
Document 4:::
The history of scientific thought about the formation and evolution of the Solar System began with the Copernican Revolution. The first recorded use of the term "Solar System" dates from 1704. Since the seventeenth century, philosophers and scientists have been forming hypotheses concerning the origins of our Solar System and the Moon and attempting to predict how the Solar System would change in the future. René Descartes was the first to hypothesize on the beginning of the Solar System; however, more scientists joined the discussion in the eighteenth century, forming the groundwork for later hypotheses on the topic. Later, particularly in the twentieth century, a variety of hypotheses began to build up, including the now-commonly accepted nebular hypothesis.
Meanwhile, hypotheses explaining the evolution of the Sun originated in the nineteenth century, especially as scientists began to understand how stars in general functioned. In contrast, hypotheses attempting to explain the origin of the Moon have been circulating for centuries, although all of the widely accepted hypotheses were proven false by the Apollo missions in the mid-twentieth century. Following Apollo, in 1984, the giant impact hypothesis was composed, replacing the already-disproven binary accretion model as the most common explanation for the formation of the Moon.
Contemporary view
The most widely accepted model of planetary formation is known as the nebular hypothesis. This model posits that, 4.6 billion years ago, the Solar System was formed by the gravitational collapse of a giant molecular cloud spanning several light-years. Many stars, including the Sun, were formed within this collapsing cloud. The gas that formed the Solar System was slightly more massive than the Sun itself. Most of the mass concentrated in the center, forming the Sun, and the rest of the mass flattened into a protoplanetary disk, out of which all of the current planets, moons, asteroids, and other celestial bodies in t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What astronomical phenomenon, formed of split asteroids or planetary rocks, provides clues about our solar system?
A. stars
B. comets
C. meteorites
D. galaxies
Answer:
|
|
sciq-2420
|
multiple_choice
|
What are large glaciers that cover a larger area than just a valley?
|
[
"ice caps",
"icebergs",
"glacial continents",
"ice floes"
] |
A
|
Relavent Documents:
Document 0:::
The Gulf of St. Lawrence lowland forests are a temperate broadleaf and mixed forest ecoregion of Eastern Canada, as defined by the World Wildlife Fund (WWF) categorization system.
Setting
Located on the Gulf of Saint Lawrence, the world's largest estuary, this ecoregion covers all of Prince Edward Island, the Les Îles-de-la-Madeleine of Quebec, most of east-central New Brunswick, the Annapolis Valley, Minas Basin and the Northumberland Strait coast of Nova Scotia. This area has a coastal climate of warm summers and cold and snowy winters with an average annual temperature of around 5 °C going up to 15 °C in summer, the coast is warmer than the islands or the sheltered inland valleys.
Flora
The colder climate allows more hardwood trees to grow in the Gulf of St Lawrence than in most of this part of northeast North America. Trees of the region include eastern hemlock (Tsuga canadensis), balsam fir (Abies balsamea), American elm (Ulmus americana), black ash (Fraxinus nigra), eastern white pine (Pinus strobus), red maple, (Acer rubrum) northern red oak (Quercus rubra), black spruce (Picea mariana), red spruce (Picea rubens) and white spruce (Picea glauca).
Fauna
The forests are home to a variety of wildlife including American black bear (Ursus americanus), moose (Alces alces), white-tailed deer (Odocoileus virginianus), red fox (Vulpes vulpes), snowshoe hare (Lepus americanus), North American porcupine (Erithyzon dorsatum), fisher (Martes pennanti), North American beaver (Castor canadensis), bobcat (Lynx rufus), American marten (Martes americana), raccoon (Procyon lotor) and muskrat (Ondatra zibethica). The area is habitat for maritime ringlet butterflies (Coenonympha nipisiquit) and other invertebrates. Birds include many seabirds, a large colony of great blue heron (Ardea herodias), the largest remaining population of the endangered piping plover and one of the largest colonies of double-crested cormorant (Phalacrocorax auritus) in the world.
Threats and preserva
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
Glacio-geological databases compile data on glacially associated sedimentary deposits and erosional activity from former and current ice-sheets, usually from published peer-reviewed sources. Their purposes are generally directed towards two ends: (Mode 1) compiling information about glacial landforms, which often inform about former ice-flow directions; and (Mode 2) compiling information which dates the absence or presence of ice.
These databases are used for a variety of purposes: (i) as bibliographic tools for researchers; (ii) as the quantitative basis of mapping of landforms or dates of ice presence/absence; and (iii) as quantitative databases which are used to constrain physically based mathematical models of ice-sheets.
Antarctic Ice Sheet: The AGGDB is a Mode 2 glacio-geological database for the Antarctic ice-sheet using information from around 150 published sources, covering glacial activity mainly from the past 30,000 years. It is available online, and aims to be comprehensive to the end of 2007.
British Ice Sheet: BRITICE is a Mode 1 database which aims to map all glacial landforms of Great Britain.
Eurasian Ice Sheet: DATED-1 is a Mode 2 database for the Eurasian ice-sheet. Its sister-project DATED-2 uses the information in DATED-1 to map the retreat of the Eurasian ice-sheet since the Last Glacial Maximum.
See also
Glacial landforms
Sediment
Geology
Ice sheet
Exposure Age Dating
Radio-carbon dating
Document 3:::
Pavilion Lake is a freshwater lake located in Marble Canyon, British Columbia, Canada home to colonies of freshwater microbialites.
Location and Local Communities
It is located between the towns of Lillooet and Cache Creek (29.44 kilometres WNW, as the crow flies, from Cache Creek) and lies along BC Highway 99, 8.85 highway kilometres (northeast then southeast) from Pavilion, British Columbia. There is a small community of lakeshore residences, some recreational and seasonal only, located on the lake's eastern shore adjacent to the highway. The lake is overlooked by the cliffs of Marble Canyon, which is the southern buttress of the Marble Range, and the forests of the northernmost Clear Range. Also overlooking the lake is Chimney Rock (K'lpalekw in Secwepemc'tsn, "Coyote's Penis"), which like the lake and the canyon have spiritual significance to the adjoining native communities, the Tskwaylaxw people of Pavilion and the Bonaparte band of Secwepemc at Upper Hat Creek. One of the rancheries and a rodeo and pow-wow ground of the Pavilion Band is located at Marble Canyon's south entrance. The lake area and its foreshore were added to Marble Canyon Provincial Park in order to protect its special scientific and heritage values.
Characteristics
The lake demonstrates karst hydrology, with underground inflows from Marble Canyon creeks. The lake has generally low biological productivity, and is classified as ultraoligotrophic. It also features a high degree of water clarity. The lake gets covered with ice annually, and is dimictic, going through two thermal overturns per year. The lake reaches a maximum depth of 65 meters below the surface. It is also a hard water lake, due to its high mineral content.
Microbialites and Scientific Research
Part of a karst formation, the lake is most notable for being home to colonies of microbialites, a type of stromatolite. Colonies of microbialites grow from depths of 5 to 55 meters. Low sedimentation rates may allow for continued
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The Older Dryas was a stadial (cold) period between the Bølling and Allerød interstadials (warmer phases), about 14,000 years Before Present, towards the end of the Pleistocene. Its date is not well defined, with estimates varying by 400 years, but its duration is agreed to have been around 200 years.
The gradual warming since the Last Glacial Maximum (27,000 to 24,000 years BP) has been interrupted by two cold spells: the Older Dryas and the Younger Dryas (c. 12,900–11,650 BP). In northern Scotland, the glaciers were thicker and deeper during the Older Dryas than the succeeding Younger Dryas, and there is no evidence of human occupation of Britain. In Northwestern Europe there was also an earlier Oldest Dryas (18.5–17 ka BP 15–14 ka BP). The Dryas are named after an indicator genus, the Arctic and Alpine plant Dryas, the remains of which are found in higher concentrations in deposits from colder periods.
The Older Dryas was a variable cold, dry Blytt–Sernander period, observed in climatological evidence in only some regions, dependent on latitude. In regions in which it is not observed, the Bølling–Allerød is considered a single interstadial period. Evidence of the Older Dryas is strongest in northern Eurasia, particularly part of Northern Europe, roughly equivalent to Pollen zone Ic.
Dates
In the Greenland oxygen isotope record, the Older Dryas appears as a downward peak establishing a small, low-intensity gap between the Bølling and the Allerød. That configuration presents a difficulty in estimating its time, as it is more of a point than a segment. The segment is small enough to escape the resolution of most carbon-14 series, as the points are not close enough together to find the segment.
One approach to the problem assigns a point and then picks an arbitrary segment. The Older Dryas is sometimes considered to be "centered" near 14,100 BP or to be 100 to 150 years long "at" 14,250 BP.
A second approach finds carbon-14 or other dates as close to the end of
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are large glaciers that cover a larger area than just a valley?
A. ice caps
B. icebergs
C. glacial continents
D. ice floes
Answer:
|
|
sciq-7598
|
multiple_choice
|
What is the process that moves particles by rolling or dragging along the bottom of the water?
|
[
"compression",
"traction",
"isolation",
"compaction"
] |
B
|
Relavent Documents:
Document 0:::
Active matter is matter composed of large numbers of active "agents", each of which consumes energy in order to move or to exert mechanical forces. Such systems are intrinsically out of thermal equilibrium. Unlike thermal systems relaxing towards equilibrium and systems with boundary conditions imposing steady currents, active matter systems break time reversal symmetry because energy is being continually dissipated by the individual constituents. Most examples of active matter are biological in origin and span all the scales of the living, from bacteria and self-organising bio-polymers such as microtubules and actin (both of which are part of the cytoskeleton of living cells), to schools of fish and flocks of birds. However, a great deal of current experimental work is devoted to synthetic systems such as artificial self-propelled particles. Active matter is a relatively new material classification in soft matter: the most extensively studied model, the Vicsek model, dates from 1995.
Research in active matter combines analytical techniques, numerical simulations and experiments. Notable analytical approaches include hydrodynamics, kinetic theory, and non-equilibrium statistical physics. Numerical studies mainly involve self-propelled-particles models, making use of agent-based models such as molecular dynamics algorithms or lattice-gas models, as well as computational studies of hydrodynamic equations of active fluids. Experiments on biological systems extend over a wide range of scales, including animal groups (e.g., bird flocks, mammalian herds, fish schools and insect swarms), bacterial colonies, cellular tissues (e.g. epithelial tissue layers, cancer growth and embryogenesis), cytoskeleton components (e.g., in vitro motility assays, actin-myosin networks and molecular-motor driven filaments). Experiments on synthetic systems include self-propelled colloids (e.g., phoretically propelled particles), driven granular matter (e.g. vibrated monolayers), swarming r
Document 1:::
Microrheology is a technique used to measure the rheological properties of a medium, such as microviscosity, via the measurement of the trajectory of a flow tracer (a micrometre-sized particle). It is a new way of doing rheology, traditionally done using a rheometer. There are two types of microrheology: passive microrheology and active microrheology. Passive microrheology uses inherent thermal energy to move the tracers, whereas active microrheology uses externally applied forces, such as from a magnetic field or an optical tweezer, to do so. Microrheology can be further differentiated into 1- and 2-particle methods.
Passive microrheology
Passive microrheology uses the thermal energy (kT) to move the tracers, although recent evidence suggests that active random forces inside cells may instead move the tracers in a diffusive-like manner. The trajectories of the tracers are measured optically either by microscopy, or alternatively by light scattering techniques. Diffusing-wave spectroscopy (DWS) is a common choice that extends light scattering measurement techniques to account for multiple scattering events. From the mean squared displacement with respect to time (noted MSD or <Δr2> ), one can calculate the visco-elastic moduli G′(ω) and G″(ω) using the generalized Stokes–Einstein relation (GSER). Here is a view of the trajectory of a particle of micrometer size.
In a standard passive microrheology test, the movement of dozens of tracers is tracked in a single video frame. The motivation is to average the movements of the tracers and calculate a robust MSD profile.
Observing the MSD for a wide range of integration time scales (or frequencies) gives information on the microstructure of the medium where are diffusing the tracers.
If the tracers are experiencing free diffusion in a purely viscous material, the MSD should grow linearly with sampling integration time:
.
If the tracers are moving in a spring-like fashion within a purely elastic material, the MSD
Document 2:::
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity.
The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube such as a straw, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell.
It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.
Etymology
Capillary comes from the Latin word capillaris, meaning "of or resembling hair." The meaning stems from the tiny, hairlike diameter of a capillary. While capillary is usually used as a noun, the word also is used as an adjective, as in "capillary action," in which a liquid is moved along — even upward, against gravity — as the liquid is attracted to the internal surface of the capillaries.
History
The first recorded observation of capillary action was by Leonardo da Vinci. A former student of Galileo, Niccolò Aggiunti, was said to have investigated capillary action. In 1660, capillary action was still a novelty to the Irish chemist Robert Boyle, when he reported that "some inquisitive French Men" had observed that when a capillary tube was dipped into water, the water would ascend to "some height in the Pipe". Boyle then reported an experiment in which he dipped a capillary tube into red wine and then subjected the tube to a partial vacuum. He found that the vacuum had no observable influence on the height of the liquid in the capillary, so the behavior of liquids in capillary tubes was due to some phenomenon different from that
Document 3:::
A biohybrid microswimmer can be defined as a microswimmer that consist of both biological and artificial constituents, for instance, one or several living microorganisms attached to one or various synthetic parts.
In recent years nanoscopic and mesoscopic objects have been designed to collectively move through direct inspiration from nature or by harnessing its existing tools. Small mesoscopic to nanoscopic systems typically operate at low Reynolds numbers (Re ≪ 1), and understanding their motion becomes challenging. For locomotion to occur, the symmetry of the system must be broken.
In addition, collective motion requires a coupling mechanism between the entities that make up the collective. To develop mesoscopic to nanoscopic entities capable of swarming behaviour, it has been hypothesised that the entities are characterised by broken symmetry with a well-defined morphology, and are powered with some material capable of harvesting energy. If the harvested energy results in a field surrounding the object, then this field can couple with the field of a neighbouring object and bring some coordination to the collective behaviour. Such robotic swarms have been categorised by an online expert panel as among the 10 great unresolved group challenges in the area of robotics. Although investigation of their underlying mechanism of action is still in its infancy, various systems have been developed that are capable of undergoing controlled and uncontrolled swarming motion by harvesting energy (e.g., light, thermal, etc.).
Over the past decade, biohybrid microrobots, in which living mobile microorganisms are physically integrated with untethered artificial structures, have gained growing interest to enable the active locomotion and cargo delivery to a target destination. In addition to the motility, the intrinsic capabilities of sensing and eliciting an appropriate response to artificial and environmental changes make cell-based biohybrid microrobots appealing for transpo
Document 4:::
A jet mill grinds materials by using a high speed jet of compressed air or inert gas to impact particles into each other. Jet mills can be designed to output particles below a certain size while continuing to mill particles above that size, resulting in a narrow size distribution of the resulting product. Particles leaving the mill can be separated from the gas stream by cyclonic separation.
Particle size
A jet mill consists of a short cylinder, meaning the cylinder's height is less than its diameter. Compressed gas is forced into the mill through nozzles tangent to the cylinder wall, creating a vortex. The gas leaves the mill through a tube along the axis of the cylinder. Solid particles in the mill are subject to two competing forces:
Centrifugal force created by the particles traveling in circles
Centripetal force created by the drag from the gas as it flows from the nozzles along the wall to the outlet in the center of the mill
The drag on small particles is less than large particles, according to the formula derived from Stokes' law,
,
where V is the flow settling velocity (m/s) (vertically downwards if ρp > ρf, upwards if ρp < ρf ), g is the gravitational acceleration (m/s2), ρp is the mass density of the particles (kg/m3), ρf is the mass density of the fluid (kg/m3), μ is the dynamic viscosity (kg /m*s), and R is the radius of the spherical particle (m).
The formula shows that particles will be pulled toward the wall of the mill according to the square of their radius or diameter. Large particles will continue the comminution process, until they are small enough to stay in the center of the mill where the discharge port is located.
Typical parameters
Diameter of mill: from 0.05 meters to 1 meter (from 2 inches to 42 inches)
Gas pressure: 8.3 Bar (120 PSI)
Starting particle size: 800 microns or less, or as limited by the size of the inlet of the feed venturi
Final particle size: down to 0.5 microns
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the process that moves particles by rolling or dragging along the bottom of the water?
A. compression
B. traction
C. isolation
D. compaction
Answer:
|
|
sciq-4492
|
multiple_choice
|
What does fluorine attract better than any other element?
|
[
"shared electrons",
"electron shells",
"magnets",
"ionic bonds"
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 2:::
In chemistry and physics, the iron group refers to elements that are in some way related to iron; mostly in period (row) 4 of the periodic table. The term has different meanings in different contexts.
In chemistry, the term is largely obsolete, but it often means iron, cobalt, and nickel, also called the iron triad; or, sometimes, other elements that resemble iron in some chemical aspects.
In astrophysics and nuclear physics, the term is still quite common, and it typically means those three plus chromium and manganese—five elements that are exceptionally abundant, both on Earth and elsewhere in the universe, compared to their neighbors in the periodic table. Titanium and vanadium are also produced in Type Ia supernovae.
General chemistry
In chemistry, "iron group" used to refer to iron and the next two elements in the periodic table, namely cobalt and nickel. These three comprised the "iron triad". They are the top elements of groups 8, 9, and 10 of the periodic table; or the top row of "group VIII" in the old (pre-1990) IUPAC system, or of "group VIIIB" in the CAS system. These three metals (and the three of the platinum group, immediately below them) were set aside from the other elements because they have obvious similarities in their chemistry, but are not obviously related to any of the other groups. The iron group and its alloys exhibit ferromagnetism.
The similarities in chemistry were noted as one of Döbereiner's triads and by Adolph Strecker in 1859. Indeed, Newlands' "octaves" (1865) were harshly criticized for separating iron from cobalt and nickel. Mendeleev stressed that groups of "chemically analogous elements" could have similar atomic weights as well as atomic weights which increase by equal increments, both in his original 1869 paper and his 1889 Faraday Lecture.
Analytical chemistry
In the traditional methods of qualitative inorganic analysis, the iron group consists of those cations which
have soluble chlorides; and
are not precipitated
Document 3:::
Advanced Placement (AP) Physics C: Electricity and Magnetism (also known as AP Physics C: E&M or AP E&M) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a second-semester calculus-based university course in electricity and magnetism. The content of Physics C: E&M overlaps with that of AP Physics 2, but Physics 2 is algebra-based and covers other topics outside of electromagnetism, while Physics C is calculus-based and only covers electromagnetism. Physics C: E&M may be combined with its mechanics counterpart to form a year-long course that prepares for both exams.
Course content
E&M is equivalent to an introductory college course in electricity and magnetism for physics or engineering majors. The course modules are:
Electrostatics
Conductors, capacitors, and dielectrics
Electric circuits
Magnetic fields
Electromagnetism.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a calculus class.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Electricity and Magnetism is separate from the AP examination for AP Physics C: Mechanics. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday afternoon in May. The exam is configured in two categories: a 35-question multiple choice section and a 3-question free response section. Test takers are allowed to use an approved calculator during the entire exam. The test is weighted such that each section is worth half of the final score. This and AP Physics C: Mechanics are the shortest AP exams, with
Document 4:::
There are four Advanced Placement (AP) Physics courses administered by the College Board as part of its Advanced Placement program: the algebra-based Physics 1 and Physics 2 and the calculus-based Physics C: Mechanics and Physics C: Electricity and Magnetism. All are intended to be at the college level. Each AP Physics course has an exam for which high-performing students may receive credit toward their college coursework.
AP Physics 1 and 2
AP Physics 1 and AP Physics 2 were introduced in 2015, replacing AP Physics B. The courses were designed to emphasize critical thinking and reasoning as well as learning through inquiry. They are algebra-based and do not require any calculus knowledge.
AP Physics 1
AP Physics 1 covers Newtonian mechanics, including:
Unit 1: Kinematics
Unit 2: Dynamics
Unit 3: Circular Motion and Gravitation
Unit 4: Energy
Unit 5: Momentum
Unit 6: Simple Harmonic Motion
Unit 7: Torque and Rotational Motion
Until 2020, the course also covered topics in electricity (including Coulomb's Law and resistive DC circuits), mechanical waves, and sound. These units were removed because they are included in AP Physics 2.
