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sciq-3217
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multiple_choice
|
The name of a monatomic cation is simply the name of the element followed by this word?
|
[
"ion",
"laser",
"amine",
"bond"
] |
A
|
Relavent Documents:
Document 0:::
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 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:::
A monatomic ion (also called simple ion) is an ion consisting of exactly one atom. If, instead of being monatomic, an ion contains more than one atom, even if these are of the same element, it is called a polyatomic ion. For example, calcium carbonate consists of the monatomic cation Ca2+ and the polyatomic anion ; both pentazenium () and azide () are polyatomic as well.
A type I binary ionic compound contains a metal that forms only one type of ion. A type II ionic compound contains a metal that forms more than one type of ion, i.e., the same element in different oxidation states.
{|class="wikitable"
|-
! colspan="2" | Common type I monatomic cations
|-
| Hydrogen
| H+
|-
| Lithium
| Li+
|-
| Sodium
| Na+
|-
| Potassium
| K+
|-
| Rubidium
| Rb+
|-
| Caesium
| Cs+
|-
| Magnesium
| Mg2+
|-
| Calcium
| Ca2+
|-
| Strontium
| Sr2+
|-
| Barium
| Ba2+
|-
| Aluminium
| Al3+
|-
| Silver
| Ag+
|-
| Zinc
| Zn2+
|-
|}
{|class="wikitable"
|-
! colspan="3" | Common type II monatomic cations
|-
|-
| iron(II)
| Fe2+
| ferrous
|-
| iron(III)
| Fe3+
| ferric
|-
| copper(I)
| Cu+
| cuprous
|-
| copper(II)
| Cu2+
| cupric
|-
| cobalt(II)
| Co+2
| cobaltous
|-
| cobalt(III)
| Co3+
| cobaltic
|-
| tin(II)
| Sn2+
| stannous
|-
| tin(IV)
| Sn4+
| stannic
|}
Document 3:::
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
Document 4:::
Further Mathematics is the title given to a number of advanced secondary mathematics courses. The term "Higher and Further Mathematics", and the term "Advanced Level Mathematics", may also refer to any of several advanced mathematics courses at many institutions.
In the United Kingdom, Further Mathematics describes a course studied in addition to the standard mathematics AS-Level and A-Level courses. In the state of Victoria in Australia, it describes a course delivered as part of the Victorian Certificate of Education (see § Australia (Victoria) for a more detailed explanation). Globally, it describes a course studied in addition to GCE AS-Level and A-Level Mathematics, or one which is delivered as part of the International Baccalaureate Diploma.
In other words, more mathematics can also be referred to as part of advanced mathematics, or advanced level math.
United Kingdom
Background
A qualification in Further Mathematics involves studying both pure and applied modules. Whilst the pure modules (formerly known as Pure 4–6 or Core 4–6, now known as Further Pure 1–3, where 4 exists for the AQA board) build on knowledge from the core mathematics modules, the applied modules may start from first principles.
The structure of the qualification varies between exam boards.
With regard to Mathematics degrees, most universities do not require Further Mathematics, and may incorporate foundation math modules or offer "catch-up" classes covering any additional content. Exceptions are the University of Warwick, the University of Cambridge which requires Further Mathematics to at least AS level; University College London requires or recommends an A2 in Further Maths for its maths courses; Imperial College requires an A in A level Further Maths, while other universities may recommend it or may promise lower offers in return. Some schools and colleges may not offer Further mathematics, but online resources are available
Although the subject has about 60% of its cohort obtainin
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The name of a monatomic cation is simply the name of the element followed by this word?
A. ion
B. laser
C. amine
D. bond
Answer:
|
|
sciq-9221
|
multiple_choice
|
Human actions such as plowing, logging, construction and other actions contribute to what kind of erosion?
|
[
"weathering",
"wind erosion",
"soil erosion",
"flooding"
] |
C
|
Relavent Documents:
Document 0:::
Mass wasting, also known as mass movement, is a general term for the movement of rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is not entrained in a moving medium, such as water, wind, or ice. Types of mass wasting include creep, solifluction, rockfalls, debris flows, and landslides, each with its own characteristic features, and taking place over timescales from seconds to hundreds of years. Mass wasting occurs on both terrestrial and submarine slopes, and has been observed on Earth, Mars, Venus, Jupiter's moon Io, and on many other bodies in the Solar System.
Subsidence is sometimes regarded as a form of mass wasting. A distinction is then made between mass wasting by subsidence, which involves little horizontal movement, and mass wasting by slope movement.
Rapid mass wasting events, such as landslides, can be deadly and destructive. More gradual mass wasting, such as soil creep, poses challenges to civil engineering, as creep can deform roadways and structures and break pipelines. Mitigation methods include slope stabilization, construction of walls, catchment dams, or other structures to contain rockfall or debris flows, afforestation, or improved drainage of source areas.
Types
Mass wasting is a general term for any process of erosion that is driven by gravity and in which the transported soil and rock is not entrained in a moving medium, such as water, wind, or ice. The presence of water usually aids mass wasting, but the water is not abundant enough to be regarded as a transporting medium. Thus, the distinction between mass wasting and stream erosion lies between a mudflow (mass wasting) and a very muddy stream (stream erosion), without a sharp dividing line. Many forms of mass wasting are recognized, each with its own characteristic features, and taking place over timescales from seconds to hundreds of years.
Based on how the soil, regolith or rock moves dow
Document 1:::
Sediment transport is the movement of solid particles (sediment), typically due to a combination of gravity acting on the sediment, and the movement of the fluid in which the sediment is entrained. Sediment transport occurs in natural systems where the particles are clastic rocks (sand, gravel, boulders, etc.), mud, or clay; the fluid is air, water, or ice; and the force of gravity acts to move the particles along the sloping surface on which they are resting. Sediment transport due to fluid motion occurs in rivers, oceans, lakes, seas, and other bodies of water due to currents and tides. Transport is also caused by glaciers as they flow, and on terrestrial surfaces under the influence of wind. Sediment transport due only to gravity can occur on sloping surfaces in general, including hillslopes, scarps, cliffs, and the continental shelf—continental slope boundary.
Sediment transport is important in the fields of sedimentary geology, geomorphology, civil engineering, hydraulic engineering and environmental engineering (see applications, below). Knowledge of sediment transport is most often used to determine whether erosion or deposition will occur, the magnitude of this erosion or deposition, and the time and distance over which it will occur.
Mechanisms
Aeolian
Aeolian or eolian (depending on the parsing of æ) is the term for sediment transport by wind. This process results in the formation of ripples and sand dunes. Typically, the size of the transported sediment is fine sand (<1 mm) and smaller, because air is a fluid with low density and viscosity, and can therefore not exert very much shear on its bed.
Bedforms are generated by aeolian sediment transport in the terrestrial near-surface environment. Ripples and dunes form as a natural self-organizing response to sediment transport.
Aeolian sediment transport is common on beaches and in the arid regions of the world, because it is in these environments that vegetation does not prevent the presence and motion
Document 2:::
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 3:::
The Physics of Blown Sand and Desert Dunes is a scientific book written by Ralph A. Bagnold. The book laid the foundations of the scientific investigation of the transport of sand by wind. It also discusses the formation and movement of sand dunes in the Libyan Desert. During his expeditions into the Libyan Desert, Bagnold had been fascinated by the shapes of the sand dunes, and after returning to England he built a wind tunnel and conducted the experiments which are the basis of the book.
Bagnold finished writing the book in 1939, and it was first published on 26 June 1941. A reprinted version, with minor revisions by Bagnold, was published by Chapman and Hall in 1953, and reprinted again in 1971. The book was reissued by Dover Publications in 2005.
The book explores the movement of sand in desert environments, with a particular emphasis on how wind affects the formation and movement of dunes and ripples. Bagnold's interest in this subject was spurred by his extensive desert expeditions, during which he observed various sand storms. One pivotal observation was that the movement of sand, unlike that of dust, predominantly occurs near the ground, within a height of one metre, and was less influenced by large-scale eddy currents in the air.
The book emphasises the feasibility of replicating these natural phenomena under controlled conditions in a laboratory. By using a wind tunnel, Bagnold sought to gain a deeper understanding of the physics governing the interaction between airstreams and sand grains, and vice versa. His aim was to ensure that findings from controlled experiments mirrored real-world conditions, with verifications of these laboratory results conducted through field observations in the Libyan Desert in the late 1930s.
Bagnold delineates his research into two distinct stages. The first, which constitutes the primary focus of the book, investigates the dynamics of sand movement across mostly flat terrains. This includes understanding how sand is l
Document 4:::
Lisa Schulte Moore is an American landscape ecologist. Schulte Moore is a professor of natural resource ecology and management at Iowa State University. In 2020 she received a $10 million USD grant to study anerobic digestion and its application to turning manure into usable energy. In 2021 she was named a MacArthur fellow.
Work
Moore has worked with farmers to develop resilient and sustainable agricultural practices and systems that take into consideration climate change, water quality and loss of biodiversity.
Moore has written on various ecological topics, including the ecological effects of fire on landscapes; soil carbon storage, biodiversity improvement, the effects of wind and fire on forests, among others.
Awards and honors
John D. and Katherine T. MacArthur Foundation Fellowship
Citation for Leadership and Achievement, Council for Scientific Society Presidents (2022)
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Human actions such as plowing, logging, construction and other actions contribute to what kind of erosion?
A. weathering
B. wind erosion
C. soil erosion
D. flooding
Answer:
|
|
sciq-4233
|
multiple_choice
|
Hair color and skin color are known as what?
|
[
"abominations",
"traits",
"mutations",
"habits"
] |
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:::
The Bateson Lecture is an annual genetics lecture held as a part of the John Innes Symposium since 1972, in honour of the first Director of the John Innes Centre, William Bateson.
Past Lecturers
Source: John Innes Centre
1951 Sir Ronald Fisher - "Statistical methods in Genetics"
1953 Julian Huxley - "Polymorphic variation: a problem in genetical natural history"
1955 Sidney C. Harland - "Plant breeding: present position and future perspective"
1957 J.B.S. Haldane - "The theory of evolution before and after Bateson"
1959 Kenneth Mather - "Genetics Pure and Applied"
1972 William Hayes - "Molecular genetics in retrospect"
1974 Guido Pontecorvo - "Alternatives to sex: genetics by means of somatic cells"
1976 Max F. Perutz - "Mechanism of respiratory haemoglobin"
1979 J. Heslop-Harrison - "The forgotten generation: some thoughts on the genetics and physiology of Angiosperm Gametophytes "
1982 Sydney Brenner - "Molecular genetics in prospect"
1984 W.W. Franke - "The cytoskeleton - the insoluble architectural framework of the cell"
1986 Arthur Kornberg - "Enzyme systems initiating replication at the origin of the E. coli chromosome"
1988 Gottfried Schatz - "Interaction between mitochondria and the nucleus"
1990 Christiane Nusslein-Volhard - "Axis determination in the Drosophila embryo"
1992 Frank Stahl - "Genetic recombination: thinking about it in phage and fungi"
1994 Ira Herskowitz - "Violins and orchestras: what a unicellular organism can do"
1996 R.J.P. Williams - "An Introduction to Protein Machines"
1999 Eugene Nester - "DNA and Protein Transfer from Bacteria to Eukaryotes - the Agrobacterium story"
2001 David Botstein - "Extracting biological information from DNA Microarray Data"
2002 Elliot Meyerowitz
2003 Thomas Steitz - "The Macromolecular machines of gene expression"
2008 Sean Carroll - "Endless flies most beautiful: the role of cis-regulatory sequences in the evolution of animal form"
2009 Sir Paul Nurse - "Genetic transmission through
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:::
Tinbergen's four questions, named after 20th century biologist Nikolaas Tinbergen, are complementary categories of explanations for animal behaviour. These are also commonly referred to as levels of analysis. It suggests that an integrative understanding of behaviour must include ultimate (evolutionary) explanations, in particular:
behavioural adaptive functions
phylogenetic history; and the proximate explanations
underlying physiological mechanisms
ontogenetic/developmental history.
Four categories of questions and explanations
When asked about the purpose of sight in humans and animals, even elementary-school children can answer that animals have vision to help them find food and avoid danger (function/adaptation). Biologists have three additional explanations: sight is caused by a particular series of evolutionary steps (phylogeny), the mechanics of the eye (mechanism/causation), and even the process of an individual's development (ontogeny).
This schema constitutes a basic framework of the overlapping behavioural fields of ethology, behavioural ecology, comparative psychology, sociobiology, evolutionary psychology, and anthropology. Julian Huxley identified the first three questions. Niko Tinbergen gave only the fourth question, as Huxley's questions failed to distinguish between survival value and evolutionary history; Tinbergen's fourth question helped resolve this problem.
Evolutionary (ultimate) explanations
First question: Function (adaptation)
Darwin's theory of evolution by natural selection is the only scientific explanation for why an animal's behaviour is usually well adapted for survival and reproduction in its environment. However, claiming that a particular mechanism is well suited to the present environment is different from claiming that this mechanism was selected for in the past due to its history of being adaptive.
The literature conceptualizes the relationship between function and evolution in two ways. On the one hand, function
Document 4:::
An acquired characteristic is a non-heritable change in a function or structure of a living organism caused after birth by disease, injury, accident, deliberate modification, variation, repeated use, disuse, misuse, or other environmental influence. Acquired traits are synonymous with acquired characteristics. They are not passed on to offspring through reproduction.
The changes that constitute acquired characteristics can have many manifestations and degrees of visibility, but they all have one thing in common. They change a facet of a living organism's function or structure after birth.
For example:
The muscles acquired by a bodybuilder through physical training and diet.
The loss of a limb due to an injury.
The miniaturization of bonsai plants through careful cultivation techniques.
Acquired characteristics can be minor and temporary like bruises, blisters, or shaving body hair. Permanent but inconspicuous or invisible ones are corrective eye surgery and organ transplant or removal.
Semi-permanent but inconspicuous or invisible traits are vaccination and laser hair removal. Perms, tattoos, scars, and amputations are semi-permanent and highly visible.
Applying makeup, nail polish, dying one's hair, applying henna to the skin, and tooth whitening are not examples of acquired traits. They change the appearance of a facet of an organism, but do not change the structure or functionality.
Inheritance of acquired characteristics was historically proposed by renowned theorists such as Hippocrates, Aristotle, and French naturalist Jean-Baptiste Lamarck. Conversely, this hypothesis was denounced by other renowned theorists such as Charles Darwin.
Today, although Lamarckism is generally discredited, there is still debate on whether some acquired characteristics in organisms are actually inheritable.
Disputes
Acquired characteristics, by definition, are characteristics that are gained by an organism after birth as a result of external influences or the organism's ow
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Hair color and skin color are known as what?
A. abominations
B. traits
C. mutations
D. habits
Answer:
|
|
ai2_arc-800
|
multiple_choice
|
Most of the volume of the universe is found in the space between galaxies. Objects found in the regions between galaxies are most likely to be closest in size to which of these?
|
[
"a dust particle",
"an asteroid",
"a planet",
"a star"
] |
A
|
Relavent Documents:
Document 0:::
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 1:::
Types
Quasar
Supermassive black hole
Hypercompact stellar system (hypothetical object organized around a supermassive black hole)
Intermediate-mass black holes and candidates
Cigar Galaxy (Messier 82, NGC 3034)
GCIRS 13E
HLX-1
M82 X-1
Messier 15 (NGC 7078)
Messier 110 (NGC 205)
Sculptor Galaxy (NGC 253)
Triangulum Galaxy (Messier 33, NGC 598
Document 2:::
Eris is a computer simulation of the Milky Way galaxy's physics. It was done by astrophysicists from the Institute for Theoretical Physics at the University of Zurich, Switzerland and University of California, Santa Cruz. The simulation project was undertaken at the NASA Advanced Supercomputer Division's Pleiades and the Swiss National Supercomputing Centre for nearly eight months, which would have otherwise taken 570 years in a personal computer. The Eris simulation is the first successful detailed simulation of a Milky Way like galaxy. The results of the simulation were announced in August 2011.
Background
Simulation projects intending to simulate spiral galaxies have been undertaken for the past 20 years. All of these projects had failed as the simulation results showed central bulges which are huge compared to the disk size.
Simulation
The simulation was undertaken using supercomputers which include the Pleiades supercomputer, the Swiss National Supercomputing Centre and the supercomputers at the University of California, Santa Cruz. The simulation used 1.4 million processor-hours of the Pleiades supercomputer.
It is based on the theory that in the early universe, cold and slow moving dark matter particles clumped together. These dark matter clumps then formed the "scaffolding" around galaxies and galactic clusters. The motions of more than 60 million particles which represented dark matter and galactic gas were simulated for a period of 13 billion years. The software platform Gasoline was used for the simulation.
Simulation results
The Eris simulation is the first successful simulation to have resolved the high-density gas clouds where stars formed. The simulation result consisted of a galaxy which is very similar to the Milky Way galaxy. Some of the parameters which were similar to Milky Way are stellar content, gas content, kinematic decomposition, brightness profile and the bulge-to-disk ratio.
Document 3:::
The Delaunay tessellation field estimator (DTFE), (or Delone tessellation field estimator (DTFE)) is a mathematical tool for reconstructing a volume-covering and continuous density or intensity field from a discrete point set. The DTFE has various astrophysical applications, such as the analysis of numerical simulations of cosmic structure formation, the mapping of the large-scale structure of the universe and improving computer simulation programs of cosmic structure formation. It has been developed by Willem Schaap and Rien van de Weijgaert. The main advantage of the DTFE is that it automatically adapts to (strong) variations in density and geometry. It is therefore very well suited for studies of the large scale galaxy distribution.
Method
The DTFE consists of three main steps:
Step 1
The starting point is a given discrete point
distribution. In the upper left-hand frame of the figure, a point distribution is plotted in which at the center of the frame an object is located whose density diminishes radially outwards. In the
first step of the DTFE, the Delaunay tessellation of the point
distribution is constructed. This is a volume-covering division
of space into triangles (tetrahedra in three dimensions), whose
vertices are formed by the point distribution (see figure, upper right-hand frame). The Delaunay tessellation is defined such
that inside the interior of the circumcircle of each Delaunay triangle
no other points from the defining point distribution are present.
Step 2
The Delaunay tessellation forms the heart of
the DTFE. In the figure it is clearly visible that the tessellation
automatically adapts to both the local density and geometry of the
point distribution: where the density is high, the triangles are small
and vice versa. The size of the triangles is therefore a measure of
the local density of the point distribution.
This property of the Delaunay tessellation is exploited in step 2 of
the DTFE, in which the local density is estimated at
Document 4:::
Galactic clusters are gravitationally bound large-scale structures of multiple galaxies. The evolution of these aggregates is determined by time and manner of formation and the process of how their structures and constituents have been changing with time. Gamow (1952) and Weizscker (1951) showed that the observed rotations of galaxies are important for cosmology. They postulated that the rotation of galaxies might be a clue of physical conditions under which these systems formed. Thus, understanding the distribution of spatial orientations of the spin vectors of galaxies is critical to understanding the origin of the angular momenta of galaxies.
There are mainly three scenarios for the origin of galaxy clusters and superclusters. These models are based on different assumptions of the primordial conditions, so they predict different spin vector alignments of the galaxies. The three hypotheses are the pancake model, the hierarchy model, and the primordial vorticity theory. The three are mutually exclusive as they produce contradictory predictions. However, the predictions made by all three theories are based on the precepts of cosmology. Thus, these models can be tested using a database with appropriate methods of analysis.
Galaxies
A galaxy is a large gravitational aggregation of stars, dust, gas, and an unknown component termed dark matter. The Milky Way Galaxy is only one of the billions of galaxies in the known universe. Galaxies are classified into spirals, ellipticals, irregular, and peculiar. Sizes can range from only a few thousand stars (dwarf irregulars) to 1013 stars in giant ellipticals. Elliptical galaxies are spherical or elliptical in appearance. Spiral galaxies range from S0, the lenticular galaxies, to Sb, which have a bar across the nucleus, to Sc galaxies which have strong spiral arms. In total count, ellipticals amount to 13%, S0 to 22%, Sa, b, c galaxies to 61%, irregulars to 3.5%, and peculiars to 0.9%.
At the center of most galaxies is a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Most of the volume of the universe is found in the space between galaxies. Objects found in the regions between galaxies are most likely to be closest in size to which of these?
A. a dust particle
B. an asteroid
C. a planet
D. a star
Answer:
|
|
sciq-9136
|
multiple_choice
|
Where does carbohydrate digestion begin in the body?
|
[
"stomach",
"intestines",
"mouth",
"throat"
] |
C
|
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:::
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 3:::
The mouth is the body orifice through which many animals ingest food and vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alimentary canal which leads to the pharynx and the gullet. In tetrapod vertebrates, the mouth is bounded on the outside by the lips and cheeks — thus the oral cavity is also known as the buccal cavity (from Latin , meaning "cheek") — and contains the tongue on the inside. Except for some groups like birds and lissamphibians, vertebrates usually have teeth in their mouths, although some fish species have pharyngeal teeth instead of oral teeth.
Most bilaterian phyla, including arthropods, molluscs and chordates, have a two-opening gut tube with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes.
Development
In the first multicellular animals, there was probably no mouth or gut and food particles were engulfed by the cells on the exterior surface by a process known as endocytosis. The particles became enclosed in vacuoles into which enzymes were secreted and digestion took place intracellularly. The digestive products were absorbed into the cytoplasm and diffused into other cells. This form of digestion is used nowadays by simple organisms such as Amoeba and Paramecium and also by sponges which, despite their large size, have no mouth or gut and capture their food by endocytosis.
However, most animals have a mouth and a gut, the lining of which is continuous with the epithelial cells on the surface of the body. A few animals which live parasitically originally had guts but have secondarily lost these structures. The original gut of diploblastic animals probably consisted of a mouth and a one-way gut. Some modern invertebrates still have such a system: food being ingested through the mouth, partially broken down by enzymes secreted in the gut, and t
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where does carbohydrate digestion begin in the body?
A. stomach
B. intestines
C. mouth
D. throat
Answer:
|
|
scienceQA-10948
|
multiple_choice
|
What do these two changes have in common?
an iceberg melting slowly
breaking a plate
|
[
"Both are chemical changes.",
"Both are only physical changes.",
"Both are caused by heating.",
"Both are caused by cooling."
] |
B
|
Step 1: Think about each change.
An iceberg melting is a change of state. So, it is a physical change. An iceberg is made of frozen water. As it melts, the water changes from a solid to a liquid. But a different type of matter is not formed.
Breaking a plate is a physical change. The plate gets broken into pieces. But each piece is still made of the same type of matter.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
An iceberg melting is caused by heating. But breaking a plate 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:::
In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure. This can be a discontinuous change; for example, a liquid may become gas upon heating to its boiling point, resulting in an abrupt change in volume. The identification of the external conditions at which a transformation occurs defines the phase transition point.
Types of phase transition
States of matter
Phase transitions commonly refer to when a substance transforms between one of the four states of matter to another. At the phase transition point for a substance, for instance the boiling point, the two phases involved - liquid and vapor, have identical free energies and therefore are equally likely to exist. Below the boiling point, the liquid is the more stable state of the two, whereas above the boiling point the gaseous form is the more stable.
Common transitions between the solid, liquid, and gaseous phases of a single component, due to the effects of temperature and/or pressure are identified in the following table:
For a single component, the most stable phase at different temperatures and pressures can be shown on a phase diagram. Such a diagram usually depicts states in equilibrium. A phase transition usually occurs when the pressure or temperature changes and the system crosses from one region to another, like water turning from liquid to solid as soon as the temperature drops below the freezing point. In exception to the usual case, it is sometimes possible to change the state of a system dia
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 characteristic property is a chemical or physical property that helps identify and classify substances. The characteristic properties of a substance are always the same whether the sample being observed is large or small. Thus, conversely, if the property of a substance changes as the sample size changes, that property is not a characteristic property. Examples of physical properties that are not characteristic properties are mass and volume. Examples of characteristic properties include melting points, boiling points, density, viscosity, solubility, crystal shape, and color. Substances with characteristic properties can be separated. For example, in fractional distillation, liquids are separated using the boiling point. The water Boiling point is 212 degrees Fahrenheit.
Identifying a substance
Every characteristic property is unique to one given substance. Scientists use characteristic properties to identify unknown substances. However, characteristic properties are most useful for distinguishing between two or more substances, not identifying a single substance. For example, isopropanol and water can be distinguished by the characteristic property of odor. Characteristic properties are used because the sample size and the shape of the substance does not matter. For example, 1 gram of lead is the same color as 100 tons of lead.
See also
Intensive and extensive properties
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?
an iceberg melting slowly
breaking a plate
A. Both are chemical changes.
B. Both are only physical changes.
C. Both are caused by heating.
D. Both are caused by cooling.
Answer:
|
sciq-9732
|
multiple_choice
|
Telescopes use which kind of lenses to enlarge images?
|
[
"convex",
"concave",
"crystalline",
"spherical"
] |
A
|
Relavent Documents:
Document 0:::
In 2-dimensional geometry, a lens is a convex region bounded by two circular arcs joined to each other at their endpoints. In order for this shape to be convex, both arcs must bow outwards (convex-convex). This shape can be formed as the intersection of two circular disks. It can also be formed as the union of two circular segments (regions between the chord of a circle and the circle itself), joined along a common chord.
Types
If the two arcs of a lens have equal radius, it is called a symmetric lens, otherwise is an asymmetric lens.
The vesica piscis is one form of a symmetric lens, formed by arcs of two circles whose centers each lie on the opposite arc. The arcs meet at angles of 120° at their endpoints.
Area
Symmetric
The area of a symmetric lens can be expressed in terms of the radius R and arc lengths θ in radians:
Asymmetric
The area of an asymmetric lens formed from circles of radii R and r with distance d between their centers is
where
is the area of a triangle with sides d, r, and R.
The two circles overlap if . For sufficiently large , the coordinate of the lens centre lies between the coordinates of the two circle centers:
For small the coordinate of the lens centre lies outside the line that connects the circle centres:
By eliminating y from the circle equations and the abscissa of the intersecting rims is
.
The sign of x, i.e., being larger or smaller than , distinguishes the two cases shown in the images.
The ordinate of the intersection is
.
Negative values under the square root indicate that the rims of the two circles do not touch
because the circles are too far apart or one circle lies entirely within the other.
The value under the square root is a biquadratic polynomial of d. The four roots of this polynomial are associated with y=0 and with the four values of d where the two circles have only one point in common.
The angles in the blue triangle of sides d, r and R are
where y is the ordinate of the intersection. Th
Document 1:::
The plate scale of a telescope connects the angular separation of an object with the linear separation of its image at the focal plane.
If focal length is measured in mm, the plate scale in radians per mm is given by angular separation θ and the linear separation of the image at the focal plane s, or by simply the focal length f:
since
Plate scale is usually expressed in arcseconds per mm:
where f is in mm,
or expressed in arcseconds per pixel after further division through the pixel scale.
Plate scale on JWST FGS/NIRISS
The plate scale of the James Webb Space Telescope component Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph is about 0.065 arcsec/pixel. It uses a 2048 x 2048 pixel array with a pixel size of 18 microns a side with a field of view of 2.2' x 2.2'
See also
Photographic plate
Notes
Astrophotography
Document 2:::
The extended hemispherical lens is a commonly used lens for millimeter-wave electromagnetic radiation. Such lenses are typically fabricated from dielectric materials such as Teflon or silicon. The geometry consists of a hemisphere of radius on a cylinder of length , with the same radius.
Scanning performance
When a feed element is placed a distance off the central axis, then the main beam will be steered an angle off-axis. The relation between and can be determined from geometrical optics:
This relation is used when designing focal plane arrays to be used with the extended hemispherical lens.
See also
Luneburg lens
Fresnel lens
Lens antenna
Document 3:::
The study of image formation encompasses the radiometric and geometric processes by which 2D images of 3D objects are formed. In the case of digital images, the image formation process also includes analog to digital conversion and sampling.
Imaging
The imaging process is a mapping of an object to an image plane. Each point on the image corresponds to a point on the object. An illuminated object will scatter light toward a lens and the lens will collect and focus the light to create the image. The ratio of the height of the image to the height of the object is the magnification. The spatial extent of the image surface and the focal length of the lens determines the field of view of the lens. Image formation of mirror these have a center of curvature and its focal length of the mirror is half of the center of curvature.
Illumination
An object may be illuminated by the light from an emitting source such as the sun, a light bulb or a Light Emitting Diode. The light incident on the object is reflected in a manner dependent on the surface properties of the object. For rough surfaces, the reflected light is scattered in a manner described by the Bi-directional Reflectance Distribution Function (BRDF) of the surface. The BRDF of a surface is the ratio of the exiting power per square meter per steradian (radiance) to the incident power per square meter (irradiance). The BRDF typically varies with angle and may vary with wavelength, but a specific important case is a surface that has constant BRDF. This surface type is referred to as Lambertian and the magnitude of the BRDF is R/π, where R is the reflectivity of the surface. The portion of scattered light that propagates toward the lens is collected by the entrance pupil of the imaging lens over the field of view.
Field of view and imagery
The Field of view of a lens is limited by the size of the image plane and the focal length of the lens. The relationship between a location on the image and a location on t
Document 4:::
Dioptrics is the branch of optics dealing with refraction, especially by lenses. In contrast, the branch dealing with mirrors is known as catoptrics. Telescopes that create their image with an objective that is a convex lens (refractors) are said to be "dioptric" telescopes.
An early study of dioptrics was conducted by Ptolemy in relationship to the human eye as well as refraction in media such as water. The understanding of the principles of dioptrics was further expanded by Alhazen, considered the father of modern optics.
See also
Diopter/Dioptre (unit of measurement)
Dioptrice (work by Johannes Kepler)
Catoptrics (study of and optical systems utilizing reflection)
Catadioptrics (study of and optical systems utilizing reflection and refraction)
Optical telescope
List of telescope types
Image-forming optical system
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Telescopes use which kind of lenses to enlarge images?
A. convex
B. concave
C. crystalline
D. spherical
Answer:
|
|
scienceQA-12474
|
multiple_choice
|
Select the living thing.
|
[
"clay",
"mangrove tree",
"crayon",
"mug"
] |
B
|
A mug is not a living thing.
Mugs do not have all of the traits of living things. They do not grow or respond to their environment. They do not need food or water.
Clay is not a living thing.
Clay does not have all of the traits of a living thing. It can be formed into different shapes, but it does not grow or respond to the world around it. It does not need food or water.
A crayon is not a living thing.
Crayons do not have all of the traits of living things. They do not grow or respond to their environment. They do not need food or water.
A mangrove tree is a living thing.
Mangrove trees grow and respond to their environment. They need food and water. Mangrove trees are made up of many cells.
Mangrove trees are plants. They make their own food using water, carbon dioxide, and energy from sunlight.
|
Relavent Documents:
Document 0:::
Plant life-form schemes constitute a way of classifying plants alternatively to the ordinary species-genus-family scientific classification. In colloquial speech, plants may be classified as trees, shrubs, herbs (forbs and graminoids), etc. The scientific use of life-form schemes emphasizes plant function in the ecosystem and that the same function or "adaptedness" to the environment may be achieved in a number of ways, i.e. plant species that are closely related phylogenetically may have widely different life-form, for example Adoxa moschatellina and Sambucus nigra are from the same family, but the former is a small herbaceous plant and the latter is a shrub or tree. Conversely, unrelated species may share a life-form through convergent evolution.
While taxonomic classification is concerned with the production of natural classifications (being natural understood either in philosophical basis for pre-evolutionary thinking, or phylogenetically as non-polyphyletic), plant life form classifications uses other criteria than naturalness, like morphology, physiology and ecology.
Life-form and growth-form are essentially synonymous concepts, despite attempts to restrict the meaning of growth-form to types differing in shoot architecture. Most life form schemes are concerned with vascular plants only. Plant construction types may be used in a broader sense to encompass planktophytes, benthophytes (mainly algae) and terrestrial plants.
A popular life-form scheme is the Raunkiær system.
History
One of the earliest attempts to classify the life-forms of plants and animals was made by Aristotle, whose writings are lost. His pupil, Theophrastus, in Historia Plantarum (c. 350 BC), was the first who formally recognized plant habits: trees, shrubs and herbs.
Some earlier authors (e.g., Humboldt, 1806) did classify species according to physiognomy, but were explicit about the entities being merely practical classes without any relation to plant function. A marked exception was
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:::
Macroflora is a term used for all the plants occurring in a particular area that are large enough to be seen with the naked eye. It is usually synonymous with the Flora and can be contrasted with the microflora, a term used for all the bacteria and other microorganisms in an ecosystem.
Macroflora is also an informal term used by many palaeobotanists to refer to an assemblage of plant fossils as preserved in the rock. This is in contrast to the flora, which in this context refers to the assemblage of living plants that were growing in a particular area, whose fragmentary remains became entrapped within the sediment from which the rock was formed and thus became the macroflora.
Document 3:::
This article lists the largest organisms for various types of life and mostly considers extant species, which found on Earth can be determined according to various aspects of an organism's size, such as: mass, volume, area, length, height, or even genome size. Some organisms group together to form a superorganism (such as ants or bees), but such are not classed as single large organisms. The Great Barrier Reef is the world's largest structure composed of living entities, stretching , but contains many organisms of many types of species.
If considered individual entities, the largest organisms are clonal colonies which can spread over large areas. Pando, a clonal colony of the quaking aspen tree, is widely considered to be the largest such organism by mass. Even if such colonies are excluded, trees retain their dominance of this listing, with the giant sequoia being the most massive tree. In 2006 a huge clonal colony of the seagrass Posidonia oceanica was discovered south of the island of Ibiza. At across, and estimated at 100,000 years old, it may be one of the largest and oldest clonal colonies on Earth.
Among animals, the largest species are all marine mammals, specifically whales. The blue whale is believed to be the largest animal to have ever lived. The living land animal classification is also dominated by mammals, with the African bush elephant being the largest of these.
Plants
The largest single-stem tree by wood volume and mass is the giant sequoia (Sequoiadendron giganteum), native to Sierra Nevada and California; it typically grows to a height of and in diameter.
The largest organism in the world, according to mass, is the aspen tree whose colonies of clones can grow up to long. The largest such colony is Pando, in the Fishlake National Forest in Utah.
A form of flowering plant that far exceeds Pando as the largest organism on Earth in area and probably also mass, is the giant marine plant, Posidonia australis, living in Shark Bay, Australia. I
Document 4:::
Phytotechnology (; ) implements solutions to scientific and engineering problems in the form of plants. It is distinct from ecotechnology and biotechnology as these fields encompass the use and study of ecosystems and living beings, respectively. Current study of this field has mostly been directed into contaminate removal (phytoremediation), storage (phytosequestration) and accumulation (see hyperaccumulators). Plant-based technologies have become alternatives to traditional cleanup procedures because of their low capital costs, high success rates, low maintenance requirements, end-use value, and aesthetic nature.
Overview
Phytotechnology is the application of plants to engineering and science problems. Phytotechnology uses ecosystem services to provide for a specifically engineered solution to a problem. Ecosystem services, broadly defined fall into four broad categories: provisioning (i.e. production of food and water), regulating (i.e. the control of climate and disease) supporting (i.e. nutrient cycles and crop pollination), and cultural (i.e. spiritual and recreational benefits). Many times only one of these ecosystem services is maximized in the design of the space. For instance a constructed wetland may attempt to maximize the cooling properties of the system to treat water from a wastewater treatment facility before introduction to a river. The designed benefit is a reduction of water temperature for the river system while the constructed wetland itself provides habitat and food for wildlife as well as walking trails for recreation. Most phytotechnology has been focused on the abilities of plants to remove pollutants from the environment. Other technologies such as green roofs, green walls and bioswales are generally considered phytotechnology. Taking a broad view: even parks and landscaping could be viewed as phytotechnology.
However, there is very little consensus over a definition of phytotechnology even within the field. The Phytotechnology Technical
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the living thing.
A. clay
B. mangrove tree
C. crayon
D. mug
Answer:
|
sciq-10596
|
multiple_choice
|
What type of fish are the majority of living species?
|
[
"freshwater fish",
"cartilaginous fish",
"lungfish",
"ray-finned fish"
] |
D
|
Relavent Documents:
Document 0:::
A fish (: fish or fishes) is an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. Fish can acoustically communicate with each other, most often in the context of feeding, aggression or courtship.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., cusk-eels and snailfish), although no species has yet been documented in the deepest 25% of the ocean. With 34,300 described species, fish exhibit greater species diversity than any other group of vertebrates.
Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean (in aquaculture). They are also caught by recreational
Document 1:::
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
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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
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Fish are very diverse animals and can be categorised in many ways. Although most fish species have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase about 34,800 species of fish had been described as of February 2022, which is more than the combined total of all other vertebrate species: mammals, amphibians, reptiles and birds.
Fish species diversity is roughly divided equally between marine (oceanic) and freshwater ecosystems. Coral reefs in the Indo-Pacific constitute the centre of diversity for marine fishes, whereas continental freshwater fishes are most diverse in large river basins of tropical rainforests, especially the Amazon, Congo, and Mekong basins. More than 5,600 fish species inhabit Neotropical freshwaters alone, such that Neotropical fishes represent about 10% of all vertebrate species on the Earth. Exceptionally rich sites in the Amazon basin, such as Cantão State Park, can contain more freshwater fish species than occur in all of Europe.
By taxonomy
Fish systematics is the formal description and organisation of fish taxa into systems. It is complex and still evolving. Controversies over "arcane, but important, details of classification are still quietly raging".
The term "fish" describes any non-tetrapod chordate, (i.e., an animal with a backbone), that has gills throughout life and has limbs, if any, in the shape of fins. Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including jawless, cartilaginous and skeletal types.
Jawless fish
Jawless fish were the earliest fish to evolve. There is current debate over whether these are really fish at all. They have no jaw, no scales, no paired fins, and no bony skeleton. Their skin is smooth and soft to the touch, and they are very flexible. Instead of a jaw, they possess an oral sucker. They use this to fasten onto other fish, and then use their rasp-like teeth to grind through
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of fish are the majority of living species?