AP Physics 2
AP Physics 2 covers the following topics:
Unit 1: Fluids
Unit 2: Thermodynamics
Unit 3: Electric Force, Field, and Potential
Unit 4: Electric Circuits
Unit 5: Magnetism and Electromagnetic Induction
Unit 6: Geometric and Physical Optics
Unit 7: Quantum, Atomic, and Nuclear Physics
AP Physics C
From 1969 to 1972, AP Physics C was a single course with a single exam that covered all standard introductory university physics topics, including mechanics, fluids, electricity and magnetism, optics, and modern physics. In 1973, the College Board split the course into AP Physics C: Mechanics and AP Physics C: Electricity and Magnetism. The exam was also split into two separate 90-minute tests, each equivalent to a semester-length calculus-based college course. Until 2006, both exams could be taken for a single
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does fluorine attract better than any other element?
A. shared electrons
B. electron shells
C. magnets
D. ionic bonds
Answer:
|
|
sciq-3581
|
multiple_choice
|
Glucose and fructose are considered this type of sugar?
|
[
"monosaccharides, or simple",
"alcohols",
"polysaccharides",
"complex carbohydrates"
] |
A
|
Relavent Documents:
Document 0:::
Structure and nomenclature
Carbohydrates are generally divided into monosaccharides, oligosaccharides, and polysaccharides depending on the number of sugar subunits. Maltose, with two sugar units, is a disaccharide, which falls under oligosaccharides. Glucose is a hexose: a monosaccharide containing six carbon atoms. The two glucose units are in the pyranose form and are joined by an O-glycosidic bond, with the first carbon (C1) of the first glucose linked to the fourth carbon (C4) of the second glucose, indicated as (1→4). The link is characterized as α because the glycosidic bond to the anomeric carbon (C1) is in the opposite plane from the substituent in the same ring (C6 of the first glucose). If the glycosidic bond to the anomeric carbon (C1) were in the same plane as the substituent, it would be classified as a β(1→4) bond, and the resulting molecule would be cellobiose. The anomeric carbon (C1) of the second glucose molecule, which is not involved in a glycosidic bond, could be either an α- or β-anomer depending on the bond direction of the attached hydroxyl group relative to the substituent of the same ring, resulting in either α-
Document 1:::
A diose is a monosaccharide containing two carbon atoms. Because the general chemical formula of an unmodified monosaccharide is (C·H2O)n, where n is three or greater, it does not meet the formal definition of a monosaccharide. However, since it does fit the formula (C·H2O)n, it is sometimes thought of as the most basic sugar.
There is only one possible diose, glycolaldehyde (2-hydroxyethanal), which is an aldodiose (a ketodiose is not possible since there are only two carbons).
See also
Triose
Tetrose
Pentose
Hexose
Heptose
Document 2:::
A reducing sugar is any sugar that is capable of acting as a reducing agent. In an alkaline solution, a reducing sugar forms some aldehyde or ketone, which allows it to act as a reducing agent, for example in Benedict's reagent. In such a reaction, the sugar becomes a carboxylic acid.
All monosaccharides are reducing sugars, along with some disaccharides, some oligosaccharides, and some polysaccharides. The monosaccharides can be divided into two groups: the aldoses, which have an aldehyde group, and the ketoses, which have a ketone group. Ketoses must first tautomerize to aldoses before they can act as reducing sugars. The common dietary monosaccharides galactose, glucose and fructose are all reducing sugars.
Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an aldehyde group; they are stuck in the cyclic form. Reducing disaccharides like lactose and maltose have only one of their two anomeric carbons involved in the glycosidic bond, while the other is free and can convert to an open-chain form with an aldehyde group.
The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens' test or Benedict's test. The cyclic hemiacetal forms of aldoses can open to reveal an aldehyde, and certain ketoses can undergo tautomerization to become aldoses. However, acetals, including those found in polysaccharide linkages, cannot easily become free aldehydes.
Reducing sugars react with amino acids in the Maillard reaction, a series of reactions that occurs while cooking food at high temperatures and that is important in determining the flavor of food. Also, the levels of reducing sugars in wine, juice, and sugarcane are indicative of the quality of these food products.
Terminology
Oxidation-reduction
A reducing sugar is on
Document 3:::
Added sugars or free sugars are sugar carbohydrates (caloric sweeteners) added to food and beverages at some point before their consumption. These include added carbohydrates (monosaccharides and disaccharides), and more broadly, sugars naturally present in honey, syrup, fruit juices and fruit juice concentrates. They can take multiple chemical forms, including sucrose (table sugar), glucose (dextrose), and fructose.
Medical consensus holds that added sugars contribute little nutritional value to food, leading to a colloquial description as "empty calories". Overconsumption of sugar is correlated with excessive calorie intake and increased risk of weight gain and various diseases.
Uses
United States
In the United States, added sugars may include sucrose or high-fructose corn syrup, both primarily composed of about half glucose and half fructose. Other types of added sugar ingredients include beet and cane sugars, malt syrup, maple syrup, pancake syrup, fructose sweetener, liquid fructose, fruit juice concentrate, honey, and molasses. The most common types of foods containing added sugars are sweetened beverages, including most soft drinks, and also desserts and sweet snacks, which represent 20% of daily calorie consumption, twice the recommendation of the World Health Organization (WHO). Based on a 2012 study on the use of caloric and noncaloric sweeteners in some 85,000 food and beverage products, 74% of the products contained added sugar.
Sweetened beverages
Sweetened beverages contain a syrup mixture of the monosaccharides glucose and fructose formed by hydrolytic saccharification of the disaccharide sucrose. The bioavailability of liquid carbohydrates is higher than in solid sugars, as characterized by sugar type and by the estimated rate of digestion. There is evidence for a positive and causal relationship between excessive intake of fruit juices and increased risk of some chronic metabolic diseases.
Guidelines
World Health Organization
In 2003, the
Document 4:::
Nucleotide sugars are the activated forms of monosaccharides. Nucleotide sugars act as glycosyl donors in glycosylation reactions. Those reactions are catalyzed by a group of enzymes called glycosyltransferases.
History
The anabolism of oligosaccharides - and, hence, the role of nucleotide sugars - was not clear until the 1950s when Leloir and his coworkers found that the key enzymes in this process are the glycosyltransferases. These enzymes transfer a glycosyl group from a sugar nucleotide to an acceptor.
Biological importance and energetics
To act as glycosyl donors, those monosaccharides should exist in a highly energetic form. This occurs as a result of a reaction between nucleoside triphosphate (NTP) and glycosyl monophosphate (phosphate at anomeric carbon). The recent discovery of the reversibility of many glycosyltransferase-catalyzed reactions calls into question the designation of sugar nucleotides as 'activated' donors.
Types
There are nine sugar nucleotides in humans which act as glycosyl donors and they can be classified depending on the type of the nucleoside forming them:
Uridine Diphosphate: UDP-α-D-Glc, UDP-α-D-Gal, UDP-α-D-GalNAc, UDP-α-D-GlcNAc, UDP-α-D-GlcA, UDP-α-D-Xyl
Guanosine Diphosphate: GDP-α-D-Man, GDP-β-L-Fuc.
Cytidine Monophosphate: CMP-β-D-Neu5Ac; in humans, it is the only nucleotide sugar in the form of nucleotide monophosphate.
Cytidine Diphosphate: CDP-D-Ribitol (i.e. CMP-[ribitol phosphate]); though not a sugar, the phosphorylated sugar alcohol ribitol phosphate is incorporated into matriglycan as if it were a monosaccharide.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Glucose and fructose are considered this type of sugar?
A. monosaccharides, or simple
B. alcohols
C. polysaccharides
D. complex carbohydrates
Answer:
|
|
sciq-6372
|
multiple_choice
|
After fertilization is complete, no other sperm can enter. the fertilized ovule forms the seed, whereas the tissues of the ovary become this?
|
[
"fruit",
"vegetables",
"wheat",
"plant"
] |
A
|
Relavent Documents:
Document 0:::
Reproductive biology includes both sexual and asexual reproduction.
Reproductive biology includes a wide number of fields:
Reproductive systems
Endocrinology
Sexual development (Puberty)
Sexual maturity
Reproduction
Fertility
Human reproductive biology
Endocrinology
Human reproductive biology is primarily controlled through hormones, which send signals to the human reproductive structures to influence growth and maturation. These hormones are secreted by endocrine glands, and spread to different tissues in the human body. In humans, the pituitary gland synthesizes hormones used to control the activity of endocrine glands.
Reproductive systems
Internal and external organs are included in the reproductive system. There are two reproductive systems including the male and female, which contain different organs from one another. These systems work together in order to produce offspring.
Female reproductive system
The female reproductive system includes the structures involved in ovulation, fertilization, development of an embryo, and birth.
These structures include:
Ovaries
Oviducts
Uterus
Vagina
Mammary Glands
Estrogen is one of the sexual reproductive hormones that aid in the sexual reproductive system of the female.
Male reproductive system
The male reproductive system includes testes, rete testis, efferent ductules, epididymis, sex accessory glands, sex accessory ducts and external genitalia.
Testosterone, an androgen, although present in both males and females, is relatively more abundant in males. Testosterone serves as one of the major sexual reproductive hormones in the male reproductive system However, the enzyme aromatase is present in testes and capable of synthesizing estrogens from androgens. Estrogens are present in high concentrations in luminal fluids of the male reproductive tract. Androgen and estrogen receptors are abundant in epithelial cells of the male reproductive tract.
Animal Reproductive Biology
Animal reproduction oc
Document 1:::
Oogenesis, ovogenesis, or oögenesis is the differentiation of the ovum (egg cell) into a cell competent to further develop when fertilized. It is developed from the primary oocyte by maturation. Oogenesis is initiated in the embryonic stage.
Oogenesis in non-human mammals
In mammals, the first part of oogenesis starts in the germinal epithelium, which gives rise to the development of ovarian follicles, the functional unit of the ovary.
Oogenesis consists of several sub-processes: oocytogenesis, ootidogenesis, and finally maturation to form an ovum (oogenesis proper). Folliculogenesis is a separate sub-process that accompanies and supports all three oogenetic sub-processes.
Oogonium —(Oocytogenesis)—> Primary Oocyte —(Meiosis I)—> First Polar body (Discarded afterward) + Secondary oocyte —(Meiosis II)—> Second Polar Body (Discarded afterward) + Ovum
Oocyte meiosis, important to all animal life cycles yet unlike all other instances of animal cell division, occurs completely without the aid of spindle-coordinating centrosomes.
The creation of oogonia
The creation of oogonia traditionally doesn't belong to oogenesis proper, but, instead, to the common process of gametogenesis, which, in the female human, begins with the processes of folliculogenesis, oocytogenesis, and ootidogenesis. Oogonia enter meiosis during embryonic development, becoming oocytes. Meiosis begins with DNA replication and meiotic crossing over. It then stops in early prophase.
Maintenance of meiotic arrest
Mammalian oocytes are maintained in meiotic prophase arrest for a very long time—months in mice, years in humans. Initially the arrest is due to lack of sufficient cell cycle proteins to allow meiotic progression. However, as the oocyte grows, these proteins are synthesized, and meiotic arrest becomes dependent on cyclic AMP. The cyclic AMP is generated by the oocyte by adenylyl cyclase in the oocyte membrane. The adenylyl cyclase is kept active by a constitutively active G-protein-coupled
Document 2:::
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid cells.
Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion. Spermatogenesis is highly dependent upon optimal conditions for the process to occur correctly, and is essential for sexual reproduction. DNA methylation and histone modification have been implicated in the regulation of this process. It starts during puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age (see Male infertility).
Spermatogenesis starts in the bottom part of seminiferous tubes and, progressively, cells go deeper into tubes and moving along it until mature spermatozoa reaches the lumen, where mature spermatozoa are deposited. The division happens asynchronically; if the tube is cut transversally one could observe different
Document 3:::
In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres are an essential part of blastula formation, and blastocyst formation in mammals.
Human blastomere characteristics
In humans, blastomere formation begins immediately following fertilization and continues through the first week of embryonic development. About 90 minutes after fertilization, the zygote divides into two cells. The two-cell blastomere state, present after the zygote first divides, is considered the earliest mitotic product of the fertilized oocyte. These mitotic divisions continue and result in a grouping of cells called blastomeres. During this process, the total size of the embryo does not increase, so each division results in smaller and smaller cells. When the zygote contains 16 to 32 blastomeres it is referred to as a morula. These are the preliminary stages in the embryo beginning to form. Once this begins, microtubules within the morula's cytosolic material in the blastomere cells can develop into important membrane functions, such as sodium pumps. These pumps allow the inside of the embryo to fill with blastocoelic fluid, which supports the further growth of life.
The blastomere is considered totipotent; that is, blastomeres are capable of developing from a single cell into a fully fertile adult organism. This has been demonstrated through studies and conjectures made with mouse blastomeres, which have been accepted as true for most mammalian blastomeres as well. Studies have analyzed monozygotic twin mouse blastomeres in their two-cell state, and have found that when one of the twin blastomeres is destroyed, a fully fertile adult mouse can still develop. Thus, it can be assumed that since one of the twin cells was totipotent, the destroyed one originally was as well.
Relative blastomere size within the embryo is dependent not only on the stage of the cleavage, but also on the regularity of the cleavage amongst t
Document 4:::
Oocyte selection is a procedure that is performed prior to in vitro fertilization, in order to use oocytes with maximal chances of resulting in pregnancy. In contrast, embryo selection takes place after fertilization.
Techniques
Chromosomal evaluation may be performed. Embryos from rescued in vitro-matured metaphase II (IVM-MII) oocytes show significantly higher fertilization rates and more blastomeres per embryo compared with those from arrested metaphase I (MI) oocytes (58.5% vs. 43.9% and 5.7 vs. 5.0, respectively).
Also, morphological features of the oocyte that can be obtained by standard light or polarized light microscopy. However, there is no clear tendency in recent publications to a general increase in predictive value of morphological features. Suggested techniques include zona pellucida imaging, which can detect differences in birefringence between eggs, which is a predictor of compaction, blastulation and pregnancy.
Potentially, polar body biopsy may be used for molecular analysis, and can be used for preimplantation genetic screening.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
After fertilization is complete, no other sperm can enter. the fertilized ovule forms the seed, whereas the tissues of the ovary become this?
A. fruit
B. vegetables
C. wheat
D. plant
Answer:
|
|
sciq-8937
|
multiple_choice
|
What do you call the atomic "ingredients" that go into a chemical reaction?
|
[
"complexes",
"propellants",
"reactants",
"Starters"
] |
C
|
Relavent Documents:
Document 0:::
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas. The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction. The chemical formulas may be symbolic, structural (pictorial diagrams), or intermixed. The coefficients next to the symbols and formulas of entities are the absolute values of the stoichiometric numbers. The first chemical equation was diagrammed by Jean Beguin in 1615.
Structure
A chemical equation (see an example below) consists of a list of reactants (the starting substances) on the left-hand side, an arrow symbol, and a list of products (substances formed in the chemical reaction) on the right-hand side. Each substance is specified by its chemical formula, optionally preceded by a number called stoichiometric coefficient. The coefficient specifies how many entities (e.g. molecules) of that substance are involved in the reaction on a molecular basis. If not written explicitly, the coefficient is equal to 1. Multiple substances on any side of the equation are separated from each other by a plus sign.
As an example, the equation for the reaction of hydrochloric acid with sodium can be denoted:
Given the formulas are fairly simple, this equation could be read as "two H-C-L plus two N-A yields two N-A-C-L and H two." Alternately, and in general for equations involving complex chemicals, the chemical formulas are read using IUPAC nomenclature, which could verbalise this equation as "two hydrochloric acid molecules and two sodium atoms react to form two formula units of sodium chloride and a hydrogen gas molecule."
Reaction types
Different variants of the arrow symbol are used to denote the type of a reaction:
{|
| style="text-align: center; padding-right: 0.5em;" | -> || net forwa
Document 1:::
This is an index of lists of molecules (i.e. by year, number of atoms, etc.). Millions of molecules have existed in the universe since before the formation of Earth. Three of them, carbon dioxide, water and oxygen were necessary for the growth of life. Although humanity had always been surrounded by these substances, it has not always known what they were composed of.
By century
The following is an index of list of molecules organized by time of discovery of their molecular formula or their specific molecule in case of isomers:
List of compounds
By number of carbon atoms in the molecule
List of compounds with carbon number 1
List of compounds with carbon number 2
List of compounds with carbon number 3
List of compounds with carbon number 4
List of compounds with carbon number 5
List of compounds with carbon number 6
List of compounds with carbon number 7
List of compounds with carbon number 8
List of compounds with carbon number 9
List of compounds with carbon number 10
List of compounds with carbon number 11
List of compounds with carbon number 12
List of compounds with carbon number 13
List of compounds with carbon number 14
List of compounds with carbon number 15
List of compounds with carbon number 16
List of compounds with carbon number 17
List of compounds with carbon number 18
List of compounds with carbon number 19
List of compounds with carbon number 20
List of compounds with carbon number 21
List of compounds with carbon number 22
List of compounds with carbon number 23
List of compounds with carbon number 24
List of compounds with carbon numbers 25-29
List of compounds with carbon numbers 30-39
List of compounds with carbon numbers 40-49
List of compounds with carbon numbers 50+
Other lists
List of interstellar and circumstellar molecules
List of gases
List of molecules with unusual names
See also
Molecule
Empirical formula
Chemical formula
Chemical structure
Chemical compound
Chemical bond
Coordination complex
L
Document 2:::
An elementary reaction is a chemical reaction in which one or more chemical species react directly to form products in a single reaction step and with a single transition state. In practice, a reaction is assumed to be elementary if no reaction intermediates have been detected or need to be postulated to describe the reaction on a molecular scale. An apparently elementary reaction may be in fact a stepwise reaction, i.e. a complicated sequence of chemical reactions, with reaction intermediates of variable lifetimes.
In a unimolecular elementary reaction, a molecule dissociates or isomerises to form the products(s)
At constant temperature, the rate of such a reaction is proportional to the concentration of the species
In a bimolecular elementary reaction, two atoms, molecules, ions or radicals, and , react together to form the product(s)
The rate of such a reaction, at constant temperature, is proportional to the product of the concentrations of the species and
The rate expression for an elementary bimolecular reaction is sometimes referred to as the Law of Mass Action as it was first proposed by Guldberg and Waage in 1864. An example of this type of reaction is a cycloaddition reaction.
This rate expression can be derived from first principles by using collision theory for ideal gases. For the case of dilute fluids equivalent results have been obtained from simple probabilistic arguments.
According to collision theory the probability of three chemical species reacting simultaneously with each other in a termolecular elementary reaction is negligible. Hence such termolecular reactions are commonly referred as non-elementary reactions and can be broken down into a more fundamental set of bimolecular reactions, in agreement with the law of mass action. It is not always possible to derive overall reaction schemes, but solutions based on rate equations are often possible in terms of steady-state or Michaelis-Menten approximations.
Notes
Chemical kinetics
Phy
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms reactant and reagent are often used interchangeably, but reactant specifies a substance consumed in the course of a chemical reaction. Solvents, though involved in the reaction mechanism, are usually not called reactants. Similarly, catalysts are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates.
Definitions
Organic chemistry
In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents.
Analytical chemistry
In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by colorimetry. Examples include Fehling's reagent, Millon's reagent, and Tollens' reagent.
Commercial or laboratory preparations
In commercial or laboratory preparations, reagent-grade designates chemical substances meeting standards of purity that ensure the scientific precision and reliability of chemical analysis, chemical reactions or physical testing. Purity standards for reagents are set by organizations such as ASTM International or the American Chemical Society. For instance, reagent-quality water must have very low levels of impurities such as sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity. Laboratory products which are less pure, but still useful and economical for undemanding work, may be designated as technical, practical, or crude grade to distinguish them from reagent versions.
Biology
In t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do you call the atomic "ingredients" that go into a chemical reaction?
A. complexes
B. propellants
C. reactants
D. Starters
Answer:
|
|
sciq-11212
|
multiple_choice
|
In single-celled organisms, plasma membrane extensions, such as whip-like flagella or brush-like cilia, aid in what?
|
[
"sound",
"movement",
"pressure",
"sensation"
] |
B
|
Relavent Documents:
Document 0:::
Bacterial motility is the ability of bacteria to move independently using metabolic energy. Most motility mechanisms that evolved among bacteria also evolved in parallel among the archaea. Most rod-shaped bacteria can move using their own power, which allows colonization of new environments and discovery of new resources for survival. Bacterial movement depends not only on the characteristics of the medium, but also on the use of different appendages to propel. Swarming and swimming movements are both powered by rotating flagella. Whereas swarming is a multicellular 2D movement over a surface and requires the presence of surfactants, swimming is movement of individual cells in liquid environments.