A. freshwater fish
B. cartilaginous fish
C. lungfish
D. ray-finned fish
Answer:
|
|
sciq-3360
|
multiple_choice
|
When gas particles heat up and gain energy, what do they do?
|
[
"move slower",
"stop",
"move faster",
"go up"
] |
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:::
Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work or moving (e.g. lifting an object) or provides heat. In addition to being converted, according to the law of conservation of energy, energy is transferable to a different location or object, but it cannot be created or destroyed.
The energy in many of its forms may be used in natural processes, or to provide some service to society such as heating, refrigeration, lighting or performing mechanical work to operate machines. For example, to heat a home, the furnace burns fuel, whose chemical potential energy is converted into thermal energy, which is then transferred to the home's air to raise its temperature.
Limitations in the conversion of thermal energy
Conversions to thermal energy from other forms of energy may occur with 100% efficiency. Conversion among non-thermal forms of energy may occur with fairly high efficiency, though there is always some energy dissipated thermally due to friction and similar processes. Sometimes the efficiency is close to 100%, such as when potential energy is converted to kinetic energy as an object falls in a vacuum. This also applies to the opposite case; for example, an object in an elliptical orbit around another body converts its kinetic energy (speed) into gravitational potential energy (distance from the other object) as it moves away from its parent body. When it reaches the furthest point, it will reverse the process, accelerating and converting potential energy into kinetic. Since space is a near-vacuum, this process has close to 100% efficiency.
Thermal energy is unique because it in most cases (willow) cannot be converted to other forms of energy. Only a difference in the density of thermal/heat energy (temperature) can be used to perform work, and the efficiency of this conversion will be (much) less than 100%. This is because t
Document 2:::
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer. While these mechanisms have distinct characteristics, they often occur simultaneously in the same system.
Heat conduction, also called diffusion, is the direct microscopic exchanges of kinetic energy of particles (such as molecules) or quasiparticles (such as lattice waves) through the boundary between two systems. When an object is at a different temperature from another body or its surroundings, heat flows so that the body and the surroundings reach the same temperature, at which point they are in thermal equilibrium. Such spontaneous heat transfer always occurs from a region of high temperature to another region of lower temperature, as described in the second law of thermodynamics.
Heat convection occurs when the bulk flow of a fluid (gas or liquid) carries its heat through the fluid. All convective processes also move heat partly by diffusion, as well. The flow of fluid may be forced by external processes, or sometimes (in gravitational fields) by buoyancy forces caused when thermal energy expands the fluid (for example in a fire plume), thus influencing its own transfer. The latter process is often called "natural convection". The former process is often called "forced convection." In this case, the fluid is forced to flow by use of a pump, fan, or other mechanical means.
Thermal radiation occurs through a vacuum or any transparent medium (solid or fluid or gas). It is the transfer of energy by means of photons or electromagnetic waves governed by the same laws.
Overview
Heat
Document 3:::
Physics First is an educational program in the United States, that teaches a basic physics course in the ninth grade (usually 14-year-olds), rather than the biology course which is more standard in public schools. This course relies on the limited math skills that the students have from pre-algebra and algebra I. With these skills students study a broad subset of the introductory physics canon with an emphasis on topics which can be experienced kinesthetically or without deep mathematical reasoning. Furthermore, teaching physics first is better suited for English Language Learners, who would be overwhelmed by the substantial vocabulary requirements of Biology.
Physics First began as an organized movement among educators around 1990, and has been slowly catching on throughout the United States. The most prominent movement championing Physics First is Leon Lederman's ARISE (American Renaissance in Science Education).
Many proponents of Physics First argue that turning this order around lays the foundations for better understanding of chemistry, which in turn will lead to more comprehension of biology. Due to the tangible nature of most introductory physics experiments, Physics First also lends itself well to an introduction to inquiry-based science education, where students are encouraged to probe the workings of the world in which they live.
The majority of high schools which have implemented "physics first" do so by way of offering two separate classes, at two separate levels: simple physics concepts in 9th grade, followed by more advanced physics courses in 11th or 12th grade. In schools with this curriculum, nearly all 9th grade students take a "Physical Science", or "Introduction to Physics Concepts" course. These courses focus on concepts that can be studied with skills from pre-algebra and algebra I. With these ideas in place, students then can be exposed to ideas with more physics related content in chemistry, and other science electives. After th
Document 4:::
In physics, energy density is the amount of energy stored in a given system or region of space per unit volume. It is sometimes confused with energy per unit mass which is properly called specific energy or .
Often only the useful or extractable energy is measured, which is to say that inaccessible energy (such as rest mass energy) is ignored. In cosmological and other general relativistic contexts, however, the energy densities considered are those that correspond to the elements of the stress-energy tensor and therefore do include mass energy as well as energy densities associated with pressure.
Energy per unit volume has the same physical units as pressure and in many situations is synonymous. For example, the energy density of a magnetic field may be expressed as and behaves like a physical pressure. Likewise, the energy required to compress a gas to a certain volume may be determined by multiplying the difference between the gas pressure and the external pressure by the change in volume. A pressure gradient describes the potential to perform work on the surroundings by converting internal energy to work until equilibrium is reached.
Overview
There are different types of energy stored in materials, and it takes a particular type of reaction to release each type of energy. In order of the typical magnitude of the energy released, these types of reactions are: nuclear, chemical, electrochemical, and electrical.
Nuclear reactions take place in stars and nuclear power plants, both of which derive energy from the binding energy of nuclei. Chemical reactions are used by organisms to derive energy from food and by automobiles to derive energy from gasoline. Liquid hydrocarbons (fuels such as gasoline, diesel and kerosene) are today the densest way known to economically store and transport chemical energy at a large scale (1 kg of diesel fuel burns with the oxygen contained in ≈15 kg of air). Electrochemical reactions are used by most mobile devices such as laptop
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When gas particles heat up and gain energy, what do they do?
A. move slower
B. stop
C. move faster
D. go up
Answer:
|
|
sciq-6338
|
multiple_choice
|
When something loses electrons, it must also?
|
[
"slow down",
"gain protons",
"reduce protons",
"gain electrons"
] |
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: 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 2:::
In physics, a charge carrier is a particle or quasiparticle that is free to move, carrying an electric charge, especially the particles that carry electric charges in electrical conductors. Examples are electrons, ions and holes. The term is used most commonly in solid state physics. In a conducting medium, an electric field can exert force on these free particles, causing a net motion of the particles through the medium; this is what constitutes an electric current.
The electron and the proton are the elementary charge carriers, each carrying one elementary charge (e), of the same magnitude and opposite sign.
In conductors
In conducting media, particles serve to carry charge:
In many metals, the charge carriers are electrons. One or two of the valence electrons from each atom are able to move about freely within the crystal structure of the metal. The free electrons are referred to as conduction electrons, and the cloud of free electrons is called a Fermi gas. Many metals have electron and hole bands. In some, the majority carriers are holes.
In electrolytes, such as salt water, the charge carriers are ions, which are atoms or molecules that have gained or lost electrons so they are electrically charged. Atoms that have gained electrons so they are negatively charged are called anions, atoms that have lost electrons so they are positively charged are called cations. Cations and anions of the dissociated liquid also serve as charge carriers in melted ionic solids (see e.g. the Hall–Héroult process for an example of electrolysis of a melted ionic solid). Proton conductors are electrolytic conductors employing positive hydrogen ions as carriers.
In a plasma, an electrically charged gas which is found in electric arcs through air, neon signs, and the sun and stars, the electrons and cations of ionized gas act as charge carriers.
In a vacuum, free electrons can act as charge carriers. In the electronic component known as the vacuum tube (also called valve), the mobil
Document 3:::
Secondary electrons are electrons generated as ionization products. They are called 'secondary' because they are generated by other radiation (the primary radiation). This radiation can be in the form of ions, electrons, or photons with sufficiently high energy, i.e. exceeding the ionization potential. Photoelectrons can be considered an example of secondary electrons where the primary radiation are photons; in some discussions photoelectrons with higher energy (>50 eV) are still considered "primary" while the electrons freed by the photoelectrons are "secondary".
Applications
Secondary electrons are also the main means of viewing images in the scanning electron microscope (SEM). The range of secondary electrons depends on the energy. Plotting the inelastic mean free path as a function of energy often shows characteristics of the "universal curve" familiar to electron spectroscopists and surface analysts. This distance is on the order of a few nanometers in metals and tens of nanometers in insulators. This small distance allows such fine resolution to be achieved in the SEM.
For SiO2, for a primary electron energy of 100 eV, the secondary electron range is up to 20 nm from the point of incidence.
See also
Delta ray
Everhart-Thornley detector
Document 4:::
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:
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When something loses electrons, it must also?
A. slow down
B. gain protons
C. reduce protons
D. gain electrons
Answer:
|
|
sciq-1805
|
multiple_choice
|
Balanced chemical reactions are balanced in what?
|
[
"electrical charge",
"atoms",
"molecular bonds",
"terms of moles"
] |
D
|
Relavent Documents:
Document 0:::
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
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In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products. Such a state is known as dynamic equilibrium.
Historical introduction
The concept of chemical equilibrium was developed in 1803, after Berthollet found that some chemical reactions are reversible. For any reaction mixture to exist at equilibrium, the rates of the forward and backward (reverse) reactions must be equal. In the following chemical equation, arrows point both ways to indicate equilibrium. A and B are reactant chemical species, S and T are product species, and α, β, σ, and τ are the stoichiometric coefficients of the respective reactants and products:
α A + β B σ S + τ T
The equilibrium concentration position of a reaction is said to lie "far to the right" if, at equilibrium, nearly all the reactants are consumed. Conversely the equilibrium position is said to be "far to the left" if hardly any product is formed from the reactants.
Guldberg and Waage (1865), building on Berthollet's ideas, proposed the law of mass action:
where A, B, S and T are active masses and k+ and k− are rate constants. Since at equilibrium forward and backward rates are equal:
and the ratio of the rate constants is also a constant, now known as an equilibrium constant.
By convention, the products form the numerator.
However, the law of mass action is valid only for concerted one-step reactions that proceed through a single transition state and is not valid in general because rate equations do not, in general, follow the stoichiometry of the reaction
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The theory of response reactions (RERs) was elaborated for systems in which several physico-chemical processes run simultaneously in mutual interaction, with local thermodynamic equilibrium, and in which state variables called extents of reaction are allowed, but thermodynamic equilibrium proper is not required. It is based on detailed analysis of the Hessian determinant, using either the Gibbs or the De Donder method of analysis. The theory derives the sensitivity coefficient as the sum of the contributions of individual RERs. Thus phenomena which are in contradiction to over-general statements of the Le Chatelier principle can be interpreted. With the help of RERs the equilibrium coupling was defined. RERs could be derived based either on the species, or on the stoichiometrically independent reactions of a parallel system. The set of RERs is unambiguous in a given system; and the number of them (M) is , where S denotes the number of species and C refers to the number of components. In the case of three-component systems, RERs can be visualized on a triangle diagram.
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In chemical thermodynamics, the reaction quotient (Qr or just Q) is a dimensionless quantity that provides a measurement of the relative amounts of products and reactants present in a reaction mixture for a reaction with well-defined overall stoichiometry, at a particular point in time. Mathematically, it is defined as the ratio of the activities (or molar concentrations) of the product species over those of the reactant species involved in the chemical reaction, taking stoichiometric coefficients of the reaction into account as exponents of the concentrations. In equilibrium, the reaction quotient is constant over time and is equal to the equilibrium constant.
A general chemical reaction in which α moles of a reactant A and β moles of a reactant B react to give ρ moles of a product R and σ moles of a product S can be written as
\it \alpha\,\rm A{} + \it \beta\,\rm B{} <=> \it \rho\,\rm R{} + \it \sigma\,\rm S{}.
The reaction is written as an equilibrium even though in many cases it may appear that all of the reactants on one side have been converted to the other side. When any initial mixture of A, B, R, and S is made, and the reaction is allowed to proceed (either in the forward or reverse direction), the reaction quotient Qr, as a function of time t, is defined as
where {X}t denotes the instantaneous activity of a species X at time t.
A compact general definition is
where Пj denotes the product across all j-indexed variables, aj(t) is the activity of species j at time t, and νj is the stoichiometric number (the stoichiometric coefficient multiplied by +1 for products and –1 for starting materials).
Relationship to K (the equilibrium constant)
As the reaction proceeds with the passage of time, the species' activities, and hence the reaction quotient, change in a way that reduces the free energy of the chemical system. The direction of the change is governed by the Gibbs free energy of reaction by the relation
,
where K is a constant independent of initi
Document 4:::
Equilibrium chemistry is concerned with systems in chemical equilibrium. The unifying principle is that the free energy of a system at equilibrium is the minimum possible, so that the slope of the free energy with respect to the reaction coordinate is zero. This principle, applied to mixtures at equilibrium provides a definition of an equilibrium constant. Applications include acid–base, host–guest, metal–complex, solubility, partition, chromatography and redox equilibria.
Thermodynamic equilibrium
A chemical system is said to be in equilibrium when the quantities of the chemical entities involved do not and cannot change in time without the application of an external influence. In this sense a system in chemical equilibrium is in a stable state. The system at chemical equilibrium will be at a constant temperature, pressure or volume and a composition. It will be insulated from exchange of heat with the surroundings, that is, it is a closed system. A change of temperature, pressure (or volume) constitutes an external influence and the equilibrium quantities will change as a result of such a change. If there is a possibility that the composition might change, but the rate of change is negligibly slow, the system is said to be in a metastable state. The equation of chemical equilibrium can be expressed symbolically as
reactant(s) product(s)
The sign means "are in equilibrium with". This definition refers to macroscopic properties. Changes do occur at the microscopic level of atoms and molecules, but to such a minute extent that they are not measurable and in a balanced way so that the macroscopic quantities do not change. Chemical equilibrium is a dynamic state in which forward and backward reactions proceed at such rates that the macroscopic composition of the mixture is constant. Thus, equilibrium sign symbolizes the fact that reactions occur in both forward and backward directions.
A steady state, on the other hand, is not necessarily an equilibrium state
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Balanced chemical reactions are balanced in what?
A. electrical charge
B. atoms
C. molecular bonds
D. terms of moles
Answer:
|
|
sciq-3006
|
multiple_choice
|
To figure out the height of a wave you measure the distance between the crest and what?
|
[
"crater",
"core",
"trough",
"drift"
] |
C
|
Relavent Documents:
Document 0:::
A crest point on a wave is the maximum value of upward displacement within a cycle. A crest is a point on a surface wave where the displacement of the medium is at a maximum. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.
When the crests and troughs of two sine waves of equal amplitude and frequency intersect or collide, while being in phase with each other, the result is called constructive interference and the magnitudes double (above and below the line). When in antiphase – 180° out of phase – the result is destructive interference: the resulting wave is the undisturbed line having zero amplitude.
See also
Crest factor
Superposition principle
Wave
Document 1:::
In fluid dynamics, the wave height of a surface wave is the difference between the elevations of a crest and a neighboring trough. Wave height is a term used by mariners, as well as in coastal, ocean and naval engineering.
At sea, the term significant wave height is used as a means to introduce a well-defined and standardized statistic to denote the characteristic height of the random waves in a sea state, including wind sea and swell. It is defined in such a way that it more or less corresponds to what a mariner observes when estimating visually the average wave height.
Definitions
Depending on context, wave height may be defined in different ways:
For a sine wave, the wave height H is twice the amplitude (i.e., the peak-to-peak amplitude):
For a periodic wave, it is simply the difference between the maximum and minimum of the surface elevation : with cp the phase speed (or propagation speed) of the wave. The sine wave is a specific case of a periodic wave.
In random waves at sea, when the surface elevations are measured with a wave buoy, the individual wave height Hm of each individual wave—with an integer label m, running from 1 to N, to denote its position in a sequence of N waves—is the difference in elevation between a wave crest and trough in that wave. For this to be possible, it is necessary to first split the measured time series of the surface elevation into individual waves. Commonly, an individual wave is denoted as the time interval between two successive downward-crossings through the average surface elevation (upward crossings might also be used). Then the individual wave height of each wave is again the difference between maximum and minimum elevation in the time interval of the wave under consideration.
Significant wave height
RMS wave height
Another wave-height statistic in common usage is the root-mean-square (or RMS) wave height Hrms, defined as: with Hm again denoting the individual wave heights in a certain time series.
See also
Se
Document 2:::
In physical oceanography, the significant wave height (SWH, HTSGW or Hs)
is defined traditionally as the mean wave height (trough to crest) of the highest third of the waves (H1/3). It is usually defined as four times the standard deviation of the surface elevation – or equivalently as four times the square root of the zeroth-order moment (area) of the wave spectrum. The symbol Hm0 is usually used for that latter definition. The significant wave height (Hs) may thus refer to Hm0 or H1/3; the difference in magnitude between the two definitions is only a few percent.
SWH is used to characterize sea state, including winds and swell.
Origin and definition
The original definition resulted from work by the oceanographer Walter Munk during World War II. The significant wave height was intended to mathematically express the height estimated by a "trained observer". It is commonly used as a measure of the height of ocean waves.
Time domain definition
Significant wave height H1/3, or Hs or Hsig, as determined in the time domain, directly from the time series of the surface elevation, is defined as the average height of that one-third of the N measured waves having the greatest heights: where Hm represents the individual wave heights, sorted into descending order of height as m increases from 1 to N. Only the highest one-third is used, since this corresponds best with visual observations of experienced mariners, whose vision apparently focuses on the higher waves.
Frequency domain definition
Significant wave height Hm0, defined in the frequency domain, is used both for measured and forecasted wave variance spectra. Most easily, it is defined in terms of the variance m0 or standard deviation ση of the surface elevation: where m0, the zeroth-moment of the variance spectrum, is obtained by integration of the variance spectrum. In case of a measurement, the standard deviation ση is the easiest and most accurate statistic to be used.
Another wave-height statistic in common u
Document 3:::
The Mountain Wave Project (MWP) pursues global scientific research of gravity waves and associated turbulence. MWP seeks to develop new scientific insights and knowledge through high altitude and record seeking glider flights with the goal of increasing overall flight safety and improving pilot training.
Corporate history
Motivation
Wind movement over terrain and ground obstacles can create wavelike wind formations which can reach up to the stratosphere. In 1998 the pilots René Heise and Klaus Ohlmann founded the MWP, a project for global classification, research, and analysis of orographically created wind structures (e.g. Chinook, Foehn, Mistral, Zonda). The MWP is an independent non-profit-project of the Scientific and Meteorological Section of the Organisation Scientifique et Technique du Vol à Voile (OSTIV) and is supported by the Fédération Aéronautique Internationale (FAI).
The MWP was originally focused on achieving better understanding. of the complex thermal and dynamic air movements in the atmosphere, and using that knowledge to achieve ever greater long distance soaring flights. As MWP gained greater awareness of the power inherent to mountain wave-like structures in the atmosphere, and their strong vertical airflows, it became obvious that they presented great dangers to civil aviation in multiple ways. Therefore, the focus of the MWP shifted to a more scientific approach to the airflow phenomena, with the goal of discovering new ways to increase overall aviation safety. Through the support of other scientists and cooperation partners the core group became more powerful and gained greater depth of knowledge. The integration of Joerg Hacker from the Airborne Research Australia (ARA) into the core group significantly enhanced the overall depth of knowledge of the group.
Airborne measurements
In order to learn more about the relevant physical process in the atmosphere, the MWP Team launched two expeditions in the Argentinean Andes in 1999 and 2006. F
Document 4:::
A hundred-year wave is a statistically projected water wave, the height of which, on average, is met or exceeded once in a hundred years for a given location. The likelihood of this wave height being attained at least once in the hundred-year period is 63%. As a projection of the most extreme wave which can be expected to occur in a given body of water, the hundred-year wave is a factor commonly taken into consideration by designers of oil platforms and other offshore structures. Periods of time other than a hundred years may also be taken into account, resulting in, for instance, a fifty-year wave.
Various methods are employed to predict the possible steepness and period of these waves, in addition to their height.
See also
Index of wave articles
Significant wave height
Shallow water equations
Rogue wave
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
To figure out the height of a wave you measure the distance between the crest and what?
A. crater
B. core
C. trough
D. drift
Answer:
|
|
sciq-11283
|
multiple_choice
|
What specific part of the brain regulates the endocrine system?
|
[
"hippocampus",
"hypothalamus",
"parietal lobe",
"frontal lobe"
] |
B
|
Relavent Documents:
Document 0:::
The British Society for Neuroendocrinology (BSN) was formally established in 2001 to promote learning and research into neuroendocrinology. Publications of the Society include the Journal of Neuroendocrinology and Neuroendorcrine Briefings. Since 1989 the society has awarded annually the Mortyn Jones Lectureship to a researcher who has made a major contribution to neuroendocrine research. The BSN is a registered charity in the UK; however, participation is welcomed from around the world.
History
This society was founded as the British Neuroendocrine Group in 1985, formally constituting as the British Society for Neuroendocrinology (BSN) in 2001.
Major activities
The society is a registered charity in the United Kingdom (no 1002014) whose aims are to promote learning and research into neuroendocrinology: the interplay between the endocrine and nervous systems that control important body functions and behaviour. The ultimate aim of this research is to provide therapies for the many neuroendocrine diseases and disorders that may develop throughout life, and to develop methods to beneficially regulate normal neuroendocrine function in humans and animals. The society offers educational resources and networking opportunities to support members at all stages of their career.
Publications
The society established the Journal of Neuroendocrinology in 1989 under the editorship of Prof Stafford Lightman. It is now published by Wiley, Prof Julian Mercer (University of Aberdeen) is the Editor-in-Chief. The society also publishes Neuroendorcrine Briefings, a resource for teaching and communication, on an occasional basis.
Membership
Ordinary membership is open to researchers, clinicians and students in the field of neuroendocrinology, endocrinology and related disciplines. Although based in the UK, the BSN welcomes participation from around the world. Honorary membership is awarded by the executive committee of the society to persons of special distinction in neuroendocrinolo
Document 1:::
Hypothalamic-pituitary axis
Hypothalamus
Pineal body (epiphysis)
Pituitary gland (hypophysis)
The pituitary gland (or hypophysis) is an endocrine gland about the size of a pea and weighing in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold (diaphragma sellae). The pituitary is functionally connected to the hypothalamus by the median eminence via a small tube called the infundibular stem or pituitary stalk. The anterior pituitary (adenohypophysis) is connected to the hypothalamus via the hypothalamo–hypophyseal portal vessels, which allows for quicker and more efficient communication between the hypothalamus and the pituitary.
Anterior pituitary lobe (adenohypophysis)
Posterior pituitary lobe (neurohypophysis)
Oxytocin and anti-diuretic hormone are not secreted in the posterior lobe, merely stored.
Thyroid
Digestive system
Stomach
Duodenum (small intestine)
Liver
Pancreas
The pancreas is a heterocrine gland as it functions both as an endocrine and as an exocrine gland.
Kidney
Adrenal glands
Adrenal cortex
Adrenal medulla
Reproductive
Testes
Ovarian follicle and corpus luteum
Placenta (when pregnant)
Uterus (when pregnant)
Calcium regulation
Parathyroid
Skin
Other
Heart
Bone
Skeletal muscle
In 1998, skeletal muscle was identified as an endocrine organ due to its now well-established role in the secretion of myokines. The use of the term myokine to describe cytokines and other peptides produced by muscle as signalling molecules was proposed in 2003.
Adipose tissue
Signalling molecules released by adipose tissue are referred to as adipokines.
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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:::
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 4:::
Neural top–down control of physiology concerns the direct regulation by the brain of physiological functions (in addition to smooth muscle and glandular ones). Cellular functions include the immune system’s production of T-lymphocytes and antibodies, and nonimmune related homeostatic functions such as liver gluconeogenesis, sodium reabsorption, osmoregulation, and brown adipose tissue nonshivering thermogenesis. This regulation occurs through the sympathetic and parasympathetic system (the autonomic nervous system), and their direct innervation of body organs and tissues that starts in the brainstem. There is also a noninnervation hormonal control through the hypothalamus and pituitary (HPA). These lower brain areas are under control of cerebral cortex ones. Such cortical regulation differs between its left and right sides. Pavlovian conditioning shows that brain control over basic cell level physiological function can be learned.
Higher brain
Cerebral cortex
Sympathetic and parasympathetic nervous systems and the hypothalamus are regulated by the higher brain. Through them, the higher cerebral cortex areas can control the immune system, and the body’s homeostatic and stress physiology. Areas doing this include the insular cortex, the orbital, and the medial prefrontal cortices. These cerebral areas also control smooth muscle and glandular physiological processes through the sympathetic and parasympathetic nervous system including blood circulation, urogenital, gastrointestinal functions, pancreatic gut secretions, respiration, coughing, vomiting, piloerection, pupil dilation, lacrimation and salivation.
Lateralization
The sympathetic nervous system is predominantly controlled by the right side of the brain (focused upon the insular cortex), while the left side predominantly controls the parasympathetic nervous system. The cerebral cortex in rodents shows lateral specialization in its regulation of immunity with immunosuppression being controlled by the righ
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What specific part of the brain regulates the endocrine system?
A. hippocampus
B. hypothalamus
C. parietal lobe
D. frontal lobe
Answer:
|
|
sciq-7358
|
multiple_choice
|
What is the outermost occupied shell of electrons in an atom.
|
[
"Inner Shell",
"radiative shell",
"valence shell",
"modular shell"
] |
C
|
Relavent Documents:
Document 0:::
In chemistry and atomic physics, an electron shell may be thought of as an orbit that electrons follow around an atom's nucleus. The closest shell to the nucleus is called the "1 shell" (also called the "K shell"), followed by the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), and so on farther and farther from the nucleus. The shells correspond to the principal quantum numbers (n = 1, 2, 3, 4 ...) or are labeled alphabetically with the letters used in X-ray notation (K, L, M, ...). A useful guide when understanding electron shells in atoms is to note that each row on the conventional periodic table of elements represents an electron shell.
Each shell can contain only a fixed number of electrons: the first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons. For an explanation of why electrons exist in these shells, see electron configuration.
Each shell consists of one or more subshells, and each subshell consists of one or more atomic orbitals.
History
In 1913 Bohr proposed a model of the atom, giving the arrangement of electrons in their sequential orbits. At that time, Bohr allowed the capacity of the inner orbit of the atom to increase to eight electrons as the atoms got larger, and "in the scheme given below the number of electrons in this [outer] ring is arbitrary put equal to the normal valency of the corresponding element." Using these and other constraints, he proposed configurations that are in accord with those now known only for the first six elements. "From the above we are led to the following possible scheme for the arrangement of the electrons in light atoms:"
The shell terminology comes from Arnold Sommerfeld's modification of the 1913 Bohr model. During this period Bohr was working with Walther Kossel, whose papers in 1914 and in 1916 called the or
Document 1:::
A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The term is commonly used for the energy levels of the electrons in atoms, ions, or molecules, which are bound by the electric field of the nucleus, but can also refer to energy levels of nuclei or vibrational or rotational energy levels in molecules. The energy spectrum of a system with such discrete energy levels is said to be quantized.
In chemistry and atomic physics, an electron shell, or principal energy level, may be thought of as the orbit of one or more electrons around an atom's nucleus. The closest shell to the nucleus is called the " shell" (also called "K shell"), followed by the " shell" (or "L shell"), then the " shell" (or "M shell"), and so on farther and farther from the nucleus. The shells correspond with the principal quantum numbers (n = 1, 2, 3, 4 ...) or are labeled alphabetically with letters used in the X-ray notation (K, L, M, N...).
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2n2 electrons. Since electrons are electrically attracted to the nucleus, an atom's electrons will generally occupy outer shells only if the more inner shells have already been completely filled by other electrons. However, this is not a strict requirement: atoms may have two or even three incomplete outer shells. (See Madelung rule for more details.) For an explanation of why electrons exist in these shells see electron configuration.
If the potential energy is set to zero at infinite distance from the atomic nucleus or molecule, the usual convention, then bound electron states have negative pot
Document 2:::
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. For example, the electron configuration of the neon atom is , meaning that the 1s, 2s and 2p subshells are occupied by 2, 2 and 6 electrons respectively.
Electronic configurations describe each electron as moving independently in an orbital, in an average field created by all other orbitals. Mathematically, configurations are described by Slater determinants or configuration state functions.
According to the laws of quantum mechanics, for systems with only one electron, a level of energy is associated with each electron configuration and in certain conditions, electrons are able to move from one configuration to another by the emission or absorption of a quantum of energy, in the form of a photon.
Knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements. This is also useful for describing the chemical bonds that hold atoms together, and for understanding the chemical formulas of compounds and the geometries of molecules. In bulk materials, this same idea helps explain the peculiar properties of lasers and semiconductors.
Shells and subshells
Electron configuration was first conceived under the Bohr model of the atom, and it is still common to speak of shells and subshells despite the advances in understanding of the quantum-mechanical nature of electrons.
An electron shell is the set of allowed states that share the same principal quantum number, n (the number before the letter in the orbital label), that electrons may occupy. An atom's nth electron shell can accommodate 2n2 electrons. For example, the first shell can accommodate 2 electrons, the second shell 8 electrons, the third shell 18 electrons and so on. The factor of two arises because the allowed states are doubled due to electron spin—each
Document 3:::
In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus that uses the Pauli exclusion principle to describe the structure of nuclei in terms of energy levels. The first shell model was proposed by Dmitri Ivanenko (together with E. Gapon) in 1932. The model was developed in 1949 following independent work by several physicists, most notably Maria Goeppert Mayer and J. Hans D. Jensen, who shared half of the 1963 Nobel Prize in Physics for their contributions.
The nuclear shell model is partly analogous to the atomic shell model, which describes the arrangement of electrons in an atom, in that a filled shell results in better stability. When adding nucleons (protons and neutrons) to a nucleus, there are certain points where the binding energy of the next nucleon is significantly less than the last one. This observation, that there are specific magic quantum numbers of nucleons (2, 8, 20, 28, 50, 82, 126) which are more tightly bound than the following higher number, is the origin of the shell model.
The shells for protons and neutrons are independent of each other. Therefore, there can exist both "magic nuclei", in which one nucleon type or the other is at a magic number, and "doubly magic quantum nuclei", where both are. Due to some variations in orbital filling, the upper magic numbers are 126 and, speculatively, 184 for neutrons, but only 114 for protons, playing a role in the search for the so-called island of stability. Some semi-magic numbers have been found, notably Z = 40, which gives the nuclear shell filling for the various elements; 16 may also be a magic number.
In order to get these numbers, the nuclear shell model starts from an average potential with a shape somewhere between the square well and the harmonic oscillator. To this potential, a spin orbit term is added. Even so, the total perturbation does not coincide with experiment, and an empirical spin orbit coupling must be added with at le
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the outermost occupied shell of electrons in an atom.
A. Inner Shell
B. radiative shell
C. valence shell
D. modular shell
Answer:
|
|
sciq-6417
|
multiple_choice
|
What is a measurement of the amount of variation of the species in a given area called?
|
[
"degradation",
"biodiversity",
"population",
"ecosystem"
] |
B
|
Relavent Documents:
Document 0:::
The species–area relationship or species–area curve describes the relationship between the area of a habitat, or of part of a habitat, and the number of species found within that area. Larger areas tend to contain larger numbers of species, and empirically, the relative numbers seem to follow systematic mathematical relationships. The species–area relationship is usually constructed for a single type of organism, such as all vascular plants or all species of a specific trophic level within a particular site. It is rarely if ever, constructed for all types of organisms if simply because of the prodigious data requirements. It is related but not identical to the species discovery curve.
Ecologists have proposed a wide range of factors determining the slope and elevation of the species–area relationship. These factors include the relative balance between immigration and extinction, rate and magnitude of disturbance on small vs. large areas, predator-prey dynamics, and clustering of individuals of the same species as a result of dispersal limitation or habitat heterogeneity. The species–area relationship has been reputed to follow from the 2nd law of thermodynamics. In contrast to these "mechanistic" explanations, others assert the need to test whether the pattern is simply the result of a random sampling process. Species–area relationships are often evaluated in conservation science in order to predict extinction rates in the case of habitat loss and habitat fragmentation.
Authors have classified the species–area relationship according to the type of habitats being sampled and the census design used. Frank W. Preston, an early investigator of the theory of the species–area relationship, divided it into two types: samples (a census of a contiguous habitat that grows in the census area, also called "mainland" species–area relationships), and isolates (a census of discontiguous habitats, such as islands, also called "island" species–area relationships). Michael Rosenzwe
Document 1:::
A diversity index is a quantitative measure that reflects how many different types (such as species) there are in a dataset (a community), and that can simultaneously take into account the phylogenetic relations among the individuals distributed among those types, such as richness, divergence or evenness. These indices are statistical representations of biodiversity in different aspects (richness, evenness, and dominance).
Effective number of species or Hill numbers
When diversity indices are used in ecology, the types of interest are usually species, but they can also be other categories, such as genera, families, functional types, or haplotypes. The entities of interest are usually individual plants or animals, and the measure of abundance can be, for example, number of individuals, biomass or coverage. In demography, the entities of interest can be people, and the types of interest various demographic groups. In information science, the entities can be characters and the types of the different letters of the alphabet. The most commonly used diversity indices are simple transformations of the effective number of types (also known as 'true diversity'), but each diversity index can also be interpreted in its own right as a measure corresponding to some real phenomenon (but a different one for each diversity index).
Many indices only account for categorical diversity between subjects or entities. Such indices, however do not account for the total variation (diversity) that can be held between subjects or entities which occurs only when both categorical and qualitative diversity are calculated.
True diversity, or the effective number of types, refers to the number of equally abundant types needed for the average proportional abundance of the types to equal that observed in the dataset of interest (where all types may not be equally abundant). The true diversity in a dataset is calculated by first taking the weighted generalized mean of the proportional abundance
Document 2:::
Ecosystem diversity deals with the variations in ecosystems within a geographical location and its overall impact on human existence and the environment.
Ecosystem diversity addresses the combined characteristics of biotic properties (biodiversity) and abiotic properties (geodiversity). It is a variation in the ecosystems found in a region or the variation in ecosystems over the whole planet. Ecological diversity includes the variation in both terrestrial and aquatic ecosystems. Ecological diversity can also take into account the variation in the complexity of a biological community, including the number of different niches, the number of and other ecological processes. An example of ecological diversity on a global scale would be the variation in ecosystems, such as deserts, forests, grasslands, wetlands and oceans. Ecological diversity is the largest scale of biodiversity, and within each ecosystem, there is a great deal of both species and genetic diversity.
Impact
Diversity in the ecosystem is significant to human existence for a variety of reasons. Ecosystem diversity boosts the availability of oxygen via the process of photosynthesis amongst plant organisms domiciled in the habitat. Diversity in an aquatic environment helps in the purification of water by plant varieties for use by humans. Diversity increases plant varieties which serves as a good source for medicines and herbs for human use. A lack of diversity in the ecosystem produces an opposite result.
Examples
Some examples of ecosystems that are rich in diversity are:
Deserts
Forests
Large marine ecosystems
Marine ecosystems
Old-growth forests
Rainforests
Tundra
Coral reefs
Marine
Ecosystem diversity as a result of evolutionary pressure
Ecological diversity around the world can be directly linked to the evolutionary and selective pressures that constrain the diversity outcome of the ecosystems within different niches. Tundras, Rainforests, coral reefs and deciduous forests all are form
Document 3:::
Landscape genetics is the scientific discipline that combines population genetics and landscape ecology. It broadly encompasses any study that analyses plant or animal population genetic data in conjunction with data on the landscape features and matrix quality where the sampled population lives. This allows for the analysis of microevolutionary processes affecting the species in light of landscape spatial patterns, providing a more realistic view of how populations interact with their environments. Landscape genetics attempts to determine which landscape features are barriers to dispersal and gene flow, how human-induced landscape changes affect the evolution of populations, the source-sink dynamics of a given population, and how diseases or invasive species spread across landscapes.
Landscape genetics differs from the fields of biogeography and phylogeography by providing information at finer temporal and spatial scales (i.e., at the level of individual genetic variation within a population). Because it focuses on sampling individuals, landscape genetics has the advantage of not having to subjectively define discrete populations prior to analysis. Genetic tools are used to detect abrupt genetic differences between individuals within a population and statistical tools are used to correlate these genetic discontinuities with landscape and environmental features. The results of landscape genetics studies have potentially important applications to conservation biology and land management practices.
History
Landscape genetics emerged as its own discipline after the seminal article entitled "Landscape genetics: combining landscape ecology and population genetics" by Manel et al. appeared in the journal Trends in Ecology and Evolution in 2003. According to that article, the concept that landscape patterns affect how organisms are distributed dates back to the 18th and 19th centuries in the writings of Augustin Pyramus de Candolle and Alfred Russel Wallace. The mo
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Molecular ecology is a field of evolutionary biology that is concerned with applying molecular population genetics, molecular phylogenetics, and more recently genomics to traditional ecological questions (e.g., species diagnosis, conservation and assessment of biodiversity, species-area relationships, and many questions in behavioral ecology). It is virtually synonymous with the field of "Ecological Genetics" as pioneered by Theodosius Dobzhansky, E. B. Ford, Godfrey M. Hewitt, and others. These fields are united in their attempt to study genetic-based questions "out in the field" as opposed to the laboratory. Molecular ecology is related to the field of conservation genetics.
Methods frequently include using microsatellites to determine gene flow and hybridization between populations. The development of molecular ecology is also closely related to the use of DNA microarrays, which allows for the simultaneous analysis of the expression of thousands of different genes. Quantitative PCR may also be used to analyze gene expression as a result of changes in environmental conditions or different responses by differently adapted individuals.
Molecular ecology uses molecular genetic data to answer ecological question related to biogeography, genomics, conservation genetics, and behavioral ecology. Studies mostly use data based on deoxyribonucleic acid sequences (DNA). This approach has been enhanced over a number of years to allow researchers to sequence thousands of genes from a small amount of starting DNA. Allele sizes are another way researchers are able to compare individuals and populations which allows them to quantify the genetic diversity within a population and the genetic similarities among populations.
Bacterial diversity
Molecular ecological techniques are used to study in situ questions of bacterial diversity. Many microorganisms are not easily obtainable as cultured strains in the laboratory, which would allow for identification and characterization. I
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a measurement of the amount of variation of the species in a given area called?
A. degradation
B. biodiversity
C. population
D. ecosystem
Answer:
|
|
sciq-6080
|
multiple_choice
|
What type of change occurs when matter changes chemically into an entirely different substance with different chemical properties?
|
[
"material",
"physical",
"genetic",
"chemical"
] |
D
|
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:::
Material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geological origin or biological function. Materials science is the study of materials, their properties and their applications.
Raw materials can be processed in different ways to influence their properties, by purification, shaping or the introduction of other materials. New materials can be produced from raw materials by synthesis.
In industry, materials are inputs to manufacturing processes to produce products or more complex materials.
Historical elements
Materials chart the history of humanity. The system of the three prehistoric ages (Stone Age, Bronze Age, Iron Age) were succeeded by historical ages: steel age in the 19th century, polymer age in the middle of the following century (plastic age) and silicon age in the second half of the 20th century.
Classification by use
Materials can be broadly categorized in terms of their use, for example:
Building materials are used for construction
Building insulation materials are used to retain heat within buildings
Refractory materials are used for high-temperature applications
Nuclear materials are used for nuclear power and weapons
Aerospace materials are used in aircraft and other aerospace applications
Biomaterials are used for applications interacting with living systems
Material selection is a process to determine which material should be used for a given application.
Classification by structure
The relevant structure of materials has a different length scale depending on the material. The structure and composition of a material can be determined by microscopy or spectroscopy.
Microstructure
In engineering, materials can be categorised according to their microscopic structure:
Plastics: a wide range of synthetic or semi-synthetic materials that use polymers as a main ingred
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In chemistry, a mixture is a material made up of two or more different chemical substances which are not chemically bonded. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.
Mixtures are one product of mechanically blending or mixing chemical substances such as elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup. Despite the fact that there are no chemical changes to its constituents, the physical properties of a mixture, such as its melting point, may differ from those of the components. Some mixtures can be separated into their components by using physical (mechanical or thermal) means. Azeotropes are one kind of mixture that usually poses considerable difficulties regarding the separation processes required to obtain their constituents (physical or chemical processes or, even a blend of them).
Characteristics of mixtures
All mixtures can be characterized as being separable by mechanical means (e.g. purification, distillation, electrolysis, chromatography, heat, filtration, gravitational sorting, centrifugation). Mixtures differ from chemical compounds in the following ways:
the substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.
there is little or no energy change when a mixture forms (see Enthalpy of mixing).
The substances in a mixture keep its separate properties.
In the example of sand and water, neither one of the two substances changed in any way when they are mixed. Although the sand is in the water it still keeps the same properties that it had when it was outside the water.
mixtures have variable compositions, while compounds have a fixed, definite formula.
when mixed, individual substances keep their properties in a mixture, while if they form a compound their properties
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of change occurs when matter changes chemically into an entirely different substance with different chemical properties?
A. material
B. physical
C. genetic
D. chemical
Answer:
|
|
sciq-6777
|
multiple_choice
|
Which bones are flat and triangular and located at the back of the pectoral girdle?
|
[
"scapulae",
"cochlea",
"vertebrae",
"laminae"
] |
A
|
Relavent Documents:
Document 0:::
The spine of the scapula or scapular spine is a prominent plate of bone, which crosses obliquely the medial four-fifths of the scapula at its upper part, and separates the supra- from the infraspinatous fossa.
Structure
It begins at the vertical [vertebral or medial border] border by a smooth, triangular area over which the tendon of insertion of the lower part of the Trapezius glides, and, gradually becoming more elevated, ends in the acromion, which overhangs the shoulder-joint.
The spine is triangular, and flattened from above downward, its apex being directed toward the vertebral border.
Root
The root of the spine of the scapula is the most medial part of the scapular spine. It is termed "triangular area of the spine of scapula", based on its triangular shape giving it distinguishable visible shape on x-ray images. The root of the spine is on a level with the tip of the spinous process of the third thoracic vertebra.
Function
It presents two surfaces and three borders.
Its superior surface is concave; it assists in forming the supraspinatous fossa, and gives origin to part of the supraspinatus.
Its inferior surface forms part of the infraspinatous fossa, gives origin to a portion of the infraspinatus, and presents near its center the orifice of a nutrient canal.
Of the three borders, the anterior is attached to the dorsal surface of the bone; the posterior, or crest of the spine, is broad, and presents two lips and an intervening rough interval.
The trapezius is attached to the superior lip, and a rough tubercle is generally seen on that portion of the spine which receives the tendon of insertion of the lower part of this muscle.
The deltoideus is attached to the whole length of the inferior lip.
The interval between the lips is subcutaneous and partly covered by the tendinous fibers of these muscles.
The lateral border, or base, the shortest of the three, is slightly concave; its edge, thick and round, is continuous above with the under surface of th
Document 1:::
The human skeleton is the internal framework of the human body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together. The bone mass in the skeleton makes up about 14% of the total body weight (ca. 10–11 kg for an average person) and reaches maximum mass between the ages of 25 and 30. The human skeleton can be divided into the axial skeleton and the appendicular skeleton. The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones. The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.
The human skeleton performs six major functions: support, movement, protection, production of blood cells, storage of minerals, and endocrine regulation.
The human skeleton is not as sexually dimorphic as that of many other primate species, but subtle differences between sexes in the morphology of the skull, dentition, long bones, and pelvis exist. In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population. The human female pelvis is also different from that of males in order to facilitate childbirth. Unlike most primates, human males do not have penile bones.
Divisions
Axial
The axial skeleton (80 bones) is formed by the vertebral column (32–34 bones; the number of the vertebrae differs from human to human as the lower 2 parts, sacral and coccygeal bone may vary in length), a part of the rib cage (12 pairs of ribs and the sternum), and the skull (22 bones and 7 associated bones).
The upright posture of humans is maintained by the axial skeleton, which transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the hip joints. The bones of the spine are supported by many ligaments. The erector spinae muscles are also supporting an
Document 2:::
The coccyx (: coccyges or coccyxes), commonly referred to as the tailbone, is the final segment of the vertebral column in all apes, and analogous structures in certain other mammals such as horses. In tailless primates (e.g. humans and other great apes) since Nacholapithecus (a Miocene hominoid), the coccyx is the remnant of a vestigial tail. In animals with bony tails, it is known as tailhead or dock, in bird anatomy as tailfan. It comprises three to five separate or fused coccygeal vertebrae below the sacrum, attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between the sacrum and the coccyx.
Structure
The coccyx is formed of three, four or five rudimentary vertebrae. It articulates superiorly with the sacrum. In each of the first three segments may be traced a rudimentary body and articular and transverse processes; the last piece (sometimes the third) is a mere nodule of bone. The transverse processes are most prominent and noticeable on the first coccygeal segment. All the segments lack pedicles, laminae and spinous processes. The first segment is the largest; it resembles the lowest sacral vertebra, and often exists as a separate piece; the remaining ones diminish in size rostrally.
Most anatomy books incorrectly state that the coccyx is normally fused in adults. It has been shown that the coccyx may, in some people, consist of up to five separate bony segments, the most common configuration being two or three segments.
Surfaces
The anterior surface is slightly concave and marked with three transverse grooves which indicate the junctions of the different segments. It gives attachment to the anterior sacrococcygeal ligament and the levatores ani and supports part of the rectum. The posterior surface is convex, marked by transverse grooves similar to those on the anterior surface, and presents on either side a linear row of tubercles – the undeveloped articular processes of the coccygeal ve
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The irregular bones are bones which, from their peculiar form, cannot be grouped as long, short, flat or sesamoid bones. Irregular bones serve various purposes in the body, such as protection of nervous tissue (such as the vertebrae protect the spinal cord), affording multiple anchor points for skeletal muscle attachment (as with the sacrum), and maintaining pharynx and trachea support, and tongue attachment (such as the hyoid bone). They consist of cancellous tissue enclosed within a thin layer of compact bone. Irregular bones can also be used for joining all parts of the spinal column together. The spine is the place in the human body where the most irregular bones can be found. There are, in all, 33 irregular bones found here.
The irregular bones are: the vertebrae, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid.
Additional images
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Flat bones are bones whose principal function is either extensive protection or the provision of broad surfaces for muscular attachment. These bones are expanded into broad, flat plates, as in the cranium (skull), the ilium (pelvis), sternum and the rib cage.
The flat bones are: the occipital, parietal, frontal, nasal, lacrimal, vomer, sternum, ribs, and scapulae.
These bones are composed of two thin layers of compact bone enclosing between them a variable quantity of cancellous bone, which is the location of red bone marrow. In an adult, most red blood cells are formed in flat bones. In the cranial bones, the layers of compact tissue are familiarly known as the tables of the skull; the outer one is thick and tough; the inner is thin, dense, and brittle, and hence is termed the vitreous (glass-like) table. The intervening cancellous tissue is called the diploë, and this, in the nasal region of the skull, becomes absorbed so as to leave spaces filled with air–the paranasal sinuses between the two tables.
Ossification in flat bones
Ossification is started by the formation of layers of undifferentiated connective tissue that hold the area where the flat bone is to come. On a baby, those spots are known as fontanelles. The fontanelles contain connective tissue stem cells, which form into osteoblasts, which secrete calcium phosphate into a matrix of canals. They form a ring in between the membranes, and begin to expand outwards. As they expand they make a bony matrix.
This hardened matrix forms the body of the bone. Since flat bones are usually thinner than the long bones, they only have red bone marrow, rather than both red and yellow bone marrow (yellow bone marrow being made up of mostly fat). The bone marrow fills the space in the ring of osteoblasts, and eventually fills the bony matrix.
After the bone is completely ossified, the osteoblasts retract their calcium phosphate secreting tendrils, leaving tiny canals in the bony matrix, known as canaliculi. These
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which bones are flat and triangular and located at the back of the pectoral girdle?
A. scapulae
B. cochlea
C. vertebrae
D. laminae
Answer:
|
|
sciq-375
|
multiple_choice
|
Animals require air, water, and what in order to live and survive?
|
[
"shade",
"food?",
"time",
"mates"
] |
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
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 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 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:::
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)
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Animals require air, water, and what in order to live and survive?
A. shade
B. food?
C. time
D. mates
Answer:
|
|
sciq-7436
|
multiple_choice
|
The simplest system is that of contractile vacuoles present in what?
|
[
"microorganisms",
"parasites",
"crystals",
"macroorganisms"
] |
A
|
Relavent Documents:
Document 0:::
Cellular components are the complex biomolecules and structures of which cells, and thus living organisms, are composed. Cells are the structural and functional units of life. The smallest organisms are single cells, while the largest organisms are assemblages of trillions of cells. DNA, double stranded macromolecule that carries the hereditary information of the cell and found in all living cells; each cell carries chromosome(s) having a distinctive DNA sequence.
Examples include macromolecules such as proteins and nucleic acids, biomolecular complexes such as a ribosome, and structures such as membranes, and organelles. While the majority of cellular components are located within the cell itself, some may exist in extracellular areas of an organism.
Cellular components may also be called biological matter or biological material. Most biological matter has the characteristics of soft matter, being governed by relatively small energies. All known life is made of biological matter. To be differentiated from other theoretical or fictional life forms, such life may be called carbon-based, cellular, organic, biological, or even simply living – as some definitions of life exclude hypothetical types of biochemistry.
See also
Cell (biology)
Cell biology
Biomolecule
Organelle
Tissue (biology)
External links
https://web.archive.org/web/20130918033010/http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_cell3.htm
Document 1:::
In cell biology, microtrabeculae were a hypothesised fourth element of the cytoskeleton (the other three being microfilaments, microtubules and intermediate filaments), proposed by Keith Porter based on images obtained from high-voltage electron microscopy of whole cells in the 1970s. The images showed short, filamentous structures of unknown molecular composition associated with known cytoplasmic structures. It is now generally accepted that microtrabeculae are nothing more than an artifact of certain types of fixation treatment, although the complexity of the cell's cytoskeleton is not yet fully understood.
Document 2:::
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 3:::
A micropyle is a pore in the membrane covering the ovum, through which a sperm enters.
Micropyles are also found in sporozoites of some digenetic microorganisms such as Plasmodium at the anterior part of the cell that ultimately leads towards the apical cap. Examples of other organisms that have micropyles are the Bombyx mandarina and the Ceratitis capitata.
Document 4:::
The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane, and contains many macromolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites. The term comes from the Latin word meaning 'small room'.
Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell.
Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms.
The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology.
Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
Discovery
With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as i
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The simplest system is that of contractile vacuoles present in what?
A. microorganisms
B. parasites
C. crystals
D. macroorganisms
Answer:
|
|
sciq-9585
|
multiple_choice
|
What conveys signals received by the eye to the brain?
|
[
"optic nerve",
"sensory nerve",
"motor nerve",
"sciatic nerve"
] |
A
|
Relavent Documents:
Document 0:::
A retinal implant is a visual prosthesis for restoration of sight to patients blinded by retinal degeneration. The system is meant to partially restore useful vision to those who have lost their photoreceptors due to retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Retinal implants are being developed by a number of private companies and research institutions, and three types are in clinical trials: epiretinal (on the retina), subretinal (behind the retina), and suprachoroidal (between the choroid and the sclera). The implants introduce visual information into the retina by electrically stimulating the surviving retinal neurons. So far, elicited percepts had rather low resolution, and may be suitable for light perception and recognition of simple objects.
History
Foerster was the first to discover that electrical stimulation of the occipital cortex could be used to create visual percepts, phosphenes. The first application of an implantable stimulator for vision restoration was developed by Drs. Brindley and Lewin in 1968. This experiment demonstrated the viability of creating visual percepts using direct electrical stimulation, and it motivated the development of several other implantable devices for stimulation of the visual pathway, including retinal implants. Retinal stimulation devices, in particular, have become a focus of research as approximately half of all cases of blindness are caused by retinal damage. The development of retinal implants has also been motivated in part by the advancement and success of cochlear implants, which has demonstrated that humans can regain significant sensory function with limited input.
The Argus II retinal implant, manufactured by Second Sight Medical Products received market approval in the US in Feb 2013 and in Europe in Feb 2011, becoming the first approved implant. The device may help adults with RP who have lost the ability to perceive shapes and movement to be more m
Document 1:::
The ophthalmic nerve (CN V1) is a sensory nerve of the head. It is one of three divisions of the trigeminal nerve (CN V), a cranial nerve. It has three major branches which provide sensory innervation to the eye, and the skin of the upper face and anterior scalp, as well as other structures of the head.
Structure
It measures about 2.5 cm in length.
Origin
The ophthalmic nerve is the first branch of the trigeminal nerve (CN V), the first and smallest of its three divisions. It arises from the superior part of the trigeminal ganglion.
Course
It passes anterior-ward along the lateral wall of the cavernous sinus inferior to the oculomotor nerve (CN III) and trochlear nerve (N IV). It divides into its three main branches as it approaches the superior orbital fissure.
Branches
Within the skull, the ophthalmic nerve produces:
meningeal branch (tentorial nerve)
The ophthalmic nerve divides into three major branches which pass through the superior orbital fissure:
frontal nerve
supraorbital nerve
supratrochlear nerve
lacrimal nerve
nasociliary nerve
posterior ethmoidal nerve
anterior ethmoidal nerve
external nasal nerve
long ciliary nerves
infratrochlear nerve
communicating branch to ciliary ganglion
Distribution
The ophthalmic nerve provides sensory innervation to the cornea, ciliary body, and iris; to the lacrimal gland and conjunctiva; to the part of the mucous membrane of the nasal cavity; and to the skin of the eyelids, eyebrow, forehead and nose.
It carries sensory branches from the eyes, conjunctiva, lacrimal gland, nasal cavity, frontal sinus, ethmoidal cells, falx cerebri, dura mater in the anterior cranial fossa, superior parts of the tentorium cerebelli, upper eyelid, dorsum of the nose, and anterior part of the scalp.
Roughly speaking, the ophthalmic nerve supplies general somatic afferents to the upper face, head, and eye:
Face: Upper eyelid and associated conjunctiva. Eyebrow, forehead, scalp all the way to the lambdoid suture.
Skull: Roof o
Document 2:::
The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation (ability to focus on near objects as in reading). The oculomotor nerve is derived from the basal plate of the embryonic midbrain. Cranial nerves IV and VI also participate in control of eye movement.
Structure
The oculomotor nerve originates from the third nerve nucleus at the level of the superior colliculus in the midbrain. The third nerve nucleus is located ventral to the cerebral aqueduct, on the pre-aqueductal grey matter. The fibers from the two third nerve nuclei located laterally on either side of the cerebral aqueduct then pass through the red nucleus. From the red nucleus fibers then pass via the substantia nigra to emerge from the substance of the brainstem at the oculomotor sulcus (a groove on the lateral wall of the interpeduncular fossa).
On emerging from the brainstem, the nerve is invested with a sheath of pia mater, and enclosed in a prolongation from the arachnoid. It passes between the superior cerebellar (below) and posterior cerebral arteries (above), and then pierces the dura mater anterior and lateral to the posterior clinoid process, passing between the free and attached borders of the tentorium cerebelli.
It traverses the cavernous sinus, above the other orbital nerves receiving in its course one or two filaments from the cavernous plexus of the sympathetic nervous system, and a communicating branch from the ophthalmic division of the trigeminal nerve. As the oculomotor nerve enters the orbit via the superior orbital fissure it then divides into a superior and an inferior branch.
Superior branch
The superior branch of the oculomotor nerve or
Document 3:::
Eyewire is a citizen science game from Sebastian Seung's Lab at Princeton University. It is a human-based computation game that uses players to map retinal neurons. Eyewire launched on December 10, 2012. The game utilizes data generated by the Max Planck Institute for Medical Research.
Eyewire gameplay is used for neuroscience research by enabling the reconstruction of morphological neuron data, which helps researchers model information-processing circuits.
Gameplay
The player is given a cube with a partially reconstructed neuron branch stretching through it. The player completes the reconstruction by coloring a 2D image with a 3D image generated simultaneously. Reconstructions are compared across players as each cube is submitted, yielding a consensus reconstruction that is later checked by experienced players.
Goal
Eyewire is used to advance the use of artificial intelligence in neuronal reconstruction. The project is also used in research determining how mammals see directional motion.
Methods
The activity of each neuron in a 350 × 300 × 60 μm3 portion of a retina was determined by two-photon microscopy. Using serial block-face scanning electron microscopy, the same volume was stained to bring out the contrast of the plasma membranes, sliced into layers by a microtome, and imaged using an electron microscope.
A neuron is selected by the researchers. The program chooses a cubic volume associated with that neuron for the player, along with an artificial intelligence's best guess for tracing the neuron through the two-dimensional images.
Publications
Accomplishments
Eyewire neurons featured at 2014 TED Conference Virtual Reality Exhibit.
Eyewire neurons featured at US Science and Engineering Expo in Washington, DC.
Eyewire won the National Science Foundation's 2013 International Visualization Challenge in the Games and Apps Category.
An Eyewire image by Alex Norton won MIT's 2014 Koch Image Gallery Competition.
Eyewire named one of Discover Magazines Top
Document 4:::
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.
What conveys signals received by the eye to the brain?
A. optic nerve
B. sensory nerve
C. motor nerve
D. sciatic nerve
Answer:
|
|
sciq-194
|
multiple_choice
|
What is the process of the transfer of pollen from an anther to a stigma in angiosperms called?
|
[
"wind",
"pollination",
"evolution",
"grabation"
] |
B
|
Relavent Documents:
Document 0:::
A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than to traverse the length of the pistil.
Pollen tubes were first discovered by Giovanni Battista Amici in the 19th century.
They are used as a model for understanding plant cell behavior. Research is ongoing to comprehend how the pollen tube responds to extracellular guidance signals to achieve fertilization.
Description
Pollen tubes are produced by the male gametophytes of seed plants. Pollen tubes act as conduits to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. Pollen tubes are unique to seed plants and their structures have evolved over their history since the Carboniferous period. Pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists because pollen tubes transport the male gametes produced by pollen grains to the female gametophyte. Once a pollen grain has implanted on a compatible stigma, its germination is initiated. During this process, the pollen grain begins to bulge outwards to form a tube-like structure, known as the pollen tube. The pollen tube structure rapidly descends down the length of the style via tip-directed growth, reaching rates of 1 cm/h, whilst carrying two non-motile sperm cells. Upon reaching the ovule the pollen tube ruptures, thereby delivering the sperm cells to the female gametophyte. In flowering plants a double fertilization event occurs. The first fertilization event produces a diplo
Document 1:::
The ABC model of flower development is a scientific model of the process by which flowering plants produce a pattern of gene expression in meristems that leads to the appearance of an organ oriented towards sexual reproduction, a flower. There are three physiological developments that must occur in order for this to take place: firstly, the plant must pass from sexual immaturity into a sexually mature state (i.e. a transition towards flowering); secondly, the transformation of the apical meristem's function from a vegetative meristem into a floral meristem or inflorescence; and finally the growth of the flower's individual organs. The latter phase has been modelled using the ABC model, which aims to describe the biological basis of the process from the perspective of molecular and developmental genetics.
An external stimulus is required in order to trigger the differentiation of the meristem into a flower meristem. This stimulus will activate mitotic cell division in the apical meristem, particularly on its sides where new primordia are formed. This same stimulus will also cause the meristem to follow a developmental pattern that will lead to the growth of floral meristems as opposed to vegetative meristems. The main difference between these two types of meristem, apart from the obvious disparity between the objective organ, is the verticillate (or whorled) phyllotaxis, that is, the absence of stem elongation among the successive whorls or verticils of the primordium. These verticils follow an acropetal development, giving rise to sepals, petals, stamens and carpels. Another difference from vegetative axillary meristems is that the floral meristem is "determined", which means that, once differentiated, its cells will no longer divide.
The identity of the organs present in the four floral verticils is a consequence of the interaction of at least three types of gene products, each with distinct functions. According to the ABC model, functions A and C are required in
Document 2:::
Detasseling corn is removing the pollen-producing flowers, the tassel, from the tops of corn (maize) plants and placing them on the ground. It is a form of pollination control, employed to cross-breed, or hybridize, two varieties of corn.
Fields of corn that will be detasseled are planted with two varieties of corn. Removing the tassels from all the plants of one variety leaves the grain that is growing on those plants to be fertilized by the tassels of the other, resulting in a hybrid. In addition to being more physically uniform, hybrid corn produces dramatically higher yields than corn produced by open pollination. With modern seed corn, the varieties to hybridize are carefully selected so that the new variety will exhibit specific traits found in the parent plants. The detasseling process usually involves the use of both specialized machines and human labor.
Machine detasseling
Nearly all detasseling is done in two steps; the field is first detasseled by machine and then detasseled manually. Machine detasseling itself is typically a two step process. Initially a detasseling machine called a "cutter" goes through the rows of corn to be detasseled and cuts off the top portion of the plant. This is done to make the field more uniform so that a "puller" machine can come through the corn field a few days later and pull the tassel out of the plant by catching it between two rollers moving at a high speed. This removes the majority of the tassels.
Detasseling machines typically remove 60 to 90 percent of the tassels in a seed corn field. This is far less than the 99.5 percent that need to be removed to produce the uniformity of seed desired by farmers. The main problems for the machines are that they are unable to adapt quickly to height differences in plants and they throw tassels into the air where they can become lodged in other corn plants and inadvertently allow pollination. It is desirable that the pulled tassel ends up on the ground to prevent this problem
Document 3:::
Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.
Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.
Pollen is infrequently used as food and food supplement. Because of agricultural practices, it is often contaminated by agricultural pesticides.
Structure and formation
Pollen itself is not the male gamete. It is a gametophyte, something that could be considered an entire organism, which then produces the male gamete. Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm nuclei.
Pollen comes in many different shapes. Some pollen grains are based on geodesic polyhedra like a soccer ball.
Formation
Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower. Pollen g
Document 4:::
Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.
Scope
Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin". There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.
First of all, morphology is comparative, meaning that the morphologist examines structures in many different plants of the same or different species, then draws comparisons and formulates ideas about similarities. When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany.
Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive str
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the process of the transfer of pollen from an anther to a stigma in angiosperms called?
A. wind
B. pollination
C. evolution
D. grabation
Answer:
|
|
sciq-175
|
multiple_choice
|
What are the areas located at fixed distances from the nucleus of the atom?
|
[
"orbit points",
"energy levels",
"molar levels",
"atomic regions"
] |
B
|
Relavent Documents:
Document 0:::
A fixed orbit is the concept, in atomic physics, where an electron is considered to remain in a specific orbit, at a fixed distance from an atom's nucleus, for a particular energy level.
The concept was promoted by quantum physicist Niels Bohr c. 1913.
The idea of the fixed orbit is considered a major component of the Bohr model (or Bohr theory).
Document 1:::
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The debye (D) is another unit of measurement used in atomic physics and chemistry.
Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.
Elementary definition
Often in physics the dimensions of a massive object can be ignored and can be treated as a pointlike object, i.e. a point particle. Point particles with electric charge are referred to as point charges. Two point charges, one with charge and the other one with charge separated by a distance , constitute an electric dipole (a simple case of an electric multipole). For this case, the electric dipole moment has a magnitude and is directed from the negative charge to the positive one. Some authors may split in half and use since this quantity is the distance between either charge and the center of the dipole, leading to a factor of two in the definition.
A stronger mathematical definition is to use vector algebra, since a quantity with magnitude and direction, like the dipole moment of two point charges, can be expressed in vector form where is the displacement vector pointing from the negative charge to the positive charge. The electric dipole moment vector also points from the negative charge to the positive charge. With this definition the dipole direction tends to align itself with an external electric field (and note that the electric flux lines produced by the charges of the dipole itself, which point from positive charge to negative charge then tend to oppose the flux lines of the external field). Note that this sign convention is used in physics, while the opposite sign convention for th
Document 2:::
Secondary electrons are electrons generated as ionization products. They are called 'secondary' because they are generated by other radiation (the primary radiation). This radiation can be in the form of ions, electrons, or photons with sufficiently high energy, i.e. exceeding the ionization potential. Photoelectrons can be considered an example of secondary electrons where the primary radiation are photons; in some discussions photoelectrons with higher energy (>50 eV) are still considered "primary" while the electrons freed by the photoelectrons are "secondary".
Applications
Secondary electrons are also the main means of viewing images in the scanning electron microscope (SEM). The range of secondary electrons depends on the energy. Plotting the inelastic mean free path as a function of energy often shows characteristics of the "universal curve" familiar to electron spectroscopists and surface analysts. This distance is on the order of a few nanometers in metals and tens of nanometers in insulators. This small distance allows such fine resolution to be achieved in the SEM.
For SiO2, for a primary electron energy of 100 eV, the secondary electron range is up to 20 nm from the point of incidence.
See also
Delta ray
Everhart-Thornley detector
Document 3:::
The subatomic scale is the domain of physical size that encompasses objects smaller than an atom. It is the scale at which the atomic constituents, such as the nucleus containing protons and neutrons, and the electrons in their orbitals, become apparent.
The subatomic scale includes the many thousands of times smaller subnuclear scale, which is the scale of physical size at which constituents of the protons and neutrons - particularly quarks - become apparent.
See also
Astronomical scale the opposite end of the spectrum
Subatomic particles
Document 4:::
The objective of the Thomson problem is to determine the minimum electrostatic potential energy configuration of electrons constrained to the surface of a unit sphere that repel each other with a force given by Coulomb's law. The physicist J. J. Thomson posed the problem in 1904 after proposing an atomic model, later called the plum pudding model, based on his knowledge of the existence of negatively charged electrons within neutrally-charged atoms.
Related problems include the study of the geometry of the minimum energy configuration and the study of the large behavior of the minimum energy.
Mathematical statement
The electrostatic interaction energy occurring between each pair of electrons of equal charges (, with the elementary charge of an electron) is given by Coulomb's law,
where is the electric constant and is the distance between each pair of electrons located at points on the sphere defined by vectors and , respectively.
Simplified units of and (the Coulomb constant) are used without loss of generality. Then,
The total electrostatic potential energy of each N-electron configuration may then be expressed as the sum of all pair-wise interaction energies
The global minimization of over all possible configurations of N distinct points is typically found by numerical minimization algorithms.
Thomson's problem is related to the 7th of the eighteen unsolved mathematics problems proposed by the mathematician Steve Smale — "Distribution of points on the 2-sphere".
The main difference is that in Smale's problem the function to minimise is not the electrostatic potential but a logarithmic potential given by A second difference is that Smale's question is about the asymptotic behaviour of the total potential when the number N of points goes to infinity, not for concrete values of N.
Example
The solution of the Thomson problem for two electrons is obtained when both electrons are as far apart as possible on opposite sides of the origin, , or
K
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the areas located at fixed distances from the nucleus of the atom?
A. orbit points
B. energy levels
C. molar levels
D. atomic regions
Answer:
|
|
sciq-7021
|
multiple_choice
|
The rate the magma cools determines what property of the rock?
|
[
"size",
"location",
"color",
"texture"
] |
D
|
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:::
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 3:::
Mineral tests are several methods which can help identify the mineral type. This is used widely in mineralogy, hydrocarbon exploration and general mapping. There are over 4000 types of minerals known with each one with different sub-classes. Elements make minerals and minerals make rocks so actually testing minerals in the lab and in the field is essential to understand the history of the rock which aids data, zonation, metamorphic history, processes involved and other minerals.
The following tests are used on specimen and thin sections through polarizing microscope.
Color
Color of the mineral. This is not mineral specific. For example quartz can be almost any color, shape and within many rock types.
Streak
Color of the mineral's powder. This can be found by rubbing the mineral onto a concrete. This is more accurate but not always mineral specific.
Lustre
This is the way light reflects from the mineral's surface. A mineral can be metallic (shiny) or non-metallic (not shiny).
Transparency
The way light travels through minerals. The mineral can be transparent (clear), translucent (cloudy) or opaque (none).
Specific gravity
Ratio between the weight of the mineral relative to an equal volume of water.
Mineral habitat
The shape of the crystal and habitat.
Magnetism
Magnetic or nonmagnetic. Can be tested by using a magnet or a compass. This does not apply to all ion minerals (for example, pyrite).
Cleavage
Number, behaviour, size and way cracks fracture in the mineral.
UV fluorescence
Many minerals glow when put under a UV light.
Radioactivity
Is the mineral radioactive or non-radioactive? This is measured by a Geiger counter.
Taste
This is not recommended. Is the mineral salty, bitter or does it have no taste?
Bite Test
This is not recommended. This involves biting a mineral to see if its generally soft or hard. This was used in early gold exploration to tell the difference between pyrite (fools gold, hard) and gold (soft).
Hardness
The Mohs Hardn
Document 4:::
Ringwoodite is a high-pressure phase of Mg2SiO4 (magnesium silicate) formed at high temperatures and pressures of the Earth's mantle between depth. It may also contain iron and hydrogen. It is polymorphous with the olivine phase forsterite (a magnesium iron silicate).
Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure. In this case two hydroxide ions usually take the place of a magnesium ion and two oxide ions.
Combined with evidence of its occurrence deep in the Earth's mantle, this suggests that there is from one to three times the world ocean's equivalent of water in the mantle transition zone from 410 to 660 km deep.
This mineral was first identified in the Tenham meteorite in 1969, and is inferred to be present in large quantities in the Earth's mantle.
Olivine, wadsleyite, and ringwoodite are polymorphs found in the upper mantle of the earth. At depths greater than about , other minerals, including some with the perovskite structure, are stable. The properties of these minerals determine many of the properties of the mantle.
Ringwoodite was named after the Australian earth scientist Ted Ringwood (1930–1993), who studied polymorphic phase transitions in the common mantle minerals olivine and pyroxene at pressures equivalent to depths as great as about 600 km.
Characteristics
Ringwoodite is polymorphous with forsterite, Mg2SiO4, and has a spinel structure. Spinel group minerals crystallize in the isometric system with an octahedral habit. Olivine is most abundant in the upper mantle, above about ; the olivine polymorphs wadsleyite and ringwoodite are thought to dominate the transition zone of the mantle, a zone present from about 410 to 660 km depth.
Ringwoodite is thought to be the most abundant mineral phase in the lower part of Earth's transition zone. The physical and chemical property of this mineral partly determine properties of the mantle at those depths. The pressure r
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The rate the magma cools determines what property of the rock?
A. size
B. location
C. color
D. texture
Answer:
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|
ai2_arc-997
|
multiple_choice
|
Students are learning about different types of waves. Which is the least likely way for the students to generate a wave?
|
[
"by tossing a ball in the air",
"by shaking the ends of a rope",
"by throwing a pebble into a pool of water",
"by pulling on a coiled spring toy"
] |
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:::
This is a list of wave topics.
0–9
21 cm line
A
Abbe prism
Absorption spectroscopy
Absorption spectrum
Absorption wavemeter
Acoustic wave
Acoustic wave equation
Acoustics
Acousto-optic effect
Acousto-optic modulator
Acousto-optics
Airy disc
Airy wave theory
Alfvén wave
Alpha waves
Amphidromic point
Amplitude
Amplitude modulation
Animal echolocation
Antarctic Circumpolar Wave
Antiphase
Aquamarine Power
Arrayed waveguide grating
Artificial wave
Atmospheric diffraction
Atmospheric wave
Atmospheric waveguide
Atom laser
Atomic clock
Atomic mirror
Audience wave
Autowave
Averaged Lagrangian
B
Babinet's principle
Backward wave oscillator
Bandwidth-limited pulse
beat
Berry phase
Bessel beam
Beta wave
Black hole
Blazar
Bloch's theorem
Blueshift
Boussinesq approximation (water waves)
Bow wave
Bragg diffraction
Bragg's law
Breaking wave
Bremsstrahlung, Electromagnetic radiation
Brillouin scattering
Bullet bow shockwave
Burgers' equation
Business cycle
C
Capillary wave
Carrier wave
Cherenkov radiation
Chirp
Ernst Chladni
Circular polarization
Clapotis
Closed waveguide
Cnoidal wave
Coherence (physics)
Coherence length
Coherence time
Cold wave
Collimated light
Collimator
Compton effect
Comparison of analog and digital recording
Computation of radiowave attenuation in the atmosphere
Continuous phase modulation
Continuous wave
Convective heat transfer
Coriolis frequency
Coronal mass ejection
Cosmic microwave background radiation
Coulomb wave function
Cutoff frequency
Cutoff wavelength
Cymatics
D
Damped wave
Decollimation
Delta wave
Dielectric waveguide
Diffraction
Direction finding
Dispersion (optics)
Dispersion (water waves)
Dispersion relation
Dominant wavelength
Doppler effect
Doppler radar
Douglas Sea Scale
Draupner wave
Droplet-shaped wave
Duhamel's principle
E
E-skip
Earthquake
Echo (phenomenon)
Echo sounding
Echolocation (animal)
Echolocation (human)
Eddy (fluid dynamics)
Edge wave
Eikonal equation
Ekman layer
Ekman spiral
Ekman transport
El Niño–Southern Oscillation
El
Document 2:::
A wave tank is a laboratory setup for observing the behavior of surface waves. The typical wave tank is a box filled with liquid, usually water, leaving open or air-filled space on top. At one end of the tank, an actuator generates waves; the other end usually has a wave-absorbing surface. A similar device is the ripple tank, which is flat and shallow and used for observing patterns of surface waves from above.
Wave basin
A wave basin is a wave tank which has a width and length of comparable magnitude, often used for testing ships, offshore structures and three-dimensional models of harbors (and their breakwaters).
Wave flume
A wave flume (or wave channel) is a special sort of wave tank: the width of the flume is much less than its length. The generated waves are therefore – more or less – two-dimensional in a vertical plane (2DV), meaning that the orbital flow velocity component in the direction perpendicular to the flume side wall is much smaller than the other two components of the three-dimensional velocity vector. This makes a wave flume a well-suited facility to study near-2DV structures, like cross-sections of a breakwater. Also (3D) constructions providing little blockage to the flow may be tested, e.g. measuring wave forces on vertical cylinders with a diameter much less than the flume width.
Wave flumes may be used to study the effects of water waves on coastal structures, offshore structures, sediment transport and other transport phenomena.
The waves are most often generated with a mechanical wavemaker, although there are also wind–wave flumes with (additional) wave generation by an air flow over the water – with the flume closed above by a roof above the free surface. The wavemaker frequently consists of a translating or rotating rigid wave board. Modern wavemakers are computer controlled, and can generate besides periodic waves also random waves, solitary waves, wave groups or even tsunami-like wave motion. The wavemaker is at one end of the w
Document 3:::
In physics, a mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves can be produced only in media which possess elasticity and inertia. There are three types of mechanical waves: transverse waves, longitudinal waves, and surface waves. Some of the most common examples of mechanical waves are water waves, sound waves, and seismic waves.
Like all waves, mechanical waves transport energy. This energy propagates in the same direction as the wave. A wave requires an initial energy input; once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, electromagnetic waves require no medium, but can still travel through one.
Transverse wave
A transverse wave is the form of a wave in which particles of medium vibrate about their mean position perpendicular to the direction of the motion of the wave.
To see an example, move an end of a Slinky (whose other end is fixed) to the left-and-right of the Slinky, as opposed to to-and-fro. Light also has properties of a transverse wave, although it is an electromagnetic wave.
Longitudinal wave
Longitudinal waves cause the medium to vibrate parallel to the direction of the wave. It consists of multiple compressions and rarefactions. The rarefaction is the farthest distance apart in the longitudinal wave and the compression is the closest distance together. The speed of the longitudinal wave is increased in higher index of refraction, due to the closer proximity of the atoms in the medium that is being compressed. Sound is a longitudinal wave.
Surface waves
This type of wave travels along the surface or interface between two media. An example of a surface wave would be waves in a pool, or in an ocean
Document 4:::
A waveguide is a structure that guides waves by restricting the transmission of energy to one direction. Common types of waveguides include acoustic waveguides which direct sound, optical waveguides which direct light, and radio-frequency waveguides which direct electromagnetic waves other than light like radio waves.
Without the physical constraint of a waveguide, waves would expand into three-dimensional space and their intensities would decrease according to the inverse square law.
There are different types of waveguides for different types of waves. The original and most common meaning is a hollow conductive metal pipe used to carry high frequency radio waves, particularly microwaves. Dielectric waveguides are used at higher radio frequencies, and transparent dielectric waveguides and optical fibers serve as waveguides for light. In acoustics, air ducts and horns are used as waveguides for sound in musical instruments and loudspeakers, and specially-shaped metal rods conduct ultrasonic waves in ultrasonic machining.