Other types of movement occurring on solid surfaces include twitching, gliding and sliding, which are all independent of flagella. Twitching depends on the extension, attachment to a surface, and retraction of type IV pili which pull the cell forwards in a manner similar to the action of a grappling hook, providing energy to move the cell forward. Gliding uses different motor complexes, such as the focal adhesion complexes of Myxococcus. Unlike twitching and gliding motilities, which are active movements where the motive force is generated by the individual cell, sliding is a passive movement. It relies on the motive force generated by the cell community due to the expansive forces caused by cell growth within the colony in the presence of surfactants, which reduce the friction between the cells and the surface. The overall movement of a bacterium can be the result of alternating tumble and swim phases. As a result, the trajectory of a bacterium swimming in a uniform environment will form a random walk with relatively straight swims interrupted by random tumbles that reorient the bacterium.
Bacteria can also exhibit taxis, which is the ability to move towards or away from stimuli in their environment. In chemotaxis the overall motion of bacteria responds to the presence
Document 1:::
Cell biomechanics a branch of biomechanics that involves single molecules, molecular interactions, or cells as the system of interest. Cells generate and maintain mechanical forces within their environment as a part of their physiology. Cell biomechanics deals with how mRNA, protein production, and gene expression is affected by said environment and with mechanical properties of isolated molecules or interaction of proteins that make up molecular motors.
It is known that minor alterations in mechanical properties of cells can be an indicator of an infected cell. By studying these mechanical properties, greater insight will be gained in regards to disease. Thus, the goal of understanding cell biomechanics is to combine theoretical, experimental, and computational approaches to construct a realistic description of cell mechanical behaviors to provide new insights on the role of mechanics in disease.
History
In the late seventeenth century, English polymath Robert Hooke and Dutch scientist Antonie van Leeuwenhoek looked into ciliate Vorticella with extreme fluid and cellular motion using a simple optical microscope. In 1702 on Christmas day, van Leeuwenhoek described his observations, “In structure these little animals were fashioned like a bell, and at the round opening they made such a stir, that the particles in the water thereabout were set in motion thereby…which sight I found mightily diverting” in a letter. Prior to this, Brownian motion of particles and organelles within living cells had been discovered as well as theories to measure viscosity. However, there were not enough accessible technical tools to perform these accurate experiments at the time. Thus, mechanical properties within cells were only supported qualitatively by observation.
With these new discoveries, the role of mechanical forces within biology was not always naturally accepted. In 1850, English physician William Benjamin Carpenter wrote “many of the actions taking place in the living bod
Document 2:::
This is a list of articles on biophysics.
0–9
5-HT3 receptor
A
ACCN1
ANO1
AP2 adaptor complex
Aaron Klug
Acid-sensing ion channel
Activating function
Active transport
Adolf Eugen Fick
Afterdepolarization
Aggregate modulus
Aharon Katzir
Alan Lloyd Hodgkin
Alexander Rich
Alexander van Oudenaarden
Allan McLeod Cormack
Alpha-3 beta-4 nicotinic receptor
Alpha-4 beta-2 nicotinic receptor
Alpha-7 nicotinic receptor
Alpha helix
Alwyn Jones (biophysicist)
Amoeboid movement
Andreas Mershin
Andrew Huxley
Animal locomotion
Animal locomotion on the water surface
Anita Goel
Antiporter
Aquaporin 2
Aquaporin 3
Aquaporin 4
Archibald Hill
Ariel Fernandez
Arthropod exoskeleton
Arthropod leg
Avery Gilbert
B
BEST2
BK channel
Bacterial outer membrane
Balance (ability)
Bat
Bat wing development
Bert Sakmann
Bestrophin 1
Biased random walk (biochemistry)
Bioelectrochemical reactor
Bioelectrochemistry
Biofilm
Biological material
Biological membrane
Biomechanics
Biomechanics of sprint running
Biophysical Society
Biophysics
Bird flight
Bird migration
Bisindolylmaleimide
Bleb (cell biology)
Boris Pavlovich Belousov
Brian Matthews (biochemist)
Britton Chance
Brush border
Bulk movement
Document 3:::
Durotaxis is a form of cell migration in which cells are guided by rigidity gradients, which arise from differential structural properties of the extracellular matrix (ECM). Most normal cells migrate up rigidity gradients (in the direction of greater stiffness).
History of durotaxis research
The process of durotaxis requires a cell to actively sense the environment, process the mechanical stimulus, and execute a response. Originally, this was believed to be an emergent metazoan property, as the phenomenon requires a complex sensory loop that is dependent on the communication of many different cells. However, as the wealth of relevant scientific literature grew in the late 1980s and throughout the 1990s, it became apparent that single cells possess the ability to do the same. The first observations of durotaxis in isolated cells were that mechanical stimuli could cause the initiation and elongation of axons in the sensory and brain neurons of chicks and induce motility in previously stationary fish epidermal keratocytes. ECM stiffness was also noted to influence cytoskeletal stiffness, fibronectin fibril assembly, the strength of integrin-cytoskeletal interactions, morphology and motility rate, all of which were known influence cell migration.
With information from the previous observations, Lo and colleagues formulated the hypothesis that individual cells can detect substrate stiffness by a process of active tactile exploration in which cells exert contractile forces and measure the resulting deformation in the substrate. Supported by their own experiments, this team coined the term "durotaxis" in their paper in the Biophysical Journal in the year 2000. More recent research supports the previous observations and the principle of durotaxis, with continued evidence for cell migration up rigidity gradients and stiffness-dependent morphological changes
Substrate rigidity
The rigidity of the ECM is significantly different across cell types; for example, it ranges fr
Document 4:::
Mechanosensitive channels (MSCs), mechanosensitive ion channels or stretch-gated ion channels are membrane proteins capable of responding to mechanical stress over a wide dynamic range of external mechanical stimuli. They are present in the membranes of organisms from the three domains of life: bacteria, archaea, and eukarya. They are the sensors for a number of systems including the senses of touch, hearing and balance, as well as participating in cardiovascular regulation and osmotic homeostasis (e.g. thirst). The channels vary in selectivity for the permeating ions from nonselective between anions and cations in bacteria, to cation selective allowing passage Ca2+, K+ and Na+ in eukaryotes, and highly selective K+ channels in bacteria and eukaryotes.
All organisms, and apparently all cell types, sense and respond to mechanical stimuli. MSCs function as mechanotransducers capable of generating both electrical and ion flux signals as a response to external or internal stimuli. Under extreme turgor in bacteria, non selective MSCs such as MSCL and MSCS serve as safety valves to prevent lysis. In specialized cells of the higher organisms, other types of MSCs are probably the basis of the senses of hearing and touch and sense the stress needed for muscular coordination. However, none of these channels have been cloned. MSCs also allow plants to distinguish up from down by sensing the force of gravity. MSCs are not pressure-sensitive, but sensitive to local stress, most likely tension in the surrounding lipid bilayer.
History
Mechanosensitive channels were discovered in 1983 in the skeletal muscle of embryonic chicks by Falguni Guharay and Frederick Sachs. They were also observed (pub. 1986) in Xenopus oocytes, and frequently studied since that time.
Since then, MSCs have been found in cells from bacteria to humans: they are now known to be present in all three domains of life (Archaea, Bacteria and Eukarya, incl. plants and fungi). In the decades since the disco
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In single-celled organisms, plasma membrane extensions, such as whip-like flagella or brush-like cilia, aid in what?
A. sound
B. movement
C. pressure
D. sensation
Answer:
|
|
sciq-10726
|
multiple_choice
|
What is the small intestine lined with that helps with nutrient absorption?
|
[
"cannula",
"bile",
"villi",
"hilum"
] |
C
|
Relavent Documents:
Document 0:::
The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pancreatic duct to aid in digestion. The small intestine is about long and folds many times to fit in the abdomen. Although it is longer than the large intestine, it is called the small intestine because it is narrower in diameter.
The small intestine has three distinct regions – the duodenum, jejunum, and ileum. The duodenum, the shortest, is where preparation for absorption through small finger-like protrusions called villi begins. The jejunum is specialized for the absorption through its lining by enterocytes: small nutrient particles which have been previously digested by enzymes in the duodenum. The main function of the ileum is to absorb vitamin B12, bile salts, and whatever products of digestion that were not absorbed by the jejunum.
Structure
Size
The length of the small intestine can vary greatly, from as short as to as long as , also depending on the measuring technique used. The typical length in a living person is . The length depends both on how tall the person is and how the length is measured. Taller people generally have a longer small intestine and measurements are generally longer after death and when the bowel is empty.
It is approximately in diameter in newborns after 35 weeks of gestational age, and in diameter in adults. On abdominal X-rays, the small intestine is considered to be abnormally dilated when the diameter exceeds 3 cm. On CT scans, a diameter of over 2.5 cm is considered abnormally dilated. The surface area of the human small intestinal mucosa, due to enlargement caused by folds, villi and microvilli, averages .
Parts
The small intestine is divided into three structural parts.
The duodenum is a short structure ranging from in length, and shaped like a "C". It surrounds the head of t
Document 1:::
The Joan Mott Prize Lecture is a prize lecture awarded annually by The Physiological Society in honour of Joan Mott.
Laureates
Laureates of the award have included:
- Intestinal absorption of sugars and peptides: from textbook to surprises
See also
Physiological Society Annual Review Prize Lecture
Document 2:::
The gastrointestinal wall of the gastrointestinal tract is made up of four layers of specialised tissue. From the inner cavity of the gut (the lumen) outwards, these are:
Mucosa
Submucosa
Muscular layer
Serosa or adventitia
The mucosa is the innermost layer of the gastrointestinal tract. It surrounds the lumen of the tract and comes into direct contact with digested food (chyme). The mucosa itself is made up of three layers: the epithelium, where most digestive, absorptive and secretory processes occur; the lamina propria, a layer of connective tissue, and the muscularis mucosae, a thin layer of smooth muscle.
The submucosa contains nerves including the submucous plexus (also called Meissner's plexus), blood vessels and elastic fibres with collagen, that stretches with increased capacity but maintains the shape of the intestine.
The muscular layer surrounds the submucosa. It comprises layers of smooth muscle in longitudinal and circular orientation that also helps with continued bowel movements (peristalsis) and the movement of digested material out of and along the gut. In between the two layers of muscle lies the myenteric plexus (also called Auerbach's plexus).
The serosa/adventitia are the final layers. These are made up of loose connective tissue and coated in mucus so as to prevent any friction damage from the intestine rubbing against other tissue. The serosa is present if the tissue is within the peritoneum, and the adventitia if the tissue is retroperitoneal.
Structure
When viewed under the microscope, the gastrointestinal wall has a consistent general form, but with certain parts differing along its course.
Mucosa
The mucosa is the innermost layer of the gastrointestinal tract. It surrounds the cavity (lumen) of the tract and comes into direct contact with digested food (chyme). The mucosa is made up of three layers:
The epithelium is the innermost layer. It is where most digestive, absorptive and secretory processes occur.
The lamina propr
Document 3:::
The preaortic lymph nodes lie in front of the aorta, and may be divided into celiac lymph nodes, superior mesenteric lymph nodes, and inferior mesenteric lymph nodes groups, arranged around the origins of the corresponding arteries.
The celiac lymph nodes are grouped into three sets: the gastric, hepatic and splenic lymph nodes. These groups also form their own subgroups.
The superior mesenteric lymph nodes are grouped into three sets: the mesenteric, ileocolic and mesocolic lymph nodes.
The inferior mesenteric lymph nodes have a subgroup of pararectal lymph nodes.
The preaortic lymph nodes receive a few vessels from the lateral aortic lymph nodes, but their principal afferents are derived from the organs supplied by the three arteries with which they are associated–the celiac, superior and inferior mesenteric arteries.
Some of their efferents pass to the retroaortic lymph nodes, but the majority unite to form the intestinal lymph trunk, which enters the cisterna chyli.
Additional images
Document 4:::
The food vacuole, or digestive vacuole, is an organelle found in simple eukaryotes such as protists. This organelle is essentially a lysosome. During the stage of the symbiont parasites' lifecycle where it resides within a human (or other mammalian) red blood cell, it is the site of haemoglobin digestion and the formation of the large haemozoin crystals that can be seen under a light microscope.
See also
Protists
Eukaryote
Amoeba
Lysosome
Enzymes
Euglenids
Paramecia
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the small intestine lined with that helps with nutrient absorption?
A. cannula
B. bile
C. villi
D. hilum
Answer:
|
|
sciq-7496
|
multiple_choice
|
Acetyl-coa is formed from the breakdown of carbohydrates, lipids, and what else?
|
[
"proteins",
"hydrocarbons",
"hormones",
"acids"
] |
A
|
Relavent Documents:
Document 0:::
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to the vitamin pantothenic acid (B5) through an amide linkage and 3'-phosphorylated ADP. The acetyl group (indicated in blue in the structural diagram on the right) of acetyl-CoA is linked to the sulfhydryl substituent of the β-mercaptoethylamine group. This thioester linkage is a "high energy" bond, which is particularly reactive. Hydrolysis of the thioester bond is exergonic (−31.5 kJ/mol).
CoA is acetylated to acetyl-CoA by the breakdown of carbohydrates through glycolysis and by the breakdown of fatty acids through β-oxidation. Acetyl-CoA then enters the citric acid cycle, where the acetyl group is oxidized to carbon dioxide and water, and the energy released is captured in the form of 11 ATP and one GTP per acetyl group. GTP is the equivalent of ATP and they can be interconverted by Nucleoside-diphosphate kinase.
Konrad Bloch and Feodor Lynen were awarded the 1964 Nobel Prize in Physiology and Medicine for their discoveries linking acetyl-CoA and fatty acid metabolism. Fritz Lipmann won the Nobel Prize in 1953 for his discovery of the cofactor coenzyme A.
Direct synthesis
The acetylation of CoA is determined by the carbon sources.
Document 1:::
Direct synthesis
The acetylation of CoA is determined by the carbon sources.
Extramitochondrial
At high glucose levels, glycolysis takes place rapidly, thus increasing the amount of citrate produced from the tricarboxylic acid cycle. This citrate is then exported to other organelles outside the mitochondria to be broken into acetyl-CoA and oxaloacetate by the enzyme ATP citrate lyase (ACL). This principal reaction is coupled with the hydrolysis of ATP.
At low glucose levels:
CoA is acetylated using acetate by acetyl-CoA synthetase (ACS), also coupled with ATP hydrolys
Document 2:::
Thiolases, also known as acetyl-coenzyme A acetyltransferases (ACAT), are enzymes which convert two units of acetyl-CoA to acetoacetyl CoA in the mevalonate pathway.
Thiolases are ubiquitous enzymes that have key roles in many vital biochemical pathways, including the beta oxidation pathway of fatty acid degradation and various biosynthetic pathways. Members of the thiolase family can be divided into two broad categories: degradative thiolases (EC 2.3.1.16) and biosynthetic thiolases (EC 2.3.1.9). These two different types of thiolase are found both in eukaryotes and in prokaryotes: acetoacetyl-CoA thiolase (EC:2.3.1.9) and 3-ketoacyl-CoA thiolase (EC:2.3.1.16). 3-ketoacyl-CoA thiolase (also called thiolase I) has a broad chain-length specificity for its substrates and is involved in degradative pathways such as fatty acid beta-oxidation. Acetoacetyl-CoA thiolase (also called thiolase II) is specific for the thiolysis of acetoacetyl-CoA and involved in biosynthetic pathways such as beta-hydroxybutyric acid synthesis or steroid biogenesis.
The formation of a carbon–carbon bond is a key step in the biosynthetic pathways by which fatty acids and polyketide are made. The thiolase superfamily enzymes catalyse the carbon–carbon-bond formation via a thioester-dependent Claisen condensation reaction mechanism.
Function
Document 3:::
Biological cells which form bonds with a substrate and are at the same time subject to a flow can form long thin membrane cylinders called tethers. These tethers connect the adherent area of the substrate to the main body of the cell. Under physiological conditions, neutrophil tethers can extend to several micrometers.
In biochemistry, a tether is a molecule that carries one or two carbon intermediates from one active site to another. They are commonly used in lipid synthesis, gluconeogenesis, and the conversion of pyruvate into Acetyl CoA via PDH complex. Common tethers are lipoate -lysine residue complex associated with dihydrolipoyl transacetylase, which is used for carrying hydroxyethyl from hydroxyethyl TPP. This compound forms Acetyl- CoA, a convergent molecule in metabolic pathways.
Another tether is biotin-lysine residue complex associated with pyruvate carboxylase, an enzyme which plays an important role in gluconeogenesis. It is involved in the production of oxaloacetate from pyruvate.
One of the biological tethers used in the synthesis of fats is a β- mercaptoethylamine-pantothenate complex associated with an acyl carrier protein.
Biochemistry
Cell biology
Document 4:::
In biochemistry, fatty acid synthesis is the creation of fatty acids from acetyl-CoA and NADPH through the action of enzymes called fatty acid synthases. This process takes place in the cytoplasm of the cell. Most of the acetyl-CoA which is converted into fatty acids is derived from carbohydrates via the glycolytic pathway. The glycolytic pathway also provides the glycerol with which three fatty acids can combine (by means of ester bonds) to form triglycerides (also known as "triacylglycerols" – to distinguish them from fatty "acids" – or simply as "fat"), the final product of the lipogenic process. When only two fatty acids combine with glycerol and the third alcohol group is phosphorylated with a group such as phosphatidylcholine, a phospholipid is formed. Phospholipids form the bulk of the lipid bilayers that make up cell membranes and surrounds the organelles within the cells (such as the cell nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, etc.). In addition to cytosolic fatty acid synthesis, there is also mitochondrial fatty acid synthesis (mtFASII), in which malonyl-CoA is formed from malonic acid with the help of malonyl-CoA synthetase (ACSF3), which then becomes the final product octanoyl-ACP (C8) via further intermediate steps.
Straight-chain fatty acids
Straight-chain fatty acids occur in two types: saturated and unsaturated.
Saturated straight-chain fatty acids
Much like β-oxidation, straight-chain fatty acid synthesis occurs via the six recurring reactions shown below, until the 16-carbon palmitic acid is produced.
The diagrams presented show how fatty acids are synthesized in microorganisms and list the enzymes found in Escherichia coli. These reactions are performed by fatty acid synthase II (FASII), which in general contain multiple enzymes that act as one complex. FASII is present in prokaryotes, plants, fungi, and parasites, as well as in mitochondria.
In animals, as well as some fungi such as yeast, these same reactions occur
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Acetyl-coa is formed from the breakdown of carbohydrates, lipids, and what else?
A. proteins
B. hydrocarbons
C. hormones
D. acids
Answer:
|
|
ai2_arc-768
|
multiple_choice
|
The weathering of landforms depends on various factors. Which area would most likely have the fastest rate of chemical weathering?
|
[
"freezing and dry regions",
"warm and moist regions",
"cool and humid regions",
"hot and dry regions"
] |
B
|
Relavent Documents:
Document 0:::
Bioclimatology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or longer (in contrast to biometeorology).
Examples of relevant processes
Climate processes largely control the distribution, size, shape and properties of living organisms on Earth. For instance, the general circulation of the atmosphere on a planetary scale broadly determines the location of large deserts or the regions subject to frequent precipitation, which, in turn, greatly determine which organisms can naturally survive in these environments. Furthermore, changes in climates, whether due to natural processes or to human interferences, may progressively modify these habitats and cause overpopulation or extinction of indigenous species.
The biosphere, for its part, and in particular continental vegetation, which constitutes over 99% of the total biomass, has played a critical role in establishing and maintaining the chemical composition of the Earth's atmosphere, especially during the early evolution of the planet (See History of Earth for more details on this topic). Currently, the terrestrial vegetation exchanges some 60 billion tons of carbon with the atmosphere on an annual basis (through processes of carbon fixation and carbon respiration), thereby playing a critical role in the carbon cycle. On a global and annual basis, small imbalances between these two major fluxes, as do occur through changes in land cover and land use, contribute to the current increase in atmospheric carbon dioxide.
Document 1:::
The Géotechnique lecture is an biennial lecture on the topic of soil mechanics, organised by the British Geotechnical Association named after its major scientific journal Géotechnique.
This should not be confused with the annual BGA Rankine Lecture.
List of Géotechnique Lecturers
See also
Named lectures
Rankine Lecture
Terzaghi Lecture
External links
ICE Géotechnique journal
British Geotechnical Association
Document 2:::
The Taiga of North America is a Level I ecoregion of North America designated by the Commission for Environmental Cooperation (CEC) in its North American Environmental Atlas.