The geometry of a waveguide reflects its function; in addition to more common types that channel the wave in one dimension, there are two-dimensional slab waveguides which confine waves to two dimensions. The frequency of the transmitted wave also dictates the size of a waveguide: each waveguide has a cutoff wavelength determined by its size and will not conduct waves of greater wavelength; an optical fiber that guides light will not transmit microwaves which have a much larger wavelength. Some naturally occurring structures can also act as waveguides. The SOFAR channel layer in the ocean can guide the sound of whale song across enormous distances.
Any shape of cross section of waveguide can support EM waves. Irregular shapes are difficult to analyse. Commonly used waveguides are rectangular and circular in shape.
Uses
The uses of waveguides for transmitting signals were known even before the term was coined. The phenomenon of sound waves g
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Students are learning about different types of waves. Which is the least likely way for the students to generate a wave?
A. by tossing a ball in the air
B. by shaking the ends of a rope
C. by throwing a pebble into a pool of water
D. by pulling on a coiled spring toy
Answer:
|
|
sciq-3943
|
multiple_choice
|
In eukaryotes, the cell cycle consists of a long preparatory period, called __________ before undergoing cell division.
|
[
"metaphase",
"interphase",
"mitosis",
"outerphase"
] |
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:::
Induced cell cycle arrest is the use of a chemical or genetic manipulation to artificially halt progression through the cell cycle. Cellular processes like genome duplication and cell division stop. It can be temporary or permanent. It is an artificial activation of naturally occurring cell cycle checkpoints, induced by exogenous stimuli controlled by an experimenter.
Model organisms
In an academic research context, cell cycle arrest is typically performed in model organisms and cell extracts, such as Saccharomyces cervisiae (yeast) or Xenopus oocytes (frog eggs). Frog egg cell extracts have been used extensively in cell cycle research because they are relatively large, reaching a diameter of 1mm, and so contain large amounts of protein, making protein levels more easily measurable.
Purposes
There are a variety of reasons a researcher may want to temporarily or permanently prevent progress through the cell cycle.
Cell cycle synchronization
In some experiments, a researcher may want to control and synchronize the time when a group of cells progress to the next phase of the cell cycle. The cells can be induced to arrest as they arrive (at different time points) at a certain phase, so that when the arrest is lifted (for instance, rescuing cell cycle progression by introducing another chemical) all the cells resume cell cycle progression at the same time. In addition to this method acting as a scientific control for when the cells resume the cell cycle, this can be used to investigate necessity and sufficiency.
Another reason synchrony is important is the control for amount of DNA content, which varies at different parts of the cell cycle based on whether DNA replication has occurred since the last round of completed mitosis and cytokinesis.
Furthermore, synchronization of large numbers of cells into the same phase allows for the collection of large enough groups of cells in the same cycle for the use in other assays, such as western blot and RNA sequencing.
D
Document 2:::
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 3:::
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 4:::
A synchronous or synchronized culture is a microbiological culture or a cell culture that contains cells that are all in the same growth stage.
As numerous factors influence the cell cycle (some of them stochastic) normal cultures have cells in all stages of the cell cycle. Obtaining a culture with a unified cell-cycle stage is useful for biological research where a particular stage in the cell cycle is desired (such as the culturing of parasitized cells). Since cells are too small for certain research techniques, a synchronous culture can be treated as a single cell; the number of cells in the culture can be easily estimated, and quantitative experimental results can simply be divided in the number of cells to obtain values that apply to a single cell. Synchronous cultures have been extensively used to address questions regarding cell cycle and growth, and the effects of various factors on these.
Methods
Synchronous cultures can be obtained in several ways:
External conditions can be changed, so as to arrest growth of all cells in the culture, and then changed again to resume growth. The newly growing cells are now all starting to grow at the same stage, and they are synchronized. For example, for photosynthetic cells, light can be eliminated for several hours and then re-introduced. Another method is to eliminate an essential nutrient from the growth medium and later re-introduce it.
Cell growth can also be arrested using chemical growth inhibitors. After growth has completely stopped for all cells, the inhibitor can be removed from the culture and the cells then begin to grow synchronously. Nocodazole, for example, has been used in biological research for synchronization, although some evidence suggests it may lack such ability to synchronize cells.
Cells in different growth stages have different physical properties. Cells in a culture can thus be physically separated based on their density or size, for instance. This can be achieved using centrifugation (f
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In eukaryotes, the cell cycle consists of a long preparatory period, called __________ before undergoing cell division.
A. metaphase
B. interphase
C. mitosis
D. outerphase
Answer:
|
|
scienceQA-12092
|
multiple_choice
|
Which of the following organisms is the tertiary consumer in this food web?
|
[
"sea otter",
"sea urchin",
"phytoplankton",
"kelp bass"
] |
D
|
Tertiary consumers eat secondary consumers. So, in a food web, tertiary consumers have arrows pointing to them from secondary consumers. Secondary consumers have arrows pointing to them from primary consumers. And primary consumers have arrows pointing to them from producers.
The sea otter has an arrow pointing to it from the sea urchin. The sea urchin is not a secondary consumer. So, the sea otter is not a tertiary consumer.
The sea urchin has an arrow pointing to it from the kelp. The kelp is not a secondary consumer. So, the sea urchin is not a tertiary consumer.
The phytoplankton does not have any arrows pointing to it. So, the phytoplankton is not a tertiary consumer.
The kelp bass has arrows pointing to it from the plainfin midshipman and the black rockfish. The plainfin midshipman and the black rockfish are secondary consumers, so the kelp bass is a tertiary consumer.
The orca has an arrow pointing to it from the sea otter. The sea otter is a secondary consumer, so the orca is a tertiary consumer.
|
Relavent Documents:
Document 0:::
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 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:::
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
Document 3:::
Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some are found in freshwater. In addition, a few species of land crabs are eaten, for example Cardisoma guanhumi in the Caribbean. Shellfish are among the most common food allergens.
Despite the name, shellfish are not fish. Most shellfish are low on the food chain and eat a diet composed primarily of phytoplankton and zooplankton. Many varieties of shellfish, and crustaceans in particular, are actually closely related to insects and arachnids; crustaceans make up one of the main subphyla of the phylum Arthropoda. Molluscs include cephalopods (squids, octopuses, cuttlefish) and bivalves (clams, oysters), as well as gastropods (aquatic species such as whelks and winkles; land species such as snails and slugs).
Molluscs used as a food source by humans include many species of clams, mussels, oysters, winkles, and scallops. Some crustaceans that are commonly eaten are shrimp, lobsters, crayfish, crabs and barnacles. Echinoderms are not as frequently harvested for food as molluscs and crustaceans; however, sea urchin gonads are quite popular in many parts of the world, where the live delicacy is harder to transport.
Though some shellfish harvesting has been unsustainable, and shrimp farming has been destructive in some parts of the world, shellfish farming can be important to environmental restoration, by developing reefs, filtering water and eating biomass.
Terminology
The term "shellfish" is used both broadly and specifically. In common parlance, as in "having shellfish for dinner", it can refer to anything from clams and oysters to lobster and shrimp. For regulatory purposes it is often narrowly defined as filter-feeding molluscs such as clams, mussels, and oyster to the exclusion of crustaceans and all else.
Althoug
Document 4:::
Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin vorare, meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγεῖν (), meaning "to eat".
Evolutionary history
The evolution of feeding is varied with some feeding strategies evolving several times in independent lineages. In terrestrial vertebrates, the earliest forms were large amphibious piscivores 400 million years ago. While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, other tetrapods (carnivory), and later, plants (herbivory). Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation (in contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials).
Evolutionary adaptations
The specialization of organisms towards specific food sources is one of the major causes of evolution of form and function, such as:
mouth parts and teeth, such as in whales, vampire bats, leeches, mosquitos, predatory animals such as felines and fishes, etc.
distinct forms of beaks in birds, such as in hawks, woodpeckers, pelicans, hummingbirds, parrots, kingfishers, etc.
specialized claws and other appendages, for apprehending or killing (including fingers in primates)
changes in body colour for facilitating camouflage, disguise, setting up traps for preys, etc.
changes in the digestive system, such as the system of stomachs of herbivores, commensalism and symbiosis
Classification
By mode of ingestion
There are many modes of feeding that animals exhibit, including:
Filter feeding: obtaining nutrients from particles suspended in water
Deposit feeding: obtaining nutrients from particles suspended in soil
Fluid feeding: obtaining nutrients by consuming other organisms' fluids
Bulk feeding: obtaining nutrients by eating all of an organism.
Ram feeding and suction feeding: in
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 tertiary consumer in this food web?
A. sea otter
B. sea urchin
C. phytoplankton
D. kelp bass
Answer:
|
sciq-10261
|
multiple_choice
|
What functions as a framework that reinforces the shape of the leaf?
|
[
"the central structure",
"the stylised structure",
"the vascular structure",
"the normal structure"
] |
C
|
Relavent Documents:
Document 0:::
Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.
Scope
Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin". There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.
First of all, morphology is comparative, meaning that the morphologist examines structures in many different plants of the same or different species, then draws comparisons and formulates ideas about similarities. When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany.
Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive str
Document 1:::
The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article.
The terms listed here all are supported by technical and professional usage, but they cannot be represented as mandatory or undebatable; readers must use their judgement. Authors often use terms arbitrarily, or coin them to taste, possibly in ignorance of established terms, and it is not always clear whether because of ignorance, or personal preference, or because usages change with time or context, or because of variation between specimens, even specimens from the same plant. For example, whether to call leaves on the same tree "acuminate", "lanceolate", or "linear" could depend on individual judgement, or which part of the tree one collected them from. The same cautions might apply to "caudate", "cuspidate", and "mucronate", or to "crenate", "dentate", and "serrate."
Another problem is to establish definitions that meet all cases or satisfy all authorities and readers. For example, it seems altogether reasonable to define a mucro as "a small sharp point as a continuation of the midrib", but it may not be clear how small is small enough, how sharp is sharp enough, how hard the point must be, and what to call the point when one cannot tell whether the leaf has a midrib at all. Various authors or field workers might come to incompatible conclusions, or might try to compromise by qualifying terms so vaguely that a description of a particular plant practically loses its value.
Use of these terms is not restricted to leaves, but may be applied to morphology of other parts of plants, e.g. bracts, bracteoles, stipules, sepals, petals, carpels or scales. Some of these terms are als
Document 2:::
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
The stem is normally divided into nodes and internodes:
The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaves, conifer cones, or flowers). Adventitious roots may also be produced from the nodes. Vines may produce tendrils from nodes.
The internodes distance one node from another.
The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other structures like leaves or flowers.
In most plants, stems are located above the soil surface, but some plants have underground stems.
Stems have several main functions:
Support for and the elevation of leaves, flowers, and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem.
Storage of nutrients.
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
Photosynthesis.
Stems have two pipe-like tissues called xylem and phloem. The xylem tissue arises from the cell facing inside and transports water by the action of transpiration pull, capillary action, and root pressure. The phloem tissue arises from the cell facing outside and consists of sieve tubes and their companion cells. The function of phloem tissue is to distribute food from photosynthetic tissue to other tissues. The two tissues are separated by cambium, a tis
Document 3:::
The leaf angle distribution (or LAD) of a plant canopy refers to the mathematical description of the angular orientation of the leaves in the vegetation. Specifically, if each leaf is conceptually represented by a small flat plate, its orientation can be described with the zenith and the azimuth angles of the surface normal to that plate. If the leaf has a complex structure and is not flat, it may be necessary to approximate the actual leaf by a set of small plates, in which case there may be a number of leaf normals and associated angles. The LAD describes the statistical distribution of these angles.
Examples of leaf angle distributions
Different plant canopies exhibit different LADs: For instance, grasses and willows have their leaves largely hanging vertically (such plants are said to have an erectophile LAD), while oaks tend to maintain their leaves more or less horizontally (these species are known as having a planophile LAD). In some tree species, leaves near the top of the canopy follow an erectophile LAD while those at the bottom of the canopy are more planophile. This may be interpreted as a strategy by that plant species to maximize exposure to light, an important constraint to growth and development. Yet other species (notably sunflower) are capable of reorienting their leaves throughout the day to optimize exposure to the Sun: this is known as heliotropism.
Importance of LAD
The LAD of a plant canopy has a significant impact on the reflectance, transmittance and absorption of solar light in the vegetation layer, and thus also on its growth and development. LAD can also serve as a quantitative index to monitor the state of the plants, as wilting usually results in more erectophile LADs. Models of radiation transfer need to take this distribution into account to predict, for instance, the albedo or the productivity of the canopy.
Measuring LAD
Accurately measuring the statistical properties of leaf angle distributions is not a trivial matter, especi
Document 4:::
In botany, available space theory (also known as first available space theory) is a theory used to explain why most plants have an alternating leaf pattern on their stems. The theory states that the location of a new leaf on a stem is determined by the physical space between existing leaves. In other words, the location of a new leaf on a growing stem is directly related to the amount of space between the previous two leaves. Building on ideas first put forth by Hoffmeister in 1868, Snow and Snow hypothesized in 1947 that leaves sprouted in the first available space on the stem.
See also
Repulsion theory
Phyllotaxis
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What functions as a framework that reinforces the shape of the leaf?
A. the central structure
B. the stylised structure
C. the vascular structure
D. the normal structure
Answer:
|
|
sciq-10062
|
multiple_choice
|
What kind of variation does a rate measure?
|
[
"environment to time",
"value to time",
"construction to time",
"property to time"
] |
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:::
Curriculum-based measurement, or CBM, is also referred to as a general outcomes measures (GOMs) of a student's performance in either basic skills or content knowledge.
Early history
CBM began in the mid-1970s with research headed by Stan Deno at the University of Minnesota. Over the course of 10 years, this work led to the establishment of measurement systems in reading, writing, and spelling that were: (a) easy to construct, (b) brief in administration and scoring, (c) had technical adequacy (reliability and various types of validity evidence for use in making educational decisions), and (d) provided alternate forms to allow time series data to be collected on student progress. This focus in the three language arts areas eventually was expanded to include mathematics, though the technical research in this area continues to lag that published in the language arts areas. An even later development was the application of CBM to middle-secondary areas: Espin and colleagues at the University of Minnesota developed a line of research addressing vocabulary and comprehension (with the maze) and by Tindal and colleagues at the University of Oregon developed a line of research on concept-based teaching and learning.
Increasing importance
Early research on the CBM quickly moved from monitoring student progress to its use in screening, normative decision-making, and finally benchmarking. Indeed, with the implementation of the No Child Left Behind Act in 2001, and its focus on large-scale testing and accountability, CBM has become increasingly important as a form of standardized measurement that is highly related to and relevant for understanding student's progress toward and achievement of state standards.
Key feature
Probably the key feature of CBM is its accessibility for classroom application and implementation. It was designed to provide an experimental analysis of the effects from interventions, which includes both instruction and curriculum. This is one of the most imp
Document 2:::
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
Document 3:::
Progress tests are longitudinal, feedback oriented educational assessment tools for the evaluation of development and sustainability of cognitive knowledge during a learning process. A progress test is a written knowledge exam (usually involving multiple choice questions) that is usually administered to all students in the "A" program at the same time and at regular intervals (usually twice to four times yearly) throughout the entire academic program. The test samples the complete knowledge domain expected of new graduates upon completion of their courses, regardless of the year level of the student). The differences between students’ knowledge levels show in the test scores; the further a student has progressed in the curriculum the higher the scores. As a result, these resultant scores provide a longitudinal, repeated measures, curriculum-independent assessment of the objectives (in knowledge) of the entire programme.
History
Since its inception in the late 1970s at both Maastricht University and the University of Missouri–Kansas City independently, the progress test of applied knowledge has been increasingly used in medical and health sciences programs across the globe. They are well established and increasingly used in medical education in both undergraduate and postgraduate medical education. They are used formatively and summatively.
Use in academic programs
The progress test is currently used by national progress test consortia in the United Kingdom, Italy, The Netherlands, in Germany (including Austria), and in individual schools in Africa, Saudi Arabia, South East Asia, the Caribbean, Australia, New Zealand, Sweden, Finland, UK, and the USA. The National Board of Medical Examiners in the USA also provides progress testing in various countries The feasibility of an international approach to progress testing has been recently acknowledged and was first demonstrated by Albano et al. in 1996, who compared test scores across German, Dutch and Italian medi
Document 4:::
Advanced Placement (AP) Calculus (also known as AP Calc, Calc AB / Calc BC or simply AB / BC) is a set of two distinct Advanced Placement calculus courses and exams offered by the American nonprofit organization College Board. AP Calculus AB covers basic introductions to limits, derivatives, and integrals. AP Calculus BC covers all AP Calculus AB topics plus additional topics (including integration by parts, Taylor series, parametric equations, vector calculus, and polar coordinate functions).
AP Calculus AB
AP Calculus AB is an Advanced Placement calculus course. It is traditionally taken after precalculus and is the first calculus course offered at most schools except for possibly a regular calculus class. The Pre-Advanced Placement pathway for math helps prepare students for further Advanced Placement classes and exams.
Purpose
According to the College Board:
Topic outline
The material includes the study and application of differentiation and integration, and graphical analysis including limits, asymptotes, and continuity. An AP Calculus AB course is typically equivalent to one semester of college calculus.
Analysis of graphs (predicting and explaining behavior)
Limits of functions (one and two sided)
Asymptotic and unbounded behavior
Continuity
Derivatives
Concept
At a point
As a function
Applications
Higher order derivatives
Techniques
Integrals
Interpretations
Properties
Applications
Techniques
Numerical approximations
Fundamental theorem of calculus
Antidifferentiation
L'Hôpital's rule
Separable differential equations
AP Calculus BC
AP Calculus BC is equivalent to a full year regular college course, covering both Calculus I and II. After passing the exam, students may move on to Calculus III (Multivariable Calculus).
Purpose
According to the College Board,
Topic outline
AP Calculus BC includes all of the topics covered in AP Calculus AB, as well as the following:
Convergence tests for series
Taylor series
Parametric equations
Polar functions (inclu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of variation does a rate measure?
A. environment to time
B. value to time
C. construction to time
D. property to time
Answer:
|
|
sciq-2342
|
multiple_choice
|
What kind of system do echinoderms possess?
|
[
"autonomic nerous system",
"primitive respiratory",
"photosynthetic",
"water-based circulatory"
] |
D
|
Relavent Documents:
Document 0:::
Aquatic respiration is the process whereby an aquatic organism exchanges respiratory gases with water, obtaining oxygen from oxygen dissolved in water and excreting carbon dioxide and some other metabolic waste products into the water.
Unicellular and simple small organisms
In very small animals, plants and bacteria, simple diffusion of gaseous metabolites is sufficient for respiratory function and no special adaptations are found to aid respiration. Passive diffusion or active transport are also sufficient mechanisms for many larger aquatic animals such as many worms, jellyfish, sponges, bryozoans and similar organisms. In such cases, no specific respiratory organs or organelles are found.
Higher plants
Although higher plants typically use carbon dioxide and excrete oxygen during photosynthesis, they also respire and, particularly during darkness, many plants excrete carbon dioxide and require oxygen to maintain normal functions. In fully submerged aquatic higher plants specialised structures such as stoma on leaf surfaces to control gas interchange. In many species, these structures can be controlled to be open or closed depending on environmental conditions. In conditions of high light intensity and relatively high carbonate ion concentrations, oxygen may be produced in sufficient quantities to form gaseous bubbles on the surface of leaves and may produce oxygen super-saturation in the surrounding water body.
Animals
All animals that practice truly aquatic respiration are poikilothermic. All aquatic homeothermic animals and birds including cetaceans and penguins are air breathing despite a fully aquatic life-style.
Echinoderms
Echinoderms have a specialised water vascular system which provides a number of functions including providing the hydraulic power for tube feet but also serves to convey oxygenated sea water into the body and carry waste water out again. In many genera, the water enters through a madreporite, a sieve like structure on the upper surfac
Document 1:::
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 2:::
Polydactyly in stem-tetrapods should here be understood as having more than five digits to the finger or foot, a condition that was the natural state of affairs in the earliest stegocephalians during the evolution of terrestriality. The polydactyly in these largely aquatic animals is not to be confused with polydactyly in the medical sense, i.e. it was not an anomaly in the sense it was not a congenital condition of having more than the typical number of digits for a given taxon. Rather, it appears to be a result of the early evolution from a limb with a fin rather than digits.
"Living tetrapods, such as the frogs, turtles, birds and mammals, are a subgroup of the tetrapod lineage. The lineage also includes finned and limbed tetrapods that are more closely related to living tetrapods than to living lungfishes." Tetrapods evolved from animals with fins such as found in lobe-finned fishes. From this condition a new pattern of limb formation evolved, where the development axis of the limb rotated to sprout secondary axes along the lower margin, giving rise to a variable number of very stout skeletal supports for a paddle-like foot. The condition is thought to have arisen from the loss of the fin ray-forming proteins actinodin 1 and actinodin 2 or modification of the expression of HOXD13. It is still unknown why exactly this happens. "SHH is produced by the mesenchymal cells of the zone of polarizing activity (ZPA) found at the posterior margin of the limbs of all vertebrates with paired appendages, including the most primitive chondrichthyian fishes. Its expression is driven by a well-conserved limb-specific enhancer called the ZRS (zone of polarizing region activity regulatory sequence) that is located approximately 1 Mb upstream of the coding sequence of Shh."
Devonian taxa were polydactylous. Acanthostega had eight digits on both the hindlimbs and forelimbs. Ichthyostega, which was both more derived and more specialized, had seven digits on the hindlimb, though th
Document 3:::
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 4:::
History of Animals (, Ton peri ta zoia historion, "Inquiries on Animals"; , "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. It was written in the fourth century BC; Aristotle died in 322 BC.
Generally seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the what (the existing facts about animals) prior to establishing the why (the causes of these characteristics). The book is thus an attempt to apply philosophy to part of the natural world. Throughout the work, Aristotle seeks to identify differences, both between individuals and between groups. A group is established when it is seen that all members have the same set of distinguishing features; for example, that all birds have feathers, wings, and beaks. This relationship between the birds and their features is recognized as a universal.
The History of Animals contains many accurate eye-witness observations, in particular of the marine biology around the island of Lesbos, such as that the octopus had colour-changing abilities and a sperm-transferring tentacle, that the young of a dogfish grow inside their mother's body, or that the male of a river catfish guards the eggs after the female has left. Some of these were long considered fanciful before being rediscovered in the nineteenth century. Aristotle has been accused of making errors, but some are due to misinterpretation of his text, and others may have been based on genuine observation. He did however make somewhat uncritical use of evidence from other people, such as travellers and beekeepers.
The History of Animals had a powerful influence on zoology for some two thousand years. It continued to be a primary source of knowledge until zoologists in the sixteenth century, such as Conrad Gessner, all influenced by Aristotle, wrote their own studies of the subject.
Context
Aristotle (384–322 BC) studied at Plat
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of system do echinoderms possess?
A. autonomic nerous system
B. primitive respiratory
C. photosynthetic
D. water-based circulatory
Answer:
|
|
sciq-802
|
multiple_choice
|
What change the physical properties of solvents?
|
[
"molecules",
"chemical reactions",
"cells",
"solutes"
] |
D
|
Relavent Documents:
Document 0:::
Physical biochemistry is a branch of biochemistry that deals with the theory, techniques, and methodology used to study the physical chemistry of biomolecules.
It also deals with the mathematical approaches for the analysis of biochemical reaction and the modelling of biological systems. It provides insight into the structure of macromolecules, and how chemical structure influences the physical properties of a biological substance.
It involves the use of physics, physical chemistry principles, and methodology to study biological systems. It employs various physical chemistry techniques such as chromatography, spectroscopy, Electrophoresis, X-ray crystallography, electron microscopy, and hydrodynamics.
See also
Physical chemistry
Document 1:::
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
Document 2:::
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
Document 3:::
Solvent exposure occurs when a chemical, material, or person comes into contact with a solvent. Chemicals can be dissolved in solvents, materials such as polymers can be broken down chemically by solvents, and people can develop certain ailments from exposure to solvents both organic and inorganic.
Some common solvents include acetone, methanol, tetrahydrofuran, dimethylsulfoxide, and water among countless others.
In biology, the solvent exposure of an amino acid in a protein measures to what extent the amino acid is accessible to the solvent (usually water) surrounding the protein. Generally speaking, hydrophobic amino acids will be buried inside the protein and thus shielded from the solvent, while hydrophilic amino acids will be close to the surface and thus exposed to the solvent. However, as with many biological rules exceptions are common and hydrophilic residues are frequently found to be buried in the native structure and vice versa.
Solvent exposure can be numerically described by several measures, the most popular measures being accessible surface area and relative accessible surface area. Other measures are for example:
Contact number: number of amino acid neighbors within a sphere around the amino acid.
Residue depth: distance of the amino acid to the molecular surface.
Half sphere exposure: number of amino acid neighbors within two half spheres around the amino acid.
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What change the physical properties of solvents?
A. molecules
B. chemical reactions
C. cells
D. solutes
Answer:
|
|
sciq-1727
|
multiple_choice
|
Which atomic model shows that the distances of electrons from the nucleus is not a fixed value?
|
[
"the quantum model",
"the distance model",
"the electron model",
"the equivocation model"
] |
A
|
Relavent Documents:
Document 0:::
The objective of the Thomson problem is to determine the minimum electrostatic potential energy configuration of electrons constrained to the surface of a unit sphere that repel each other with a force given by Coulomb's law. The physicist J. J. Thomson posed the problem in 1904 after proposing an atomic model, later called the plum pudding model, based on his knowledge of the existence of negatively charged electrons within neutrally-charged atoms.
Related problems include the study of the geometry of the minimum energy configuration and the study of the large behavior of the minimum energy.
Mathematical statement
The electrostatic interaction energy occurring between each pair of electrons of equal charges (, with the elementary charge of an electron) is given by Coulomb's law,
where is the electric constant and is the distance between each pair of electrons located at points on the sphere defined by vectors and , respectively.
Simplified units of and (the Coulomb constant) are used without loss of generality. Then,
The total electrostatic potential energy of each N-electron configuration may then be expressed as the sum of all pair-wise interaction energies
The global minimization of over all possible configurations of N distinct points is typically found by numerical minimization algorithms.
Thomson's problem is related to the 7th of the eighteen unsolved mathematics problems proposed by the mathematician Steve Smale — "Distribution of points on the 2-sphere".
The main difference is that in Smale's problem the function to minimise is not the electrostatic potential but a logarithmic potential given by A second difference is that Smale's question is about the asymptotic behaviour of the total potential when the number N of points goes to infinity, not for concrete values of N.
Example
The solution of the Thomson problem for two electrons is obtained when both electrons are as far apart as possible on opposite sides of the origin, , or
K
Document 1:::
The classical electron radius is a combination of fundamental physical quantities that define a length scale for problems involving an electron interacting with electromagnetic radiation. It links the classical electrostatic self-interaction energy of a homogeneous charge distribution to the electron's relativistic mass-energy. According to modern understanding, the electron is a point particle with a point charge and no spatial extent. Nevertheless, it is useful to define a length that characterizes electron interactions in atomic-scale problems. The classical electron radius is given as
where is the elementary charge, is the electron mass, is the speed of light, and is the permittivity of free space. This numerical value is several times larger than the radius of the proton.
In cgs units, the permittivity factor and do not enter, but the classical electron radius has the same value.
The classical electron radius is sometimes known as the Lorentz radius or the Thomson scattering length. It is one of a trio of related scales of length, the other two being the Bohr radius and the reduced Compton wavelength of the electron . Any one of these three length scales can be written in terms of any other using the fine-structure constant :
Derivation
The classical electron radius length scale can be motivated by considering the energy necessary to assemble an amount of charge into a sphere of a given radius . The electrostatic potential at a distance from a charge is
.
To bring an additional amount of charge from infinity necessitates putting energy into the system, , by an amount
.
If the sphere is assumed to have constant charge density, , then
and .
Integrating for from zero to the final radius yields the expression for the total energy , necessary to assemble the total charge into a uniform sphere of radius :
.
This is called the electrostatic self-energy of the object. The charge is now interpreted as the electron charge, , and th
Document 2:::
A fixed orbit is the concept, in atomic physics, where an electron is considered to remain in a specific orbit, at a fixed distance from an atom's nucleus, for a particular energy level.
The concept was promoted by quantum physicist Niels Bohr c. 1913.
The idea of the fixed orbit is considered a major component of the Bohr model (or Bohr theory).
Document 3:::
In atomic physics, the Bohr model or Rutherford–Bohr model of the atom, presented by Niels Bohr and Ernest Rutherford in 1913, consists of a small, dense nucleus surrounded by orbiting electrons. It is analogous to the structure of the Solar System, but with attraction provided by electrostatic force rather than gravity, and with the electron energies quantized (assuming only discrete values).
In the history of atomic physics, it followed, and ultimately replaced, several earlier models, including Joseph Larmor's Solar System model (1897), Jean Perrin's model (1901), the cubical model (1902), Hantaro Nagaoka's Saturnian model (1904), the plum pudding model (1904), Arthur Haas's quantum model (1910), the Rutherford model (1911), and John William Nicholson's nuclear quantum model (1912). The improvement over the 1911 Rutherford model mainly concerned the new quantum mechanical interpretation introduced by Haas and Nicholson, but forsaking any attempt to explain radiation according to classical physics.
The model's key success lay in explaining the Rydberg formula for hydrogen's spectral emission lines. While the Rydberg formula had been known experimentally, it did not gain a theoretical basis until the Bohr model was introduced. Not only did the Bohr model explain the reasons for the structure of the Rydberg formula, it also provided a justification for the fundamental physical constants that make up the formula's empirical results.
The Bohr model is a relatively primitive model of the hydrogen atom, compared to the valence shell model. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics and thus may be considered to be an obsolete scientific theory. However, because of its simplicity, and its correct results for selected systems (see below for application), the Bohr model is still commonly taught to introduce students to quantum mechanics or energy level diagrams before mov
Document 4:::
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The debye (D) is another unit of measurement used in atomic physics and chemistry.
Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.
Elementary definition
Often in physics the dimensions of a massive object can be ignored and can be treated as a pointlike object, i.e. a point particle. Point particles with electric charge are referred to as point charges. Two point charges, one with charge and the other one with charge separated by a distance , constitute an electric dipole (a simple case of an electric multipole). For this case, the electric dipole moment has a magnitude and is directed from the negative charge to the positive one. Some authors may split in half and use since this quantity is the distance between either charge and the center of the dipole, leading to a factor of two in the definition.
A stronger mathematical definition is to use vector algebra, since a quantity with magnitude and direction, like the dipole moment of two point charges, can be expressed in vector form where is the displacement vector pointing from the negative charge to the positive charge. The electric dipole moment vector also points from the negative charge to the positive charge. With this definition the dipole direction tends to align itself with an external electric field (and note that the electric flux lines produced by the charges of the dipole itself, which point from positive charge to negative charge then tend to oppose the flux lines of the external field). Note that this sign convention is used in physics, while the opposite sign convention for th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which atomic model shows that the distances of electrons from the nucleus is not a fixed value?
A. the quantum model
B. the distance model
C. the electron model
D. the equivocation model
Answer:
|
|
sciq-928
|
multiple_choice
|
What part of the plant holds the plant upright?
|
[
"roots",
"leaves",
"the stem",
"notochord"
] |
C
|
Relavent Documents:
Document 0:::
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
The stem is normally divided into nodes and internodes:
The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaves, conifer cones, or flowers). Adventitious roots may also be produced from the nodes. Vines may produce tendrils from nodes.
The internodes distance one node from another.
The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other structures like leaves or flowers.
In most plants, stems are located above the soil surface, but some plants have underground stems.
Stems have several main functions:
Support for and the elevation of leaves, flowers, and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem.
Storage of nutrients.
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
Photosynthesis.
Stems have two pipe-like tissues called xylem and phloem. The xylem tissue arises from the cell facing inside and transports water by the action of transpiration pull, capillary action, and root pressure. The phloem tissue arises from the cell facing outside and consists of sieve tubes and their companion cells. The function of phloem tissue is to distribute food from photosynthetic tissue to other tissues. The two tissues are separated by cambium, a tis
Document 1:::
Edible plant stems are one part of plants that are eaten by humans. Most plants are made up of stems, roots, leaves, flowers, and produce fruits containing seeds. Humans most commonly eat the seeds (e.g. maize, wheat), fruit (e.g. tomato, avocado, banana), flowers (e.g. broccoli), leaves (e.g. lettuce, spinach, and cabbage), roots (e.g. carrots, beets), and stems (e.g. asparagus of many plants. There are also a few edible petioles (also known as leaf stems) such as celery or rhubarb.
Plant stems have a variety of functions. Stems support the entire plant and have buds, leaves, flowers, and fruits. Stems are also a vital connection between leaves and roots. They conduct water and mineral nutrients through xylem tissue from roots upward, and organic compounds and some mineral nutrients through phloem tissue in any direction within the plant. Apical meristems, located at the shoot tip and axillary buds on the stem, allow plants to increase in length, surface, and mass. In some plants, such as cactus, stems are specialized for photosynthesis and water storage.
Modified stems
Typical stems are located above ground, but there are modified stems that can be found either above or below ground. Modified stems located above ground are phylloids, stolons, runners, or spurs. Modified stems located below ground are corms, rhizomes, and tubers.
Detailed description of edible plant stems
Asparagus The edible portion is the rapidly emerging stems that arise from the crowns in the
Bamboo The edible portion is the young shoot (culm).
Birch Trunk sap is drunk as a tonic or rendered into birch syrup, vinegar, beer, soft drinks, and other foods.
Broccoli The edible portion is the peduncle stem tissue, flower buds, and some small leaves.
Cauliflower The edible portion is proliferated peduncle and flower tissue.
Cinnamon Many favor the unique sweet flavor of the inner bark of cinnamon, and it is commonly used as a spice.
Fig The edible portion is stem tissue. The
Document 2:::
Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.
Scope
Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin". There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.
First of all, morphology is comparative, meaning that the morphologist examines structures in many different plants of the same or different species, then draws comparisons and formulates ideas about similarities. When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany.
Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive str
Document 3:::
Stem succulents are fleshy succulent columnar shaped plants which conduct photosynthesis mainly through their stems rather than their leaves. These plants are defined by their succulent stems and have evolved to have similar forms by convergent evolution to occupy similar niches.
Description
Stem succulents are succulent plants defined by their succulent stems, which function to store water and conduct photosynthesis. These plants, like many others native to hot dessert regions, undergo CAM photosynthesis, an alternative metabolic pathway where the plants' stomata open to exchange gasses and fix almost exclusively at night. Their leaves are absent or highly reduced, instead forming protective spines or thorns to deter herbivores and collect drip condensed water vapor at night.
Stem succulents are related by form, but not by evolution. They evolved to have similar forms and physiological characteristics by convergent evolution. Examples are tall thin Euphorbias from deserts and arid regions of southern African and Madagascar, similarly shaped cacti from North America and South America, which occupy a similar xeric evolutionary niche, and members of two genera of the family Asclepiadaceae (Hoodia and Stapelia).
Document 4:::
In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word succulent comes from the Latin word sucus, meaning "juice" or "sap".
Succulent plants may store water in various structures, such as leaves and stems. The water content of some succulent organs can get up to 90–95%, such as Glottiphyllum semicyllindricum and Mesembryanthemum barkleyii. Some definitions also include roots, thus geophytes that survive unfavorable periods by dying back to underground storage organs may be regarded as succulents. The habitats of these water-preserving plants are often in areas with high temperatures and low rainfall, such as deserts, but succulents may be found even in alpine ecosystems growing in rocky soil. Succulents are characterized by their ability to thrive on limited water sources, such as mist and dew, which makes them equipped to survive in an ecosystem that contains scarce water sources.
Succulents are not a taxonomic category, since the term describes only the attributes of a particular species; some species in a genus (such as Euphorbia spp) or family (such as Asphodelaceae) may be succulent, whereas others are less so or not at all. Many plant families have multiple succulent species found within them (more than 25 plant families). In some families, such as Aizoaceae, Cactaceae, and Crassulaceae, most species are succulents. In horticultural use, the term is sometimes used in a way that excludes plants that botanists would regard as succulents, such as cacti. Succulents are often grown as ornamental plants because of their striking and unusual appearance, as well as their ability to thrive with relatively minimal care.
Definition
By definition, succulent plants are drought-resistant plants in which the leaves, stem, or roots have become more than usually fleshy by the development of water-storing tissue. Other sources exclude roots as
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What part of the plant holds the plant upright?
A. roots
B. leaves
C. the stem
D. notochord
Answer:
|
|
sciq-10245
|
multiple_choice
|
Photographs of the heat emitted by an object are called what?
|
[
"thermal images",
"radio images",
"variable images",
"cosmic images"
] |
A
|
Relavent Documents:
Document 0:::
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
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:::
Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. Thermal radiation is generated when heat from the movement of charges in the material (electrons and protons in common forms of matter) is converted to electromagnetic radiation. All matter with a temperature greater than absolute zero emits thermal radiation. At room temperature, most of the emission is in the infrared (IR) spectrum. Particle motion results in charge-acceleration or dipole oscillation which produces electromagnetic radiation.
Infrared radiation emitted by animals (detectable with an infrared camera) and cosmic microwave background radiation are examples of thermal radiation.
If a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium, the radiation is called blackbody radiation. Planck's law describes the spectrum of blackbody radiation, which depends solely on the object's temperature. Wien's displacement law determines the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the radiant intensity.
Thermal radiation is also one of the fundamental mechanisms of heat transfer.
Overview
Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. Thermal radiation reflects the conversion of thermal energy into electromagnetic energy. Thermal energy is the kinetic energy of random movements of atoms and molecules in matter. All matter with a nonzero temperature is composed of particles with kinetic energy. These atoms and molecules are composed of charged particles, i.e., protons and electrons. The kinetic interactions among matter particles result in charge acceleration and dipole oscillation. This results in the electrodynamic generation of coupled electric and magnetic fields, resulting in the emission of photons, radiating energy away from the body. Electromagnetic radiation, including visible light, will pr
Document 3:::
Heliophysics (from the prefix "helio", from Attic Greek hḗlios, meaning Sun, and the noun "physics": the science of matter and energy and their interactions) is the physics of the Sun and its connection with the Solar System. NASA defines heliophysics as "(1) the comprehensive new term for the science of the Sun - Solar System Connection, (2) the exploration, discovery, and understanding of Earth's space environment, and (3) the system science that unites all of the linked phenomena in the region of the cosmos influenced by a star like our Sun."