The taiga ecoregion includes much of interior Alaska as well as the Yukon forested area, and extends on the west from the Bering Sea to the Richardson Mountains in on the east, with the Brooks Range on the north and the Alaska Range on the south end. It is a region with a vast mosaic of habitats and a fragile yet extensive patchwork of ecological characteristics. All aspects of the region such as soils and plant species, hydrology, and climate interaction, and are affected by climate change, new emerging natural resources, and other environmental threats such as deforestation. These threats alter the biotic and abiotic components of the region, which lead to further degradation and to various endangered species.
Flora, fauna, and soil
Soils and plant species
The main type of soil in the taiga is Spodosol. These soils contain a Spodic horizon, a sandy layer of soil that has high accumulations of iron and aluminum oxides, which lays underneath a leached A horizon. The color contrast between the Spodic horizon and the overlying horizon is very easy to identify. The color change is the result of the migration of iron and aluminum oxides from small, but consistent amounts of rainfall from the top horizon to the lower horizon of the soil.
The decomposition of organic matter is very slow in the taiga because of the cold climate and low moisture. With the slow decomposition of organic matter, nutrient cycling is very slow and the nutrient level of the soil is also very low. The soils in the taiga are quite acidic as well. A relatively small amount of rainfall coupled with the slow decomposition of organic material allows the acidic plant debris to sit and saturate the top horizons of the soil profile.
As a result of the infertile soil, only a few plant species can really thrive in the taiga. The c
Document 3:::
The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the International Union of Soil Sciences (IUSS).
Background
History
Since the 19th century, several countries developed national soil classification systems. During the 20th century, the need for an international soil classification system became more and more obvious.
From 1971 to 1981, the Food and Agriculture Organization (FAO) and UNESCO published the Soil Map of the World, 10 volumes, scale 1 : 5 M). The Legend for this map, published in 1974 under the leadership of Rudi Dudal, became the FAO soil classification. Many ideas from national soil classification systems were brought together in this worldwide-applicable system, among them the idea of diagnostic horizons as established in the '7th approximation to the USDA soil taxonomy' from 1960. The next step was the Revised Legend of the Soil Map of the World, published in 1988.
In 1982, the International Soil Science Society (ISSS; now: International Union of Soil Sciences, IUSS) established a working group named International Reference Base for Soil Classification (IRB). Chair of this working group was Ernst Schlichting. Its mandate was to develop an international soil classification system that should better consider soil-forming processes than the FAO soil classification. Drafts were presented in 1982 and 1990.
In 1992, the IRB working group decided to develop a new system named World Reference Base for Soil Resources (WRB) that should further develop the Revised Legend of the FAO soil classification and include some ideas of the more systematic IRB approach. Otto Spaargaren (International Soil Reference and Information Centre) and Freddy Nachtergaele (FAO) were nominated to prepare a draft. This draft was presented at the 15th World Congress of Soil Science in Acapu
Document 4:::
USDA soil taxonomy (ST) developed by the United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate classification of soil types according to several parameters (most commonly their properties) and in several levels: Order, Suborder, Great Group, Subgroup, Family, and Series. The classification was originally developed by Guy Donald Smith, former director of the U.S. Department of Agriculture's soil survey investigations.
Discussion
A taxonomy is an arrangement in a systematic manner; the USDA soil taxonomy has six levels of classification. They are, from most general to specific: order, suborder, great group, subgroup, family and series. Soil properties that can be measured quantitatively are used in this classification system – they include: depth, moisture, temperature, texture, structure, cation exchange capacity, base saturation, clay mineralogy, organic matter content and salt content. There are 12 soil orders (the top hierarchical level) in soil taxonomy. The names of the orders end with the suffix -sol. The criteria for the different soil orders include properties that reflect major differences in the genesis of soils. The orders are:
Alfisol – soils with aluminium and iron. They have horizons of clay accumulation, and form where there is enough moisture and warmth for at least three months of plant growth. They constitute 10% of soils worldwide.
Andisol – volcanic ash soils. They are young soils. They cover 1% of the world's ice-free surface.
Aridisol – dry soils forming under desert conditions which have fewer than 90 consecutive days of moisture during the growing season and are nonleached. They include nearly 12% of soils on Earth. Soil formation is slow, and accumulated organic matter is scarce. They may have subsurface zones of caliche or duripan. Many aridisols have well-developed Bt horizons showing clay movement from past periods of greater moisture.
Entisol – recently formed soils that lack well-d
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The weathering of landforms depends on various factors. Which area would most likely have the fastest rate of chemical weathering?
A. freezing and dry regions
B. warm and moist regions
C. cool and humid regions
D. hot and dry regions
Answer:
|
|
sciq-4564
|
multiple_choice
|
How many pairs of chromosomes are there?
|
[
"24",
"23",
"16",
"25"
] |
B
|
Relavent Documents:
Document 0:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 1:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 4:::
Single Best Answer (SBA or One Best Answer) is a written examination form of multiple choice questions used extensively in medical education.
Structure
A single question is posed with typically five alternate answers, from which the candidate must choose the best answer. This method avoids the problems of past examinations of a similar form described as Single Correct Answer. The older form can produce confusion where more than one of the possible answers has some validity. The newer form makes it explicit that more than one answer may have elements that are correct, but that one answer will be superior.
Prior to the widespread introduction of SBAs into medical education, the typical form of examination was true-false multiple choice questions. But during the 2000s, educators found that SBAs would be superior.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How many pairs of chromosomes are there?
A. 24
B. 23
C. 16
D. 25
Answer:
|
|
sciq-2349
|
multiple_choice
|
What is the world’s most serious resource problem?
|
[
"citrus blight",
"gas shortage",
"deforestation",
"water scarcity"
] |
D
|
Relavent Documents:
Document 0:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 1:::
Resource refers to all the materials available in our environment which are technologically accessible, economically feasible and culturally sustainable and help us to satisfy our needs and wants. Resources can broadly be classified upon their availability — they are classified into renewable and non-renewable resources. They can also be classified as actual and potential on the basis of the level of development and use, on the basis of origin they can be classified as biotic and abiotic, and on the basis of their distribution, as ubiquitous and localised (private, community-owned, national and international resources). An item becomes a resource with time and developing technology. The benefits of resource utilization may include increased wealth, proper functioning of a system, or enhanced well-being. From a human perspective, a natural resource is anything obtained from the environment to satisfy human needs and wants. From a broader biological or ecological perspective, a resource satisfies the needs of a living organism (see biological resource).
The concept of resources has been developed across many established areas of work, in economics, biology and ecology, computer science, management, and human resources for example - linked to the concepts of competition, sustainability, conservation, and stewardship. In application within human society, commercial or non-commercial factors require resource allocation through resource management.
The concept of a resource can also be tied to the direction of leadership over resources, this can include the things leaders have responsibility for over the human resources, with management, help, support or direction such as in charge of a professional group, technical experts, innovative leaders, archiving expertise, academic management, association management, business management, healthcare management, military management, public administration, spiritual leadership and social networking administrator.
individuals exp
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A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
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Female education in STEM refers to child and adult female representation in the educational fields of science, technology, engineering, and mathematics (STEM). In 2017, 33% of students in STEM fields were women.
The organization UNESCO has stated that this gender disparity is due to discrimination, biases, social norms and expectations that influence the quality of education women receive and the subjects they study. UNESCO also believes that having more women in STEM fields is desirable because it would help bring about sustainable development.
Current status of girls and women in STEM education
Overall trends in STEM education
Gender differences in STEM education participation are already visible in early childhood care and education in science- and math-related play, and become more pronounced at higher levels of education. Girls appear to lose interest in STEM subjects with age, particularly between early and late adolescence. This decreased interest affects participation in advanced studies at the secondary level and in higher education. Female students represent 35% of all students enrolled in STEM-related fields of study at this level globally. Differences are also observed by disciplines, with female enrollment lowest in engineering, manufacturing and construction, natural science, mathematics and statistics and ICT fields. Significant regional and country differences in female representation in STEM studies can be observed, though, suggesting the presence of contextual factors affecting girls’ and women's engagement in these fields. Women leave STEM disciplines in disproportionate numbers during their higher education studies, in their transition to the world of work and even in their career cycle.
Learning achievement in STEM education
Data on gender differences in learning achievement present a complex picture, depending on what is measured (subject, knowledge acquisition against knowledge application), the level of education/age of students, and
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The Science, Technology, Engineering and Mathematics Network or STEMNET is an educational charity in the United Kingdom that seeks to encourage participation at school and college in science and engineering-related subjects (science, technology, engineering, and mathematics) and (eventually) work.
History
It is based at Woolgate Exchange near Moorgate tube station in London and was established in 1996. The chief executive is Kirsten Bodley. The STEMNET offices are housed within the Engineering Council.
Function
Its chief aim is to interest children in science, technology, engineering and mathematics. Primary school children can start to have an interest in these subjects, leading secondary school pupils to choose science A levels, which will lead to a science career. It supports the After School Science and Engineering Clubs at schools. There are also nine regional Science Learning Centres.
STEM ambassadors
To promote STEM subjects and encourage young people to take up jobs in these areas, STEMNET have around 30,000 ambassadors across the UK. these come from a wide selection of the STEM industries and include TV personalities like Rob Bell.
Funding
STEMNET used to receive funding from the Department for Education and Skills. Since June 2007, it receives funding from the Department for Children, Schools and Families and Department for Innovation, Universities and Skills, since STEMNET sits on the chronological dividing point (age 16) of both of the new departments.
See also
The WISE Campaign
Engineering and Physical Sciences Research Council
National Centre for Excellence in Teaching Mathematics
Association for Science Education
Glossary of areas of mathematics
Glossary of astronomy
Glossary of biology
Glossary of chemistry
Glossary of engineering
Glossary of physics
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the world’s most serious resource problem?
A. citrus blight
B. gas shortage
C. deforestation
D. water scarcity
Answer:
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|
sciq-11391
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multiple_choice
|
Why do adult herbivores in a herd surround their young?
|
[
"to show them love",
"to protect them from other adult herbivores",
"to keep them warm on long cold nights",
"to protect them as they are vulnerable to predators"
] |
D
|
Relavent Documents:
Document 0:::
Conservation grazing or targeted grazing is the use of semi-feral or domesticated grazing livestock to maintain and increase the biodiversity of natural or semi-natural grasslands, heathlands, wood pasture, wetlands and many other habitats. Conservation grazing is generally less intensive than practices such as prescribed burning, but still needs to be managed to ensure that overgrazing does not occur. The practice has proven to be beneficial in moderation in restoring and maintaining grassland and heathland ecosystems. The optimal level of grazing will depend on the goal of conservation, and different levels of grazing, alongside other conservation practices, can be used to induce the desired results.
History
For historic grasslands, grazing animals, herbivores, were a crucial part of the ecosystem. When grazers are removed, historically grazed lands may show a decline in both the density and the diversity of the vegetation. The history of the land may help ecologists and conservationists determine the best approach to a conservation project.
Historic threats to grasslands began with land conversion to crop fields. This shifted to improper land management techniques and more recently to the spread of woody plants due to a lack of management and to climate change.
Conservation grazing in practice
Intensive grazing maintains an area as a habitat dominated by grasses and small shrubs, largely preventing ecological succession to forest.
Extensive grazing also treats habitats dominated by grasses and small shrubs but does not prevent succession to forest, it only slows it down.
Conservation grazing is usually done with extensive grazing because of the ecological disadvantages of intensive grazing.
Conservation grazing needs to be monitored closely. Overgrazing may cause erosion, habitat destruction, soil compaction, or reduced biodiversity (species richness).
Rambo and Faeth found that the use of vertebrates for grazing of an area increased the species richness o
Document 1:::
Herding is the act of bringing individual animals together into a group (herd), maintaining the group, and moving the group from place to place—or any combination of those. Herding can refer either to the process of animals forming herds in the wild, or to human intervention forming herds for some purpose. While the layperson uses the term "herding" to describe this human intervention, most individuals involved in the process term it mustering, "working stock", or droving.
Some animals instinctively gather together as a herd. A group of animals fleeing a predator will demonstrate herd behavior for protection; while some predators, such as wolves and dogs have instinctive herding abilities derived from primitive hunting instincts. Instincts in herding dogs and trainability can be measured at noncompetitive herding tests. Dogs exhibiting basic herding instincts can be trained to aid in herding and to compete in herding and stock dog trials. Sperm whales have also been observed teaming up to herd prey in a coordinated feeding behavior.
Herding is used in agriculture to manage domesticated animals. Herding can be performed by people or trained animals such as herding dogs that control the movement of livestock under the direction of a person. The people whose occupation it is to herd or control animals often have herd added to the name of the animal they are herding to describe their occupation (shepherd, goatherd, cowherd).
A competitive sport has developed in some countries where the combined skill of man and herding dog is tested and judged in a "trial", such as a sheepdog trial. Animals such as sheep, camel, yak, and goats are mostly reared. They provide milk, meat and other products to the herders and their families.
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Grazing is a method of feeding in which a herbivore feeds on low-growing plants such as grasses or other multicellular organisms, such as algae. Many species of animals can be said to be grazers, from large animals such as hippopotamuses to small aquatic snails. Grazing behaviour is a type of feeding strategy within the ecology of a species. Specific grazing strategies include graminivory (eating grasses); coprophagy (producing part-digested pellets which are reingested); pseudoruminant (having a multi-chambered stomach but not chewing the cud); and grazing on plants other than grass, such as on marine algae.
Grazing's ecological effects can include redistributing nutrients, keeping grasslands open or favouring a particular species over another.
Ecology
Many small selective herbivores follow larger grazers which skim off the highest, tough growth of grasses, exposing tender shoots. For terrestrial animals, grazing is normally distinguished from browsing in that grazing is eating grass or forbs, whereas browsing is eating woody twigs and leaves from trees and shrubs. Grazing differs from predation because the organism being grazed upon may not be killed. It differs from parasitism because the two organisms live together in a constant state of physical externality (i.e. low intimacy). Water animals that feed by rasping algae and other micro-organisms from stones are called grazers–scrapers.
Graminivory
Graminivory is a form of grazing involving feeding primarily on grass (specifically "true" grasses in the Poaceae). Horses, cattle, capybara, hippopotamuses, grasshoppers, geese, and giant pandas are graminivores. Giant pandas (Ailuropoda melanoleuca) are obligate bamboo grazers, 99% of their diet consisting of sub-alpine bamboo species.
Coprophagy
Rabbits are herbivores that feed by grazing on grass, forbs, and leafy weeds. They graze heavily and rapidly for about the first half-hour of a grazing period (usually in the late afternoon), followed by about half an
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The Jarman–Bell principle is a concept in ecology that the food quality of a herbivore's intake decreases as the size of the herbivore increases, but the amount of such food increases to counteract the low quality foods. It operates by observing the allometric (non- linear scaling) properties of herbivores. The principle was coined by P.J Jarman (1968.) and R.H.V Bell (1971).
Large herbivores can subsist on low quality food. Their gut size is larger than smaller herbivores. The increased size allows for better digestive efficiency, and thus allow viable consumption of low quality food. Small herbivores require more energy per unit of body mass compared to large herbivores. A smaller size, thus smaller gut size and lower efficiency, imply that these animals need to select high quality food to function. Their small gut limits the amount of space for food, so they eat low quantities of high quality diet. Some animals practice coprophagy, where they ingest fecal matter to recycle untapped/ undigested nutrients.
However, the Jarman–Bell principle is not without exception. Small herbivorous members of mammals, birds and reptiles were observed to be inconsistent with the trend of small body mass being linked with high-quality food. There have also been disputes over the mechanism behind the Jarman–Bell principle; that larger body sizes does not increase digestive efficiency.
The implications of larger herbivores ably subsisting on poor quality food compared smaller herbivores mean that the Jarman–Bell principle may contribute evidence for Cope's rule. Furthermore, the Jarman–Bell principle is also important by providing evidence for the ecological framework of "resource partitioning, competition, habitat use and species packing in environments" and has been applied in several studies.
Links with allometry
Allometry refers to the non-linear scaling factor of one variable with respect to another. The relationship between such variables is expressed as a power law, wher
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Conservation behavior is the interdisciplinary field about how animal behavior can assist in the conservation of biodiversity. It encompasses proximate and ultimate causes of behavior and incorporates disciplines including genetics, physiology, behavioral ecology, and evolution.
Introduction
Conservation behavior is aimed at applying an understanding of animal behavior to solve problems in the field of conservation biology. These are problems that may arise during conservation efforts such as captive breeding, species reintroduction, reserve connectivity, and wildlife management. By using patterns in animal behavior, biologists can be successful in these conservation efforts. This is done by understanding the proximate and ultimate causes of problems that arise. For example, understanding how proximate processes affect survival can help biologist train captive-reared animals to recognize predators post-release. Ultimate causes also have a clear benefit to conservation. For example, understanding social relationships that lead to fitness (biology) can help biologists manage wildlife that exhibit infanticide. Conservation projects may have a better chance of being successful if biologists search for a deeper understanding of how animals make adaptive decisions.
While animal behavior and conservation biology are conceptually intertwined, the idea of using animal behavior in conservation management was only first used explicitly in 1974. Since then, conservation behavior has slowly gained prominence with a surge of publications in the field since the mid-1990s and the Animal Behavior Society even forming a committee in support of conservation behavior. A number of studies have shown that animal behavior can be an important consideration during conservation projects. More importantly, ignorance of animal behavior in conservation projects may lead to their failure. Recent calls for stronger integration of behavior and physiology to advance conservation science emphasiz
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Why do adult herbivores in a herd surround their young?
A. to show them love
B. to protect them from other adult herbivores
C. to keep them warm on long cold nights
D. to protect them as they are vulnerable to predators
Answer:
|
|
sciq-3910
|
multiple_choice
|
Which equation improves upon the ideal gas law by adding two terms: one to account for the volume of the gas molecules and another for the attractive forces between them?
|
[
"Newton's third law",
"Heidiger's principle",
"Pascal's equation",
"van der waals"
] |
D
|
Relavent Documents:
Document 0:::
The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. The ideal gas law is often written in an empirical form:
where , and are the pressure, volume and temperature respectively; is the amount of substance; and is the ideal gas constant.
It can also be derived from the microscopic kinetic theory, as was achieved (apparently independently) by August Krönig in 1856 and Rudolf Clausius in 1857.
Equation
The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation relates these simply in two main forms. The temperature used in the equation of state is an absolute temperature: the appropriate SI unit is the kelvin.
Common forms
The most frequently introduced forms are:where:
is the absolute pressure of the gas,
is the volume of the gas,
is the amount of substance of gas (also known as number of moles),
is the ideal, or universal, gas constant, equal to the product of the Boltzmann constant and the Avogadro constant,
is the Boltzmann constant,
is the Avogadro constant,
is the absolute temperature of the gas,
is the number of particles (usually atoms or molecules) of the gas.
In SI units, p is measured in pascals, V is measured in cubic metres, n is measured in moles, and T in kelvins (the Kelvin scale is a shifted Celsius scale, where 0.00 K = −273.15 °C, the lowest possible temperature). R has for value 8.314 J/(mol·K) = 1.989 ≈ 2 cal/(mol·K), or 0.0821 L⋅atm/(mol⋅K).
Molar form
How much gas is present could be specified by giving the mass instead of the chemical amount of gas. Therefore, an alternative form of the ideal gas law may be useful. The chemical amount
Document 1:::
Johannes Diderik van der Waals (; 23 November 1837 – 8 March 1923) was a Dutch theoretical physicist and thermodynamicist famous for his pioneering work on the equation of state for gases and liquids. Van der Waals started his career as a schoolteacher. He became the first physics professor of the University of Amsterdam when in 1877 the old Athenaeum was upgraded to Municipal University. Van der Waals won the 1910 Nobel Prize in physics for his work on the equation of state for gases and liquids.
His name is primarily associated with the Van der Waals equation of state that describes the behavior of gases and their condensation to the liquid phase. His name is also associated with Van der Waals forces (forces between stable molecules), with Van der Waals molecules (small molecular clusters bound by Van der Waals forces), and with Van der Waals radii (sizes of molecules). James Clerk Maxwell once said that, "there can be no doubt that the name of Van der Waals will soon be among the foremost in molecular science."