Heliophysics concentrates on the Sun's effects on Earth and other bodies within the Solar System, as well as the changing conditions in space. It is primarily concerned with the magnetosphere, ionosphere, thermosphere, mesosphere, and upper atmosphere of the Earth and other planets. Heliophysics combines the science of the Sun, corona, heliosphere and geospace, and encompasses a wide variety of astronomical phenomena, including "cosmic rays and particle acceleration, space weather and radiation, dust and magnetic reconnection, nuclear energy generation and internal solar dynamics, solar activity and stellar magnetic fields, aeronomy and space plasmas, magnetic fields and global change", and the interactions of the Solar System with the Milky Way Galaxy.
Term “heliophysics” (Russian: “гелиофизика”) was widely used in Russian-language scientific literature. The Great Soviet Encyclopedia third edition (1969—1978) defines “Heliophysics” as “[…] a division of astrophysics that studies physics of the Sun". In 1990, the Higher Attestation Commission, responsible for the advanced academic degrees in Soviet Union and later in Russia and the Former Soviet Union, established a new specialty “Heliophysics and physics of solar system”. In English-language scientific literature prior to about 2002, the term heliophysics was sporadically used to describe the study of the "physics of the Sun". As such it was a direct translation from th
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.
Photographs of the heat emitted by an object are called what?
A. thermal images
B. radio images
C. variable images
D. cosmic images
Answer:
|
|
sciq-8649
|
multiple_choice
|
A change in temperature with distance is called a what?
|
[
"speed gradient",
"solution gradient",
"temperature gradient",
"oxygen gradient"
] |
C
|
Relavent Documents:
Document 0:::
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 1:::
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 2:::
In mathematical heat conduction, the Green's function number is used to uniquely categorize certain fundamental solutions of the heat equation to make existing solutions easier to identify, store, and retrieve.
Background
Numbers have long been used to identify types of boundary conditions. The Green's function number system was proposed by Beck and Litkouhi in 1988 and has seen increasing use since then. The number system has been used to catalog a large collection of Green's functions and related solutions.
Although the examples given below are for the heat equation, this number system applies to any phenomena described by differential equations such as diffusion, acoustics, electromagnetics, fluid dynamics, etc.
Notation
The Green's function number specifies the coordinate system and the type of boundary conditions that a Green's function satisfies. The Green's function number has two parts, a letter designation followed by a number designation. The letter(s) designate the coordinate system, while the numbers designate the type of boundary conditions that are satisfied.
Some of the designations for the Greens function number system are given next. Coordinate system designations include: X, Y, and Z for Cartesian coordinates; R, Z, for cylindrical coordinates; and, RS, , for spherical coordinates.
Designations for several boundary conditions are given in Table 1. The zeroth boundary condition is important for identifying the presence of a coordinate boundary where no physical boundary exists, for example, far away in a semi-infinite body or at the center of a cylindrical or spherical body.
Examples in Cartesian coordinates
X11
As an example, number X11 denotes the Green's function that satisfies the heat equation in the domain (0 < x < L) for boundary conditions of type 1 (Dirichlet) at both boundaries x = 0 and x = L. Here X denotes the Cartesian coordinate and 11 denotes the type 1 boundary condition at both sides of the body. The boundary value p
Document 3:::
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer. While these mechanisms have distinct characteristics, they often occur simultaneously in the same system.
Heat conduction, also called diffusion, is the direct microscopic exchanges of kinetic energy of particles (such as molecules) or quasiparticles (such as lattice waves) through the boundary between two systems. When an object is at a different temperature from another body or its surroundings, heat flows so that the body and the surroundings reach the same temperature, at which point they are in thermal equilibrium. Such spontaneous heat transfer always occurs from a region of high temperature to another region of lower temperature, as described in the second law of thermodynamics.
Heat convection occurs when the bulk flow of a fluid (gas or liquid) carries its heat through the fluid. All convective processes also move heat partly by diffusion, as well. The flow of fluid may be forced by external processes, or sometimes (in gravitational fields) by buoyancy forces caused when thermal energy expands the fluid (for example in a fire plume), thus influencing its own transfer. The latter process is often called "natural convection". The former process is often called "forced convection." In this case, the fluid is forced to flow by use of a pump, fan, or other mechanical means.
Thermal radiation occurs through a vacuum or any transparent medium (solid or fluid or gas). It is the transfer of energy by means of photons or electromagnetic waves governed by the same laws.
Overview
Heat
Document 4:::
In thermal fluid dynamics, the Nusselt number (, after Wilhelm Nusselt) is the ratio of convective to conductive heat transfer at a boundary in a fluid. Convection includes both advection (fluid motion) and diffusion (conduction). The conductive component is measured under the same conditions as the convective but for a hypothetically motionless fluid. It is a dimensionless number, closely related to the fluid's Rayleigh number.
A Nusselt number of value one (zero) represents heat transfer by pure conduction. A value between one (zero) and 10 is characteristic of slug flow or laminar flow. A larger Nusselt number corresponds to more active convection, with turbulent flow typically in the 100–1000 range.
A similar non-dimensional property is the Biot number, which concerns thermal conductivity for a solid body rather than a fluid. The mass transfer analogue of the Nusselt number is the Sherwood number.
Definition
The Nusselt number is the ratio of convective to conductive heat transfer across a boundary. The convection and conduction heat flows are parallel to each other and to the surface normal of the boundary surface, and are all perpendicular to the mean fluid flow in the simple case.
where h is the convective heat transfer coefficient of the flow, L is the characteristic length, and k is the thermal conductivity of the fluid.
Selection of the characteristic length should be in the direction of growth (or thickness) of the boundary layer; some examples of characteristic length are: the outer diameter of a cylinder in (external) cross flow (perpendicular to the cylinder axis), the length of a vertical plate undergoing natural convection, or the diameter of a sphere. For complex shapes, the length may be defined as the volume of the fluid body divided by the surface area.
The thermal conductivity of the fluid is typically (but not always) evaluated at the film temperature, which for engineering purposes may be calculated as the mean-average of the bulk flu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A change in temperature with distance is called a what?
A. speed gradient
B. solution gradient
C. temperature gradient
D. oxygen gradient
Answer:
|
|
sciq-2166
|
multiple_choice
|
Rain dissolves fertilizer in the soil, what carries it away?
|
[
"runoff?",
"clouds",
"fossils",
"carbon ?"
] |
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 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:::
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:::
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:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Rain dissolves fertilizer in the soil, what carries it away?
A. runoff?
B. clouds
C. fossils
D. carbon ?
Answer:
|
|
sciq-6767
|
multiple_choice
|
What determines which codon in the mrna the trna will bind to?
|
[
"amnion",
"exon",
"anticodon",
"gene"
] |
C
|
Relavent Documents:
Document 0:::
Genomic deoxyribonucleic acid (abbreviated as gDNA) is chromosomal DNA, in contrast to extra-chromosomal DNAs like plasmids. Most organisms have the same genomic DNA in every cell; however, only certain genes are active in each cell to allow for cell function and differentiation within the body.
The genome of an organism (encoded by the genomic DNA) is the (biological) information of heredity which is passed from one generation of organism to the next. That genome is transcribed to produce various RNAs, which are necessary for the function of the organism. Precursor mRNA (pre-mRNA) is transcribed by RNA polymerase II in the nucleus. pre-mRNA is then processed by splicing to remove introns, leaving the exons in the mature messenger RNA (mRNA). Additional processing includes the addition of a 5' cap and a poly(A) tail to the pre-mRNA. The mature mRNA may then be transported to the cytosol and translated by the ribosome into a protein. Other types of RNA include ribosomal RNA (rRNA) and transfer RNA (tRNA). These types are transcribed by RNA polymerase I and RNA polymerase III, respectively, and are essential for protein synthesis. However 5s rRNA is the only rRNA which is transcribed by RNA Polymerase III.
Document 1:::
Aminoacyl-tRNA synthetases, class II is a family of proteins. These proteins catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. These proteins differ widely in size and oligomeric state, and have a limited sequence homology.
The 20 aminoacyl-tRNA synthetases are divided into two classes, I and II. Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold catalytic domain and are mostly monomeric. Class II aminoacyl-tRNA synthetases share an anti-parallel beta-sheet fold flanked by alpha-helices, and are mostly dimeric or multimeric, containing at least three conserved regions. However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases.
Human proteins containing this domain
DARS
DARS2
KARS
NARS
NARS2
Document 2:::
The B3/B4 domain, is found in tRNA synthetase beta subunits, as well as in some non-tRNA synthetase proteins.
Function
Aminoacyl-tRNA synthetases can catalyse editing reactions to correct errors produced during amino acid activation and tRNA esterification, in order to prevent the attachment of incorrect amino acids to tRNA. The B3/B4 domain of the beta subunit contains an editing site, which lies close to the active site on the alpha subunit. Disruption of this site abolished tRNA editing, a process that is essential for faithful translation of the genetic code.
Structure
This domain has a 3-layer structure, and contains a beta-sandwich fold of unusual topology, and contains a putative tRNA-binding structural motif. In Thermus thermophilus, both the catalytic alpha- and the non-catalytic beta-subunits comprise the characteristic fold of the class II active-site domains. The presence of an RNA-binding domain, similar to that of the U1A spliceosomal protein, in the beta-subunit of tRNA synthetase indicates structural relationships among different families of RNA-binding proteins.
Document 3:::
Transfer RNA-like structures (tRNA-like structures) are RNA sequences, which have a similar tertiary structure to tRNA; they frequently contain a pseudoknot close to the 3' end. The presence of tRNA-like structures has been demonstrated in many plant virus RNA genomes. These tRNA-like structures are linked to regulation of plant virus replication.
tRNA-like structures mimic some tRNA function, such as aminoacylation. There are three aminoacylation specificities, valine, histidine and tyrosine. For example, valine binds to the tRNA-like structure of the turnip yellow mosaic virus genome whilst tyrosine binds to the tRNA-like structure of the barley stripe mosaic virus genome. tRNA-like structures which lack the 3' termini lack complete or partial tRNA mimicry.
tRNA-like structures are required for RNA encapsulation and increase RNA stability. They also act as 3'-translational enhancers and regulators of minus strand synthesis.
Document 4:::
The D arm is a feature in the tertiary structure of transfer RNA (tRNA). It is composed of the two D stems and the D loop. The D loop contains the base dihydrouridine, for which the arm is named. The D loop's main function is that of recognition. It is widely believed that it acts as a recognition site for aminoacyl-tRNA synthetase, an enzyme involved in the aminoacylation of the tRNA molecule. The D stem is also believed to have a recognition role although this has yet to be verified.
It is a highly variable region and is notable for its unusual conformation due to the over-crowding on one of the guanosine residues. It appears to play a large role in the stabilization of the tRNA's tertiary structure.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What determines which codon in the mrna the trna will bind to?
A. amnion
B. exon
C. anticodon
D. gene
Answer:
|
|
ai2_arc-827
|
multiple_choice
|
Which resource when used causes the most pollution?
|
[
"solar",
"coal",
"wind",
"water"
] |
B
|
Relavent Documents:
Document 0:::
Energy quality is a measure of the ease with which a form of energy can be converted to useful work or to another form of energy: i.e. its content of thermodynamic free energy. A high quality form of energy has a high content of thermodynamic free energy, and therefore a high proportion of it can be converted to work; whereas with low quality forms of energy, only a small proportion can be converted to work, and the remainder is dissipated as heat. The concept of energy quality is also used in ecology, where it is used to track the flow of energy between different trophic levels in a food chain and in thermoeconomics, where it is used as a measure of economic output per unit of energy. Methods of evaluating energy quality often involve developing a ranking of energy qualities in hierarchical order.
Examples: Industrialization, Biology
The consideration of energy quality was a fundamental driver of industrialization from the 18th through 20th centuries. Consider for example the industrialization of New England in the 18th century. This refers to the construction of textile mills containing power looms for weaving cloth. The simplest, most economical and straightforward source of energy was provided by water wheels, extracting energy from a millpond behind a dam on a local creek. If another nearby landowner also decided to build a mill on the same creek, the construction of their dam would lower the overall hydraulic head to power the existing waterwheel, thus hurting power generation and efficiency. This eventually became an issue endemic to the entire region, reducing the overall profitability of older mills as newer ones were built. The search for higher quality energy was a major impetus throughout the 19th and 20th centuries. For example, burning coal to make steam to generate mechanical energy would not have been imaginable in the 18th century; by the end of the 19th century, the use of water wheels was long outmoded. Similarly, the quality of energy from elec
Document 1:::
A non-renewable resource (also called a finite resource) is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption. An example is carbon-based fossil fuels. The original organic matter, with the aid of heat and pressure, becomes a fuel such as oil or gas. Earth minerals and metal ores, fossil fuels (coal, petroleum, natural gas) and groundwater in certain aquifers are all considered non-renewable resources, though individual elements are always conserved (except in nuclear reactions, nuclear decay or atmospheric escape).
Conversely, resources such as timber (when harvested sustainably) and wind (used to power energy conversion systems) are considered renewable resources, largely because their localized replenishment can occur within time frames meaningful to humans as well.
Earth minerals and metal ores
Earth minerals and metal ores are examples of non-renewable resources. The metals themselves are present in vast amounts in Earth's crust, and their extraction by humans only occurs where they are concentrated by natural geological processes (such as heat, pressure, organic activity, weathering and other processes) enough to become economically viable to extract. These processes generally take from tens of thousands to millions of years, through plate tectonics, tectonic subsidence and crustal recycling.
The localized deposits of metal ores near the surface which can be extracted economically by humans are non-renewable in human time-frames. There are certain rare earth minerals and elements that are more scarce and exhaustible than others. These are in high demand in manufacturing, particularly for the electronics industry.
Fossil fuels
Natural resources such as coal, petroleum(crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually it is considered that fossil-based resources will become too costly to harvest and
Document 2:::
Twisted: The Distorted Mathematics of Greenhouse Denial is a 2007 book by Ian G. Enting, who is the Professorial Research Fellow in the ARC Centre of Excellence for Mathematics and Statistics of Complex Systems (MASCOS) based at the University of Melbourne. The book analyses the arguments of climate change deniers and the use and presentation of statistics. Enting contends there are contradictions in their various arguments. The author also presents calculations of the actual emission levels that would be required to stabilise CO2 concentrations. This is an update of calculations that he contributed to the pre-Kyoto IPCC report on Radiative Forcing of Climate.
See also
Climate change
Greenhouse effect
Radiative forcing
Document 3:::
The indirect land use change impacts of biofuels, also known as ILUC or iLUC (pronounced as i-luck), relates to the unintended consequence of releasing more carbon emissions due to land-use changes around the world induced by the expansion of croplands for ethanol or biodiesel production in response to the increased global demand for biofuels.
As farmers worldwide respond to higher crop prices in order to maintain the global food supply-and-demand balance, pristine lands are cleared to replace the food crops that were diverted elsewhere to biofuels' production. Because natural lands, such as rainforests and grasslands, store carbon in their soil and biomass as plants grow each year, clearance of wilderness for new farms translates to a net increase in greenhouse gas emissions. Due to this off-site change in the carbon stock of the soil and the biomass, indirect land use change has consequences in the greenhouse gas (GHG) balance of a biofuel.
Other authors have also argued that indirect land use changes produce other significant social and environmental impacts, affecting biodiversity, water quality, food prices and supply, land tenure, worker migration, and community and cultural stability.
History
The estimates of carbon intensity for a given biofuel depend on the assumptions regarding several variables. As of 2008, multiple full life cycle studies had found that corn ethanol, cellulosic ethanol and Brazilian sugarcane ethanol produce lower greenhouse gas emissions than gasoline. None of these studies, however, considered the effects of indirect land-use changes, and though land use impacts were acknowledged, estimation was considered too complex and difficult to model. A controversial paper published in February 2008 in Sciencexpress by a team led by Searchinger from Princeton University concluded that such effects offset the (positive) direct effects of both corn and cellulosic ethanol and that Brazilian sugarcane performed better, but still resulted in a sma
Document 4:::
Trashing the Planet: How Science Can Help Us Deal With Acid Rain, Depletion of the Ozone, and Nuclear Waste (Among Other Things) is a 1990 book by zoologist and Governor of Washington Dixy Lee Ray. The book talks about the seriousness about acid rain, the problems with the ozone layer and other environmental issues. Ray co-wrote the book with journalist Lou Guzzo.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which resource when used causes the most pollution?
A. solar
B. coal
C. wind
D. water
Answer:
|
|
sciq-5090
|
multiple_choice
|
In iceland, the mid-atlantic ridge is above sea what?
|
[
"bottom",
"level",
"atmosphere",
"tide"
] |
B
|
Relavent Documents:
Document 0:::
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin.
The production of new seafloor and oceanic lithosphere results from mantle upwelling in response to plate separation. The melt rises as magma at the linear weakness between the separating plates, and emerges as lava, creating new oceanic crust and lithosphere upon cooling.
The first discovered mid-ocean ridge was the Mid-Atlantic Ridge, which is a spreading center that bisects the North and South Atlantic basins; hence the origin of the name 'mid-ocean ridge'. Most oceanic spreading centers are not in the middle of their hosting ocean basis but regardless, are traditionally called mid-ocean ridges. Mid-ocean ridges around the globe are linked by plate tectonic boundaries and the trace of the ridges across the ocean floor appears similar to the seam of a baseball. The mid-ocean ridge system thus is the longest mountain range on Earth, reaching about .
Global system
The mid-ocean ridges of the world are connected and form the Ocean Ridge, a single global mid-oceanic ridge system that is part of every ocean, making it the longest mountain range in the world. The continuous mountain range is long (several times longer than the Andes, the longest continental mountain range), and the total length of the oceanic ridge system is long.
Description
Morphology
At the spreading center on a mid-ocean ridge, the depth of the seafloor is approximately . On the ridge flanks, the depth of the seafloor (or the height of a location on a mid-ocean ridge above a base-level) is correlated with its age (age of the lithosphere where depth is measured). The depth-age relation can be modeled by th
Document 1:::
The Tjärnö Marine Laboratory is a marine science field station in Sweden. It is part of the University of Gothenburg and located on the island Tjärnö, Strömstad Municipality in the northern part of Bohuslän province.
TML was founded as a field station for university education in marine biology in 1963. During the first half of 1970s TML became manned year round, and scientists began to choose TML for their permanent place of work. The activities have expanded and diversified. 70 people now work permanently at TML.
Within 10 minutes by boat lies the Koster fjord, a 247 meter deep fissure fault between the Koster Islands and the mainland. It is in deep-water contact with the remaining Skagerrak, the North Sea and the Atlantic Ocean beyond, leading to oceanic salinity, 35 ‰, in the bottom water. This is the only true oceanic environment in Sweden, with the highest number of marine species in Sweden. Between 5000 and 10000 species are to be found in the Skagerrak, and more than 200 of them do not occur elsewhere in Swedish waters. For instance, cold water reefs of stony corals could be found.
Annually, about 500 university students, mainly from Gothenburg, attend courses at TML, lasting from one week to one term. A large proportion of the education is devoted to identification of marine algal and animal species. Other courses are more concerned with ecology, including training in experiments and investigations. Field education, on research vessels, in smaller boats and at the shore, are common.
The major research programs are directed towards marine ecology, presented under six programs – marine chemical ecology, evolution and genetics, biodiversity, biohydrodynamics, fishery biology and aquaculture, and integrated coastal zone management. Most scientists at TML belong to the Department of Marine Sciences at the University of Gothenburg.
TML is a resource for regional industry, decision-makers and authorities, and gives support for the development of research-based
Document 2:::
InterRidge is a non-profit organisation that promotes interdisciplinary, international studies in the research of oceanic spreading centres, including mid-ocean ridge and back-arc basin systems. It does so by creating a global research community, planning and coordinating new science programmes that no single nation can achieve alone, exchanging scientific information, and sharing new technologies and facilities. InterRidge is dedicated to reaching out to the public, scientists and governments, and to providing a unified voice for ocean ridge researchers worldwide.
It was launched in 1992, and in 2011 InterRidge has 6 principal, 3 associate, and 21 corresponding member nations and regions. InterRidge has more than 2500 individual member scientists in disciplines ranging from marine geology to chemistry, biology, and ocean engineering.
The InterRidge Office rotates every 3 years. During 2013-2015, InterRidge is being hosted by the Institute of Theoretical and Applied Geophysics, Peking University, Beijing, China. InterRidge is governed by a steering committee consisting of delegates from the principal and associate member nations and regions.
Main functions
InterRidge has four main functions, which may be summarised as:
Building a community of ridge scientists
Identifying important scientific questions through working groups and workshops
Acting as a voice for ridge scientists
Education and outreach.
InterRidge serves as a "clearinghouse" for information on mid-ocean ridge research across the globe. InterRidge publishes an annual newsletter with preliminary results from field work, national and regional reports, and working group updates. InterRidge maintains 3 databases:
member database
research cruise database (past and upcoming cruises to the ridge crest)
database of active hydrothermal vent fields, established in 2000 (InterRidge Japan office)
Development
First decade (1992 - 2003)
InterRidge began at a meeting in France in 1990 that gathered ridge
Document 3:::
Project FAMOUS (French-American Mid-Ocean Undersea Study) was the first-ever marine scientific exploration by manned submersibles of a diverging tectonic plate boundary on a mid-ocean ridge. It took place between 1971 and 1974, with a multi-national team of scientists concentrating numerous underwater surveys on an area of the Mid-Atlantic Ridge about west of the Azores. By deploying new methods and specialized equipment, scientists were able to look at the sea floor in far greater detail than ever before. The project succeeded in defining the main mechanisms of creation of the median rift valley on the Mid-Atlantic Ridge, and in locating and mapping the zone of oceanic crustal accretion.
Study area
The Project FAMOUS study area was located on a section of the Mid-Atlantic Ridge about west of the Azores (Sao Miguel) at 36° 50’ north latitude. It includes a -wide median valley or rift valley on the crest of the Mid-Atlantic Ridge that trends slightly east of north. Within the median valley lies the present boundary between the North American and African tectonic plates. The floor of the rift valley is deep and wide and the bounding rift mountains are at a depth of about , or about above the floor. The rift valley is long and it is offset to the eastward in the north at Fracture Zone A; in the south, it is offset westward at Fracture Zone B.
Methodology
A significant obstacle in marine surveys was the use of echo sounders with a wide transmit beam, which smeared-out details of the sea floor features. The crustal accretion or creation process was thought to take place over a few kilometers width of sea floor, which was below the resolution of ship echo sounders. Thus, near-bottom and on-bottom approaches were employed along with new sonar mapping tools. Investigations included airborne magnetics, advanced surface ship sonar, and geophysical measurements, seismology, deep-towed instruments, large format bottom photography, fixed on-bottom instruments, and on-
Document 4:::
Blood Falls is an outflow of an iron oxide–tainted plume of saltwater, flowing from the tongue of Taylor Glacier onto the ice-covered surface of West Lake Bonney in the Taylor Valley of the McMurdo Dry Valleys in Victoria Land, East Antarctica.
Iron-rich hypersaline water sporadically emerges from small fissures in the ice cascades. The saltwater source is a subglacial pool of unknown size overlain by about of ice several kilometers from its tiny outlet at Blood Falls.
The reddish deposit was found in 1911 by the Australian geologist Thomas Griffith Taylor, who first explored the valley that bears his name. The Antarctica pioneers first attributed the red color to red algae, but later it was proven to be due to iron oxides.
Geochemistry
Poorly soluble hydrous ferric oxides are deposited at the surface of ice after the ferrous ions present in the unfrozen saltwater are oxidized in contact with atmospheric oxygen. The more soluble ferrous ions initially are dissolved in old seawater trapped in an ancient pocket remaining from the Antarctic Ocean when a fjord was isolated by the glacier in its progression during the Miocene period, some 5 million years ago, when the sea level was higher than today.
Unlike most Antarctic glaciers, the Taylor Glacier is not frozen to the bedrock, probably because of the presence of salts concentrated by the crystallization of the ancient seawater imprisoned below it. Salt cryo-concentration occurred in the deep relict seawater when pure ice crystallized and expelled its dissolved salts as it cooled down because of the heat exchange of the captive liquid seawater with the enormous ice mass of the glacier. As a consequence, the trapped seawater was concentrated in brines with a salinity two to three times that of the mean ocean water. A second mechanism sometimes also explaining the formation of hypersaline brines is the water evaporation of surface lakes directly exposed to the very dry polar atmosphere in the McMurdo Dry Valleys. Th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In iceland, the mid-atlantic ridge is above sea what?
A. bottom
B. level
C. atmosphere
D. tide
Answer:
|
|
sciq-2424
|
multiple_choice
|
If environmental conditions deteriorate, many species can form protective what?
|
[
"shells",
"cysts",
"fibers",
"proteins"
] |
B
|
Relavent Documents:
Document 0:::
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of cell biology, Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology, Glossary of environmental science and Glossary of scientific naming, or any of the organism-specific glossaries in :Category:Glossaries of biology.
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B
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D
E
F
G
H
I
J
K
L
M
N
O
P
R
S
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U
V
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X
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Related to this search
Index of biology articles
Outline of biology
Glossaries of sub-disciplines and related fields:
Glossary of botany
Glossary of ecology
Glossary of entomology
Glossary of environmental science
Glossary of genetics
Glossary of ichthyology
Glossary of ornithology
Glossary of scientific naming
Glossary of speciation
Glossary of virology
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In ecology, habitat refers to the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate.
The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, with habitat generalist species able to thrive in a wide array of environmental conditions while habitat specialist species requiring a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss; a parasitic organism has as its habitat the body of its host, part of the host's body (such as the digestive tract), or a single cell within the host's body.
Habitat types are environmental categorizations of different environments based on the characteristics of a given geographical area, particularly vegetation and climate. Thus habitat types do not refer to a single species but to multiple species living in the same area. For example, terrestrial habitat types include forest, steppe, grassland, semi-arid or desert. Fresh-water habitat types include marshes, streams, rivers, lakes, and ponds; marine habitat types include salt marshes, the coast, the intertidal zone, estuaries, reefs, bays, the open sea, the sea bed, deep water and submarine vents.
Habitat types may change over time. Causes of change may include a violent event (such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents); or change may occur mo
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Ecology: From Individuals to Ecosystems is a 2006 higher education textbook on general ecology written by Michael Begon, Colin R. Townsend and John L. Harper. Published by Blackwell Publishing, it is now in its fourth edition. The first three editions were published by Blackwell Science under the title Ecology: Individuals, Populations and Communities. Since it first became available it has had a positive reception, and has long been one of the leading textbooks on ecology.
Background and history
The book is written by Michael Begon of the University of Liverpool's School of Biosciences, Colin Townsend, from the Department of Zoology of New Zealand's University of Otago, and the University of Exeter's John L. Harper. The first edition was published in 1986. This was followed in 1990 with a second edition. The third edition became available in 1996. The most recent edition appeared in 2006 under the new subtitle From Individuals to Ecosystems.
One of the book's authors, John L. Harper, is now deceased. The fourth edition cover is an image of a mural on a Wellington street created by Christopher Meech and a group of urban artists to generate thought about the topic of environmental degradation. It reads "we did not inherit the earth from our ancestors, we borrowed it from our children."
Contents
Part 1. ORGANISMS
1. Organisms in their environments: the evolutionary backdrop
2. Conditions
3. Resources
4. Life, death and life histories
5. Intraspecific competition
6. Dispersal, dormancy and metapopulations
7. Ecological applications at the level of organisms and single-species populations
Part 2. SPECIES INTERACTIONS
8. Interspecific competition
9. The nature of predation
10. The population dynamics of predation
11. Decomposers and detritivores
12. Parasitism and disease
13. Symbiosis and mutualism
14. Abundance
15. Ecological applications at the level of population interactions
Part 3. COMMUNITIES AND ECOSYSTEMS
16. The nature of the community
17.
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Ecoimmunology or Ecological Immunology is the study of the causes and consequences of variation in immunity. The field of ecoimmunology seeks to give an ultimate perspective for proximate mechanisms of immunology. This approach places immunology in evolutionary and ecological contexts across all levels of biological organization.
Classical, or mainstream, immunology works hard to control variation (inbred/domestic model organisms, parasite-free environments, etc.) and asks questions about the mechanisms and functionality of the immune system using a reductionist method. While ecoimmunology originated from these fields, it is distinguished by its focus to explain natural variation in immune functions.
Multiple institutes engage in ecoimmunological research, such as the Center for Immunity, Infection, and Evolution at the University of Edinburgh and the Max Planck Institute for Immunoecology and Migration. The US National Science Foundation has funded a Research Coordination Network to bring methodological and conceptual unity to the field of ecoimmunology. The causes and consequences of immune variation have larger implications for public health, conservation, wildlife management, and agriculture.
History
Ecological Immunology is a discipline that uses ecological perspectives to understand variation in immune function. Specifically, to explain how abiotic and biotic factors influence the variation in immune function. Articles began discussing ecological contexts and of immune variation in the 1970s but matured into a discipline in the 1990s. Ecoimmunology is an integrative field that combines approaches from evolutionary biology, ecology, neurobiology, and endocrinology.
Seminal papers
Seminal papers in the field include Sheldon & Verhulst's which proposed concepts from Life history theory, trade-offs and allocation of resources between competing costly physiological functions, are a cause of variation in immunity One of the field’s seminal papers, by Folsta
Document 4:::
A microsite is a term used in ecology to describe a pocket within an environment with unique features, conditions or characteristics. Classifying different microsites may depend on temperature, humidity, sunlight, nutrient availability, soil physical characteristics, vegetation cover, etc. Being a
sub environment within an environment, we will examine the qualities that differentiate a microsite from another within an environment in this piece.
Microsite features
Microsites being a subset of the environment can be identified with its own:
Temperature
It refers to the temperature of the surrounding environment measured in degree Fahrenheit. The temperature of one microsite may not necessarily be the same with another one even if they are closely related in terms of location.
Humidity
It refers to the relative amount of moisture that could be held in the air. The more saturated the air is with water vapor in a microsite the more relative it is in humidity.
Sunlight
Plants uses energy from the sunlight to carry on photosynthesis. The possibility of sunlight to reach a microsite is another distinguishing characteristic which creates differences between microsites. There are some areas that the sunlight doesn’t reach which creates a different environmental condition than those that the sun reaches thus making some plants to have more fitness than others.
Availability of nutrients
Some microsites are rich in nutrients while some are not. This is a great difference because seeds germinate more in microsites that have more nutrients it needs than those that lack them. This is because plants and other autotrophs get nutrients (nitrogen, phosphorus, potassium, calcium, magnesium and Sulphur) they need from soil and water available in their microsite.
Soil physical characteristics
Plants obtain hydrogen from water found in the soil. Animals are influence by the soil physical characteristics for example where a fish will survive is not the same like that of a came
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
If environmental conditions deteriorate, many species can form protective what?
A. shells
B. cysts
C. fibers
D. proteins
Answer:
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sciq-4754
|
multiple_choice
|
What types of living beings have water vascular systems and unique tube feet?
|
[
"diatoms",
"mollusks",
"echinoderms",
"Ducks"
] |
C
|
Relavent Documents:
Document 0:::
Aquatic respiration is the process whereby an aquatic organism exchanges respiratory gases with water, obtaining oxygen from oxygen dissolved in water and excreting carbon dioxide and some other metabolic waste products into the water.
Unicellular and simple small organisms
In very small animals, plants and bacteria, simple diffusion of gaseous metabolites is sufficient for respiratory function and no special adaptations are found to aid respiration. Passive diffusion or active transport are also sufficient mechanisms for many larger aquatic animals such as many worms, jellyfish, sponges, bryozoans and similar organisms. In such cases, no specific respiratory organs or organelles are found.
Higher plants
Although higher plants typically use carbon dioxide and excrete oxygen during photosynthesis, they also respire and, particularly during darkness, many plants excrete carbon dioxide and require oxygen to maintain normal functions. In fully submerged aquatic higher plants specialised structures such as stoma on leaf surfaces to control gas interchange. In many species, these structures can be controlled to be open or closed depending on environmental conditions. In conditions of high light intensity and relatively high carbonate ion concentrations, oxygen may be produced in sufficient quantities to form gaseous bubbles on the surface of leaves and may produce oxygen super-saturation in the surrounding water body.
Animals
All animals that practice truly aquatic respiration are poikilothermic. All aquatic homeothermic animals and birds including cetaceans and penguins are air breathing despite a fully aquatic life-style.
Echinoderms
Echinoderms have a specialised water vascular system which provides a number of functions including providing the hydraulic power for tube feet but also serves to convey oxygenated sea water into the body and carry waste water out again. In many genera, the water enters through a madreporite, a sieve like structure on the upper surfac
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A rheophile is an animal that prefers to live in fast-moving water.
Examples of rheophilic animals
Insects
Many aquatic insects living in riffles require current to survive.
Epeorus sylvicola, a rheophilic mayfly species (Ephemeroptera)
Some African (Elattoneura) and Asian threadtail (Prodasineura) species
Birds
Dippers (Cinclus)
Grey wagtail (Motacilla cinerea) and mountain wagtail (Motacilla clara)
A few swifts often nest behind waterfalls, including American black swift (Cypseloides niger), giant swiftlet (Hydrochous gigas), great dusky swift (Cypseloides senex) and white-collared swift (Streptoprocne zonaris)
Some waterfowl, including African black duck (Anas sparsa), blue duck (Hymenolaimus malacorhynchos), Brazilian merganser (Mergus octosetaceus), bronze-winged duck (Speculanas specularis), harlequin duck (Histrionicus histrionicus), Salvadori's teal (Salvadorina waigiuensis) and torrent duck (Merganetta armata)
Fish
A very large number of rheophilic fish species are known and include members of at least 419 genera in 60 families. Examples include:
Many species in the family Balitoridae, also known as the hill stream loaches.
Many species in the family Loricariidae from South and Central America
Many Chiloglanis species, which are freshwater catfish from Africa
The family Gyrinocheilidae.
Rheophilic cichlid genera/species:
The Lamena group in the genus Paretroplus from Madagascar.
Oxylapia polli from Madagascar.
Retroculus species from the Amazon Basin and rivers in the Guianas in South America.
Steatocranus species from the Congo River Basin in Africa.
Teleocichla species from the Amazon Basin in South America.
Teleogramma species from the Congo River Basin in Africa.
Mylesinus, Myleus, Ossubtus, Tometes and Utiaritichthys, which are serrasalmids from tropical South America
The Danube streber (Zingel streber), family Percidae.
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Polydactyly in stem-tetrapods should here be understood as having more than five digits to the finger or foot, a condition that was the natural state of affairs in the earliest stegocephalians during the evolution of terrestriality. The polydactyly in these largely aquatic animals is not to be confused with polydactyly in the medical sense, i.e. it was not an anomaly in the sense it was not a congenital condition of having more than the typical number of digits for a given taxon. Rather, it appears to be a result of the early evolution from a limb with a fin rather than digits.
"Living tetrapods, such as the frogs, turtles, birds and mammals, are a subgroup of the tetrapod lineage. The lineage also includes finned and limbed tetrapods that are more closely related to living tetrapods than to living lungfishes." Tetrapods evolved from animals with fins such as found in lobe-finned fishes. From this condition a new pattern of limb formation evolved, where the development axis of the limb rotated to sprout secondary axes along the lower margin, giving rise to a variable number of very stout skeletal supports for a paddle-like foot. The condition is thought to have arisen from the loss of the fin ray-forming proteins actinodin 1 and actinodin 2 or modification of the expression of HOXD13. It is still unknown why exactly this happens. "SHH is produced by the mesenchymal cells of the zone of polarizing activity (ZPA) found at the posterior margin of the limbs of all vertebrates with paired appendages, including the most primitive chondrichthyian fishes. Its expression is driven by a well-conserved limb-specific enhancer called the ZRS (zone of polarizing region activity regulatory sequence) that is located approximately 1 Mb upstream of the coding sequence of Shh."
Devonian taxa were polydactylous. Acanthostega had eight digits on both the hindlimbs and forelimbs. Ichthyostega, which was both more derived and more specialized, had seven digits on the hindlimb, though th
Document 3:::
In surface anatomy, a lamella is a thin plate-like structure, often one amongst many lamellae very close to one another, with open space between. Aside from respiratory organs, they appear in other biological roles including filter feeding and the traction surfaces of geckos.
In fish, gill lamellae are used to increase the surface area in contact with the environment to maximize gas exchange (both to attain oxygen and to expel carbon dioxide) between the water and the blood. In fish gills there are two types of lamellae, primary and secondary. The primary gill lamellae (also called gill filament) extends from the gill arch, and the secondary gill lamellae extends from the primary gill lamellae. Gas exchange primarily occurs at the secondary gill lamellae, where the tissue is notably only one cell layer thick. Furthermore, countercurrent gas exchange at the secondary gill lamellae further maximizes oxygen uptake and carbon dioxide release.
See also
Pecten (biology) – the similar structure in birds
Document 4:::
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. As of 2022, 2.16 million living animal species have been described—of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are around 7.77 million animal species. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and the chordates, the latter including the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on ad
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What types of living beings have water vascular systems and unique tube feet?
A. diatoms
B. mollusks
C. echinoderms
D. Ducks
Answer:
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|
sciq-1318
|
multiple_choice
|
Which type of muscle is most common in the human body?
|
[
"skeletal",
"hormonal",
"smooth",
"digestive"
] |
A
|
Relavent Documents:
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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 1:::
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 2:::
The following outline is provided as an overview of and topical guide to physiology:
Physiology – scientific study of the normal function in living systems. A branch of biology, its focus is in how organisms, organ systems, organs, cells, and biomolecules carry out the chemical or physical functions that exist in a living system.
What type of thing is physiology?
Physiology can be described as all of the following:
An academic discipline
A branch of science
A branch of biology
Branches of physiology
By approach
Applied physiology
Clinical physiology
Exercise physiology
Nutrition physiology
Comparative physiology
Mathematical physiology
Yoga physiology
By organism
Animal physiology
Mammal physiology
Human physiology
Fish physiology
Insect physiology
Plant physiology
By process
Developmental physiology
Ecophysiology
Evolutionary physiology
By subsystem
Cardiovascular physiology
Renal physiology
Defense physiology
Gastrointestinal physiology
Musculoskeletal physiology
Neurophysiology
Respiratory physiology
History of physiology
History of physiology
General physiology concepts
Physiology organizations
American Physiological Society
International Union of Physiological Sciences
Physiology publications
American Journal of Physiology
Experimental Physiology
Journal of Applied Physiology
Persons influential in physiology
List of Nobel laureates in Physiology or Medicine
List of physiologists
See also
Outline of biology
Document 3:::
In biomechanics, Hill's muscle model refers to the 3-element model consisting of a contractile element (CE) in series with a lightly-damped elastic spring element (SE) and in parallel with lightly-damped elastic parallel element (PE). Within this model, the estimated force-velocity relation for the CE element is usually modeled by what is commonly called Hill's equation, which was based on careful experiments involving tetanized muscle contraction where various muscle loads and associated velocities were measured. They were derived by the famous physiologist Archibald Vivian Hill, who by 1938 when he introduced this model and equation had already won the Nobel Prize for Physiology. He continued to publish in this area through 1970. There are many forms of the basic "Hill-based" or "Hill-type" models, with hundreds of publications having used this model structure for experimental and simulation studies. Most major musculoskeletal simulation packages make use of this model.
AV Hill's force-velocity equation for tetanized muscle
This is a popular state equation applicable to skeletal muscle that has been stimulated to show Tetanic contraction. It relates tension to velocity with regard to the internal thermodynamics. The equation is
where
is the tension (or load) in the muscle
is the velocity of contraction
is the maximum isometric tension (or load) generated in the muscle
coefficient of shortening heat
is the maximum velocity, when
Although Hill's equation looks very much like the van der Waals equation, the former has units of energy dissipation, while the latter has units of energy. Hill's equation demonstrates that the relationship between F and v is hyperbolic. Therefore, the higher the load applied to the muscle, the lower the contraction velocity. Similarly, the higher the contraction velocity, the lower the tension in the muscle. This hyperbolic form has been found to fit the empirical constant only during isotonic contractions near resting
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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.
Which type of muscle is most common in the human body?
A. skeletal
B. hormonal
C. smooth
D. digestive
Answer:
|
|
sciq-7004
|
multiple_choice
|
Crevasses are found in glaciers. how do these come about?
|
[
"man made",
"god",
"from movement",
"rigidity"
] |
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:::
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:::
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
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:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Crevasses are found in glaciers. how do these come about?
A. man made
B. god
C. from movement
D. rigidity
Answer:
|
|
sciq-3646
|
multiple_choice
|
What are the organized instructions within dna for making proteins called?
|
[
"clones",
"genes",
"genomes",
"replicants"
] |
B
|
Relavent Documents:
Document 0:::
In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated). DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria (a Bacterial Artificial Chromosome or BAC library) or yeast such that each organism contains on average one construct (vector + insert). As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated (thus, "cloned").
Terminology
The term "library" can refer to a population of organisms, each of which carries a DNA molecule inserted into a cloning vector, or alternatively to the collection of all of the cloned vector molecules.
cDNA libraries
A cDNA library represents a sample of the mRNA purified from a particular source (either a collection of cells, a particular tissue, or an entire organism), which has been converted back to a DNA template by the use of the enzyme reverse transcriptase. It thus represents the genes that were being actively transcribed in that particular source under the physiological, developmental, or environmental conditions that existed when the mRNA was purified. cDNA libraries can be generated using techniques that promote "full-length" clones or under conditions that generate shorter f
Document 1:::
The central dogma of molecular biology is an explanation of the flow of genetic information within a biological system. It is often stated as "DNA makes RNA, and RNA makes protein", although this is not its original meaning. It was first stated by Francis Crick in 1957, then published in 1958:
He re-stated it in a Nature paper published in 1970: "The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid."
A second version of the central dogma is popular but incorrect. This is the simplistic DNA → RNA → protein pathway published by James Watson in the first edition of The Molecular Biology of the Gene (1965). Watson's version differs from Crick's because Watson describes a two-step (DNA → RNA and RNA → protein) process as the central dogma. While the dogma as originally stated by Crick remains valid today, Watson's version does not.
The dogma is a framework for understanding the transfer of sequence information between information-carrying biopolymers, in the most common or general case, in living organisms. There are 3 major classes of such biopolymers: DNA and RNA (both nucleic acids), and protein. There are conceivable direct transfers of information that can occur between these. The dogma classes these into 3 groups of 3: three general transfers (believed to occur normally in most cells), two special transfers (known to occur, but only under specific conditions in case of some viruses or in a laboratory), and four unknown transfers (believed never to occur). The general transfers describe the normal flow of biological information: DNA can be copied to DNA (DNA replication), DNA information can be copied into mRNA (transcription), and proteins can be synthesized using the information in mRNA as a template (translation). The special transfers describe: RNA being copied from RNA (RNA replication), D
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A sequence in biology is the one-dimensional ordering of monomers, covalently linked within a biopolymer; it is also referred to as the primary structure of a biological macromolecule. While it can refer to many different molecules, the term sequence is most often used to refer to a DNA sequence.
See also
Protein sequence
DNA sequence
Genotype
Self-incompatibility in plants
List of geneticists
Human Genome Project
Dot plot (bioinformatics)
Multiplex Ligation-dependent Probe Amplification
Sequence analysis
Molecular biology
Document 3:::
Molecular genetics is a branch of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the structure and/or function of genes in an organism's genome using genetic screens.
The field of study is based on the merging of several sub-fields in biology: classical Mendelian inheritance, cellular biology, molecular biology, biochemistry, and biotechnology. It integrates these disciplines to explore things like genetic inheritance, gene regulation and expression, and the molcular mechanims behind various life processes.
A key goal of molecular genetics is to identfiy and study genetic mutations. Researchers search for mutations in a gene or induce mutations in a gene to link a gene sequence to a specific phenotype. Therefore molecular genetics is a powerful methodology for linking mutations to genetic conditions that may aid the search for treatments of various genetics diseases.
History
For molecular genetics to develop as a discipline, several scientific discoveries were necessary. The discovery of DNA as a means to transfer the genetic code of life from one cell to another and between generations was essential for identifying the molecule responsible for heredity. Molecular genetics arose initially from studies involving genetic transformation in bacteria. In 1944 Avery, McLeod and McCarthy isolated DNA from a virulent strain of S. pneumoniae, and using just this DNA were able to convert a harmless strain to virulence. They called the uptake, incorporation and expression of DNA by bacteria "transformation". This finding suggested that DNA is the genetic material of bacteria. Since its discovery in 1944 genetic transformation has been found to occur in numerous bacterial species including many species that are pathogenic to humans. Bacterial transformation is often induced by conditions of stress, and the func
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the organized instructions within dna for making proteins called?
A. clones
B. genes
C. genomes
D. replicants
Answer:
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sciq-5019
|
multiple_choice
|
What is the earths crust composed of?
|
[
"metamorphic rock",
"bicellular rock",
"sedimentary rock",
"igneuos rock"
] |
D
|
Relavent Documents:
Document 0:::
Earth's crustal evolution involves the formation, destruction and renewal of the rocky outer shell at that planet's surface.
The variation in composition within the Earth's crust is much greater than that of other terrestrial planets. Mars, Venus, Mercury and other planetary bodies have relatively quasi-uniform crusts unlike that of the Earth which contains both oceanic and continental plates. This unique property reflects the complex series of crustal processes that have taken place throughout the planet's history, including the ongoing process of plate tectonics.
The proposed mechanisms regarding Earth's crustal evolution take a theory-orientated approach. Fragmentary geologic evidence and observations provide the basis for hypothetical solutions to problems relating to the early Earth system. Therefore, a combination of these theories creates both a framework of current understanding and also a platform for future study.
Early crust
Mechanisms of early crust formation
The early Earth was entirely molten. This was due to high temperatures created and maintained by the following processes:
Compression of the early atmosphere
Rapid axial rotation
Regular impacts with neighbouring planetesimals.
The mantle remained hotter than modern day temperatures throughout the Archean. Over time the Earth began to cool as planetary accretion slowed and heat stored within the magma ocean was lost to space through radiation.
A theory for the initiation of magma solidification states that once cool enough, the cooler base of the magma ocean would begin to crystallise first. This is because pressure of 25 GPa at the surface cause the solidus to lower. The formation of a thin 'chill-crust' at the extreme surface would provide thermal insulation to the shallow sub surface, keeping it warm enough to maintain the mechanism of crystallisation from the deep magma ocean.
The composition of the crystals produced during the crystallisation of the magma ocean varied with depth. Ex
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The internal structure of Earth is the layers of the Earth, excluding its atmosphere and hydrosphere. The structure consists of an outer silicate solid crust, a highly viscous asthenosphere and solid mantle, a liquid outer core whose flow generates the Earth's magnetic field, and a solid inner core.
Scientific understanding of the internal structure of Earth is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanoes or volcanic activity, analysis of the seismic waves that pass through Earth, measurements of the gravitational and magnetic fields of Earth, and experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior.
Global properties
"Note: In chondrite model (1), the light element in the core is assumed to be Si. Chondrite model (2) is a model of chemical composition of the mantle corresponding to the model of core shown in chondrite model (1)."Measurements of the force exerted by Earth's gravity can be used to calculate its mass. Astronomers can also calculate Earth's mass by observing the motion of orbiting satellites. Earth's average density can be determined through gravimetric experiments, which have historically involved pendulums. The mass of Earth is about . The average density of Earth is .
Layers
The structure of Earth can be defined in two ways: by mechanical properties such as rheology, or chemically. Mechanically, it can be divided into lithosphere, asthenosphere, mesospheric mantle, outer core, and the inner core. Chemically, Earth can be divided into the crust, upper mantle, lower mantle, outer core, and inner core. The geologic component layers of Earth are at increasing depths below the surface:
Crust and lithosphere
Earth's crust ranges from in depth and is the outermost layer. The thin parts are the oceanic crust, which underlie the ocean basins (5–10 km) and is mafic-rich (dense iron-magnesium silic
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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
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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
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A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time scales of up to thousands of years or more. The crust and upper mantle are distinguished on the basis of chemistry and mineralogy.
Earth's lithosphere
Earth's lithosphere, which constitutes the hard and rigid outer vertical layer of the Earth, includes the crust and the lithospheric mantle (or mantle lithosphere), the uppermost part of the mantle that is not convecting. The lithosphere is underlain by the asthenosphere which is the weaker, hotter, and deeper part of the upper mantle that is able to convect. The lithosphere–asthenosphere boundary is defined by a difference in response to stress. The lithosphere remains rigid for very long periods of geologic time in which it deforms elastically and through brittle failure, while the asthenosphere deforms viscously and accommodates strain through plastic deformation.
The thickness of the lithosphere is thus considered to be the depth to the isotherm associated with the transition between brittle and viscous behavior. The temperature at which olivine becomes ductile (~) is often used to set this isotherm because olivine is generally the weakest mineral in the upper mantle.
The lithosphere is subdivided horizontally into tectonic plates, which often include terranes accreted from other plates.
History of the concept
The concept of the lithosphere as Earth's strong outer layer was described by the English mathematician A. E. H. Love in his 1911 monograph "Some problems of Geodynamics" and further developed by the American geologist Joseph Barrell, who wrote a series of papers about the concept and introduced the term "lithosphere". The concept was based on the presence of significant gravity anomalies over continental crust, from which he inferred that there must exist a strong, s
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the earths crust composed of?
A. metamorphic rock
B. bicellular rock
C. sedimentary rock
D. igneuos rock
Answer:
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|
ai2_arc-281
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multiple_choice
|
When the switch in a simple series circuit is closed, what happens to the light bulb that the electricity is flowing to?
|
[
"the light cracks",
"the light goes off",
"the light burns out",
"the light comes on"
] |
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:::
Conditional short-circuit current is the value of the alternating current component of a prospective current, which a switch without integral short-circuit protection, but protected by a suitable short circuit protective device (SCPD) in series, can withstand for the operating time of the current under specified test conditions. It may be understood to be the RMS value of the maximum permissible current over a specified time interval (t0,t1) and operating conditions.
The IEC definition is critiqued to be open to interpretation.
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:::
Overheating is a phenomenon of rising temperatures in an electrical circuit. Overheating causes damage to the circuit components and can cause fire, explosion, and injury. Damage caused by overheating is usually irreversible; the only way to repair it is to replace some components.
Causes
When overheating, the temperature of the part rises above the operating temperature. Overheating can take place:
if heat is produced in more than expected amount (such as in cases of short-circuits, or applying more voltage than rated), or
if heat dissipation is poor, so that normally produced waste heat does not drain away properly.
Overheating may be caused from any accidental fault of the circuit (such as short-circuit or spark-gap), or may be caused from a wrong design or manufacture (such as the lack of a proper heat dissipation system).
Due to accumulation of heat, the system reaches an equilibrium of heat accumulation vs. dissipation at a much higher temperature than expected.
Preventive measures
Use of circuit breaker or fuse
Circuit-breakers can be placed at portions of a circuit in series to the path of current it will affect. If more current than expected goes through the circuit-breaker, the circuit breaker "opens" the circuit and stops all current. A fuse is a common type of circuit breaker that involves direct effect of Joule-overheating. A fuse is always placed in series with the path of current it will affect. Fuses usually consist of a thin strand of wire of definite-material. When more that the rated current flows through the fuse, the wire melts and breaks the circuit.
Use of heat-dissipating systems
Many systems use ventilation holes or slits kept on the box of equipment to dissipate heat. Heat sinks are often attached to portions of the circuit that produce most heat or are vulnerable to heat. Fans are also often used. Some high-voltage instruments are kept immersed in oil. In some cases, to remove unwanted heat, a cooling system like air conditioning o
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When the switch in a simple series circuit is closed, what happens to the light bulb that the electricity is flowing to?
A. the light cracks
B. the light goes off
C. the light burns out
D. the light comes on
Answer:
|
|
sciq-2016
|
multiple_choice
|
What two types of junctions do animal cells have?
|
[
"standard and specialized",
"loose and tight",
"tight and gap",
"gap and solid"
] |
C
|
Relavent Documents:
Document 0:::
Cell junctions or junctional complexes, are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also maintain the paracellular barrier of epithelia and control paracellular transport. Cell junctions are especially abundant in epithelial tissues. Combined with cell adhesion molecules and extracellular matrix, cell junctions help hold animal cells together.
Cell junctions are also especially important in enabling communication between neighboring cells via specialized protein complexes called communicating (gap) junctions. Cell junctions are also important in reducing stress placed upon cells.
In plants, similar communication channels are known as plasmodesmata, and in fungi they are called septal pores.
Types
In vertebrates, there are three major types of cell junction:
Adherens junctions, desmosomes and hemidesmosomes (anchoring junctions)
Gap junctions (communicating junction)
Tight junctions (occluding junctions)
Invertebrates have several other types of specific junctions, for example septate junctions or the C. elegans apical junction. In multicellular plants, the structural functions of cell junctions are instead provided for by cell walls. The analogues of communicative cell junctions in plants are called plasmodesmata.
Anchoring junctions
Cells within tissues and organs must be anchored to one another and attached to components of the extracellular matrix. Cells have developed several types of junctional complexes to serve these functions, and in each case, anchoring proteins extend through the plasma membrane to link cytoskeletal proteins in one cell to cytoskeletal proteins in neighboring cells as well as to proteins in the extracellular matrix.
Three types of anchoring junctions are observed, and differ from one another in the cytoskeletal protein anchor as well as the transmembrane linker protein that extends t
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Tight junctions, also known as occluding junctions or zonulae occludentes (singular, zonula occludens), are multiprotein junctional complexes whose canonical function is to prevent leakage of solutes and water and seals between the epithelial cells. They also play a critical role maintaining the structure and permeability of endothelial cells. Tight junctions may also serve as leaky pathways by forming selective channels for small cations, anions, or water. The corresponding junctions that occur in invertebrates are septate junctions.
Structure
Tight junctions are composed of a branching network of sealing strands, each strand acting independently from the others. Therefore, the efficiency of the junction in preventing ion passage increases exponentially with the number of strands.
Each strand is formed from a row of transmembrane proteins embedded in both plasma membranes, with extracellular domains joining one another directly. There are at least 40 different proteins composing the tight junctions. These proteins consist of both transmembrane and cytoplasmic proteins. The three major transmembrane proteins are occludin, claudins, and junction adhesion molecule (JAM) proteins. These associate with different peripheral membrane proteins such as ZO-1 located on the intracellular side of plasma membrane, which anchor the strands to the actin component of the cytoskeleton. Thus, tight junctions join together the cytoskeletons of adjacent cells.
Transmembrane proteins:
Occludin was the first integral membrane protein to be identified. It has a molecular weight of ~60kDa. It consists of four transmembrane domains and both the N-terminus and the C-terminus of the protein are intracellular. It forms two extracellular loops and one intracellular loop. These loops help regulate paracellular permeability. Occludin also plays a key role in cellular structure and barrier function.
Claudins were discovered after occludin and are a family of over 27 different members in
Document 2:::
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 3:::
Gap junctions are one of four broad categories of intercellular connections that form between a multitude of animal cell types. First photographed around 1952 it wasn't until 1969 that gap junctions were referred to as "gap junctions". Named after the 2-4 nm gap they bridged between cell membranes, they had been characterised in more detail by 1967.
Within a gap junction reside protein complexes, referred initially to as "globules", observed to connect one cell to another and also vesicles within a cell to the outer cell membrane. By 1974 one of the major gap junction proteins was dubbed a "connexin", and six connexins were observed to form a channels called a "connexon", due to the connections connexon pairs made between cells. The initial discovery of gap junctions in nerve cells lent credence to their function in transmission of electrical impulses. Experimental confirmation followed with molecules, ions and electrical impulses shown to pass through the connexons which proved to be a generalized regulated gate between cells in gap junctions. As a type of hemichannel connexons also form channels to the extracellular regions as well.
While more than 26 different connexins frequently populate gap junctions in various different tissues there are at least 12 other components that form the specialized area of membrane called the gap junction. These components include among others the tight junction protein ZO-1 that holds the membranes close together, sodium channels, and aquaporin.
With increasing ability to sequence the DNA of organisms the complexity of the gap junction family of proteins increased. The term connexin was used to describe the gap junction proteins connecting two cells with pores. Sequencing of these pore proteins showed them to be strucuturally similar between vertebrates and invertebrates but different in sequence. As a result the term "innexin" was used to differentiate invertebrate from vertebrate connexins. While sequencing of invertebrate sp
Document 4:::
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What two types of junctions do animal cells have?
A. standard and specialized
B. loose and tight
C. tight and gap
D. gap and solid
Answer:
|
|
sciq-3212
|
multiple_choice
|
What is the term for an organism’s underlying genetic makeup, consisting of both the physically visible and the non-expressed alleles?
|
[
"phenotype",
"trait map",
"genotype",
"divergency"
] |
C
|
Relavent Documents:
Document 0:::
Genetics is the study of genes and tries to explain what they are and how they work. Genes are how living organisms inherit features or traits from their ancestors; for example, children usually look like their parents because they have inherited their parents' genes. Genetics tries to identify which traits are inherited and to explain how these traits are passed from generation to generation.
Some traits are part of an organism's physical appearance, such as eye color, height or weight. Other sorts of traits are not easily seen and include blood types or resistance to diseases. Some traits are inherited through genes, which is the reason why tall and thin people tend to have tall and thin children. Other traits come from interactions between genes and the environment, so a child who inherited the tendency of being tall will still be short if poorly nourished. The way our genes and environment interact to produce a trait can be complicated. For example, the chances of somebody dying of cancer or heart disease seems to depend on both their genes and their lifestyle.
Genes are made from a long molecule called DNA, which is copied and inherited across generations. DNA is made of simple units that line up in a particular order within it, carrying genetic information. The language used by DNA is called genetic code, which lets organisms read the information in the genes. This information is the instructions for the construction and operation of a living organism.
The information within a particular gene is not always exactly the same between one organism and another, so different copies of a gene do not always give exactly the same instructions. Each unique form of a single gene is called an allele. As an example, one allele for the gene for hair color could instruct the body to produce much pigment, producing black hair, while a different allele of the same gene might give garbled instructions that fail to produce any pigment, giving white hair. Mutations are random
Document 1:::
In biology, the word gene (from , ; meaning generation or birth or gender) can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes.
During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. (Some viruses have an RNA genome so the genes are made of RNA that may function directly without being copied into RNA. This is an exception to the strict definition of a gene described above.)
The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gene–environment interactions. Some genetic traits are instantly visible, such as eye color or the number of limbs, and some are not, such as blood type, the risk for specific diseases, or the thousands of basic biochemical processes that constitute life.
A gene can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a gene, which may cause different phenotypical traits. Usage of the term "having a gene" (e.g., "good genes," "hair color gene") typically refers to containing a different allele of the same, shared gene. Genes evolve due to natural selection / survival of the fittest and genetic drift of the alleles.
The term gene was introduced by Danish botanist, plant physiologist and geneticist Wilhelm Johannsen in 1909. It is inspired by the Ancient Greek: γόνος, gonos, that means offspring and procreation
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The genotype–phenotype map is a conceptual model in genetic architecture. Coined in a 1991 paper by Pere Alberch, it models the interdependency of genotype (an organism's full hereditary information) with phenotype (an organism's actual observed properties).
Application
The map visualises a relationship between genotype & phenotype which, crucially:
is of greater complexity than a straightforward one-to-one mapping of genotype to/from phenotype.
accommodates a parameter space, along which at different points a given phenotype is said to be more or less stable.
accommodates transformational boundaries in the parameter space, which divide phenotype states from one another.
accounts for different polymorphism and/or polyphenism in populations, depending on their area of parameter space they occupy.
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The genotype–phenotype distinction is drawn in genetics. "Genotype" is an organism's full hereditary information. "Phenotype" is an organism's actual observed properties, such as morphology, development, or behavior, and the consequences thereof. This distinction is fundamental in the study of inheritance of traits and their evolution.
Overview
The terms "genotype" and "phenotype" were created by Wilhelm Johannsen in 1911, although the meaning of the terms and the significance of the distinction have evolved since they were introduced.
It is the organism's physical properties that directly determine its chances of survival and reproductive output, but the inheritance of physical properties is dependent on the inheritance of genes. Therefore, understanding the theory of evolution via natural selection requires understanding the genotype–phenotype distinction. The genes contribute to a trait, and the phenotype is the observable expression of the genes (and therefore the genotype that affects the trait). If a white mouse had recessive genes that caused the genes responsible for color to be inactive, its genotype would be responsible for its phenotype (the white color).
The mapping of a set of genotypes to a set of phenotypes is sometimes referred to as the genotype–phenotype map.
An organism's genotype is a major (the largest by far for morphology) influencing factor in the development of its phenotype, but it is not the only one. Even two organisms with identical genotypes normally differ in their phenotypes.
One experiences this in everyday life with monozygous (i.e. identical) twins. Identical twins share the same genotype, since their genomes are identical; but they never have the same phenotype, although their phenotypes may be very similar. This is apparent in the fact that close relations can always tell them apart, even though others might not be able to see the subtle differences. Further, identical twins can be distinguished by their fingerprints, which
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In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (de novo) or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance, such as incomplete dominance, in which a gene variant has a partial effect compared to when it is present on both chromosomes, and co-dominance, in which different variants on each chromosome both show their associated traits.
Dominance is a key concept in Mendelian inheritance and classical genetics. Letters and Punnett squares are used to demonstrate the principles of dominance in teaching, and the use of upper-case letters for dominant alleles and lower-case letters for recessive alleles is a widely followed convention. A classic example of dominance is the inheritance of seed shape in peas. Peas may be round, associated with allele R, or wrinkled, associated with allele r. In this case, three combinations of alleles (genotypes) are possible: RR, Rr, and rr. The RR (homozygous) individuals have round peas, and the rr (homozygous) individuals have wrinkled peas. In Rr (heterozygous) individuals, the R allele masks the presence of the r allele, so these individuals also have round peas. Thus, allele R is d
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the term for an organism’s underlying genetic makeup, consisting of both the physically visible and the non-expressed alleles?
A. phenotype
B. trait map
C. genotype
D. divergency
Answer:
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|
sciq-9201
|
multiple_choice
|
Energy is the capacity to do work or to produce what?
|
[
"heat",
"humidity",
"light",
"vibration"
] |
A
|
Relavent Documents:
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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 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
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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
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Engineering mathematics is a branch of applied mathematics concerning mathematical methods and techniques that are typically used in engineering and industry. Along with fields like engineering physics and engineering geology, both of which may belong in the wider category engineering science, engineering mathematics is an interdisciplinary subject motivated by engineers' needs both for practical, theoretical and other considerations outside their specialization, and to deal with constraints to be effective in their work.
Description
Historically, engineering mathematics consisted mostly of applied analysis, most notably: differential equations; real and complex analysis (including vector and tensor analysis); approximation theory (broadly construed, to include asymptotic, variational, and perturbative methods, representations, numerical analysis); Fourier analysis; potential theory; as well as linear algebra and applied probability, outside of analysis. These areas of mathematics were intimately tied to the development of Newtonian physics, and the mathematical physics of that period. This history also left a legacy: until the early 20th century subjects such as classical mechanics were often taught in applied mathematics departments at American universities, and fluid mechanics may still be taught in (applied) mathematics as well as engineering departments.
The success of modern numerical computer methods and software has led to the emergence of computational mathematics, computational science, and computational engineering (the last two are sometimes lumped together and abbreviated as CS&E), which occasionally use high-performance computing for the simulation of phenomena and the solution of problems in the sciences and engineering. These are often considered interdisciplinary fields, but are also of interest to engineering mathematics.
Specialized branches include engineering optimization and engineering statistics.
Engineering mathematics in tertiary educ
Document 4:::
Energy quality is a measure of the ease with which a form of energy can be converted to useful work or to another form of energy: i.e. its content of thermodynamic free energy. A high quality form of energy has a high content of thermodynamic free energy, and therefore a high proportion of it can be converted to work; whereas with low quality forms of energy, only a small proportion can be converted to work, and the remainder is dissipated as heat. The concept of energy quality is also used in ecology, where it is used to track the flow of energy between different trophic levels in a food chain and in thermoeconomics, where it is used as a measure of economic output per unit of energy. Methods of evaluating energy quality often involve developing a ranking of energy qualities in hierarchical order.
Examples: Industrialization, Biology
The consideration of energy quality was a fundamental driver of industrialization from the 18th through 20th centuries. Consider for example the industrialization of New England in the 18th century. This refers to the construction of textile mills containing power looms for weaving cloth. The simplest, most economical and straightforward source of energy was provided by water wheels, extracting energy from a millpond behind a dam on a local creek. If another nearby landowner also decided to build a mill on the same creek, the construction of their dam would lower the overall hydraulic head to power the existing waterwheel, thus hurting power generation and efficiency. This eventually became an issue endemic to the entire region, reducing the overall profitability of older mills as newer ones were built. The search for higher quality energy was a major impetus throughout the 19th and 20th centuries. For example, burning coal to make steam to generate mechanical energy would not have been imaginable in the 18th century; by the end of the 19th century, the use of water wheels was long outmoded. Similarly, the quality of energy from elec
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Energy is the capacity to do work or to produce what?
A. heat
B. humidity
C. light
D. vibration
Answer:
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|
sciq-7413
|
multiple_choice
|
What is the term for reproductive cells, such as sperm and egg?
|
[
"gametes",
"parasites",
"nucleus",
"spores"
] |
A
|
Relavent Documents:
Document 0:::
Microgametogenesis is the process in plant reproduction where a microgametophyte develops in a pollen grain to the three-celled stage of its development. In flowering plants it occurs with a microspore mother cell inside the anther of the plant.
When the microgametophyte is first formed inside the pollen grain four sets of fertile cells called sporogenous cells are apparent. These cells are surrounded by a wall of sterile cells called the tapetum, which supplies food to the cell and eventually becomes the cell wall for the pollen grain. These sets of sporogenous cells eventually develop into diploid microspore mother cells. These microspore mother cells, also called microsporocytes, then undergo meiosis and become four microspore haploid cells. These new microspore cells then undergo mitosis and form a tube cell and a generative cell. The generative cell then undergoes mitosis one more time to form two male gametes, also called sperm.
See also
Gametogenesis
Document 1:::
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 2:::
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
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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 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 is the term for reproductive cells, such as sperm and egg?
A. gametes
B. parasites
C. nucleus
D. spores
Answer:
|
|
sciq-249
|
multiple_choice
|
Which pathway carries somatosensory information from the face, head, mouth, and nasal cavity?
|
[
"dual pathway",
"cranial pathway",
"trigeminal pathway",
"posterior pathway"
] |
C
|
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
Document 1:::
The ophthalmic nerve (CN V1) is a sensory nerve of the head. It is one of three divisions of the trigeminal nerve (CN V), a cranial nerve. It has three major branches which provide sensory innervation to the eye, and the skin of the upper face and anterior scalp, as well as other structures of the head.
Structure
It measures about 2.5 cm in length.
Origin
The ophthalmic nerve is the first branch of the trigeminal nerve (CN V), the first and smallest of its three divisions. It arises from the superior part of the trigeminal ganglion.
Course
It passes anterior-ward along the lateral wall of the cavernous sinus inferior to the oculomotor nerve (CN III) and trochlear nerve (N IV). It divides into its three main branches as it approaches the superior orbital fissure.
Branches
Within the skull, the ophthalmic nerve produces:
meningeal branch (tentorial nerve)
The ophthalmic nerve divides into three major branches which pass through the superior orbital fissure:
frontal nerve
supraorbital nerve
supratrochlear nerve
lacrimal nerve
nasociliary nerve
posterior ethmoidal nerve
anterior ethmoidal nerve
external nasal nerve
long ciliary nerves
infratrochlear nerve
communicating branch to ciliary ganglion
Distribution
The ophthalmic nerve provides sensory innervation to the cornea, ciliary body, and iris; to the lacrimal gland and conjunctiva; to the part of the mucous membrane of the nasal cavity; and to the skin of the eyelids, eyebrow, forehead and nose.
It carries sensory branches from the eyes, conjunctiva, lacrimal gland, nasal cavity, frontal sinus, ethmoidal cells, falx cerebri, dura mater in the anterior cranial fossa, superior parts of the tentorium cerebelli, upper eyelid, dorsum of the nose, and anterior part of the scalp.
Roughly speaking, the ophthalmic nerve supplies general somatic afferents to the upper face, head, and eye:
Face: Upper eyelid and associated conjunctiva. Eyebrow, forehead, scalp all the way to the lambdoid suture.
Skull: Roof o
Document 2:::
The sphenopalatine artery passes through the sphenopalatine foramen into the cavity of the nose, at the back part of the superior meatus. Here it gives off its posterior lateral nasal branches which spread forward over the conchæ and meatuses, anastomose with the ethmoidal arteries and the nasal branches of the descending palatine, and assist in supplying the frontal, maxillary, ethmoidal, and sphenoidal sinuses.
Document 3:::
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
Document 4:::
The carotid canal is a passage in the petrous part of the temporal bone of the skull through which the internal carotid artery and its internal carotid (nervous) plexus pass from the neck into (the middle cranial fossa of) the cranial cavity.
Structure
The carotid canal is located within the middle cranial fossa, at the petrous part of the temporal bone. Anteriorly, it is limited by posterior margin of the greater wing of sphenoid bone. Posteromedially, it is limited by basilar part of occipital bone. It is divided in three parts, namely, ascending petrous, transverse petrous, and ascending cavernous parts. The carotid canal has two openings, namely internal and external openings. The internal opening is situated laterally to foramen lacerum. The external opening of the carotid canal is located posterolaterally to the foramen lacerum. Both internal and external openings of the carotid canal lies anterior to the jugular foramen, where the latter is located inside the posterior cranial fossa. The carotid canal is separated from middle ear and inner ear by a thin plate of bone.
Contents
The canal transmits internal carotid artery together with its associated nervous plexus and venous plexus.
Clinical significance
Any skull fractures that damage the carotid canal can put the internal carotid artery at risk. Angiography can be used to ensure that there is no damage, and to aid in treatment if there is.
Other animals
The carotid canal starts on the inferior surface of the temporal bone of the skull at the external opening of the carotid canal (also referred to as the carotid foramen). The canal ascends at first superiorly, and then, making a bend, runs anteromedially. Its internal opening is near the foramen lacerum, above which the internal carotid artery passes on its way anteriorly to the cavernous sinus.
The carotid canal allows the internal carotid artery to pass into the cranium, as well as the carotid plexus traveling on the artery.
The carotid plexus cont
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which pathway carries somatosensory information from the face, head, mouth, and nasal cavity?
A. dual pathway
B. cranial pathway
C. trigeminal pathway
D. posterior pathway
Answer:
|
|
sciq-7897
|
multiple_choice
|
Which system refers to the skin and its accessory structures?
|
[
"malpighian system",
"tomoxia system",
"digestive system",
"integumentary system"
] |
D
|
Relavent Documents:
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A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways. A biological system is not to be confused with a living system, such as a living organism.
Organ and tissue systems
These specific systems are widely studied in human anatomy and are also present in many other animals.
Respiratory system: the organs used for breathing, the pharynx, larynx, bronchi, lungs and diaphragm.
Digestive system: digestion and processing food with salivary glands, oesophagus, stomach, liver, gallbladder, pancreas, intestines, rectum and anus.
Cardiovascular system (heart and circulatory system): pumping and channeling blood to and from the body and lungs with heart, blood and blood vessels.
Urinary system: kidneys, ureters, bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.
Integumentary system: skin, hair, fat, and nails.
Skeletal system: structural support and protection with bones, cartilage, ligaments and tendons.
Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid, parathyroid and adrenals, i.e., adrenal glands.
Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream; includes the lymph and the nodes and vessels. The lymphatic system includes functions including immune responses and development of antibodies.
Immune system: protects the organism from
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In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
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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:
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Splanchnology is the study of the visceral organs, i.e. digestive, urinary, reproductive and respiratory systems.
The term derives from the Neo-Latin splanchno-, from the Greek σπλάγχνα, meaning "viscera". More broadly, splanchnology includes all the components of the Neuro-Endo-Immune (NEI) Supersystem. An organ (or viscus) is a collection of tissues joined in a structural unit to serve a common function. In anatomy, a viscus is an internal organ, and viscera is the plural form. Organs consist of different tissues, one or more of which prevail and determine its specific structure and function. Functionally related organs often cooperate to form whole organ systems.
Viscera are the soft organs of the body. There are organs and systems of organs that differ in structure and development but they are united for the performance of a common function. Such functional collection of mixed organs, form an organ system. These organs are always made up of special cells that support its specific function. The normal position and function of each visceral organ must be known before the abnormal can be ascertained.
Healthy organs all work together cohesively and gaining a better understanding of how, helps to maintain a healthy lifestyle. Some functions cannot be accomplished only by one organ. That is why organs form complex systems. The system of organs is a collection of homogeneous organs, which have a common plan of structure, function, development, and they are connected to each other anatomically and communicate through the NEI supersystem.
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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.
Which system refers to the skin and its accessory structures?
A. malpighian system
B. tomoxia system
C. digestive system
D. integumentary system
Answer:
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|
ai2_arc-222
|
multiple_choice
|
When a blue light is shone on a yellow banana, what color does the banana appear to be?
|
[
"blue",
"yellow",
"green",
"black"
] |
D
|
Relavent Documents:
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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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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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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
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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 Natural Color System (NCS) is a proprietary perceptual color model. It is based on the color opponency hypothesis of color vision, first proposed by German physiologist Ewald Hering. The current version of the NCS was developed by the Swedish Colour Centre Foundation, from 1964 onwards. The research team consisted of Anders Hård, Lars Sivik and Gunnar Tonnquist, who in 1997 received the AIC Judd award for their work. The system is based entirely on the phenomenology of human perception and not on color mixing. It is illustrated by a color atlas, marketed by NCS Colour AB in Stockholm.
Definition
The NCS states that there are six elementary color percepts of human vision—which might coincide with the psychological primaries—as proposed by the hypothesis of color opponency: white, black, red, yellow, green, and blue. The last four are also called unique hues. In the NCS all six are defined as elementary colors, irreducible qualia, each of which would be impossible to define in terms of the other elementary colors. All other experienced colors are considered composite perceptions, i.e. experiences that can be defined in terms of similarity to the six elementary colors. E.g. a saturated pink would be fully defined by its visual similarity to red, blue, black and white.
Colors in the NCS are defined by three values, expressed in percentages, specifying the degree of blackness (s , = relative visual similarity to the black elementary color), chromaticness (c, = relative visual similarity to the "strongest", most saturated, color in that hue triangle), and hue (Φ, = relative similarity to one or two of the chromatic elementary colors red, yellow, green and blue, expressed in at most two percentages). This means that a color can be expressed as either Y (yellow), YR (yellow with a red component), R (Red), RB (red with a blue component), B (blue), etc. No hue is considered to have visual similarity to both hues of an opponent pair; i.e. there is no "redgreen" or "yell
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When a blue light is shone on a yellow banana, what color does the banana appear to be?
A. blue
B. yellow
C. green
D. black
Answer:
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|
sciq-3587
|
multiple_choice
|
Heavily vegetated lands are less likely to experience what?
|
[
"rains",
"expansion",
"flooding",
"drought"
] |
C
|
Relavent Documents:
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Plant ecology is a subdiscipline of ecology that studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, and the interactions among plants and between plants and other organisms. Examples of these are the distribution of temperate deciduous forests in North America, the effects of drought or flooding upon plant survival, and competition among desert plants for water, or effects of herds of grazing animals upon the composition of grasslands.
A global overview of the Earth's major vegetation types is provided by O.W. Archibold. He recognizes 11 major vegetation types: tropical forests, tropical savannas, arid regions (deserts), Mediterranean ecosystems, temperate forest ecosystems, temperate grasslands, coniferous forests, tundra (both polar and high mountain), terrestrial wetlands, freshwater ecosystems and coastal/marine systems. This breadth of topics shows the complexity of plant ecology, since it includes plants from floating single-celled algae up to large canopy forming trees.