In his 1873 thesis, Van der Waals noted the non-ideality of real gases and attributed it to the existence of intermolecular interactions. He introduced the first equation of state derived by the assumption of a finite volume occupied by the constituent molecules. Spearheaded by Ernst Mach and Wilhelm Ostwald, a strong philosophical current that denied the existence of molecules arose towards the end of the 19th century. The molecular existence was considered unproven and the molecular hypothesis unnecessary. At the time Van der Waals's thesis was written (1873), the molecular structure of fluids had not been accepted by most physicists, and liquid and vapor were often considered as chemically distinct. But Van der Waals's work affirmed the reality of molecules and allowed an assessment of their size and attractive strength. His new formula revolutionized the study of equations of state. By comparing his equation of state with experimental data, Van der W
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Cubic equations of state are a specific class of thermodynamic models for modeling the pressure of a gas as a function of temperature and density and which can be rewritten as a cubic function of the molar volume.
Equations of state are generally applied in the fields of physical chemistry and chemical engineering, particularly in the modeling of vapor–liquid equilibrium and chemical engineering process design.
Van der Waals equation of state
The van der Waals equation of state may be written as
where is the absolute temperature, is the pressure, is the molar volume and is the universal gas constant. Note that , where is the volume, and , where is the number of moles, is the number of particles, and is the Avogadro constant. These definitions apply to all equations of state below as well.
The substance-specific constants and can be calculated from the critical properties and (noting that is the molar volume at the critical point and is the critical pressure) as:
Expressions for written as functions of may also be obtained and are often used to parameterize the equation because the critical temperature and pressure are readily accessible to experiment. They are
Proposed in 1873, the van der Waals equation of state was one of the first to perform markedly better than the ideal gas law. In this landmark equation is called the attraction parameter and the repulsion parameter or the effective molecular volume. While the equation is definitely superior to the ideal gas law and does predict the formation of a liquid phase, the agreement with experimental data is limited for conditions where the liquid forms. While the van der Waals equation is commonly referenced in textbooks and papers for historical reasons, it is now obsolete. Other modern equations of only slightly greater complexity are much more accurate.
The van der Waals equation may be considered as the ideal gas law, "improved" due to including two non-ideal contributions t
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In chemistry and thermodynamics, the Van der Waals equation (or Van der Waals equation of state) is an equation of state which extends the ideal gas law to include the effects of interaction between molecules of a gas, as well as accounting for the finite size of the molecules.
The ideal gas law treats gas molecules as point particles that interact with their containers but not each other, meaning they neither take up space nor change kinetic energy during collisions (i.e. all collisions are perfectly elastic). The ideal gas law states that the volume V occupied by n moles of any gas has a pressure P at temperature T given by the following relationship, where R is the gas constant:
To account for the volume occupied by real gas molecules, the Van der Waals equation replaces in the ideal gas law with , where Vm is the molar volume of the gas and b is the volume occupied by the molecules of one mole, given by Avogadro constant times the volume of a single molecule:
The second modification made to the ideal gas law accounts for interaction between molecules of the gas. The Van der Waals equation includes intermolecular interaction by adding to the observed pressure P in the equation of state a term of the form , where a is a constant whose value depends on the gas.
The complete Van der Waals equation is therefore:
For n moles of gas, it can also be written as:
When the molar volume Vm is large, b becomes negligible in comparison with Vm, a/Vm2 becomes negligible with respect to P, and the Van der Waals equation reduces to the ideal gas law, PVm=RT.
This equation approximates the behavior of real fluids above their critical temperatures and is qualitatively reasonable for their liquid and low-pressure gaseous states at low temperatures. However, near the phase transitions between gas and liquid, in the range of p, V, and T where the liquid phase and the gas phase are in equilibrium, the Van der Waals equation fails to accurately model observed experimental beha
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In physics and engineering, a perfect gas is a theoretical gas model that differs from real gases in specific ways that makes certain calculations easier to handle. In all perfect gas models, intermolecular forces are neglected. This means that one can neglect many complications that may arise from the Van der Waals forces. All perfect gas models are ideal gas models in the sense that they all follow the ideal gas equation of state. However, the idea of a perfect gas model is often invoked as a combination of the ideal gas equation of state with specific additional assumptions regarding the variation (or nonvariation) of the heat capacity with temperature.
Perfect gas nomenclature
The terms perfect gas and ideal gas are sometimes used interchangeably, depending on the particular field of physics and engineering. Sometimes, other distinctions are made, such as between thermally perfect gas and calorically perfect gas, or between imperfect, semi-perfect, and perfect gases, and as well as the characteristics of ideal gases. Two of the common sets of nomenclatures are summarized in the following table.
Thermally and calorically perfect gas
Along with the definition of a perfect gas, there are also two more simplifications that can be made although various textbooks either omit or combine the following simplifications into a general "perfect gas" definition.
For a fixed number of moles of gas , a thermally perfect gas
is in thermodynamic equilibrium
is not chemically reacting
has internal energy , enthalpy , and constant volume / constant pressure heat capacities , that are solely functions of temperature and not of pressure or volume , i.e., , , , . These latter expressions hold for all tiny property changes and are not restricted to constant- or constant- variations.
A calorically perfect gas
is in thermodynamic equilibrium
is not chemically reacting
has internal energy , and enthalpy that are functions of temperature only, i.e., ,
has heat capacities
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which equation improves upon the ideal gas law by adding two terms: one to account for the volume of the gas molecules and another for the attractive forces between them?
A. Newton's third law
B. Heidiger's principle
C. Pascal's equation
D. van der waals
Answer:
|
|
ai2_arc-741
|
multiple_choice
|
Water evaporates and falls back to Earth as rain or snow. What is the primary energy source that drives this cycle?
|
[
"The wind",
"The Sun",
"Air pressure",
"Ocean currents"
] |
B
|
Relavent Documents:
Document 0:::
The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water (salt water) and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, transpiration, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation.
The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment. These heat exchanges influence climate.
The evaporative phase of the cycle purifies water, causing salts and other solids picked up during the cycle to be left behind, and then the condensation phase in the atmosphere replenishes the land with freshwater. The flow of liquid water and ice transports minerals across the globe. It is also involved in reshaping the geological features of the Earth, through processes including erosion and sedimentation. The water cycle is also essential for the maintenance of most life and ecosystems on the planet.
Description
Overall process
The water cycle is powered from the energy emitted by the sun. This energy heats water in the ocean and seas. Water evaporates as water vapor into the air. Some ice and snow sublimates directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the soil. Th
Document 1:::
Evapotranspiration (ET) is the combined processes which move water from the Earth's surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in agricultural irrigation and water resource management.
Definition of evapotranspiration
Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evapotranspiration are:
Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, solar radiation and wind speed.
Transpiration: the movement of water from root systems, through a plant, and exit into the air as water vapor. This exit occurs through stomata in the plant. Rate of transpiration can be influenced by factors including plant type, soil type, weather conditions and water content, and also cultivation practices.
Evapotranspiration is typically measured in millimeters of water (i.e. volume of water moved per unit area of the Earth's surface) in a set unit of time. Globally, it is estimated that on average between three-fifths and three-quarters of land precipitation is returned to the atmosphere via evapotranspiration.
Evapotranspiration does not, in general, account for other mechanisms which are involved in returning water to the atmosphere, though some of these, such as snow and ice sublimation in regions of high elevation or high latitude, can make a large contribution to atmospheric moisture even under standard conditions.
Factors that impact evapotranspiration levels
Primary factors
Because evaporation and transpiration
Document 2:::
Primary energy (PE) is the energy found in nature that has not been subjected to any human engineered conversion process. It encompasses energy contained in raw fuels and other forms of energy, including waste, received as input to a system. Primary energy can be non-renewable or renewable.
Total primary energy supply (TPES) is the sum of production and imports, plus or minus stock changes, minus exports and international bunker storage.
The International Recommendations for Energy Statistics (IRES) prefers total energy supply (TES) to refer to this indicator. These expressions are often used to describe the total energy supply of a national territory.
Secondary energy is a carrier of energy, such as electricity. These are produced by conversion from a primary energy source.
Primary energy is used as a measure in energy statistics in the compilation of energy balances, as well as in the field of energetics. In energetics, a primary energy source (PES) refers to the energy forms required by the energy sector to generate the supply of energy carriers used by human society. Primary energy only counts raw energy and not usable energy and fails to account well for energy losses, particularly the large losses in thermal sources. It therefore generally grossly undercounts non thermal renewable energy sources .
Examples of sources
Primary energy sources should not be confused with the energy system components (or conversion processes) through which they are converted into energy carriers.
Usable energy
Primary energy sources are transformed in energy conversion processes to more convenient forms of energy that can directly be used by society, such as electrical energy, refined fuels, or synthetic fuels such as hydrogen fuel. In the field of energetics, these forms are called energy carriers and correspond to the concept of "secondary energy" in energy statistics.
Conversion to energy carriers (or secondary energy)
Energy carriers are energy forms which have been tra
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
Water-use efficiency (WUE) refers to the ratio of water used in plant metabolism to water lost by the plant through transpiration. Two types of water-use efficiency are referred to most frequently:
photosynthetic water-use efficiency (also called instantaneous water-use efficiency), which is defined as the ratio of the rate of carbon assimilation (photosynthesis) to the rate of transpiration, and
water-use efficiency of productivity (also called integrated water-use efficiency), which is typically defined as the ratio of biomass produced to the rate of transpiration.
Increases in water-use efficiency are commonly cited as a response mechanism of plants to moderate to severe soil water deficits and have been the focus of many programs that seek to increase crop tolerance to drought. However, there is some question as to the benefit of increased water-use efficiency of plants in agricultural systems, as the processes of increased yield production and decreased water loss due to transpiration (that is, the main driver of increases in water-use efficiency) are fundamentally opposed. If there existed a situation where water deficit induced lower transpirational rates without simultaneously decreasing photosynthetic rates and biomass production, then water-use efficiency would be both greatly improved and the desired trait in crop production.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Water evaporates and falls back to Earth as rain or snow. What is the primary energy source that drives this cycle?
A. The wind
B. The Sun
C. Air pressure
D. Ocean currents
Answer:
|
|
sciq-3119
|
multiple_choice
|
What causes continents to drift closer to the poles or the equator?
|
[
"plate movements",
"wind",
"sediment movements",
"tidal pull"
] |
A
|
Relavent Documents:
Document 0:::
The cataclysmic pole shift hypothesis is a pseudo-scientific claim that there have been recent, geologically rapid shifts in the axis of rotation of Earth, causing calamities such as floods and tectonic events or relatively rapid climate changes.
There is evidence of precession and changes in axial tilt, but this change is on much longer time-scales and does not involve relative motion of the spin axis with respect to the planet. However, in what is known as true polar wander, the Earth rotates with respect to a fixed spin axis. Research shows that during the last 200 million years a total true polar wander of some 30° has occurred, but that no rapid shifts in Earth's geographic axial pole were found during this period. A characteristic rate of true polar wander is 1° or less per million years. Between approximately 790 and 810 million years ago, when the supercontinent Rodinia existed, two geologically rapid phases of true polar wander may have occurred. In each of these, the magnetic poles of Earth shifted by approximately 55° due to a large shift in the crust.
Definition and clarification
The geographic poles are defined by the points on the surface of Earth that are intersected by the axis of rotation. The pole shift hypothesis describes a change in location of these poles with respect to the underlying surface – a phenomenon distinct from the changes in axial orientation with respect to the plane of the ecliptic that are caused by precession and nutation, and is an amplified event of a true polar wander. Geologically, a surface shift separate from a planetary shift, enabled by earth's molten core.
Pole shift hypotheses are not connected with plate tectonics, the well-accepted geological theory that Earth's surface consists of solid plates which shift over a viscous, or semifluid asthenosphere; nor with continental drift, the corollary to plate tectonics which maintains that locations of the continents have moved slowly over the surface of Earth, resulting
Document 1:::
Polar motion of the Earth is the motion of the Earth's rotational axis relative to its crust. This is measured with respect to a reference frame in which the solid Earth is fixed (a so-called Earth-centered, Earth-fixed or ECEF reference frame). This variation is a few meters on the surface of the Earth.
Analysis
Polar motion is defined relative to a conventionally defined reference axis, the CIO (Conventional International Origin), being the pole's average location over the year 1900. It consists of three major components: a free oscillation called Chandler wobble with a period of about 435 days, an annual oscillation, and an irregular drift in the direction of the 80th meridian west, which has lately been less extremely west.
Causes
The slow drift, about 20 m since 1900, is partly due to motions in the Earth's core and mantle, and partly to the redistribution of water mass as the Greenland ice sheet melts, and to isostatic rebound, i.e. the slow rise of land that was formerly burdened with ice sheets or glaciers. The drift is roughly along the 80th meridian west. Since about 2000, the pole has found a less extreme drift, which is roughly along the central meridian. This less dramatically westward drift of motion is attributed to the global scale mass transport between the oceans and the continents.
Major earthquakes cause abrupt polar motion by altering the volume distribution of the Earth's solid mass. These shifts are quite small in magnitude relative to the long-term core/mantle and isostatic rebound components of polar motion.
Principle
In the absence of external torques, the vector of the angular momentum M of a rotating system remains constant and is directed toward a fixed point in space. If the earth were perfectly symmetrical and rigid, M would remain aligned with its axis of symmetry, which would also be its axis of rotation. In the case of the Earth, it is almost identical with its axis of rotation, with the discrepancy due to shifts of mass on the
Document 2:::
Polar wander is the motion of a pole in relation to some reference frame. It can be used, for example, to measure the degree to which Earth's magnetic poles have been observed to move relative to the Earth's rotation axis. It is also possible to use continents as reference and observe the relative motion of the magnetic pole relative to the different continents; by doing so, the relative motion of those two continents to each other can be observed over geologic time as paleomagnetism.
Apparent polar wander
The magnetic poles are relatively stationary in position over time and because of this, researchers often use magnetic minerals, like magnetite, in order to find at what latitude the continent was positioned relative to the magnetic poles of that time. Since the continents have been moving relative to the pole; it is as if they were immobile and the magnetic pole was moving instead. If enough data is collected, it is then possible to reconstruct the motion of the continents relative to the magnetic poles. The apparent polar wander is the path that the magnetic pole appears to take according to the data on a continent. When multiple continents are moving relative to each other, the path their magnetic pole follows will be different from others. Conversely, when two continents are moving parallel to each other their path will be the same.
True polar wander
Earth
True polar wander represents the shift in the geographical poles relative to Earth's surface, after accounting for the motion of the tectonic plates. This motion is caused by the rearrangement of the mantle and the crust in order to align the maximum inertia with the current rotation axis (fig.1). This is the situation with the lowest kinetic energy for the given, unchanging, angular momentum of the earth, and is attained as kinetic energy is dissipated due to the non-rigidity of the earth.
Evidence for true polar wander has been observed from the study of large apparent polar wander datasets which, whe
Document 3:::
Glacio-geological databases compile data on glacially associated sedimentary deposits and erosional activity from former and current ice-sheets, usually from published peer-reviewed sources. Their purposes are generally directed towards two ends: (Mode 1) compiling information about glacial landforms, which often inform about former ice-flow directions; and (Mode 2) compiling information which dates the absence or presence of ice.
These databases are used for a variety of purposes: (i) as bibliographic tools for researchers; (ii) as the quantitative basis of mapping of landforms or dates of ice presence/absence; and (iii) as quantitative databases which are used to constrain physically based mathematical models of ice-sheets.
Antarctic Ice Sheet: The AGGDB is a Mode 2 glacio-geological database for the Antarctic ice-sheet using information from around 150 published sources, covering glacial activity mainly from the past 30,000 years. It is available online, and aims to be comprehensive to the end of 2007.
British Ice Sheet: BRITICE is a Mode 1 database which aims to map all glacial landforms of Great Britain.
Eurasian Ice Sheet: DATED-1 is a Mode 2 database for the Eurasian ice-sheet. Its sister-project DATED-2 uses the information in DATED-1 to map the retreat of the Eurasian ice-sheet since the Last Glacial Maximum.
See also
Glacial landforms
Sediment
Geology
Ice sheet
Exposure Age Dating
Radio-carbon dating
Document 4:::
This is a list of former oceans that disappeared due to tectonic movements and other geographical and climatic changes. In alphabetic order:
List
Bridge River Ocean, the ocean between the ancient Insular Islands (that is, Stikinia) and North America
Cache Creek Ocean, a Paleozoic ocean between the Wrangellia Superterrane and Yukon-Tanana Terrane
Iapetus Ocean, the Southern hemisphere ocean between Baltica and Avalonia
Kahiltna-Nutotzin Ocean, Mesozoic
Khanty Ocean, the Precambrian to Silurian ocean between Baltica and the Siberian continent
Medicine Hat Ocean
Mezcalera Ocean, the ocean between the Guerrero Terrane and Laurentia
Mirovia, the ocean that surrounded the Rodinia supercontinent
Mongol-Okhotsk Ocean, the early Mesozoic ocean between the North China and Siberia cratons
Oimyakon Ocean, the northernmost part of the Mesozoic Panthalassa Ocean
Paleo-Tethys Ocean, the ocean between Gondwana and the Hunic terranes
Pan-African Ocean, the ocean that surrounded the Pannotia supercontinent
Panthalassa, the vast world ocean that surrounded the Pangaea supercontinent, also referred to as the Paleo-Pacific Ocean
Pharusian Ocean, Neoproterozoic
Poseidon Ocean, Mesoproterozoic
Pontus Ocean, the western part of the early Mesozoic Panthalassa Ocean
Proto-Tethys Ocean, Neoproterozoic
Rheic Ocean, the Paleozoic ocean between Gondwana and Laurussia
Slide Mountain Ocean, the Mesozoic ocean between the ancient Intermontane Islands (that is, Wrangellia) and North America
South Anuyi Ocean, Mesozoic ocean related to the formation of the Arctic Ocean
Tethys Ocean, the ocean between the ancient continents of Gondwana and Laurasia
Thalassa Ocean, the eastern part of the early Mesozoic Panthalassa Ocean
Ural Ocean, the Paleozoic ocean between Siberia and Baltica
See also
:Category:Historical oceans
, an ocean that surrounds a global supercontinent
ancient oceans
ancient oceans
Historical oceans
Mesozoic paleogeography
Paleozoic paleogeography
Pro
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What causes continents to drift closer to the poles or the equator?
A. plate movements
B. wind
C. sediment movements
D. tidal pull
Answer:
|
|
sciq-11254
|
multiple_choice
|
How many chromosomes do bacterial dna have?
|
[
"one rectangular chromosome",
"one circular chromosome",
"one simple chromosome",
"one triangular chromosome"
] |
B
|
Relavent Documents:
Document 0:::
The Escherichia coli chromosome shows two main levels of global organization, macrodomains and replichores. In E. coli chromosomes, the origin and terminus of replication divide the genome into oppositely replicated halves called replichores. Replichore 1, which is replicated clockwise, has the presented strand of E. coli as its leading strand; in replichore 2 the complementary strand is the leading one. Many features of E. coli are oriented with respect to replication.
Document 1:::
Bacterial genetics is the subfield of genetics devoted to the study of bacterial genes. Bacterial genetics are subtly different from eukaryotic genetics, however bacteria still serve as a good model for animal genetic studies. One of the major distinctions between bacterial and eukaryotic genetics stems from the bacteria's lack of membrane-bound organelles (this is true of all prokaryotes. While it is a fact that there are prokaryotic organelles, they are never bound by a lipid membrane, but by a shell of proteins), necessitating protein synthesis occur in the cytoplasm.
Like other organisms, bacteria also breed true and maintain their characteristics from generation to generation, yet at the same time, exhibit variations in particular properties in a small proportion of their progeny. Though heritability and variations in bacteria had been noticed from the early days of bacteriology, it was not realised then that bacteria too obey the laws of genetics. Even the existence of a bacterial nucleus was a subject of controversy. The differences in morphology and other properties were attributed by Nageli in 1877, to bacterial pleomorphism, which postulated the existence of a single, a few species of bacteria, which possessed a protein capacity for a variation. With the development and application of precise methods of pure culture, it became apparent that different types of bacteria retained constant form and function through successive generations. This led to the concept of monomorphism.
Transformation
Transformation in bacteria was first observed in 1928 by Frederick Griffith and later (in 1944) examined at the molecular level by Oswald Avery and his colleagues who used the process to demonstrate that DNA was the genetic material of bacteria. In transformation, a cell takes up extraneous DNA found in the environment and incorporates it into its genome (genetic material) through recombination. Not all bacteria are competent to be transformed, and not all extracellu
Document 2:::
A centisome is a unit of length defined as one percent of the length of a particular chromosome. This course unit of physical DNA length began to be used in the early exploration of genomes through molecular biology before the resolution of the nucleic acid sequences of chromosomes was possible.