One feature that defines plants is photosynthesis. Photosynthesis is the process of a chemical reactions to create glucose and oxygen, which is vital for plant life. One of the most important aspects of plant ecology is the role plants have played in creating the oxygenated atmosphere of earth, an event that occurred some 2 billion years ago. It can be dated by the deposition of banded iron formations, distinctive sedimentary rocks with large amounts of iron oxide. At the same time, plants began removing carbon dioxide from the atmosphere, thereby initiating the process of controlling Earth's climate. A long term trend of the Earth has been toward increasing oxygen and decreasing carbon dioxide, and many other events in the Earth's history, like the first movement of life onto land, are likely tied to this sequence of events.
One of the early classic books on plant ecology was written by J.E. Weaver and F.E. Clements. It
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Land cover is the physical material at the surface of Earth. Land covers include grass, asphalt, trees, bare ground, water, etc. Earth cover is the expression used by ecologist Frederick Edward Clements that has its closest modern equivalent being vegetation. The expression continues to be used by the United States Bureau of Land Management.
There are two primary methods for capturing information on land cover: field survey, and analysis of remotely sensed imagery. Land change models can be built from these types of data to assess changes in land cover over time.
One of the major land cover issues (as with all natural resource inventories) is that every survey defines similarly named categories in different ways. For instance, there are many definitions of "forest"—sometimes within the same organisation—that may or may not incorporate a number of different forest features (e.g., stand height, canopy cover, strip width, inclusion of grasses, and rates of growth for timber production). Areas without trees may be classified as forest cover "if the intention is to re-plant" (UK and Ireland), while areas with many trees may not be labelled as forest "if the trees are not growing fast enough" (Norway and Finland).
Distinction from "land use"
"Land cover" is distinct from "land use", despite the two terms often being used interchangeably. Land use is a description of how people utilize the land and of socio-economic activity. Urban and agricultural land uses are two of the most commonly known land use classes. At any one point or place, there may be multiple and alternate land uses, the specification of which may have a political dimension. The origins of the "land cover/land use" couplet and the implications of their confusion are discussed in Fisher et al. (2005).
Types
Following table is Land Cover statistics by Food and Agriculture Organization (FAO) with 14 classes.
Mapping
Land cover change detection using remote sensing and geospatial data provides baselin
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In viticulture, there are several levels of regional climates that are used to describe the terroir or immutable characteristics of an area. These levels can be as broad as a macroclimate which includes entire wine regions or as small as a microclimate which includes the unique environment around an individual grapevine. In the middle is the mesoclimate which usually describes the characteristics of a particular vineyard site.
Levels
Macroclimate, in viticulture, refers to the regional climate of a broad area such as an American Viticultural Area (AVA) or a French Appellation d'origine contrôlée (AOC). It can include an area on the scale of tens to hundreds of kilometers. On smaller scales are the related designations of mesoclimate and microclimate.
Mesoclimate refers to the climate of a particular vineyard site and is generally restricted to a space of tens or hundreds of meters.
Microclimate refers to the specific environment in a small restricted spaces-such as a row of vines. The more delineated term canopy microclimate refers to the environment around an individual grapevine. although many viticulturists use the term "microclimate" when talking about an individual vine and the effects of canopy management.
See also
Climate categorizations in viticulture
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Biodiversity in agriculture is the measure of biodiversity found on agricultural land. Biodiversity is the total diversity of species present in an area at all levels of biological organization. It is characterized by heterogeneous habitats that support the diverse ecological structure. In agricultural areas, biodiversity decreases as varying landscapes are lost and native plants are replaced with cultivated crops. Increasing biodiversity in agriculture can increase the sustainability of farms through the restoration of ecosystem services that aid in regulating agricultural lands. Biodiversity in agriculture can be increased through the process of agroecological restoration, as farm biodiversity is an aspect of agroecology.
Biodiversity is the measure of biotic and abiotic diversity in an ecosystem, described by heterogeneity. The loss of biodiversity in agriculture has been an increasing issue since the global increase of food demands and success of popular crops. This loss of heterogeneity declines species biodiversity on agricultural lands. Biodiversity in agriculture is essential in providing ecosystem services, which conserves biodiversity while providing agricultural services.
Biodiversity loss
Agriculture creates a conflict over the use of land between wildlife and humans. Land use for agriculture has been a driving force in creating biodiversity loss An increase in the amount of pasture and crop land over the last few hundred years has led to the rapid loss of natural habitats. The Food and Agriculture Organization of the United Nations estimates that more than 40% of earth’s land surface is currently used for agriculture. Because so much land has been converted to agriculture, habitat loss is recognized as the driving force in biodiversity loss. A decline in farmland biodiversity can be traced to changes in farming practices and increased agricultural intensity. Nonetheless, according to the FAO, "biodiversity is just as important on farms and in fields
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Satellite crop monitoring is the technology which facilitates real-time crop vegetation index monitoring via spectral analysis of high resolution satellite images for different fields and crops which enables to track positive and negative dynamics of crop development. The difference in vegetation index informs about single-crop development disproportions that speaks for the necessity of additional agriculture works on particular field zones—that is because satellite crop monitoring belongs to precision agriculture methods.
Satellite crop monitoring technology allows to perform online crop monitoring on different fields, located in different areas, regions, even countries and on different continents. The technology's advantage is a high automation level of sown area condition and its interpretation in an interactive map which can be read by different groups of users.
Satellite crop monitoring technology users are:
agronomists and agriculture companies management (crop vegetation control, crop yield forecasting, management decisions optimization);
business owners (business prospects estimates, making reasonable decisions on capital investments, providing information for management decisions);
investors and investment analysts (investment potential estimation, making investment decisions, making sustainable forecasts);
insurance brokers (data collection, clients claims verification, scale of rates and insurance premium amounts calculation);
agriculture machinery producers (integration of crop monitoring solutions with agriculture machinery board computers operations, functional development);
state and sectoral organisations engaged in agriculture, food security and ecological problems.
See also
Normalized Difference Vegetation Index
Precision agriculture
Remote sensing
Satellite imaging
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Heavily vegetated lands are less likely to experience what?
A. rains
B. expansion
C. flooding
D. drought
Answer:
|
|
sciq-5206
|
multiple_choice
|
Each pollen grain has two coverings: the exine (thicker, outer layer) and the what?
|
[
"pollen tube",
"intine",
"tube nucleus",
"cytoplasm"
] |
B
|
Relavent Documents:
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A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than to traverse the length of the pistil.
Pollen tubes were first discovered by Giovanni Battista Amici in the 19th century.
They are used as a model for understanding plant cell behavior. Research is ongoing to comprehend how the pollen tube responds to extracellular guidance signals to achieve fertilization.
Description
Pollen tubes are produced by the male gametophytes of seed plants. Pollen tubes act as conduits to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. Pollen tubes are unique to seed plants and their structures have evolved over their history since the Carboniferous period. Pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists because pollen tubes transport the male gametes produced by pollen grains to the female gametophyte. Once a pollen grain has implanted on a compatible stigma, its germination is initiated. During this process, the pollen grain begins to bulge outwards to form a tube-like structure, known as the pollen tube. The pollen tube structure rapidly descends down the length of the style via tip-directed growth, reaching rates of 1 cm/h, whilst carrying two non-motile sperm cells. Upon reaching the ovule the pollen tube ruptures, thereby delivering the sperm cells to the female gametophyte. In flowering plants a double fertilization event occurs. The first fertilization event produces a diplo
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Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.
Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.
Pollen is infrequently used as food and food supplement. Because of agricultural practices, it is often contaminated by agricultural pesticides.
Structure and formation
Pollen itself is not the male gamete. It is a gametophyte, something that could be considered an entire organism, which then produces the male gamete. Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm nuclei.
Pollen comes in many different shapes. Some pollen grains are based on geodesic polyhedra like a soccer ball.
Formation
Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower. Pollen g
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The tapetum is a specialised layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporangenous tissue and the anther wall.
Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat. The cells are usually bigger and normally have more than one nucleus per cell. As the sporogenous cells undergo mitosis, the nuclei of tapetal cells also divide. Sometimes, this mitosis is not normal due to which many cells of mature tapetum become multinucleate. Sometimes polyploidy and polyteny can also be seen. The unusually large nuclear constitution of the tapetum helps it in providing nutrients and regulatory molecules to the forming pollen grains. The following processes are responsible for this:
Endomitosis
Normal mitosis not followed by cytokinesis
Formation of restitution nuclei
Endoreduplication
Tapetum helps in pollenwall formation, transportation of nutrients to inner side of anther, synthesis of callase enzyme for separation of microspore tetrads.
Types of tapetum
Two main tapetum types are recognised, secretory (glandular) and plasmodial (amoeboid). In the secretory type a layer of tapetal cells remains around the anther locule, while in the plasmodial type the tapetal cell walls dissolve and their protoplasts fuse to form a multinucleate plasmodium. A third, less common type, the invasive non-syncytial tapetum has been described in Canna, where the tapetal cell walls break down to invade the anther locule but do not fuse to form a plasmodium.
Amongst the monocots Acorales, the first branching clade has a secretory tapetum, while the other alismatid clade, Alismatales are predominantly plasmodial. Amongst the late branching clades, the lilioid monocots are nearly all secretory while the commelinid monocots are diverse with respect to tapetal pattern.
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In biology, a theca (plural thecae) is a sheath or a covering.
Botany
In botany, the theca is related to plant's flower anatomy. The theca of an angiosperm consists of a pair of microsporangia that are adjacent to each other and share a common area of dehiscence called the stomium. Any part of a microsporophyll that bears microsporangia is called an anther. Most anthers are formed on the apex of a filament. An anther and its filament together form a typical (or filantherous) stamen, part of the male floral organ.
The typical anther is bilocular, i.e. it consists of two thecae. Each theca contains two microsporangia, also known as pollen sacs. The microsporangia produce the microspores, which for seed plants are known as pollen grains.
If the pollen sacs are not adjacent, or if they open separately, then no thecae are formed. In Lauraceae, for example, the pollen sacs are spaced apart and open independently.
The tissue between the locules and the cells is called the connective and the parenchyma. Both pollen sacs are separated by the stomium. When the anther is dehiscing, it opens at the stomium.
The outer cells of the theca form the epidermis. Below the epidermis, the somatic cells form the tapetum. These support the development of microspores into mature pollen grains. However, little is known about the underlying genetic mechanisms, which play a role in male sporo- and gametogenesis.
The thecal arrangement of a typical stamen can be as follows:
Divergent: both thecae in line, and forming an acute angle with the filament
Transverse (or explanate): both thecae exactly in line, at right angles with the filament
Oblique: the thecae fixed to each other in an oblique way
Parallel: the thecae fixed to each other in a parallel way
Zoology
In biology, the theca of follicle can also refer to the site of androgen production in females. The theca of the spinal cord is called the thecal sac, and intrathecal injections are made there or in the subarachnoid space o
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The chalaza (; from Greek "hailstone"; plural chalazas or chalazae, ) is a structure inside bird eggs and plant ovules. It attaches or suspends the yolk or nucellus within the larger structure.
In animals
In the eggs of most birds (not of the reptiles), the chalazae are two spiral bands of tissue that suspend the yolk in the center of the white (the albumen). The function of the chalazae is to hold the yolk in place. In baking, the chalazae are sometimes removed in order to ensure a uniform texture.
In plants
In plant ovules, the chalaza is located opposite the micropyle opening of the integuments. It is the tissue where the integuments and nucellus are joined. Nutrients from the plant travel through vascular tissue in the funiculus and outer integument through the chalaza into the nucellus. During the development of the embryo sac inside a flowering plant ovule, the three cells at the chalazal end become the antipodal cells.
Chalazogamy
In most flowering plants, the pollen tube enters the ovule through the micropyle opening in the integuments for fertilization (porogamy). In chalazogamous fertilization, the pollen tubes penetrate the ovule through the chalaza rather than the micropyle opening.
Chalazogamy was first discovered in monoecious plant species of the family Casuarinaceae by Melchior Treub, but has since then also been observed in others, for example in pistachio and walnut.
Notes
Oology
Plant morphology
Plant anatomy
Pollination
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Each pollen grain has two coverings: the exine (thicker, outer layer) and the what?
A. pollen tube
B. intine
C. tube nucleus
D. cytoplasm
Answer:
|
|
sciq-9181
|
multiple_choice
|
What is divided during cytokinesis?
|
[
"cytoplasm",
"nucleus",
"cytoskeleton",
"chromosomes"
] |
A
|
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 cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components:microfilaments, intermediate filaments, and microtubules, and these are all capable of rapid growth or disassembly depending on the cell's requirements.
A multitude of functions can be performed by the cytoskeleton. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material (endocytosis), the segregation of chromosomes during cellular division, the cytokinesis stage of cell division, as scaffolding to organize the contents of the cell in space and in intracellular transport (for example, the movement of vesicles and organelles within the cell) and can be a template for the construction of a cell wall. Furthermore, it can form specialized structures, such as flagella, cilia, lamellipodia and podosomes. The structure, function and dynamic behavior of the cytoskeleton can be very different, depending on organism and cell type. Even within one cell, the cytoskeleton can change through association with other proteins and the previous history of the network.
A large-scale example of an action performed by the cytoskeleton is muscle contraction. This is carried out by groups of highly specialized cells working together. A main component in the cytoskeleton that helps show the true function of this muscle contraction is the microfilament. Microfilaments are composed of the most abundant cel
Document 2:::
The midbody is a transient structure found in mammalian cells and is present near the end of cytokinesis just prior to the complete separation of the dividing cells. The structure was first described by Walther Flemming in 1891.
Structure
The midbody structure contains bundles of microtubules derived from the mitotic spindle which compacts during the final stages of cell division. It has a typical diameter of 1 micrometre and a length of 3 to 5 micrometres. Aside from microtubules it also contains various proteins involved in cytokinesis, asymmetric cell division, and chromosome segregation.
The midbody is important for completing the final stages of cytokinesis, a process called abscission. During symmetric abscission, the midbody is severed at each end and released into the cellular environment.
Role in intercellular signalling
It was long assumed that the midbody was simply a structural part of cytokinesis, and was totally degraded with the completion of mitosis. However, it is now understood that post-abscission, the midbody is converted into an endosome-like signalling molecule, and can be internalised by nearby cells.
This endosome is marked by MKLP1, and can persist for up to 48 hours once internalised into another cell. It is coated in Actin, which is slowly degraded by the internalising cell.
Related proteins
MKLP1
TEX14
CEP55
Aurora Kinase B
Document 3:::
Organelle biogenesis is the biogenesis, or creation, of cellular organelles in cells. Organelle biogenesis includes the process by which cellular organelles are split between daughter cells during mitosis; this process is called organelle inheritance.
Discovery
Following the discovery of cellular organelles in the nineteenth century, little was known about their function and synthesis until the development of electron microscopy and subcellular fractionation in the twentieth century. This allowed experiments on the function, structure, and biogenesis of these organelles to commence.
Mechanisms of protein sorting and retrieval have been found to give organelles their characteristic composition. It is known that cellular organelles can come from preexisting organelles; however, it is a subject of controversy whether organelles can be created without a preexisting one.
Process
Several processes are known to have developed for organelle biogenesis. These can range from de novo synthesis to the copying of a template organelle; the formation of an organelle 'from scratch' and using a preexisting organelle as a template to manufacture an organelle, respectively. The distinct structures of each organelle are thought to be caused by the different mechanisms of the processes which create them and the proteins that they are made up of. Organelles may also be 'split' between two cells during the process of cellular division (known as organelle inheritance), where the organelle of the parent cell doubles in size and then splits with each half being delivered to their respective daughter cells.
The process of organelle biogenesis is known to be regulated by specialized transcription networks that modulate the expression of the genes that code for specific organellar proteins. In order for organelle biogenesis to be carried out properly, the specific genes coding for the organellar proteins must be transcribed properly and the translation of the resulting mRNA must be succes
Document 4:::
This lecture, named in memory of Keith R. Porter, is presented to an eminent cell biologist each year at the ASCB Annual Meeting. The ASCB Program Committee and the ASCB President recommend the Porter Lecturer to the Porter Endowment each year.
Lecturers
Source: ASCB
See also
List of biology awards
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is divided during cytokinesis?
A. cytoplasm
B. nucleus
C. cytoskeleton
D. chromosomes
Answer:
|
|
sciq-3115
|
multiple_choice
|
In the radiative zone, light particles called what can only travel a few millimeters before they hit another particle?
|
[
"neutrons",
"photons",
"electrons",
"positrons"
] |
B
|
Relavent Documents:
Document 0:::
Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum.
Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet, visible light, nearly all types of laser light, infrared, microwaves, and radio waves are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV.
Typical ionizing subatomic particles include alpha particles, beta particles, and neutrons. These are typically created by radioactive decay, and almost all are energetic enough to ionize. There are also secondary cosmic particles produced after cosmic rays interact with Earth's atmosphere, including muons, mesons, and positrons. Cosmic rays may also produce radioisotopes on Earth (for example, carbon-14), which in turn decay and emit ionizing radiation. Cosmic rays and the decay of radioactive isotopes are the primary sources of natural ionizing radiation on Earth, contributing to background radiation. Ionizing radiation is also generated artificially by X-ray tubes, particle accelerators, and nuclear fission.
Ionizing radiation is not immediately detectable by human senses, so instruments such as Geiger counters are used to detect and measure it. However, very high energy particles can produce visible effects on both organic and inorganic matter (e.g. water lighting in Cherenkov radiation) or humans (e.g. acute radiation syndrome).
Ionizing radiation is used in a wide variety of field
Document 1:::
Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk is deflected off into space by the magnetosphere or the heliosphere.
Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics.
Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays.
Data from the Fermi Space Telescope (2013) have been interpreted as evidence that a significant fraction of primary cosmic rays originate from the supernova explosions of stars. Based on observations of neutrinos and gamma rays from blazar TXS 0506+056 in 2018, active galactic nuclei also appear to produce cosmic rays.
Etymology
The term ray (as in optical ray) seems to have arisen from an initial belief, due to their penetrating power, that cosmic rays were mostly electromagnetic radiation. Nevertheless, following wider recognition of cosmic rays as being various high-energy particles with intrinsic mass, the term "rays" was still consistent with then known particles such as cathode rays, canal rays, alpha rays and beta rays. Meanwhile "cosmic" ray photons, which are quanta of electromagnetic radiation (and so have no intrinsic mass) are known by their common names, such as gamma rays or X-rays, depending on their photon energy.
Composition
Of primary cosmic rays, which originate outside of Earth's atmosphere, about 99% are the bare nuclei of common at
Document 2:::
In particle physics, the radiation length is a characteristic of a material, related to the energy loss of high energy particles electromagnetically interacting with it. It is defined as the mean length (in cm) into the material at which the energy of an electron is reduced by the factor 1/e.
Definition
In materials of high atomic number (e.g. tungsten, uranium, plutonium) the electrons of energies >~10 MeV predominantly lose energy by , and high-energy photons by pair production. The characteristic amount of matter traversed for these related interactions is called the radiation length , usually measured in g·cm−2. It is both the mean distance over which a high-energy electron loses all but of its energy by , and of the mean free path for pair production by a high-energy photon. It is also the appropriate length scale for describing high-energy electromagnetic cascades.
The radiation length for a given material consisting of a single type of nucleus can be approximated by the following expression:
where is the atomic number and is mass number of the nucleus.
For , a good approximation is
where
is the number density of the nucleus,
denotes the reduced Planck constant,
is the electron rest mass,
is the speed of light,
is the fine-structure constant.
For electrons at lower energies (below few tens of MeV), the energy loss by ionization is predominant.
While this definition may also be used for other electromagnetic interacting particles beyond leptons and photons, the presence of the stronger hadronic and nuclear interaction makes it a far less interesting characterisation of the material; the nuclear collision length and nuclear interaction length are more relevant.
Comprehensive tables for radiation lengths and other properties of materials are available from the Particle Data Group.
See also
Mean free path
Attenuation length
Attenuation coefficient
Attenuation
Range (particle radiation)
Stopping power (particle radiation)
Electron en
Document 3:::
Minicharged particles (or milli-charged particles) are a proposed type of subatomic particle. They are charged, but with a tiny fraction of the charge of the electron. They weakly interact with matter. Minicharged particles are not part of the Standard Model. One proposal to detect them involved photons tunneling through an opaque barrier in the presence of a perpendicular magnetic field, the rationale being that a pair of oppositely charged minicharged particles are produced that curve in opposite directions, and recombine on the other side of the barrier reproducing the photon again.
Minicharged particles would result in vacuum magnetic dichroism, and would cause energy loss in microwave cavities. Photons from the cosmic microwave background would be dissipated by galactic-scale magnetic fields if minicharged particles existed, so this effect could be observable. In fact the dimming observed of remote supernovae that was used to support dark energy could also be explained by the formation of minicharged particles.
Tests of Coulomb's law can be applied to set bounds on minicharged particles.
Document 4:::
In physics, a neutral particle is a particle without an electric charge, such as a neutron.
The term neutral particles should not be confused with truly neutral particles, the subclass of neutral particles that are also identical to their own antiparticles.
Stable or long-lived neutral particles
Long-lived neutral particles provide a challenge in the construction of particle detectors, because they do not interact electromagnetically, except possibly through their magnetic moments. This means that they do not leave tracks of ionized particles or curve in magnetic fields. Examples of such particles include photons, neutrons, and neutrinos.
Other neutral particles
Other neutral particles are very short-lived and decay before they could be detected even if they were charged. They have been observed only indirectly. They include:
Z bosons
Dozens of heavy neutral hadrons:
Neutral mesons such as the and
The neutral Delta baryon (), and other neutral baryons, such as the and
See also
Neutral particle oscillation
Truly neutral particle
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In the radiative zone, light particles called what can only travel a few millimeters before they hit another particle?
A. neutrons
B. photons
C. electrons
D. positrons
Answer:
|
|
sciq-4820
|
multiple_choice
|
As air pressures inside and outside of the ear equalize, what phenomenon is produced?
|
[
"throat scratching",
"eyes blinking",
"heart skipping",
"ear popping"
] |
D
|
Relavent Documents:
Document 0:::
An otoacoustic emission (OAE) is a sound that is generated from within the inner ear. Having been predicted by Austrian astrophysicist Thomas Gold in 1948, its existence was first demonstrated experimentally by British physicist David Kemp in 1978, and otoacoustic emissions have since been shown to arise through a number of different cellular and mechanical causes within the inner ear. Studies have shown that OAEs disappear after the inner ear has been damaged, so OAEs are often used in the laboratory and the clinic as a measure of inner ear health.
Broadly speaking, there are two types of otoacoustic emissions: spontaneous otoacoustic emissions (SOAEs), which occur without external stimulation, and evoked otoacoustic emissions (EOAEs), which require an evoking stimulus.
Mechanism of occurrence
OAEs are considered to be related to the amplification function of the cochlea. In the absence of external stimulation, the activity of the cochlear amplifier increases, leading to the production of sound. Several lines of evidence suggest that, in mammals, outer hair cells are the elements that enhance cochlear sensitivity and frequency selectivity and hence act as the energy sources for amplification.
Types
Spontaneous
Spontaneous otoacoustic emissions (SOAEs) are sounds that are emitted from the ear without external stimulation and are measurable with sensitive microphones in the external ear canal. At least one SOAE can be detected in approximately 35–50% of the population. The sounds are frequency-stable between 500 Hz and 4,500 Hz and have unstable volumes between -30 dB SPL and +10 dB SPL. The majority of those with SOAEs are unaware of them, however 1–9% perceive a SOAE as an annoying tinnitus. It has been suggested that "The Hum" phenomena are SOAEs.
Evoked
Evoked otoacoustic emissions are currently evoked using three different methodologies.
Stimulus-frequency OAEs (SFOAEs) are measured during the application of a pure-tone stimulus and are detected by the vec
Document 1:::
Tullio phenomenon, sound-induced vertigo, dizziness, nausea or eye movement (nystagmus) was first described in 1929 by the Italian biologist Prof. Pietro Tullio. (1881–1941) During his experiments on pigeons, Tullio discovered that by drilling tiny holes in the semicircular canals of his subjects, he could subsequently cause them balance problems when exposed to sound.
The cause is usually a fistula in the middle or inner ear, allowing abnormal sound-synchronized pressure changes in the balance organs. Such an opening may be caused by a barotrauma (e.g. incurred when diving or flying), or may be a side effect of fenestration surgery, syphilis or Lyme disease.
Patients with this disorder may also experience vertigo, imbalance and eye movement set off by changes in pressure, e.g. when nose-blowing, swallowing or when lifting heavy objects.
Tullio phenomenon is also one of the common symptoms of superior canal dehiscence syndrome (SCDS), first diagnosed in 1998 by Dr. Lloyd B. Minor, Johns Hopkins University, Baltimore, United States.
Document 2:::
Endaural phenomena are sounds that are heard without any external acoustic stimulation. Endaural means "in the ear". Phenomena include transient ringing in the ears (that sound like sine tones), white noise-like sounds, and subjective tinnitus. Endaural phenomena need to be distinguished from otoacoustic emissions, in which a person's ear emits sounds. The emitter typically cannot hear the sounds made by his or her ear. Endaural phenomena also need to be distinguished from auditory hallucinations, which are sometimes associated with psychosis.
See also
Bruit
Entoptic phenomenon
Document 3:::
Auditory events describe the subjective perception, when listening to a certain sound situation. This term was introduced by Jens Blauert (Ruhr-University Bochum) in 1966, in order to distinguish clearly between the physical sound field and the auditory perception of the sound.
Auditory events are the central objects of psychoacoustical investigations.
Focus of these investigations is the relationship between the characteristics of a physical sound field and the corresponding perception of listeners. From this relationship conclusions can be drawn about the processing methods of the human auditory system.
Aspects of auditory event investigations can be:
is there an auditory event? Is a certain sound noticeable? => Determination of perception thresholds like hearing threshold, auditory masking thresholds etc.
Which characteristics has the auditory event? => Determination of loudness, pitch, sound, harshness etc.
How is the spatial impression of the auditory event? => Determination of sound localization, lateralization, perceived direction etc.
When can differences in auditory events be noticed? How big are the discrimination possibilities of the auditory system? => Determination of just noticeable differences
Relationships between sound field and auditory events
The sound field is described by physical quantities, while auditory events are described by quantities of psychoacoustical perception.
Below you can find a list with physical sound field quantities and the related psychoacoustical quantities of corresponding auditory events.
Mostly there is no simple or proportional relationship between sound field characteristics and auditory events.
For example, the auditory event property loudness depends not only on the physical quantity sound pressure but also on the spectral characteristics of the sound and on the sound history.
Document 4:::
Earwax, also known by the medical term cerumen, is a waxy substance secreted in the ear canal of humans and other mammals. Earwax can be many colors, including brown, orange, red, yellowish, and gray. Earwax protects the skin of the human ear canal, assists in cleaning and lubrication, and provides protection against bacteria, fungi, particulate matter, and water.
Major components of earwax include cerumen, produced by a type of modified sweat gland, and sebum, an oily substance. Both components are made by glands located in the outer ear canal. The chemical composition of earwax includes long chain fatty acids, both saturated and unsaturated, alcohols, squalene, and cholesterol. Earwax also contains dead skin cells and hair.
Excess or compacted cerumen is the buildup of ear wax causing a blockage in the ear canal and it can press against the eardrum or block the outside ear canal or hearing aids, potentially causing hearing loss.
Physiology
Cerumen is produced in the cartilaginous outer third portion of the ear canal. It is a mixture of secretions from sebaceous glands and less-viscous ones from modified apocrine sweat glands. The primary components of both wet and dry earwax are shed layers of skin, with, on average, 60% of the earwax consisting of keratin, 12–20% saturated and unsaturated long-chain fatty acids, alcohols, squalene and 6–9% cholesterol.
Wet or dry
There are two genetically-determined types of earwax: the wet type, which is dominant, and the dry type, which is recessive. This distinction is caused by a single base change in the "ATP-binding cassette C11 gene". Dry-type individuals are homozygous for adenine (AA) whereas wet-type requires at least one guanine (AG or GG). Dry earwax is gray or tan and brittle, and is about 20% lipid. It has a smaller concentration of lipid and pigment granules than wet earwax. Wet earwax is light brown or dark brown and has a viscous and sticky consistency, and is about 50% lipid. Wet-type earwax is associated
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
As air pressures inside and outside of the ear equalize, what phenomenon is produced?
A. throat scratching
B. eyes blinking
C. heart skipping
D. ear popping
Answer:
|
|
sciq-9437
|
multiple_choice
|
Which stage has already been completed by the time sea urchin eggs are released from the female?
|
[
"meiosis",
"fetus",
"secondary",
"mitoses"
] |
A
|
Relavent Documents:
Document 0:::
In the field of developmental biology, regional differentiation is the process by which different areas are identified in the development of the early embryo. The process by which the cells become specified differs between organisms.
Cell fate determination
In terms of developmental commitment, a cell can either be specified or it can be determined. Specification is the first stage in differentiation. A cell that is specified can have its commitment reversed while the determined state is irreversible. There are two main types of specification: autonomous and conditional. A cell specified autonomously will develop into a specific fate based upon cytoplasmic determinants with no regard to the environment the cell is in. A cell specified conditionally will develop into a specific fate based upon other surrounding cells or morphogen gradients. Another type of specification is syncytial specification, characteristic of most insect classes.
Specification in sea urchins uses both autonomous and conditional mechanisms to determine the anterior/posterior axis. The anterior/posterior axis lies along the animal/vegetal axis set up during cleavage. The micromeres induce the nearby tissue to become endoderm while the animal cells are specified to become ectoderm. The animal cells are not determined because the micromeres can induce the animal cells to also take on mesodermal and endodermal fates. It was observed that β-catenin was present in the nuclei at the vegetal pole of the blastula. Through a series of experiments, one study confirmed the role of β-catenin in the cell-autonomous specification of vegetal cell fates and the micromeres inducing ability. Treatments of lithium chloride sufficient to vegetalize the embryo resulted in increases in nuclearly localized b-catenin. Reduction of expression of β-catenin in the nucleus correlated with loss of vegetal cell fates. Transplants of micromeres lacking nuclear accumulation of β-catenin were unable to induce a second axis.
Document 1:::
In embryology, Carnegie stages are a standardized system of 23 stages used to provide a unified developmental chronology of the vertebrate embryo.
The stages are delineated through the development of structures, not by size or the number of days of development, and so the chronology can vary between species, and to a certain extent between embryos. In the human being only the first 60 days of development are covered; at that point, the term embryo is usually replaced with the term fetus.
It was based on work by Streeter (1942) and O'Rahilly and Müller (1987). The name "Carnegie stages" comes from the Carnegie Institution of Washington.
While the Carnegie stages provide a universal system for staging and comparing the embryonic development of most vertebrates, other systems are occasionally used for the common model organisms in developmental biology, such as the Hamburger–Hamilton stages in the chick.
Stages
Days are approximate and reflect the days since the last ovulation before pregnancy ("Postovulatory age").
Stage 1: 1 days
fertilization
polar bodies
Carnegie stage 1 is the unicellular embryo. This stage is divided into three substages.
Stage 1 a
Primordial embryo. All the genetic material necessary for a new individual, along with some redundant chromosomes, are present within a single plasmalemma. Penetration of the fertilising sperm allows the oocyte to resume meiosis and the polar body is extruded.
Stage 1 b
Pronuclear embryo. Two separate haploid components are present - the maternal and paternal pronuclei. The pronuclei move towards each other and eventually compress their envelopes where they lie adjacent near the centre of the wall.
Stage 1 c
Syngamic embryo. The last phase of fertilisation. The pronuclear envelopes disappear and the parental chromosomes come together in a process called syngamy.
Stage 2: 2-3 days
cleavage
morula
compaction
Carnegie stage 2 begins when the zygote undergoes its first cell division, and ends when the blas
Document 2:::
Skeletogenesis is a key morphogenetic event in the embryonic development of vertebrates and is of equal, although transient, importance in the development of the sea urchin, a marine invertebrate. The larval sea urchin does not resemble its adult form, because the sea urchin is an indirect developer, meaning its larva form must undergo metamorphosis to form the juvenile adult. Here, the focus is on skeletogenesis in the sea urchin species Strongylocentrotus purpuratus, as this species has been most thoroughly studied and characterized.
Morphological changes
Skeletogenesis begins in the early sea urchin blastula (9–10 hours post fertilization) when the primary mesenchyme cells (PMCs), the sole descendants of the large micromere daughter cells, undergo an epithelial–mesenchymal transition (EMT) and break away from the apical layer, thus entering the blastocoel, forming a cell cluster at the vegetal pole. It is a key interaction between the two principal populations of mesodermal cells in the sea urchin embryo, PMCs and secondary mesenchyme cells (SMCs), that regulates SMC fates and the process of skeletogenesis. In a wild type embryo, skeletal elements are exclusively produced by PMCs. Due to their nature in giving rise to the larval skeleton, they are sometimes called the skeletogenic mesenchyme. Certain SMCs have a skeletogenic potential, however, signals transmitted by the PMCs suppress this potential in the SMCs and direct these cells into alternative developmental pathways.
Once in the blastocoel, the mesenchyme cells extend and contract long, thin processes called filopodia. The filopodia are 250 nm in diameter and 25 um long. At this point, the filopodia appear to move randomly along the surface of the inner blastocoel, making and breaking filopodial connections to the blastocoel wall. During the gastrula stage, once the blastopore has formed, the PMCs are localized within the prospective ventrolateral (from front to side) region of the blastocoel. I
Document 3:::
This glossary of developmental biology is a list of definitions of terms and concepts commonly used in the study of developmental biology and related disciplines in biology, including embryology and reproductive biology, primarily as they pertain to vertebrate animals and particularly to humans and other mammals. The developmental biology of invertebrates, plants, fungi, and other organisms is treated in other articles; e.g. terms relating to the reproduction and development of insects are listed in Glossary of entomology, and those relating to plants are listed in Glossary of botany.
This glossary is intended as introductory material for novices; for more specific and technical detail, see the article corresponding to each term. Additional terms relevant to vertebrate reproduction and development may also be found in Glossary of biology, Glossary of cell biology, Glossary of genetics, and Glossary of evolutionary biology.
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
See also
Introduction to developmental biology
Outline of developmental biology
Outline of cell biology
Glossary of biology
Glossary of cell biology
Glossary of genetics
Glossary of evolutionary biology
Document 4:::
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.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which stage has already been completed by the time sea urchin eggs are released from the female?
A. meiosis
B. fetus
C. secondary
D. mitoses
Answer:
|
|
sciq-7421
|
multiple_choice
|
What system transports many substances to and from cells throughout the body?
|
[
"circulatory",
"cardiovascular",
"physiological",
"nutritional"
] |
B
|
Relavent Documents:
Document 0:::
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 1:::
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
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Paracellular transport refers to the transfer of substances across an epithelium by passing through the intercellular space between the cells. It is in contrast to transcellular transport, where the substances travel through the cell, passing through both the apical membrane and basolateral membrane.
The distinction has particular significance in renal physiology and intestinal physiology. Transcellular transport often involves energy expenditure whereas paracellular transport is unmediated and passive down a concentration gradient, or by osmosis (for water) and solvent drag for solutes. Paracellular transport also has the benefit that absorption rate is matched to load because it has no transporters that can be saturated.
In most mammals, intestinal absorption of nutrients is thought to be dominated by transcellular transport, e.g., glucose is primarily absorbed via the SGLT1 transporter and other glucose transporters. Paracellular absorption therefore plays only a minor role in glucose absorption, although there is evidence that paracellular pathways become more available when nutrients are present in the intestinal lumen. In contrast, small flying vertebrates (small birds and bats) rely on the paracellular pathway for the majority of glucose absorption in the intestine. This has been hypothesized to compensate for an evolutionary pressure to reduce mass in flying animals, which resulted in a reduction in intestine size and faster transit time of food through the gut.
Capillaries of the blood–brain barrier have only transcellular transport, in contrast with normal capillaries which have both transcellular and paracellular transport.
The paracellular pathway of transport is also important for the absorption of drugs in the gastrointestinal tract. The paracellular pathway allows the permeation of hydrophilic molecules that are not able to permeate through the lipid membrane by the transcellular pathway of absorption. This is particularly important for hydrophi
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The Starling principle holds that extracellular fluid movements between blood and tissues are determined by differences in hydrostatic pressure and colloid osmotic (oncotic) pressure between plasma inside microvessels and interstitial fluid outside them. The Starling Equation, proposed many years after the death of Starling, describes that relationship in mathematical form and can be applied to many biological and non-biological semipermeable membranes. The classic Starling principle and the equation that describes it have in recent years been revised and extended.
Every day around 8 litres of water (solvent) containing a variety of small molecules (solutes) leaves the blood stream of an adult human and perfuses the cells of the various body tissues. Interstitial fluid drains by afferent lymph vessels to one of the regional lymph node groups, where around 4 litres per day is reabsorbed to the blood stream. The remainder of the lymphatic fluid is rich in proteins and other large molecules and rejoins the blood stream via the thoracic duct which empties into the great veins close to the heart. Filtration from plasma to interstitial (or tissue) fluid occurs in microvascular capillaries and post-capillary venules. In most tissues the micro vessels are invested with a continuous internal surface layer that includes a fibre matrix now known as the endothelial glycocalyx whose interpolymer spaces function as a system of small pores, radius circa 5 nm. Where the endothelial glycocalyx overlies a gap in the junction molecules that bind endothelial cells together (inter endothelial cell cleft), the plasma ultrafiltrate may pass to the interstitial space, leaving larger molecules reflected back into the plasma.
A small number of continuous capillaries are specialised to absorb solvent and solutes from interstitial fluid back into the blood stream through fenestrations in endothelial cells, but the volume of solvent absorbed every day is small.
Discontinuous capillaries as
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The Society of General Physiologists (SGP) is a scientific organization whose purpose is to promote and disseminate knowledge in the field of general physiology, and otherwise to advance understanding and interest in the subject of general physiology. The Society’s main office is located at the Marine Biological Laboratory in Woods Hole, MA, where the society was founded in 1946. Past Presidents of the Society include Richard W. Aldrich, Richard W. Tsien, Clay Armstrong, and Andrew Szent-Gyorgi. The society's archives is held at the National Library of Medicine in Bethesda, Maryland.