One of the main uses for this unit was for describing the locus of a gene by giving a distance in centisomes from a reference point on the chromosome. For instance, when the complete genome of the bacterium Escherichia coli was finally completed in 1997, it was presented with a scale given in centisomes (as well as one in kilobases). Since bacterial chromosomes are circular, the reference point cannot be an end of the DNA molecule, but must be some point that has some easily determinable unique characteristic. Often this point is the origin of replication, although for E. coli it is the origin of transfer during conjugation. Hence, the reference point for centisome positions is simply a convention established for each individual species of organism.
For the most part, modern scientific literature uses "centisome" as part of a shorthand way of referring to a particular region of interest on the chromosome of particular organisms. For instance, much research has been done on the "Centisome 63" area of the chromosomes of Salmonella species.
Document 3:::
Chromids, formerly (and less specifically) secondary chromosomes, are a class of bacterial replicons (replicating DNA molecules). These replicons are called "chromids" because they have characteristic features of both chromosomes and plasmids. Early on, it was thought that all core genes could be found on the main chromosome of the bacteria. However, in 1989 a replicon (now known as a chromid) was discovered containing core genes outside of the main chromosome. These core genes make the chromid indispensable to the organism. Chromids are large replicons, although not as large as the main chromosome. However, chromids are almost always larger than a plasmid (or megaplasmid). Chromids also share many genomic signatures of the chromosome, including their GC-content and their codon usage bias. On the other hand, chromids do not share the replication systems of chromosomes. Instead, they use the replication system of plasmids. Chromids are present in 10% of bacteria species sequenced by 2009.
Bacterial genomes divided between a main chromosome and one or more chromids (and / or megaplasmids) are said to be divided or multipartite genomes. The vast majority of chromid-encoding bacteria only have a single chromid, although 9% have more than one (compared with 12% of megaplasmid-encoding bacteria containing multiple megaplasmids). The genus Azospirillum contains three species which have up to five chromids, the most chromids known in a single species to date. Chromids also appear to be more common in bacteria which have a symbiotic or pathogenic relationship with eukaryotes and with organisms with high tolerance to abiotic stressors.
Chromids were discovered in 1989, in a species of Alphaproteobacteria known as Rhodobacter sphaeroides. However, the formalization of the concept of a "chromid" as an independent type of replicon only came about in 2010. Several classifications further distinguish between chromids depending on conditions of their essentiality, their replica
Document 4:::
The Escherichia coli chromosome shows two main levels of global organization: macrodomains and replichores. Macrodomains were discovered by cytological studies. They contain loci showing the same intracellular positioning and choreography during the cell cycle.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How many chromosomes do bacterial dna have?
A. one rectangular chromosome
B. one circular chromosome
C. one simple chromosome
D. one triangular chromosome
Answer:
|
|
sciq-11310
|
multiple_choice
|
What can be calculated given the mass and speed of an object?
|
[
"residual energy",
"harmonic energy",
"kinetic energy",
"systematic energy"
] |
C
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
This is a list of topics that are included in high school physics curricula or textbooks.
Mathematical Background
SI Units
Scalar (physics)
Euclidean vector
Motion graphs and derivatives
Pythagorean theorem
Trigonometry
Motion and forces
Motion
Force
Linear motion
Linear motion
Displacement
Speed
Velocity
Acceleration
Center of mass
Mass
Momentum
Newton's laws of motion
Work (physics)
Free body diagram
Rotational motion
Angular momentum (Introduction)
Angular velocity
Centrifugal force
Centripetal force
Circular motion
Tangential velocity
Torque
Conservation of energy and momentum
Energy
Conservation of energy
Elastic collision
Inelastic collision
Inertia
Moment of inertia
Momentum
Kinetic energy
Potential energy
Rotational energy
Electricity and magnetism
Ampère's circuital law
Capacitor
Coulomb's law
Diode
Direct current
Electric charge
Electric current
Alternating current
Electric field
Electric potential energy
Electron
Faraday's law of induction
Ion
Inductor
Joule heating
Lenz's law
Magnetic field
Ohm's law
Resistor
Transistor
Transformer
Voltage
Heat
Entropy
First law of thermodynamics
Heat
Heat transfer
Second law of thermodynamics
Temperature
Thermal energy
Thermodynamic cycle
Volume (thermodynamics)
Work (thermodynamics)
Waves
Wave
Longitudinal wave
Transverse waves
Transverse wave
Standing Waves
Wavelength
Frequency
Light
Light ray
Speed of light
Sound
Speed of sound
Radio waves
Harmonic oscillator
Hooke's law
Reflection
Refraction
Snell's law
Refractive index
Total internal reflection
Diffraction
Interference (wave propagation)
Polarization (waves)
Vibrating string
Doppler effect
Gravity
Gravitational potential
Newton's law of universal gravitation
Newtonian constant of gravitation
See also
Outline of physics
Physics education
Document 2:::
Specific kinetic energy is the kinetic energy of an object per unit of mass.
It is defined as .
Where is the specific kinetic energy and is velocity. It has units of J/kg, which is equivalent to m2/s2.
Energy (physics)
Document 3:::
Advanced Placement (AP) Physics C: Mechanics (also known as AP Mechanics) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester calculus-based university course in mechanics. The content of Physics C: Mechanics overlaps with that of AP Physics 1, but Physics 1 is algebra-based, while Physics C is calculus-based. Physics C: Mechanics may be combined with its electricity and magnetism counterpart to form a year-long course that prepares for both exams.
Course content
Intended to be equivalent to an introductory college course in mechanics for physics or engineering majors, the course modules are:
Kinematics
Newton's laws of motion
Work, energy and power
Systems of particles and linear momentum
Circular motion and rotation
Oscillations and gravitation.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a Calculus I class.
This course is often compared to AP Physics 1: Algebra Based for its similar course material involving kinematics, work, motion, forces, rotation, and oscillations. However, AP Physics 1: Algebra Based lacks concepts found in Calculus I, like derivatives or integrals.
This course may be combined with AP Physics C: Electricity and Magnetism to make a unified Physics C course that prepares for both exams.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Mechanics is separate from the AP examination for AP Physics C: Electricity and Magnetism. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday aftern
Document 4:::
Working mass, also referred to as reaction mass, is a mass against which a system operates in order to produce acceleration.
In the case of a chemical rocket, for example, the reaction mass is the product of the burned fuel shot backwards to provide propulsion. All acceleration requires an exchange of momentum, which can be thought of as the "unit of movement". Momentum is related to mass and velocity, as given by the formula P = mv, where P is the momentum, m the mass, and v the velocity. The velocity of a body is easily changeable, but in most cases the mass is not, which makes it important.
Rockets and rocket-like reaction engines
In rockets, the total velocity change can be calculated (using the Tsiolkovsky rocket equation) as follows:
Where:
v = ship velocity.
u = exhaust velocity.
M = ship mass, not including the working mass.
m = total mass ejected from the ship (working mass).
The term working mass is used primarily in the aerospace field. In more "down to earth" examples the working mass is typically provided by the Earth, which contains so much momentum in comparison to most vehicles that the amount it gains or loses can be ignored. However, in the case of an aircraft the working mass is the air, and in the case of a rocket, it is the rocket fuel itself. Most rocket engines use light-weight fuels (liquid hydrogen, oxygen, or kerosene) accelerated to super-sonic speeds. However, ion engines often use heavier elements like xenon as the reaction mass, accelerated to much higher speeds using electric fields.
In many cases the working mass is separate from the energy used to accelerate it. In a car the engine provides power to the wheels, which then accelerates the Earth backward to make the car move forward. This is not the case for most rockets however, where the rocket propellant is the working mass, as well as the energy source. This means that rockets stop accelerating as soon as they run out of fuel, regardless of other power sources they may have
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What can be calculated given the mass and speed of an object?
A. residual energy
B. harmonic energy
C. kinetic energy
D. systematic energy
Answer:
|
|
scienceQA-5976
|
multiple_choice
|
Which of the following organisms is the decomposer in this food web?
|
[
"beaver",
"gray fox",
"persimmon tree",
"parasol fungus"
] |
D
|
Decomposers help break down dead organisms into simpler matter, such as nutrients. These nutrients can then help plants and other organisms grow. In a food web, there is an arrow pointing from another organism to a decomposer. There are no arrows pointing from a decomposer to another organism.
The bolete fungus does not have arrows pointing from it to other organisms. So, the bolete fungus is a decomposer.
The gray fox has arrows pointing from it. So, the gray fox is not a decomposer.
The beaver has arrows pointing from it. So, the beaver is not a decomposer.
The parasol fungus does not have arrows pointing from it to other organisms. So, the parasol fungus is a decomposer.
The persimmon tree has arrows pointing from it. So, the persimmon tree is not a decomposer.
|
Relavent Documents:
Document 0:::
Decomposers are organisms that break down dead or decaying organisms; they carry out decomposition, a process possible by only certain kingdoms, such as fungi. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores ingest and digest dead matter internally, while decomposers directly absorb nutrients through external chemical and biological processes. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they are unable to absorb nutrients without ingesting them.
Fungi
The primary decomposer of litter in many ecosystems is fungi. Unlike bacteria, which are unicellular organisms and are decomposers as well, most saprotrophic fungi grow as a branching network of hyphae. While bacteria are restricted to growing and feeding on the exposed surfaces of organic matter, fungi can use their hyphae to penetrate larger pieces of organic matter, below the surface. Additionally, only wood-decay fungi have evolved the enzymes necessary to decompose lignin, a chemically complex substance found in wood. These two factors make fungi the primary decomposers in forests, where litter has high concentrations of lignin and often occurs in large pieces. Fungi decompose organic matter by releasing enzymes to break down the decaying material, after which they absorb the nutrients in the decaying material. Hyphae are used to break down matter and absorb nutrients and are also used in reproduction. When two compatible fungi hyphae grow close to each other, they will then fuse together for reproduction, and form another fungus.
See also
Chemotroph
Micro-animals
Microorganism
Document 1:::
Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator (see predation), host-parasite (see parasitism), plant-herbivore and victim-exploiter systems. These kinds of interactions have been studied and modeled by population ecologists for nearly a century. Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources. Species higher up in the food chain survive by consuming other species and can be classified by what they eat and how they obtain or find their food.
Classification of consumer types
The standard categorization
Various terms have arisen to define consumers by what they eat, such as meat-eating carnivores, fish-eating piscivores, insect-eating insectivores, plant-eating herbivores, seed-eating granivores, and fruit-eating frugivores and omnivores are meat eaters and plant eaters. An extensive classification of consumer categories based on a list of feeding behaviors exists.
The Getz categorization
Another way of categorizing consumers, proposed by South African American ecologist Wayne Getz, is based on a biomass transformation web (BTW) formulation that organizes resources into five components: live and dead animal, live and dead plant, and particulate (i.e. broken down plant and animal) matter. It also distinguishes between consumers that gather their resources by moving across landscapes from those that mine their resources by becoming sessile once they have located a stock of resources large enough for them to feed on during completion of a full life history stage.
In Getz's scheme, words for miners are of Greek etymology and words for gatherers are of Latin etymology. Thus a bestivore, such as a cat, preys on live animal
Document 2:::
The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a food "web". Ecological communities with higher biodiversity form more complex trophic paths.
The word trophic derives from the Greek τροφή (trophē) referring to food or nourishment.
History
The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers", and "reducers" (modified to "decomposers" by Lindeman).
Overview
The three basic ways in which organisms get food are as producers, consumers, and decomposers.
Producers (autotrophs) are typically plants or algae. Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers. In this way, it is energy from the sun that usually powers the base of the food chain. An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight. Here primary producers manufacture food through a process called chemosynthesis.
Consumers (heterotrophs) are species that cannot manufacture their own food and need to consume other organisms. Animals that eat primary producers (like plants) are called herbivores. Animals that eat other animals are called carnivores, and animals that eat both plants and other animals are called omnivores.
Decomposers (detritivores) break down dead plant and animal material and wastes and release it again as energy and nutrients into
Document 3:::
The soil food web is the community of organisms living all or part of their lives in the soil. It describes a complex living system in the soil and how it interacts with the environment, plants, and animals.
Food webs describe the transfer of energy between species in an ecosystem. While a food chain examines one, linear, energy pathway through an ecosystem, a food web is more complex and illustrates all of the potential pathways. Much of this transferred energy comes from the sun. Plants use the sun’s energy to convert inorganic compounds into energy-rich, organic compounds, turning carbon dioxide and minerals into plant material by photosynthesis. Plant flowers exude energy-rich nectar above ground and plant roots exude acids, sugars, and ectoenzymes into the rhizosphere, adjusting the pH and feeding the food web underground.
Plants are called autotrophs because they make their own energy; they are also called producers because they produce energy available for other organisms to eat. Heterotrophs are consumers that cannot make their own food. In order to obtain energy they eat plants or other heterotrophs.
Above ground food webs
In above ground food webs, energy moves from producers (plants) to primary consumers (herbivores) and then to secondary consumers (predators). The phrase, trophic level, refers to the different levels or steps in the energy pathway. In other words, the producers, consumers, and decomposers are the main trophic levels. This chain of energy transferring from one species to another can continue several more times, but eventually ends. At the end of the food chain, decomposers such as bacteria and fungi break down dead plant and animal material into simple nutrients.
Methodology
The nature of soil makes direct observation of food webs difficult. Since soil organisms range in size from less than 0.1 mm (nematodes) to greater than 2 mm (earthworms) there are many different ways to extract them. Soil samples are often taken using a metal
Document 4:::
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated "soil organic matter". The detritus of aquatic ecosystems is organic substances that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow".
Theory
The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which organic matter is decomposed, occurs in several phases. Micro- and macro-organisms that feed on it rapidly consume and absorb materials such as proteins, lipids, and sugars that are low in molecular weight, while other compounds such as complex carbohydrates are decomposed more slowly. The decomposing microorganisms degrade the organic materials so as to gain the resources they require for their survival and reproduction. Accordingly, simultaneous to microorganisms' decomposition of the materials of dead plants and animals is their assimilation of decomposed compounds to construct more of their biomass (i.e. to grow their own bodies). When microorganisms die, fine organic particles are produced, and if small animals that feed on microorganisms eat these particles they collect inside the intestines of the consumers, and change shape into large pellets of dung. As a result of this process, most of the materials of dead organisms disappear and are not visible and recognizable in any form, but are pres
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which of the following organisms is the decomposer in this food web?
A. beaver
B. gray fox
C. persimmon tree
D. parasol fungus
Answer:
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sciq-11068
|
multiple_choice
|
What did volcanic gases help to form on earth?
|
[
"atmosphere",
"rocks",
"plants",
"water"
] |
A
|
Relavent Documents:
Document 0:::
Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities (vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
The sources of volcanic gases on Earth include:
primordial and recycled constituents from the Earth's mantle,
assimilated constituents from the Earth's crust,
groundwater and the Earth's atmosphere.
Substances that may become gaseous or give off gases when heated are termed volatile substances.
Composition
The principal components of volcanic gases are water vapor (H2O), carbon dioxide (CO2), sulfur either as sulfur dioxide (SO2) (high-temperature volcanic gases) or hydrogen sulfide (H2S) (low-temperature volcanic gases), nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen (meteoric), hydrogen chloride, hydrogen fluoride, hydrogen bromide, sulfur hexafluoride, carbonyl sulfide, and organic compounds. Exotic trace compounds include mercury, halocarbons (including CFCs), and halogen oxide radicals.
The abundance of gases varies considerably from volcano to volcano, with volcanic activity and with tectonic setting. Water vapour is consistently the most abundant volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions.
Volcanoes located at convergent plate boundaries emit more water vapor and chlorine than volcanoes at hot spots or divergent plate boundaries. This is caused by the addition of seawater into magmas formed at subduction zones. Convergent plate boundary volcanoes also have higher H2O/H2, H2O/CO2, CO2/He and N2/He ratios than hot spot or divergent plate boundary volcanoes.
Magmatic gases and high-temperature volcanic gases
Magma contains dissolved volatile componen
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Biogeology is the study of the interactions between the Earth's biosphere and the lithosphere.
Biogeology examines biotic, hydrologic, and terrestrial systems in relation to each other, to help understand the Earth's climate, oceans, and other effects on geologic systems.
For example, bacteria are responsible for the formation of some minerals such as pyrite, and can concentrate economically important metals such as tin and uranium. Bacteria are also responsible for the chemical composition of the atmosphere, which affects weathering rates of rocks.
Prior to the late Devonian period, there was little plant life beyond lichens, and bryophytes. At this time large vascular plants evolved, growing up to in height. These large plants changed the atmosphere, and altered the composition of the soil by increasing the amount of organic carbon. This helped prevent the soil being washed away through erosion.
See also
Pedology
Geobiology
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An ecosphere is a planetary closed ecological system. In this global ecosystem, the various forms of energy and matter that constitute a given planet interact on a continual basis. The forces of the four Fundamental interactions cause the various forms of matter to settle into identifiable layers. These layers are referred to as component spheres with the type and extent of each component sphere varying significantly from one particular ecosphere to another. Component spheres that represent a significant portion of an ecosphere are referred to as a primary component spheres. For instance, Earth's ecosphere consists of five primary component spheres which are the Geosphere, Hydrosphere, Biosphere, Atmosphere, and Magnetosphere.
Types of component spheres
Geosphere
The layer of an ecosphere that exists at a Terrestrial planet's Center of mass and which extends radially outward until ending in a solid and spherical layer known as the Crust (geology).
This includes rocks and minerals that are present on the Earth as well as parts of soil and skeletal remains of animals that have become fossilized over the years. This is all about process how rocks metamorphosize. They go through solids to weathered to washing away and back to being buried and resurrected. The primary agent driving these processes is the movement of Earth’s tectonic plates, which creates mountains, volcanoes, and ocean basins. The inner core of the Earth contains liquid iron, which is an important factor in the geosphere as well as the magnetosphere.
Hydrosphere
The total mass of water, regardless of phase (e.g. liquid, solid, gas), that exists within an ecosphere. It's possible for the hydrosphere to be highly distributed throughout other component spheres such as the geosphere and atmosphere.
There are about 1.4 billion km of water on Earth. That includes liquid water in the ocean, lakes, and rivers. It includes frozen water in snow, ice, and glaciers, and water that’s underground in soils and rocks
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An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules.
The atmosphere of Earth is composed of nitrogen (78 %), oxygen (21 %), argon (0.9 %), carbon dioxide (0.04 %) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, solar wind, and cosmic rays to protect organisms from genetic damage. The current composition of the atmosphere of the Earth is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.
Composition
The initial gaseous composition of an atmosphere is determined by the chemistry and temperature of the local solar nebula from which a planet is formed, and the subsequent escape of some gases from the interior of the atmosphere proper. The original atmosphere of the planets originated from a rotating disc of gases, which collapsed onto itself and then divided into a series of spaced rings of gas and matter that, which later condensed to form the planets of the Solar System. The atmospheres of the planets Venus and Mars are principally composed of carbon dioxide and nitrogen, argon and oxygen.
The composition of Earth's atmosphere is determined by the by-products of the life that it sustains. Dry air (mixture of gases) from Earth's atmosphere contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and traces of hydrogen,
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What did volcanic gases help to form on earth?
A. atmosphere
B. rocks
C. plants
D. water
Answer:
|
|
sciq-6030
|
multiple_choice
|
What quality of sound makes a tuba and a piccolo very different to a listener?
|
[
"curve",
"tune",
"pitch",
"wavelength"
] |
C
|
Relavent Documents:
Document 0:::
Whenever a wave forms through a medium/object (organ pipe) with a closed/open end, there is a chance of error in the formation of the wave, i.e. it may not actually start from the opening of the object but instead before the opening, thus resulting on an error when studying it theoretically. Hence an end correction is sometimes required to appropriately study its properties. The end correction depends on the radius of the object.
An acoustic pipe, such as an organ pipe, marimba, or flute resonates at a specific pitch or frequency. Longer pipes resonate at lower frequencies, producing lower-pitched sounds. The details of acoustic resonance are taught in many elementary physics classes. In an ideal tube, the wavelength of the sound produced is directly proportional to the length of the tube. A tube which is open at one end and closed at the other produces sound with a wavelength equal to four times the length of the tube. A tube which is open at both ends produces sound whose wavelength is just twice the length of the tube. Thus, when a Boomwhacker with two open ends is capped at one end, the pitch produced by the tube goes down by one octave.
The analysis above applies only to an ideal tube, of zero diameter. When designing an organ or Boomwhacker, the diameter of the tube must be taken into account. In acoustics, end correction is a short distance applied or added to the actual length of a resonance pipe, in order to calculate the precise resonant frequency of the pipe. The pitch of a real tube is lower than the pitch predicted by the simple theory. A finite diameter pipe appears to be acoustically somewhat longer than its physical length.
A theoretical basis for computation of the end correction is the radiation acoustic impedance of a circular piston. This impedance represents the ratio of acoustic pressure at the piston, divided by the flow rate induced by it. The air speed is typically assumed to be uniform across the tube end. This is a good approximation,
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In music, timbre (), also known as tone color or tone quality (from psychoacoustics), is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musical instruments. It also enables listeners to distinguish different instruments in the same category (e.g., an oboe and a clarinet, both woodwind instruments).
In simple terms, timbre is what makes a particular musical instrument or human voice have a different sound from another, even when they play or sing the same note. For instance, it is the difference in sound between a guitar and a piano playing the same note at the same volume. Both instruments can sound equally tuned in relation to each other as they play the same note, and while playing at the same amplitude level each instrument will still sound distinctively with its own unique tone color. Experienced musicians are able to distinguish between different instruments of the same type based on their varied timbres, even if those instruments are playing notes at the same fundamental pitch and loudness.
The physical characteristics of sound that determine the perception of timbre include frequency spectrum and envelope. Singers and instrumental musicians can change the timbre of the music they are singing/playing by using different singing or playing techniques. For example, a violinist can use different bowing styles or play on different parts of the string to obtain different timbres (e.g., playing sul tasto produces a light, airy timbre, whereas playing sul ponticello produces a harsh, even and aggressive tone). On electric guitar and electric piano, performers can change the timbre using effects units and graphic equalizers.
Synonyms
Tone quality and tone color are synonyms for timbre, as well as the "texture attributed to a single instrument". However, the word texture can also refer to the type of music, such as multiple, interweaving melody lines versus a singable me
Document 2:::
A monochord, also known as sonometer (see below), is an ancient musical and scientific laboratory instrument, involving one (mono-) string (chord). The term monochord is sometimes used as the class-name for any musical stringed instrument having only one string and a stick shaped body, also known as musical bows. According to the Hornbostel–Sachs system, string bows are bar zithers (311.1) while monochords are traditionally board zithers (314). The "harmonical canon", or monochord is, at its least, "merely a string having a board under it of exactly the same length, upon which may be delineated the points at which the string must be stopped to give certain notes," allowing comparison.
A string is fixed at both ends and stretched over a sound box. One or more movable bridges are then manipulated to demonstrate mathematical relationships among the frequencies produced. "With its single string, movable bridge and graduated rule, the monochord (kanōn [Greek: law]) straddled the gap between notes and numbers, intervals and ratios, sense-perception and mathematical reason." However, "music, mathematics, and astronomy were [also] inexorably linked in the monochord." As a pedagogical tool for demonstrating mathematical relationships between intervals, the monochord remained in use throughout the Middle Ages.
Experimental use
The monochord can be used to illustrate the mathematical properties of musical pitch and to illustrate Mersenne's laws regarding string length and tension: "essentially a tool for measuring musical intervals". For example, when a monochord's string is open it vibrates at a particular frequency and produces a pitch. When the length of the string is halved, and plucked, it produces a pitch an octave higher and the string vibrates at twice the frequency of the original (2:1) . Half of this length will produce a pitch two octaves higher than the original—four times the initial frequency (4:1)—and so on. Standard diatonic Pythagorean tuning (Ptolemy's Di
Document 3:::
Three-valve instruments and trombones without valves have seven possible configurations or positions. Four-valve instruments, tenor trombones with F attachments and bass trombones (potentially with multiple valves) are more complicated. The extra length of tubing utilized when instruments are extended by nearly half their length throws off the ratios of the other tubes' lengths, which were designed to produce half-steps without the extra fourth valve. Compensating euphoniums and tubas allow for this by having two sets of tubes for each of the first three valves. Non-compensating instruments and trombones must not use the third position or valve
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This list contains musical instruments of symbolic or cultural importance within a nation, state, ethnicity, tribe or other group of people.
In some cases, national instruments remain in wide use within the nation (such as the Puerto Rican cuatro), but in others, their importance is primarily symbolic (such as the Welsh triple harp). Danish ethnologist Lisbet Torp has concluded that some national instrument traditions, such as the Finnish kantele, are invented, pointing to the "influence of intellectuals and nationalists in the nationwide promotion of selected musical instruments as a vehicle for nationalistic ideas". Governments do not generally officially recognize national instruments; some exceptions being the Paraguayan harp, the Japanese koto and the Trinidadian steelpan.
This list compiles instruments that have been alleged to be a national instrument by any of a variety of sources, and an instrument's presence on the list does not indicate that its status as a national instrument is indisputable, only that its status has been credibly argued. Each instrument on this list has a Hornbostel-Sachs number immediately below it. This number indicates the instrument's classification within the Hornbostel-Sachs system (H-S), which organizes instruments numerically based on the manner in which they produce sound.
Images and recordings are supplied where available; note that there are often variations within a national musical tradition, and thus the images and recordings may not be accurate in depicting the entire spectrum of the given nation's music, and that some images and recordings may be taken from a region outside the core of the national instrument's home when such distinctions have little relevance to the information present in the image and recordings. A number of countries have more than one instrument listed, each having been described as a national instrument, not usually by the same source; neither the presence of multiple entries for one nation, nor
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What quality of sound makes a tuba and a piccolo very different to a listener?
A. curve
B. tune
C. pitch
D. wavelength
Answer:
|
|
sciq-1204
|
multiple_choice
|
What type of disease is caused by pathogens?
|
[
"autoimmune diseases",
"nervous diseases",
"infectious diseases",
"viral diseases"
] |
C
|
Relavent Documents:
Document 0:::
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.
The term pathogen came into use in the 1880s. Typically, the term pathogen is used to describe an infectious microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them.
There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time frames, but soil has the longest or most persistent potential for harboring a pathogen.
Diseases in humans that are caused by infectious agents are known as pathogenic diseases. Not all diseases are caused by pathogens, such as black lung from exposure to the pollutant coal dust, genetic disorders like sickle cell disease, and autoimmune diseases like lupus.
Pathogenicity
Pathogenicity is the potential disease-causing capacity of pathogens, involving a combination of infectivity (pathogen's ability to infect hosts) and virulence (severity of host disease). Koch's postulates are used to establish causal relationships between microbial pathogens and diseases. Whereas meningitis can be caused by a variety of bacterial, viral, fungal, and parasitic pathogens, cholera is only caused by some strains of Vibrio cholerae. Additionally, some pathogens may only cause disease in hosts with an immunodeficiency. These opportunistic infections often involve hospital-acquired infections among patients already combating another condition.
Infectivity involves path
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Infectious diseases or ID, also known as infectiology, is a medical specialty dealing with the diagnosis and treatment of infections. An infectious diseases specialist's practice consists of managing nosocomial (healthcare-acquired) infections or community-acquired infections. An ID specialist investigates the cause of a disease to determine what kind of Bacteria, viruses, parasites, or fungi the disease is caused by. Once the pathogen is known, an ID specialist can then run various tests to determine the best antimicrobial drug to kill the pathogen and treat the disease. While infectious diseases have always been around, the infectious disease specialty did not exist until the late 1900s after scientists and physicians in the 19th century paved the way with research on the sources of infectious disease and the development of vaccines.
Scope
Infectious diseases specialists typically serve as consultants to other physicians in cases of complex infections, and often manage patients with HIV/AIDS and other forms of immunodeficiency. Although many common infections are treated by physicians without formal expertise in infectious diseases, specialists may be consulted for cases where an infection is difficult to diagnose or manage. They may also be asked to help determine the cause of a fever of unknown origin.
Specialists in infectious diseases can practice both in hospitals (inpatient) and clinics (outpatient). In hospitals, specialists in infectious diseases help ensure the timely diagnosis and treatment of acute infections by recommending the appropriate diagnostic tests to identify the source of the infection and by recommending appropriate management such as prescribing antibiotics to treat bacterial infections. For certain types of infections, involvement of specialists in infectious diseases may improve patient outcomes. In clinics, specialists in infectious diseases can provide long-term care to patients with chronic infections such as HIV/AIDS.
History
Inf
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In pathology, pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes .
Description
Types of pathogenesis include microbial infection, inflammation, malignancy and tissue breakdown. For example, bacterial pathogenesis is the process by which bacteria cause infectious illness.
Most diseases are caused by multiple processes. For example, certain cancers arise from dysfunction of the immune system (skin tumors and lymphoma after a renal transplant, which requires immunosuppression), Streptococcus pneumoniae is spread through contact with respiratory secretions, such as saliva, mucus, or cough droplets from an infected person and colonizes the upper respiratory tract and begins to multiply.
The pathogenic mechanisms of a disease (or condition) are set in motion by the underlying causes, which if controlled would allow the disease to be prevented. Often, a potential cause is identified by epidemiological observations before a pathological link can be drawn between the cause and the disease. The pathological perspective can be directly integrated into an epidemiological approach in the interdisciplinary field of molecular pathological epidemiology. Molecular pathological epidemiology can help to assess pathogenesis and causality by means of linking a potential risk factor to molecular pathologic signatures of a disease. Thus, the molecular pathological epidemiology paradigm can advance the area of causal inference.
See also
Causal inference
Epidemiology
Molecular pathological epidemiology
Molecular pathology
Pathology
Pathophysiology
Salutogenesis
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The host–pathogen interaction is defined as how microbes or viruses sustain themselves within host organisms on a molecular, cellular, organismal or population level. This term is most commonly used to refer to disease-causing microorganisms although they may not cause illness in all hosts. Because of this, the definition has been expanded to how known pathogens survive within their host, whether they cause disease or not.
On the molecular and cellular level, microbes can infect the host and divide rapidly, causing disease by being there and causing a homeostatic imbalance in the body, or by secreting toxins which cause symptoms to appear. Viruses can also infect the host with virulent DNA, which can affect normal cell processes (transcription, translation, etc.), protein folding, or evading the immune response.
Pathogenicity
Pathogen history
One of the first pathogens observed by scientists was Vibrio cholerae, described in detail by Filippo Pacini in 1854. His initial findings were just drawings of the bacteria but, up until 1880, he published many other papers concerning the bacteria. He described how it causes diarrhea as well as developed effective treatments against it. Most of these findings went unnoticed until Robert Koch rediscovered the organism in 1884 and linked it to the disease.
was discovered by Leeuwenhoeck in the 1600s< but was not found to be pathogenic until the 1970s, when an EPA-sponsored symposium was held following a large outbreak in Oregon involving the parasite. Since then, many other organisms have been identified as pathogens, such as H. pylori and E. coli, which have allowed scientists to develop antibiotics to combat these harmful microorganisms.
Types of pathogens
Pathogens include bacteria, fungi, protozoa, helminths, and viruses.
Each of these different types of organisms can then be further classified as a pathogen based on its mode of transmission. This includes the following: food borne, airborne, waterborne, blood-bor
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Cause, also known as etiology () and aetiology, is the reason or origination of something.
The word etiology is derived from the Greek , aitiologia, "giving a reason for" (, aitia, "cause"; and , -logia).
Description
In medicine, etiology refers to the cause or causes of diseases or pathologies. Where no etiology can be ascertained, the disorder is said to be idiopathic.
Traditional accounts of the causes of disease may point to the "evil eye".
The Ancient Roman scholar Marcus Terentius Varro put forward early ideas about microorganisms in a 1st-century BC book titled On Agriculture.
Medieval thinking on the etiology of disease showed the influence of Galen and of Hippocrates. Medieval European doctors generally held the view that disease was related to the air and adopted a miasmatic approach to disease etiology.
Etiological discovery in medicine has a history in Robert Koch's demonstration that species of the pathogenic bacteria Mycobacterium tuberculosis causes the disease tuberculosis; Bacillus anthracis causes anthrax, and Vibrio cholerae causes cholera. This line of thinking and evidence is summarized in Koch's postulates. But proof of causation in infectious diseases is limited to individual cases that provide experimental evidence of etiology.
In epidemiology, several lines of evidence together are required to for causal inference. Austin Bradford Hill demonstrated a causal relationship between tobacco smoking and lung cancer, and summarized the line of reasoning in the Bradford Hill criteria, a group of nine principles to establish epidemiological causation. This idea of causality was later used in a proposal for a Unified concept of causation.
Disease causative agent
The infectious diseases are caused by infectious agents or pathogens. The infectious agents that cause disease fall into five groups: viruses, bacteria, fungi, protozoa, and helminths (worms).
The term can also refer to a toxin or toxic chemical that causes illness.
Chain of causatio
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of disease is caused by pathogens?
A. autoimmune diseases
B. nervous diseases
C. infectious diseases
D. viral diseases
Answer:
|
|
sciq-6852
|
multiple_choice
|
Which waves have the longest wavelengths but the least energy in the atmosphere?
|
[
"radio waves",
"microwaves",
"light waves",
"channel waves"
] |
A
|
Relavent Documents:
Document 0:::
Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahertz (THz), although the upper boundary is somewhat arbitrary and is considered by some sources as 30 THz. One terahertz is 1012 Hz or 1000 GHz. Wavelengths of radiation in the terahertz band correspondingly range from 1 mm to 0.1 mm = 100 µm. Because terahertz radiation begins at a wavelength of around 1 millimeter and proceeds into shorter wavelengths, it is sometimes known as the submillimeter band, and its radiation as submillimeter waves, especially in astronomy. This band of electromagnetic radiation lies within the transition region between microwave and far infrared, and can be regarded as either.
At some frequencies, terahertz radiation is strongly absorbed by the gases of the atmosphere, and in air is attenuated to zero within a few meters, so it is not practical for terrestrial radio communication at such frequencies. However, there are frequency windows in Earth's atmosphere, where the terahertz radiation could propagate up to 1 km or even longer depending on atmospheric conditions. The most important is the 0.3 THz band that will be used for 6G communications. It can penetrate thin layers of materials but is blocked by thicker objects. THz beams transmitted through materials can be used for material characterization, layer inspection, relief measurement, and as a lower-energy alternative to X-rays for producing high resolution images of the interior of solid objects.
Terahertz radiation occupies a middle ground where the ranges of microwaves and infrared light waves overlap, known as the “terahertz gap”; it is called a “gap” because the technology for its generation and manipulation is still in its infancy. The generation and modulation of electromagnetic waves in this frequency range ceases to be pos
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The radio window is a range of frequencies of electromagnetic radiation that penetrate the Earth's atmosphere. Typically, the lower limit of the radio window's range has a value of about 10 MHz (λ ≈ 30 m); the best upper limit achievable from optimal terrestrial observation sites is equal to approximately 1 THz (λ ≈ 0.3 mm).
It plays an important role in astronomy; up until the 1940s, astronomers could only use the visible and near infrared spectra for their measurements and observations. With the development of radio telescopes, the radio window became more and more utilizable, leading to the development of radio astronomy that provided astrophysicists with valuable observational data.
Factors affecting lower and upper limits
The lower and upper limits of the radio window's range of frequencies are not fixed; they depend on a variety of factors.
Absorption of mid-IR
The upper limit is affected by the vibrational transitions of atmospheric molecules such as oxygen (O2), carbon dioxide (CO2), and water (H2O), whose energies are comparable to the energies of mid-infrared photons: these molecules largely absorb the mid-infrared radiation that heads towards Earth.
Ionosphere
The radio window's lower frequency limit is greatly affected by the ionospheric refraction of the radio waves whose frequencies are approximately below 30 MHz (λ > 10 m); radio waves with frequencies below the limit of 10 MHz (λ > 30 m) are reflected back into space by the ionosphere. The lower limit is proportional to the density of the ionosphere's free electrons and coincides with the plasma frequency:
where is the plasma frequency in Hz and the electron density in electrons per cubic meter. Since it is highly dependent on sunlight, the value of changes significantly from daytime to nighttime usually being lower during the day, leading to a decrease of the radio window's lower limit and higher during the night, causing an increase of the radio window's lower frequency end. However, thi
Document 2:::
Radio Science is a quarterly peer-reviewed scientific journal published by Wiley-Blackwell on behalf of the American Geophysical Union and co-sponsored by the International Union of Radio Science. It contains original scientific contributions on radio-frequency electromagnetic propagation and its applications (radio science). Its full aims and scope read:
Volumes for the years 1966 through 1968 were issued by the Environmental Science Services Administration (ESSA), the precursor of the National Oceanic and Atmospheric Administration (NOAA), in cooperation with the United States National Committee of the International Scientific Radio Union.
See also
Advances in Radio Science
Document 3:::
Longwave (LW) radiation, in the context of climate science, is electromagnetic thermal radiation emitted by Earth's surface, atmosphere, and clouds. Longwave radiation may also be referred to as terrestrial radiation, thermal infrared radiation, or thermal radiation. This radiation is in the infrared portion of the spectrum, but is distinct from (i.e., has a longer wavelength than) the shortwave (SW) near-infrared radiation found in sunlight.
Outgoing longwave radiation (OLR) is the longwave radiation emitted to space from the top of Earth's atmosphere. It may also be referred to as emitted terrestrial radiation. Outgoing longwave radiation plays an important role in planetary cooling.
Longwave radiation generally spans wavelengths ranging from 3–100 microns (μm). A cutoff of 4 μm is sometimes used to differentiate sunlight from longwave radiation. Less than 1% of sunlight has wavelengths greater than 4 μm. Over 99% of outgoing longwave radiation has wavelengths between 4 μm and 100 μm.
The flux of energy transported by outgoing longwave radiation is typically measured in units of watts per meter squared (W m−2). In the case of global energy flux, the W/m2 value is obtained by dividing the total energy flow over the surface of the globe (measured in watts) by the surface area of the Earth, .
Emitting outgoing longwave radiation is the only way Earth loses energy to space, i.e., the only way the planet cools itself. Radiative heating from absorbed sunlight, and radiative cooling to space via OLR power the heat engine that drives atmospheric dynamics.
The balance between OLR (energy lost) and incoming solar shortwave radiation (energy gained) determines whether the Earth is experiencing global heating or cooling (see Earth's energy budget).
Planetary energy balance
Outgoing longwave radiation (OLR) constitutes a critical component of Earth's energy budget.
The principle of conservation of energy says that energy cannot appear or disappear. Thus, any energy
Document 4:::
Ionospheric absorption (ISAB) is the scientific name for absorption occurring as a result of the interaction between various types of electromagnetic waves and the free electrons in the ionosphere, which can interfere with radio transmissions.
Description
Ionosphere absorption is of critical importance when radio networks, telecommunication systems or interlinked radio systems are being planned, particularly when trying to determine propagation conditions.
The ionosphere can be described as an area of the atmosphere in which radio waves on shortwave bands are refracted or reflected back to Earth. As a result of this reflection, which is often key in the long-distance propagation of radio waves, some of the shortwave signal strength is decreased. In this regard, ISAB is the primary limiting factor in radio propagation.
Attenuation mechanics
ISAB is only a factor in the period of the day where radio signals travel through the portion of the ionosphere facing the Sun. The solar wind and radiation cause the ionosphere to become charged with electrons in the first place. At night, the atmosphere becomes drained of its charge, and radio signals can go much farther with less loss of signal. In particular, low frequency signals that would be attenuated to nothing during the day will be received much farther away at night.
The specific amount of attenuation can be derived as a function of the Inverse-square law. The lower the frequency, the greater the attenuation.
Relative ionospheric absorption can be measured using a riometer.
See also
Radio horizon
Sudden Ionospheric Disturbance
Resources
Ionosphere
Radio frequency propagation
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which waves have the longest wavelengths but the least energy in the atmosphere?
A. radio waves
B. microwaves
C. light waves
D. channel waves
Answer:
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|
sciq-1766
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multiple_choice
|
Name the multi-phase process in which the nucleus of a eukaryotic cell divides?
|
[
"meiosis",
"mitosis",
"symbiosis",
"cytokinesis"
] |
B
|
Relavent Documents:
Document 0:::
In cell biology, the cleavage furrow is the indentation of the cell's surface that begins the progression of cleavage, by which animal and some algal cells undergo cytokinesis, the final splitting of the membrane, in the process of cell division. The same proteins responsible for muscle contraction, actin and myosin, begin the process of forming the cleavage furrow, creating an actomyosin ring. Other cytoskeletal proteins and actin binding proteins are involved in the procedure.
Mechanism
Plant cells do not perform cytokinesis through this exact method but the two procedures are not totally different. Animal cells form an actin-myosin contractile ring within the equatorial region of the cell membrane that constricts to form the cleavage furrow. In plant cells, Golgi vesicle secretions form a cell plate or septum on the equatorial plane of the cell wall by the action of microtubules of the phragmoplast. The cleavage furrow in animal cells and the phragmoplast in plant cells are complex structures made up of microtubules and microfilaments that aide in the final separation of the cells into two identical daughter cells.
Cell cycle
The cell cycle begins with interphase when the DNA replicates, the cell grows and prepares to enter mitosis. Mitosis includes four phases: prophase, metaphase, anaphase, and telophase. Prophase is the initial phase when spindle fibers appear that function to move the chromosomes toward opposite poles. This spindle apparatus consists of microtubules, microfilaments and a complex network of various proteins. During metaphase, the chromosomes line up using the spindle apparatus in the middle of the cell along the equatorial plate. The chromosomes move to opposite poles during anaphase and remain attached to the spindle fibers by their centromeres. Animal cell cleavage furrow formation is caused by a ring of actin microfilaments called the contractile ring, which forms during early anaphase. Myosin is present in the region of the contracti
Document 1:::
The nucleoplasm, also known as karyoplasm, is the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. It is enclosed by the nuclear envelope, also known as the nuclear membrane. The nucleoplasm resembles the cytoplasm of a eukaryotic cell in that it is a gel-like substance found within a membrane, although the nucleoplasm only fills out the space in the nucleus and has its own unique functions. The nucleoplasm suspends structures within the nucleus that are not membrane-bound and is responsible for maintaining the shape of the nucleus. The structures suspended in the nucleoplasm include chromosomes, various proteins, nuclear bodies, the nucleolus, nucleoporins, nucleotides, and nuclear speckles.
The soluble, liquid portion of the nucleoplasm is called the karyolymph nucleosol, or nuclear hyaloplasm.
History
The existence of the nucleus, including the nucleoplasm, was first documented as early as 1682 by the Dutch microscopist Leeuwenhoek and was later described and drawn by Franz Bauer. However, the cell nucleus was not named and described in detail until Robert Brown's presentation to the Linnean Society in 1831.
The nucleoplasm, while described by Bauer and Brown, was not specifically isolated as a separate entity until its naming in 1882 by Polish-German scientist Eduard Strasburger, one of the most famous botanists of the 19th century, and the first person to discover mitosis in plants.
Role
Many important cell functions take place in the nucleus, more specifically in the nucleoplasm. The main function of the nucleoplasm is to provide the proper environment for essential processes that take place in the nucleus, serving as the suspension substance for all organelles inside the nucleus, and storing the structures that are used in these processes. 34% of proteins encoded in the human genome are ones that localize to the nucleoplasm. These proteins take part in RNA transcription and gene regulation in the n
Document 2:::
Multinucleate cells (also known as multinucleated or polynuclear cells) are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordinated, synchronous manner where all nuclei divide simultaneously or asynchronously where individual nuclei divide independently in time and space. Certain organisms may have a multinuclear stage of their life cycle. For example, slime molds have a vegetative, multinucleate life stage called a plasmodium.
Although not normally viewed as a case of multinucleation, plant cells share a common cytoplasm by plasmodesmata, and most cells in animal tissues are in communication with their neighbors via gap junctions.
Multinucleate cells, depending on the mechanism by which they are formed, can be divided into "syncytia" (formed by cell fusion) or "coenocytes" (formed by nuclear division not being followed by cytokinesis).
A number of dinoflagellates are known to have two nuclei. Unlike other multinucleated cells these nuclei contain two distinct lineages of DNA: one from the dinoflagellate and the other from a symbiotic diatom.
Some bacteria, such as Mycoplasma pneumoniae, a pathogen of the respiratory tract, may display multinuclear filaments as a result of a delay between genome replication and cellular division.
Terminology
Some biologists use the term "acellular" to refer to multinucleate cell forms (syncitia and plasmodia), such as to differentiate "acellular" slime molds from the purely "cellular" ones (which do not form such structures). This usage is incorrect and highly misleading to laymen, and as such it is strongly discouraged.
Some use the term "syncytium" in a wide sense, to mean any type of multinucleate cell, while others differentiate the terms for each type.
Physiological examples
Syncytia
Syncytia are multinuclear cells that can form either through normal biological processes, such as the mammalian placenta
Document 3:::
Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term physiology refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show similarities in their functions even though they vary in structure.
General characteristics
There are two types of cells: prokaryotes and eukaryotes.
Prokaryotes were the first of the two to develop and do not have a self-contained nucleus. Their mechanisms are simpler than later-evolved eukaryotes, which contain a nucleus that envelops the cell's DNA and some organelles.
Prokaryotes
Prokaryotes have DNA located in an area called the nucleoid, which is not separated from other parts of the cell by a membrane. There are two domains of prokaryotes: bacteria and archaea. Prokaryotes have fewer organelles than eukaryotes. Both have plasma membranes and ribosomes (structures that synthesize proteins and float free in cytoplasm). Two unique characteristics of prokaryotes are fimbriae (finger-like projections on the surface of a cell) and flagella (threadlike structures that aid movement).
Eukaryotes
Eukaryotes have a nucleus where DNA is contained. They are usually larger than prokaryotes and contain many more organelles. The nucleus, the feature of a eukaryote that distinguishes it from a prokaryote, contains a nuclear envelope, nucleolus and chromatin. In cytoplasm, endoplasmic reticulum (ER) synthesizes membranes and performs other metabolic activities. There are two types, rough ER (containing ribosomes) and smooth ER (lacking ribosomes). The Golgi apparatus consists of multiple membranous sacs, responsible for manufacturing and shipping out materials such as proteins. Lysosomes are structures that use enzymes to break down substances through phagocytosis, a process that comprises endocytosis and exocytosis. In the mitochondria, metabolic processes such as cellular respiration occur. The cytoskeleton is made of fibers that support the str
Document 4:::
Mitotic index is defined as the ratio between the number of a population's cells undergoing mitosis to its total number of cells.
Purpose
The mitotic index is a measure of cellular proliferation.
It is defined as the percentage of cells undergoing mitosis in a given population of cells. Mitosis is the division of somatic cells into two daughter cells. Durations of the cell cycle and mitosis vary in different cell types. An elevated mitotic index indicates more cells are dividing. In cancer cells, the mitotic index may be elevated compared to normal growth of tissues or cellular repair of the site of an injury. The mitotic index is therefore an important prognostic factor predicting both overall survival and response to chemotherapy in most types of cancer. It may lose much of its predictive value for elderly populations. For example, a low mitotic index loses any prognostic value for women over 70 years old with breast cancer.
Calculation
The mitotic index is the number of cells undergoing mitosis divided by the total number of cells.
A typical figure of mitotic index includes statements like "10 mitotic figures are noted per 10 high power fields" followed by "4 mitotic figures noted per 50 high power fields."
Formula
where (P+M+A+T) is the sum of all cells in phase as prophase, metaphase, anaphase and telophase, respectively and N is total number of cells.
Examples
The fastest rate of mitosis happens in the zygote, embryo and infant stage for humans and animals because mitosis is essential for embryological development. Mitosis is also required at a higher rate to grow and repair tissue. Some examples include human lymph nodes and bone marrow. Also, skin, hair, and the cells lining the intestines (epithelial cells) have high rates of mitosis. That's because those tissues constantly need to be repaired (by the cells being replaced) or growing. Plants have higher rates of mitosis at the cells of the shoot and root tips.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Name the multi-phase process in which the nucleus of a eukaryotic cell divides?
A. meiosis
B. mitosis
C. symbiosis
D. cytokinesis
Answer:
|
|
sciq-9069
|
multiple_choice
|
What celestial object has been visited by manned spacecraft and is easily seen from earth?
|
[
"venus",
"moon",
"the Sun",
"Jupiter"
] |
B
|
Relavent Documents:
Document 0:::
The following tables list all minor planets and comets that have been visited by robotic spacecraft.
List of minor planets visited by spacecraft
A total of 17 minor planets (asteroids, dwarf planets, and Kuiper belt objects) have been visited by space probes. Moons (not directly orbiting the Sun) and planets are not minor planets and thus are not included in the table below.
Incidental flybys
In addition to the above listed objects, four asteroids have been imaged by spacecraft at distances too large to resolve features (over 100,000 km), and are labeled as such.
List of comets visited by spacecraft
{| class="wikitable sortable"
|-
! colspan=4 style="background-color:#D4E2FC;" | Comet
! colspan=5 style="background-color:#FFFF99;" | Space probe
|-
! rowspan=2 style="background-color:#edf3fe;" width=110 | Name
! rowspan=2 style="background-color:#edf3fe;" class="unsortable"| Image
! rowspan=2 style="background-color:#edf3fe; font-weight: normal;" | Dimensions(km)(a)
! rowspan=2 style="background-color:#edf3fe;" width=70 | Discoveryyear
! rowspan=2 style="background-color:#ffffcc;" | Name
! colspan=3 style="background-color:#ffffcc;"| Closest approach
! rowspan=2 style="background-color:#ffffcc;" class="unsortable"| Remarks
|-
! width=60 style="background-color:#ffffcc;" | year
! width=60 style="background-color:#ffffcc;" | in km
! width=60 style="background-color:#ffffcc; font-weight: normal;" | in radii(b)
|-
| 21P/Giacobini–Zinner
| bgcolor=#334d4c |
| align=center | 2
| align=center | 1900
| ICE
| align=center | 1985
| align=right | 7,800
| align=right | 7,800
| first flyby of a comet
Document 1:::
This article is a list of notable unsolved problems in astronomy. Some of these problems are theoretical, meaning that existing theories may be incapable of explaining certain observed phenomena or experimental results. Others are experimental, meaning that experiments necessary to test proposed theory or investigate a phenomenon in greater detail have not yet been performed. Some pertain to unique events or occurrences that have not repeated themselves and whose causes remain unclear.
Planetary astronomy
Our solar system
Orbiting bodies and rotation:
Are there any non-dwarf planets beyond Neptune?
Why do extreme trans-Neptunian objects have elongated orbits?
Rotation rate of Saturn:
Why does the magnetosphere of Saturn rotate at a rate close to that at which the planet's clouds rotate?
What is the rotation rate of Saturn's deep interior?
Satellite geomorphology:
What is the origin of the chain of high mountains that closely follows the equator of Saturn's moon, Iapetus?
Are the mountains the remnant of hot and fast-rotating young Iapetus?
Are the mountains the result of material (either from the rings of Saturn or its own ring) that over time collected upon the surface?
Extra-solar
How common are Solar System-like planetary systems? Some observed planetary systems contain Super-Earths and Hot Jupiters that orbit very close to their stars. Systems with Jupiter-like planets in Jupiter-like orbits appear to be rare. There are several possibilities why Jupiter-like orbits are rare, including that data is lacking or the grand tack hypothesis.
Stellar astronomy and astrophysics
Solar cycle:
How does the Sun generate its periodically reversing large-scale magnetic field?
How do other Sol-like stars generate their magnetic fields, and what are the similarities and differences between stellar activity cycles and that of the Sun?
What caused the Maunder Minimum and other grand minima, and how does the solar cycle recover from a minimum state?
Coronal heat
Document 2:::
This is a list of potentially habitable exoplanets. The list is mostly based on estimates of habitability by the Habitable Exoplanets Catalog (HEC), and data from the NASA Exoplanet Archive. The HEC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. There is also a speculative list being developed of superhabitable planets.
Surface planetary habitability is thought to require orbiting at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment.
List
This is a list of exoplanets within the circumstellar habitable zone that are under 10 Earth masses and smaller than 2.5 Earth radii, and thus have a chance of being rocky. Note that inclusion on this list does not guarantee habitability, and in particular the larger planets are unlikely to have a rocky composition. Earth is included for comparison.
Note that mass and radius values prefixed with "~" have not been measured, but are estimated from a mass-radius relationship.
Previous candidates
Some exoplanet candidates detected by radial velocity that were originally thought to be potentially habitable were later found to most likely be artifacts of stellar activity. These include Gliese 581 d & g, Gliese 667 Ce & f, Gliese 682 b & c, Kapteyn b, and Gliese 832 c.
HD 85512 b was initially estimated to be potentially habitable, but updated models for the boundaries of the habitable zone placed the planet interior to the HZ, and it is now considered non-habitable. Kepler-69c has gone through a similar process; though initially estimated to be potentially habitable, it was quickly realized that the planet is more likely to be similar to Venus, and is thus no longer considered habitable. Several other planets, such as Gliese 180 b, also appear to be examples of planets once considered potentially habit
Document 3:::
The following list of instrument-resolved minor planets consists of minor planets whose disks have been resolved, whether by telescope, a visit by an uncrewed spacecraft, or by observing the occultation of a background star from multiple sites. Disk resolution allows the density of an body to be computed, providing useful information about the internal composition. It can also be used to determine the shape of the object, to search for albedo features, and to look for companions.
Techniques
Because of their distance from Earth and their small dimension, minor planets such as asteroids represent a challenge for astronomical instruments to resolve. Even two of the largest objects in the asteroid belt, 2 Pallas and 4 Vesta, have maximum angular diameters of less than an arcsecond. With a ground-based optical telescope, resolution of these objects through the Earth's thick atmosphere can require techniques such as speckle interferometry or adaptive optics.
Radio telescopes such as Arecibo or Goldstone have been used to observe asteroids. This technique can be used to measure the Doppler shifts and radar cross-sections of the bodies, while more detailed studies allow three-dimensional shape models to be built. The first radar detection of a minor planet was 1566 Icarus by JPL astronomer Richard M. Goldstein in June 1968. This was followed by 1685 Toro in 1972. A regular program of radar observation of the asteroid belt asteroids was begun in 1980 at Arecibo. Goldstone joined the effort in 1990. Together, they observed 37 main-belt asteroids between 1980–1997.
A more direct approach to asteroid study, allowing the object to be examined greater detail, is to send a spacecraft to either make a fly-by or go into orbit. The first such asteroid to be imaged in this manner was 951 Gaspra in 1991 by the Galileo spacecraft. In 2000, the NEAR Shoemaker spacecraft went into orbit around 433 Eros after making a fly-by of 253 Mathilde in 1997.
Objects
The tables below list selec
Document 4:::
Astronomy education or astronomy education research (AER) refers both to the methods currently used to teach the science of astronomy and to an area of pedagogical research that seeks to improve those methods. Specifically, AER includes systematic techniques honed in science and physics education to understand what and how students learn about astronomy and determine how teachers can create more effective learning environments.
Education is important to astronomy as it impacts both the recruitment of future astronomers and the appreciation of astronomy by citizens and politicians who support astronomical research. Astronomy has been taught throughout much of recorded human history, and has practical application in timekeeping and navigation. Teaching astronomy contributes to an understanding of physics and the origin of the world around us, a shared cultural background, and a sense of wonder and exploration. It includes education of the general public through planetariums, books, and instructive presentations, plus programs and tools for amateur astronomy, and University-level degree programs for professional astronomers. Astronomy organizations provide educational functions and societies in about 100 nation states around the world.
In schools, particularly at the collegiate level, astronomy is aligned with physics and the two are often combined to form a Department of Physics and Astronomy. Some parts of astronomy education overlap with physics education, however, astronomy education has its own arenas, practitioners, journals, and research. This can be demonstrated in the identified 20-year lag between the emergence of AER and physics education research. The body of research in this field are available through electronic sources such as the Searchable Annotated Bibliography of Education Research (SABER) and the American Astronomical Society's database of the contents of their journal "Astronomy Education Review" (see link below).
The National Aeronautics and
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What celestial object has been visited by manned spacecraft and is easily seen from earth?
A. venus
B. moon
C. the Sun
D. Jupiter
Answer:
|
|
sciq-5179
|
multiple_choice
|
Trimethylamine is one of the substances responsible for the what of spoiled fish?
|
[
"feel",
"appearance",
"smell",
"decay"
] |
C
|
Relavent Documents:
Document 0:::
Biological function
Trimethylglycine is an organic osmolyte. Sugar beet was cultivated from sea beet, which requires osmolytes in order to survive in the salty soils of coastal areas. Trimethylglycine also occurs in high concentrations (~10 mM) in many marine invertebrates, su
Document 1:::
Poison shyness, also called conditioned food aversion, is the avoidance of a toxic substance by an animal that has previously ingested that substance. Animals learn an association between stimulus characteristics, usually the taste or odor, of a toxic substance and the illness it produces; this allows them to detect and avoid the substance. Poison shyness occurs as an evolutionary adaptation in many animals, most prominently in generalists that feed on many different materials. It is often called bait shyness when it occurs during attempts at pest control of insects and animals. If the pest ingests the poison bait at sublethal doses, it typically detects and avoids the bait, rendering the bait ineffective.
In nature
For any organism to survive, it must have adaptive mechanisms to avoid toxicosis. In mammals, a variety of behavioral and physiological mechanisms have been identified that allow them to avoid being poisoned. First, there are innate rejection mechanisms such as the rejection of toxic materials that taste bitter. Second, there are other physiologically adaptive responses such as vomiting or alterations in the digestion and processing of toxic materials. Third, there are learned aversions to distinctive foods if ingestion is followed by illness.
A typical experiment tested food aversion learning in squirrel monkeys (Saimiri sciureus) and common marmosets (Callithrix jacchus), using several kinds of cues. Both species showed one-trial learning with the visual cues of color and shape, whereas only the marmosets did so with an olfactory cue. Both species showed a tendency for quicker acquisition of the association with visual cues than with the olfactory cue. All individuals from both species were able to remember the significance of the visual cues, color and shape, even after 4 months. However, illness was not necessarily prerequisite for food avoidance learning in these species, for highly concentrated but non-toxic bitter and sour tastes also induced r
Document 2:::
Off-flavours or off-flavors (see spelling differences) are taints in food products caused by the presence of undesirable compounds. They can originate in raw materials, from chemical changes during food processing and storage, and from micro-organisms. Off-flavours are a recurring issue in drinking water supply and many food products.
Water bodies are often affected by geosmin and 2-methylisoborneol, affecting the flavour of water for drinking and of fish growing in that water. Haloanisoles similarly affect water bodies, and are a recognised cause of off-flavour in wine. Cows grazing on weeds such as wild garlic can produce a ‘weedy’ off-flavour in milk.
Many more examples can be seen throughout food production sectors including in oats, coffee, glucose syrup and brewing.
Document 3:::
Taste Confusion Matrix (TCM) is a method in which many compounds are tested at the same time. It is a study of human taste perception. It characterizes the quality of taste with identification patterns of some 10 stimuli which are analyzed.
Document 4:::
The biochemistry of body odor pertains to the chemical compounds in the body responsible for body odor and their kinetics.
Causes
Body odor encompasses axillary (underarm) odor and foot odor. It is caused by a combination of sweat gland secretions and normal skin microflora. In addition, androstane steroids and the ABCC11 transporter are essential for most axillary odor. Body odor is a complex phenomenon, with numerous compounds and catalysts involved in its genesis. Secretions from sweat glands are initially odorless, but preodoriferous compounds or malodor precursors in the secretions are transformed by skin surface bacteria into volatile odorous compounds that are responsible for body malodor. Water and nutrients secreted by sweat glands also contribute to body odor by creating an ideal environment for supporting the growth of skin surface bacteria.
Types
There are three types of sweat glands: eccrine, apocrine, and apoeccrine. Apocrine glands are primarily responsible for body malodor and, along with apoeccrine glands, are mostly expressed in the axillary (underarm) regions, whereas eccrine glands are distributed throughout virtually all of the rest of the skin in the body, although they are also particularly expressed in the axillary regions, and contribute to malodor to a relatively minor extent. Sebaceous glands, another type of secretory gland, are not sweat glands but instead secrete sebum (an oily substance), and may also contribute to body odor to some degree.
The main odorous compounds that contribute to axillary odor include:
Unsaturated or hydroxylated branched fatty acids, with the key ones being (E)-3-methyl-2-hexenoic acid (3M2H) and 3-hydroxy-3-methylhexanoic acid (HMHA)
Sulfanylalkanols, particularly 3-methyl-3-sulfanylhexan-1-ol (3M3SH)
Odoriferous androstane steroids, namely the pheromones androstenone (5α-androst-16-en-3-one) and androstenol (5α-androst-16-en-3α-ol)
These malodorous compounds are formed from non-odoriferous precursors
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Trimethylamine is one of the substances responsible for the what of spoiled fish?
A. feel
B. appearance
C. smell
D. decay
Answer:
|
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