Membership
The Society's international membership is made up of nearly 600 career physiologists who work in academia, government, and industry. Membership in the Society is open to any individual actively interested in the field of general physiology and who has made significant contributions to knowledge in that field. The Society has become known for promoting research in many subfields of cellular and molecular physiology, but especially in the fields of membrane transport and ion channels, cell membrane structure, regulation, and dynamics, and cellular contractility and molecular motors.
Activities
The major activity of the Society is its annual symposium, which is held at the Marine Biological Laboratory in Woods Hole, MA. Society of General Physiologists symposia cover the forefront of physiological research and are small enough to maximize discussion and interaction among both young and established investigators. Abstracts of the annual meeting are published in The Journal of General Physiology.
The 2015 symposium (September 16–20) topic is "Macromolecular Local Signaling Complexes." Detailed information regarding the scientific agenda and registration is provided at the symposium website:
https://web.archive.org/web/20150801070408/http://www.sgpweb.org/symposium2015.html
Recent past symposium topics include:
2014 Sensory Transduction
2013 The Enigmatic Chloride Ion: Tra
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What system transports many substances to and from cells throughout the body?
A. circulatory
B. cardiovascular
C. physiological
D. nutritional
Answer:
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|
sciq-5403
|
multiple_choice
|
What type of diagnosis happens before a baby is born?
|
[
"prenatal",
"postnatal",
"maternal",
"fetal"
] |
A
|
Relavent Documents:
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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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Maternal somatic support after brain death occurs when a brain dead patient is pregnant and their body is kept alive to deliver a fetus. It occurs very rarely internationally. Even among brain dead patients, in a U.S. study of 252 brain dead patients from 1990–96, only 5 (2.8%) cases involved pregnant women between 15 and 45 years of age.
Past cases
In the 28-year period between 1982 and 2010, there were "30 [reported] cases of maternal brain death (19 case reports and 1 case series)." In 12 of those cases, a viable child was delivered via cesarean section after extended somatic support. However, according to Esmaelilzadeh, et al. there is no widely accepted protocol to manage a brain dead mother "since only a few reported cases are found in the medical literature." Moreover, the mother's wishes are rarely, if ever, known, and family should be consulted in developing a care plan.
Life support complications
Throughout their care, brain dead patients could experience a wide range of complications, including "infection, hemodynamic instability, diabetes insipidus (DI), panhypopituitarism, poikilothermia, metabolic instability, acute respiratory distress syndrome and disseminated intravascular coagulation." Treating these complications is difficult since the effects of medication on the fetus's health are unknown.
Fetus's chance of survival
According to Esmaelilzadeh, et al., "[a]t present, it seems that there is no clear lower limit to the gestational age which would restrict the physician's efforts to support the brain dead mother and her fetus." However, the older a fetus is when its mother becomes brain dead, the greater its chance for survival. Research into preterm births indicates that "a fetus born before 24 weeks of gestation has a limited chance of survival. At 24, 28 and 32 weeks, a fetus has approximately a 20–30%, 80% and 98% likelihood of survival with a 40%, 10% and less than 2% chance of suffering from a severe handicap, respectively."
Brain de
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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
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The Quilligan Scholars award, named after one of the founding fathers of Maternal-Fetal Medicine, Dr. Edward J. Quilligan, is a prestigious title in the field of Maternal-Fetal Medicine granted by the Society for Maternal-Fetal Medicine and The Pregnancy Foundation to a select group of promising residents in obstetrics and gynaecology who exhibit unparalleled potential to become future leaders in the field of perinatology.
Purpose
The purpose of the Quilligan Scholars Program is to identify future leaders in Perinatology early in their training and to offer them recognition, guidance, and educational opportunities to foster their careers. These individuals traditionally exhibit leadership, commitment, and interest in teaching, research, or public policy. Some of the activities provided by the program include paid attendance to the SMFM annual meeting, the provision of special courses and experiences, and the granting of personal mentorship from current leaders in the field of Maternal-fetal Medicine.
History
The year 2013 marked the 40th anniversary of the formal establishment of Maternal-fetal medicine (MFM) as a specialty, as 16 pioneers took the MFM boards for the first time in 1973. Amongst that group of pioneers was Dr. Edward J. Quilligan, who has gone on to dedicate decades of service to the advancement of women's health, through teaching, research, and leadership. To honour his legacy and his exemplary service to modern Obstetrics, the Society for Maternal-Fetal Medicine and The Pregnancy Foundation created the Quilligan Scholars program, and the first class of five recipients was inaugurated in 2014 at the Society for Maternal-Fetal Medicine annual meeting in New Orleans, Louisiana. Though the Quilligan Scholar title confers no monetary reward, the sponsored activities are covered by gracious donations from members of the medical community. The Society for Maternal-Fetal Medicine has agreed to give matching funds to the amount raised by The Pregnancy Fou
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of diagnosis happens before a baby is born?
A. prenatal
B. postnatal
C. maternal
D. fetal
Answer:
|
|
sciq-5002
|
multiple_choice
|
What is the hollow and muscular balloon-shaped organ that collects urine?
|
[
"prostate",
"urinary bladder",
"kidney",
"urethra"
] |
B
|
Relavent Documents:
Document 0:::
Urination is the release of urine from the bladder through the urethra to the outside of the body. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, uresis, or, rarely, emiction, and known colloquially by various names including peeing, weeing, pissing, and euphemistically going (for a) number one. In healthy humans and other animals, the process of urination is under voluntary control. In infants, some elderly individuals, and those with neurological injury, urination may occur as a reflex. It is normal for adult humans to urinate up to seven times during the day.
In some animals, in addition to expelling waste material, urination can mark territory or express submissiveness. Physiologically, urination involves coordination between the central, autonomic, and somatic nervous systems. Brain centres that regulate urination include the pontine micturition center, periaqueductal gray, and the cerebral cortex. In placental mammals, urine is drained through the urinary meatus, a urethral opening in the male penis or female vulval vestibule.
Anatomy and physiology
Anatomy of the bladder and outlet
The main organs involved in urination are the urinary bladder and the urethra. The smooth muscle of the bladder, known as the detrusor, is innervated by sympathetic nervous system fibers from the lumbar spinal cord and parasympathetic fibers from the sacral spinal cord. Fibers in the pelvic nerves constitute the main afferent limb of the voiding reflex; the parasympathetic fibers to the bladder that constitute the excitatory efferent limb also travel in these nerves. Part of the urethra is surrounded by the male or female external urethral sphincter, which is innervated by the somatic pudendal nerve originating in the cord, in an area termed Onuf's nucleus.
Smooth muscle bundles pass on either side of the urethra, and these fibers are sometimes called the internal urethral sphincter, although they do not encircle the urethra.
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The spongy urethra (cavernous portion of urethra, penile urethra) is the longest part of the male urethra, and is contained in the corpus spongiosum of the penis.
It is about 15 cm long, and extends from the termination of the membranous portion to the external urethral orifice.
Commencing below the inferior fascia of the urogenital diaphragm it passes forward and upward to the front of the pubic symphysis; and then, in the flaccid condition of the penis, it bends downward and forward.
It is narrow, and of uniform size in the body of the penis, measuring about 6 mm in diameter; it is dilated behind, within the bulb, and again anteriorly within the glans penis, where it forms the fossa navicularis urethrae.
The spongy urethra runs along the length of the penis on its ventral (underneath) surface. It is about 15–16 cm in length, and travels through the corpus spongiosum. The ducts from the urethral gland (gland of Littré) enter here. The openings of the bulbourethral glands are also found here. Some textbooks will subdivide the spongy urethra into two parts, the bulbous and pendulous urethra. The urethral lumen (interior) runs effectively parallel to the penis, except at the narrowest point, the external urethral meatus, where it is vertical. This produces a spiral stream of urine and has the effect of cleaning the external urethral meatus. The lack of an equivalent mechanism in the female urethra partly explains why urinary tract infections occur so much more frequently in females.
Epithelium
Pseudostratified columnar – proximally, Stratified squamous – distally
Additional images
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The anorectal canal is an embryonic structure in humans that develops from the posterior portion of the cloaca, after it is divided by the urorectal septum in the 6th week of embryonic development. The anterior portion becomes the urogenital sinus. The anorectal canal develops into the rectum and the anal canal.
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The urachus is a fibrous remnant of the allantois, a canal that drains the urinary bladder of the fetus that joins and runs within the umbilical cord. The fibrous remnant lies in the space of Retzius, between the transverse fascia anteriorly and the peritoneum posteriorly.
Development
The part of the urogenital sinus related to the bladder and urethra absorbs the ends of the Wolffian ducts and the associated ends of the renal diverticula. This gives rise to the trigone of the bladder and part of the prostatic urethra.
The remainder of this part of the urogenital sinus forms the body of the bladder and part of the prostatic urethra. The apex of the bladder stretches and is connected to the umbilicus as a narrow canal. This canal is initially open, but later closes as the urachus goes on to definitively form the median umbilical ligament.
Clinical significance
Failure of the inside of the urachus to be filled in leaves the urachus open. The telltale sign is leakage of urine through the umbilicus. This is often managed surgically. There are four anatomical causes:
Urachal cyst: there is no longer a connection between the bladder and the umbilicus, however a fluid filled cavity with uroepithelium lining persists between these two structures.
Urachal fistula: there is free communication between the bladder and umbilicus
Urachal diverticulum (vesicourachal diverticulum): the bladder exhibits outpouching
Urachal sinus: the pouch opens toward the umbilicus
The urachus is also subject to neoplasia. Urachal adenocarcinoma is histologically similar to adenocarcinoma of the bowel. Rarely, urachus carcinomas can metastasise to other regions of the body, including pelvic bones and the lung.
One urachal mass has been reported that was found to be a manifestation of IgG4-related disease.
Additional images
Document 4:::
The membranous urethra or intermediate part of male urethra is the shortest, least dilatable, and, with the exception of the urinary meatus, the narrowest part of the urethra.
It extends downward and forward, with a slight anterior concavity, between the apex of the prostate and the bulb of the urethra, perforating the urogenital diaphragm about 2.5 cm below and behind the pubic symphysis.
The hinder part of the urethral bulb lies in apposition with the inferior fascia of the urogenital diaphragm, but its upper portion diverges somewhat from this fascia: the anterior wall of the membranous urethra is thus prolonged for a short distance in front of the urogenital diaphragm; it measures about 2 cm in length, while the posterior wall which is between the two fasciæ of the diaphragm is only 1.25 cm long. The anatomical variation in membranous urethral length measurements in men have been reported to range from 0.5 cm to 3.4 cm.
The membranous portion of the urethra is surrounded by the fibers of the Sphincter urethrae membranaceae.
In front of it the deep dorsal vein of the penis enters the pelvis between the transverse ligament of the pelvis and the arcuate pubic ligament; on either side near its termination are the bulbourethral glands.
Additional images
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the hollow and muscular balloon-shaped organ that collects urine?
A. prostate
B. urinary bladder
C. kidney
D. urethra
Answer:
|
|
sciq-3478
|
multiple_choice
|
What occurs between long warm climate periods?
|
[
"mass extinction",
"ice ages",
"hurricanes",
"drought"
] |
B
|
Relavent Documents:
Document 0:::
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
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Climatic adaptation refers to adaptations of an organism that are triggered due to the patterns of variation of abiotic factors that determine a specific climate. Annual means, seasonal variation and daily patterns of abiotic factors are properties of a climate where organisms can be adapted to. Changes in behavior, physical structure, internal mechanisms and metabolism are forms of adaptation that is caused by climate properties. Organisms of the same species that occur in different climates can be compared to determine which adaptations are due to climate and which are influenced majorly by other factors. Climatic adaptations limits to adaptations that have been established, characterizing species that live within the specific climate. It is different from climate change adaptations which refers to the ability to adapt to gradual changes of a climate. Once a climate has changed, the climate change adaptation that led to the survival of the specific organisms as a species can be seen as a climatic adaptation. Climatic adaptation is constrained by the genetic variability of the species in question.
Climate patterns
The patterns of variation of abiotic factors determine a climate and thus climatic adaptation. There are many different climates around the world, each with its unique patterns. Because of this, the manner of climatic adaptation shows large differences between the climates. A subarctic climate, for instance, shows daylight time and temperature fluctuations as most important factors, while in rainforest climate, the most important factor is characterized by the stable high precipitation rate and high average temperature that doesn't fluctuate a lot. Humid continental climate is marked by seasonal temperature variances which commonly lead to seasonal climate adaptations. Because the variance of these abiotic factors differ depending on the type of climate, differences in the manner of climatic adaptation are expected.
Research
Research on climatic adaptat
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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
Document 3:::
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.
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In paleoecology and ecological forecasting, a no-analog community or climate is one that is compositionally different from a (typically modern) baseline for measurement. Alternative naming conventions to describe no-analog communities and climates may include novel, emerging, mosaic, disharmonious and intermingled.
Modern climates, communities and ecosystems are often studied in an attempt to understand no-analogs that have happened in the past and those that may occur in the future. This use of a modern analog to study the past draws on the concept of uniformitarianism. Along with the use of these modern analogs, actualistic studies and taphonomy are additional tools that are used in understanding no-analogs. Statistical tools are also used to identify no-analogs and their baselines, often through the use of dissimilarity analyses or analog matching Study of no-analog fossil remains are often carefully evaluated as to rule out mixing of fossils in an assemblage due to erosion, animal activity or other processes.
No-analog climates
Conditions that are considered no-analog climates are those that have no modern analog, such as the climate during the last glaciation. Glacial climates varied from current climates in seasonality and temperature, having an overall more steady climate without as many extreme temperatures as today's climate.
Climates with no modern analog may be used to infer species range shifts, biodiversity changes, ecosystem arrangements and help in understanding species fundamental niche space. Past climates are often studied to understand how changes in a species' fundamental niche may lead to the formation of no analog communities. Seasonality and temperatures that are outside the climates at present provide opportunity for no-analog communities to arise, as is seen in the late Holocene plant communities. Evidence of deglacial temperature controls having significant effects on the formation of no-analog communities in the midwestern United State
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What occurs between long warm climate periods?
A. mass extinction
B. ice ages
C. hurricanes
D. drought
Answer:
|
|
sciq-8733
|
multiple_choice
|
Lymph vessels are like blood vessels, except they move what instead of blood?
|
[
"sperm",
"marrow",
"lymph",
"air"
] |
C
|
Relavent Documents:
Document 0:::
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue.
Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries.
These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues throughout the body.
Structure
The endothelium is a thin layer of single flat (squamous) cells that line the interior surface of blood vessels and lymphatic vessels.
Endothelium is of mesodermal origin. Both blood and lymphatic capillaries are composed of a single layer of endothelial cells called a monolayer. In straight sections of a blood vessel, vascular endothelial cells typically align and elongate in the direction of fluid flow.
Terminology
The foundational model of anatomy, an index of terms used to describe anatomical structures, makes a distinction between endothelial cells and epithelial cells on the basis of which tissues they develop from, and states that the presence of vimentin rather than keratin filaments separates these from epithelial cells. Many considered the endothelium a specialized epithelial tissue.
Function
The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. This forms a barrier between v
Document 1:::
Lymph node stromal cells are essential to the structure and function of the lymph node whose functions include: creating an internal tissue scaffold for the support of hematopoietic cells; the release of small molecule chemical messengers that facilitate interactions between hematopoietic cells; the facilitation of the migration of hematopoietic cells; the presentation of antigens to immune cells at the initiation of the adaptive immune system; and the homeostasis of lymphocyte numbers. Stromal cells originate from multipotent mesenchymal stem cells.
Structure
Lymph nodes are enclosed in an external fibrous capsule, from which thin walls of sinew called trabeculae penetrate into the lymph node, partially dividing it. Beneath the external capsule and along the courses of the trabeculae, are peritrabecular and subcapsular sinuses. These sinuses are cavities containing macrophages (specialised cells which help to keep the extracellular matrix in order).
The interior of the lymph node has two regions: the cortex and the medulla. In the cortex, lymphoid tissue is organized into nodules. In the nodules, T lymphocytes are located in the T cell zone. B lymphocytes are located in the B cell follicle. The primary B cell follicle matures in germinal centers. In the medulla are hematopoietic cells (which contribute to the formation of the blood) and stromal cells.
Near the medulla is the hilum of lymph node. This is the place where blood vessels enter and leave the lymph node and lymphatic vessels leave the lymph node. Lymph vessels entering the node do so along the perimeter (outer surface).
Function
The lymph nodes, the spleen and Peyer's patches, together are known as secondary lymphoid organs. Lymph nodes are found between lymphatic ducts and blood vessels. Afferent lymphatic vessels bring lymph fluid from the peripheral tissues to the lymph nodes. The lymph tissue in the lymph nodes consists of immune cells (95%), for example lymphocytes, and stromal cells (1% to
Document 2:::
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphoid tissues and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation. (The Latin word for lymph, lympha, refers to the deity of fresh water, "Lympha").
Unlike the circulatory system that is a closed system, the lymphatic system is open. The human circulatory system processes an average of 20 litres of blood per day through capillary filtration, which removes plasma from the blood. Roughly 17 litres of the filtered blood is reabsorbed directly into the blood vessels, while the remaining three litres are left in the interstitial fluid. One of the main functions of the lymphatic system is to provide an accessory return route to the blood for the surplus three litres.
The other main function is that of immune defense. Lymph is very similar to blood plasma, in that it contains waste products and cellular debris, together with bacteria and proteins. The cells of the lymph are mostly lymphocytes. Associated lymphoid organs are composed of lymphoid tissue, and are the sites either of lymphocyte production or of lymphocyte activation. These include the lymph nodes (where the highest lymphocyte concentration is found), the spleen, the thymus, and the tonsils. Lymphocytes are initially generated in the bone marrow. The lymphoid organs also contain other types of cells such as stromal cells for support. Lymphoid tissue is also associated with mucosas such as mucosa-associated lymphoid tissue (MALT).
Fluid from circulating blood leaks into the tissues of the body by capillary action, carrying nutrients to the cells. The fluid bathes the tissues as interstitial fluid, collecting waste products, bacteria, and damaged cells, and then drains as lymph into the lymphatic capillaries and lymphatic
Document 3:::
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 4:::
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.
There are three sizes of veins, large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries.
Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of capacitance vessels. At any time, nearly 70% of the total volume of blood in the human body is in the veins. In medium and large sized veins the flow of blood is maintained by one-way (unidirectional) venous valves to prevent backflow. In the lower limbs this is also aided by muscle pumps, also known as venous pumps that exert pressure on intramuscular veins when they contract and drive blood back to the heart.
Structure
There are three sizes of vein, large, medium, and small. Smaller veins are called venules. The smallest veins are the post-capillary venules. Veins have a similar three-layered structure to arteries. The layers known as tunicae have a concentric arrangement that forms the wall of the vessel. The outer layer, is a thick layer of connective tissue called the tunica externa or adventitia; this layer is absent in the post-capillary venules. The middle layer, consists of bands of smooth muscle and is known as the tunica media. The inner layer, is a thin lining of endothelium known as the tunica intima. The tunica media in the veins is mu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Lymph vessels are like blood vessels, except they move what instead of blood?
A. sperm
B. marrow
C. lymph
D. air
Answer:
|
|
sciq-5328
|
multiple_choice
|
What is the joint where the pelvic girdle and leg come together?
|
[
"meniscus",
"hip joint",
"hip socket",
"femur joint"
] |
B
|
Relavent Documents:
Document 0:::
The medial meniscus is a fibrocartilage semicircular band that spans the knee joint medially, located between the medial condyle of the femur and the medial condyle of the tibia. It is also referred to as the internal semilunar fibrocartilage. The medial meniscus has more of a crescent shape while the lateral meniscus is more circular. The anterior aspects of both menisci are connected by the transverse ligament. It is a common site of injury, especially if the knee is twisted.
Structure
The meniscus attaches to the tibia via coronary ligaments.
Its anterior end, thin and pointed, is attached to the anterior intercondyloid fossa of the tibia, in front of the anterior cruciate ligament;
Its posterior end is fixed to the posterior intercondyloid fossa of the tibia, between the attachments of the lateral meniscus and the posterior cruciate ligament.
It is fused with the tibial collateral ligament which makes it far less mobile than the lateral meniscus. The points of attachment are relatively widely separated and, because the meniscus is wider posteriorly than anteriorly, the anterior crus is considerably thinner than the posterior crus. The greatest displacement of the meniscus is caused by external rotation, while internal rotation relaxes it.
During rotational movements of the tibia (with the knee flexed 90 degrees), the medial meniscus remains relatively fixed while the lateral part of the lateral meniscus is displaced across the tibial condyle below.
Function
The medial meniscus separates the tibia and femur to decrease the contact area between the bones, and serves as a shock absorber reducing the peak contact force experienced. It also reduces friction between the two bones to allow smooth movement in the knee and distribute load during movement.
Clinical significance
Injury
Acute injury to the medial meniscus frequently accompanies an injury to the ACL (anterior cruciate ligament) or MCL (medial collateral ligament). A person occasionally injures the
Document 1:::
The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of axes, which have one common center. This enables the joint to move in many directions.
An enarthrosis is a special kind of spheroidal joint in which the socket covers the sphere beyond its equator.
Examples
Examples of this form of articulation are found in the hip, where the round head of the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis; and in the shoulder joint, where the rounded upper extremity of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade. (The shoulder also includes a sternoclavicular joint.)
Document 2:::
In human anatomy, the body of femur (or shaft of femur) is the almost cylindrical, long part of the femur. It is a little broader above than in the center, broadest and somewhat flattened from before backward below. It is slightly arched, so as to be convex in front, and concave behind, where it is strengthened by a prominent longitudinal ridge, the linea aspera.
It presents for examination three borders, separating three surfaces.
Of the borders, one, the linea aspera, is posterior, one is medial, and the other, lateral.
Borders
The borders of the femur are the linea aspera, a medial border, and a lateral border.
Linea aspera border
The linea aspera is a prominent longitudinal ridge or crest, on the middle third of the bone, presenting a medial and a lateral lip, and a narrow rough, intermediate line.
Above, the linea aspera is prolonged by three ridges.
The lateral ridge termed the gluteal tuberosity is very rough, and runs almost vertically upward to the base of the greater trochanter. It gives attachment to part of the gluteus maximus: its upper part is often elongated into a roughened crest, on which a more or less well-marked, rounded tubercle, the third trochanter, is occasionally developed.
The intermediate ridge or pectineal line is continued to the base of the lesser trochanter and gives attachment to the pectineus; the medial ridge is lost in the intertrochanteric line; between these two a portion of the iliacus is inserted.
Below, the linea aspera is prolonged into two ridges, enclosing between them a triangular area, the popliteal surface, upon which the popliteal artery rests.
Of these two ridges, the lateral is the more prominent, and descends to the summit of the lateral condyle.
The medial is less marked, especially at its upper part, where it is crossed by the femoral artery.
It ends below at the summit of the medial condyle, in a small tubercle, the adductor tubercle, which affords insertion to the tendon of the adductor magnus.
From t
Document 3:::
The pubofemoral ligament (or pubocapsular ligament) is a ligament which reinforces the inferior and anterior portions of the joint capsule of the hip joint. The ligament attaches superiorly at the superior ramus of pubis, and the iliopubic eminence; it attaches inferiorly at the inferior portion of the intertrochanteric line (here blending with the inferior band of iliofemoral ligament). The psoas bursa intervenes between the ligament and joint capsule.
The ligament resists hyper-abduction of the hip joint.
Document 4:::
The metatarsophalangeal joints (MTP joints), also informally known as toe knuckles, are the joints between the metatarsal bones of the foot and the proximal bones (proximal phalanges) of the toes. They are condyloid joints, meaning that an elliptical or rounded surface (of the metatarsal bones) comes close to a shallow cavity (of the proximal phalanges).
The ligaments are the plantar and two collateral.
Movements
The movements permitted in the metatarsophalangeal joints are flexion, extension, abduction, adduction and circumduction.
See also
Bunion
Hallux rigidus (stiff big toe)
Metatarsophalangeal joint sprain (turf toe)
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the joint where the pelvic girdle and leg come together?
A. meniscus
B. hip joint
C. hip socket
D. femur joint
Answer:
|
|
sciq-5961
|
multiple_choice
|
Mendelian inheritance has its physical basis in the behavior of what?
|
[
"prokaryotes",
"animals",
"chromosomes",
"ribosomes"
] |
C
|
Relavent Documents:
Document 0:::
The Bateson Lecture is an annual genetics lecture held as a part of the John Innes Symposium since 1972, in honour of the first Director of the John Innes Centre, William Bateson.
Past Lecturers
Source: John Innes Centre
1951 Sir Ronald Fisher - "Statistical methods in Genetics"
1953 Julian Huxley - "Polymorphic variation: a problem in genetical natural history"
1955 Sidney C. Harland - "Plant breeding: present position and future perspective"
1957 J.B.S. Haldane - "The theory of evolution before and after Bateson"
1959 Kenneth Mather - "Genetics Pure and Applied"
1972 William Hayes - "Molecular genetics in retrospect"
1974 Guido Pontecorvo - "Alternatives to sex: genetics by means of somatic cells"
1976 Max F. Perutz - "Mechanism of respiratory haemoglobin"
1979 J. Heslop-Harrison - "The forgotten generation: some thoughts on the genetics and physiology of Angiosperm Gametophytes "
1982 Sydney Brenner - "Molecular genetics in prospect"
1984 W.W. Franke - "The cytoskeleton - the insoluble architectural framework of the cell"
1986 Arthur Kornberg - "Enzyme systems initiating replication at the origin of the E. coli chromosome"
1988 Gottfried Schatz - "Interaction between mitochondria and the nucleus"
1990 Christiane Nusslein-Volhard - "Axis determination in the Drosophila embryo"
1992 Frank Stahl - "Genetic recombination: thinking about it in phage and fungi"
1994 Ira Herskowitz - "Violins and orchestras: what a unicellular organism can do"
1996 R.J.P. Williams - "An Introduction to Protein Machines"
1999 Eugene Nester - "DNA and Protein Transfer from Bacteria to Eukaryotes - the Agrobacterium story"
2001 David Botstein - "Extracting biological information from DNA Microarray Data"
2002 Elliot Meyerowitz
2003 Thomas Steitz - "The Macromolecular machines of gene expression"
2008 Sean Carroll - "Endless flies most beautiful: the role of cis-regulatory sequences in the evolution of animal form"
2009 Sir Paul Nurse - "Genetic transmission through
Document 1:::
The Mendel Lectures is a series of lectures given by the world's top scientists in genetics, molecular biology, biochemistry, microbiology, medicine and related areas which has been held in the refectory of the Augustian Abbey of St. Thomas in Brno, Czech Republic since May 2003. The lectures were established to celebrate the 50th anniversary of the discovery of the structure of deoxyribonucleic acid (DNA) by James Watson (1928) and Francis Crick (1916-2004). The Mendel Lectures are named in honour of Gregor Johann Mendel (1822-1884), the founder of genetics, who lived and worked in the Augustinian Abbey in Brno 1843-1884. Based on his experiments conducted in the abbey between 1856 and 1863, Mendel established the basic rules of heredity, now referred to as the laws of Mendelian inheritance. The Mendel Lectures are organized by the Masaryk University, the Mendel Museum, and the St. Anne's University Hospital Brno. The twentieth season of the Mendel Lectures is running at present. More than 130 top scientists, including many Nobel Prize winners, have visited Brno to give a Mendel Lecture, for example Tim Hunt, Jack W. Szostak, John Gurdon, Elizabeth Blackburn, Paul Nurse, Venkatraman Ramakrishnan, Günter Blobel, Kurt Wüthrich, Jules A. Hoffmann, Aaron Ciechanover, Ada Yonath, Paul Modrich, Eric F. Wieschaus, Fraser Stoddart, Ben Feringa, Brian K. Kobilka and others.
History
The first idea of the Mendel Lectures occurred during the international conference ´EMBO Workshop: Genetics after the Genome´ organised by Dieter Schweizer and Kim Nasmyth in 2002. Kim Nasmyth, at the time director of the Research Institute of Molecular Pathology, and his wife Anna Nasmyth, Imma Mautner Markhof from Austria, Jan Motlík of the Academy of Sciences of the Czech Republic and Jiřina Relichová of the Masaryk University prepared and organized the very first series of Mendel Lectures. They named the series „The Road to the DNA“ and focused the lectures on the historical context of gene
Document 2:::
The Boveri–Sutton chromosome theory (also known as the chromosome theory of inheritance or the Sutton–Boveri theory) is a fundamental unifying theory of genetics which identifies chromosomes as the carriers of genetic material. It correctly explains the mechanism underlying the laws of Mendelian inheritance by identifying chromosomes with the paired factors (particles) required by Mendel's laws. It also states that chromosomes are linear structures with genes located at specific sites called loci along them.
It states simply that chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance.
Over a period of time random mutation
creates changes in the DNA sequence of a gene. Genes are located on chromosomes.
Background
The chromosome theory of inheritance is credited to papers by Walter Sutton in 1902 and 1903, as well as to independent work by Theodor Boveri during roughly the same period. Boveri was studying sea urchins, in which he found that all the chromosomes had to be present for proper embryonic development to take place. Sutton's work with grasshoppers showed that chromosomes occur in matched pairs of maternal and paternal chromosomes which separate during meiosis and "may constitute the physical basis of the Mendelian law of heredity".
This groundbreaking work led E.B. Wilson in his classic text to name the chromosome theory of inheritance the "Sutton-Boveri Theory". Wilson was close to both men since the young Sutton was his student and the prominent Boveri was his friend (in fact, Wilson dedicated the aforementioned book to Boveri). Although the naming precedence is now often reversed to "Boveri-Sutton", there are some who argue that Boveri did not actually articulate the theory until 1904.
Verification
The proposal that chromosomes carried the factors of Mendelian inheritance was initially controversial, but in 1905 it gained
strong support when Nettie Stevens showed that the
Document 3:::
The history of model organisms began with the idea that certain organisms can be studied and used to gain knowledge of other organisms or as a control (ideal) for other organisms of the same species. Model organisms offer standards that serve as the authorized basis for comparison of other organisms. Model organisms are made standard by limiting genetic variance, creating, hopefully, this broad applicability to other organisms.
The idea of the model organism first took root in the middle of the 19th century with the work of men like Charles Darwin and Gregor Mendel and their respective work on natural selection and the genetics of heredity. As the first model organisms were introduced into labs in the 20th century, these early efforts to identify standards to measure organisms against persisted. Beginning in the early 1900s Drosophila entered the research laboratories and opened up the doors for other model organisms like tobacco mosaic virus, E. coli, C57BL/6 (lab mice), etc. These organisms have led to many advances in the past century.
Preliminary works on model organisms
Some of the first work with what would be considered model organisms started because Gregor Johann Mendel felt that the views of Darwin were insufficient in describing the formation of a new species and he began his work with the pea plants that are so famously known today. In his experimentation to find a method by which Darwin's ideas could be explained he hybridized and cross-bred the peas and found that in so doing he could isolate phenotypic characteristics of the peas. These discoveries made in the 1860s lay dormant for nearly forty years until they were rediscovered in 1900. Mendel's work was then correlated with what was being called chromosomes within the nucleus of each cell. Mendel created a practical guide to breeding and this method has successfully been applied to select for some of the first model organisms of other genus and species such as Guinea pigs, Drosophila (fruit
Document 4:::
Particulate inheritance is a pattern of inheritance discovered by Mendelian genetics theorists, such as William Bateson, Ronald Fisher or Gregor Mendel himself, showing that phenotypic traits can be passed from generation to generation through "discrete particles" known as genes, which can keep their ability to be expressed while not always appearing in a descending generation.
Scientific developments leading up to the theory
Early in the 19th century, scientists had already recognized that Earth has been inhabited by living creatures for a very long time. On the other hand, they did not understand what mechanisms actually drove biological diversity. They also did not understand how physical traits are inherited from one generation to the next. Blending inheritance was the common ideal at the time, but was later discredited by the experiments of Gregor Mendel. Mendel proposed the theory of particulate inheritance by using pea plants (Pisum sativum) to explain how variation can be inherited and maintained over time.
Blending model versus particulate model
Blending model:
Offspring are a blend of both parents (i.e. in modern terms, alleles would blend together to form a completely new allele)
The characteristics of the blended offspring are passed on to the next generation
Variation is washed out over time
Particulate model:
Offspring are a combination of both parents
The characteristics of both parents are passed on to the next generation as separate entities
Variation is maintained over time
Mendel's methods
Mendel's laws
Since Mendel used experimental methods to devise his particulate inheritance theory, he developed three basic laws of inheritance: the Law of Segregation, the Law of Independent Assortment, and the Law of Dominance:
Law of segregation
Mendel's experiment with tall and short pea plants demonstrates how each individual plant has two particles called alleles. When a pea plant produces gametes (reproductive cells), it segregates one al
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Mendelian inheritance has its physical basis in the behavior of what?
A. prokaryotes
B. animals
C. chromosomes
D. ribosomes
Answer:
|
|
sciq-5498
|
multiple_choice
|
What traits are those that are inherited unchanged in a hybridization?
|
[
"recessive traits",
"dominant traits",
"mutations",
"alleles"
] |
B
|
Relavent Documents:
Document 0:::
Under the law of dominance in genetics, an individual expressing a dominant phenotype could contain either two copies of the dominant allele (homozygous dominant) or one copy of each dominant and recessive allele (heterozygous dominant). By performing a test cross, one can determine whether the individual is heterozygous or homozygous dominant.
In a test cross, the individual in question is bred with another individual that is homozygous for the recessive trait and the offspring of the test cross are examined. Since the homozygous recessive individual can only pass on recessive alleles, the allele the individual in question passes on determines the phenotype of the offspring. Thus, this test yields 2 possible situations:
If any of the offspring produced express the recessive trait, the individual in question is heterozygous for the dominant allele.
If all of the offspring produced express the dominant trait, the individual in question is homozygous for the dominant allele.
History
The first uses of test crosses were in Gregor Mendel’s experiments in plant hybridization. While studying the inheritance of dominant and recessive traits in pea plants, he explains that the “signification” (now termed zygosity) of an individual for a dominant trait is determined by the expression patterns of the following generation.
Rediscovery of Mendel’s work in the early 1900s led to an explosion of experiments employing the principles of test crosses. From 1908-1911, Thomas Hunt Morgan conducted test crosses while determining the inheritance pattern of a white eye-colour mutation in Drosophila. These test cross experiments became hallmarks in the discovery of sex-linked traits.
Applications in model organisms
Test crosses have a variety of applications. Common animal organisms, called model organisms, where test crosses are often used include Caenorhabditis elegans and Drosophila melanogaster. Basic procedures for performing test crosses in these organisms are provided belo
Document 1:::
Major gene is a gene with pronounced phenotype expression, in contrast to a modifier gene. Major gene characterizes common expression of oligogenic series, i.e. a small number of genes that determine the same trait.
Major genes control the discontinuous or qualitative characters in contrast of minor genes or polygenes with individually small effects. Major genes segregate and may be easily subject to mendelian analysis. The gene categorization into major and minor determinants is more or less arbitrary. Both of the two types are in all probability only end points in a more or less continuous series of gene action and gene interactions.
The term major gene was introduced into the science of inheritance by Keneth Mather (1941).
See also
Gene interaction
Minor gene
Gene
Document 2:::
Hybrid growth disorders refer to reduced growth or overgrowth in an organism that is a hybrid of two different species. In some sense, it is a type of hybrid dysgenesis when the growth disorder proves deleterious, making it the opposite of heterosis or hybrid vigour.
Hybrid growth disorders may be referred to as a growth dysplasia, especially when resulting in overgrowth, although this terminology may be confusing since the term dysplasia is commonly used to imply an impending cancer. However, a hybrid growth disorder is not caused by cancer.
Hybrid growth disorders are exhibited among a variety organisms, including ligers, tigons, hybrid mice, and hybrid dwarf hamsters.
A study on hybrid mice which investigated the possible causes for hybrid growth disorders reveals genomic imprinting to have a major effect. Paternal imprinting may increase growth to maximize maternal resources allocated to his progeny, while maternal imprinting may suppress growth in favor of ensuring her own survival and equal allocation of resources between offspring. This suggests that the extent of a disorder depends on the combination of parental species and their respective sexes, as demonstrated by the Vrana study. The study concludes that hybrid growth disorders most commonly affect the heterozygous sex, as expected by Haldane's rule. This would also explain why hybrid growth disorders often appear to affect one sex more than the other.
Similarly, a study of hybrids between dwarf hamster species Phodopus campbelli and Phodopus sungorus suggests that gene imprinting causes abnormal interactions between growth-promoting and growth-repressing genes which regulate placental and embryonic growth.
See also
F1 hybrid
Document 3:::
Hard inheritance was a model of heredity that explicitly excludes any acquired characteristics, such as of Lamarckism. It is the exact opposite of soft inheritance, coined by Ernst Mayr to contrast ideas about inheritance.
Hard inheritance states that characteristics of an organism's offspring (passed on through DNA) will not be affected by the actions that the parental organism performs during its lifetime. For example: a medieval blacksmith who uses only his right arm to forge steel will not sire a son with a stronger right arm than left because the blacksmith's actions do not alter his genetic code. Inheritance due to usage and non-usage is excluded. Inheritance works as described in the modern synthesis of evolutionary biology.
The existence of inherited epigenetic variants has led to renewed interest in soft inheritance.
Document 4:::
Grafting joins plant parts, forming a genetically composite organism functioning as one plant. A scion is a shoot from one plant that, after grafting, grows on the upper part of another plant. The stock receives the scion and serves as the root system for the grafted plant. Graft hybridisation refers to a form of asexual hybridisation where heritable modifications can be induced through grafting.
Differentiation from graft chimeras
Graft chimeras are not true hybrids. In graft chimeras it is possible that the two parent tissues become separated again, revealing the original parents.
Graft hybridisation however involves the transfer of genetic material.
Mechanism
The tissues of both parts are joined together through pluripotent cells. First, undifferentiated callus tissue arises, which later differentiates and forms vascular tissue, which connects both partners of the graft union. Plasmodesmata form between the cells of tissues of both ends of the graft junction. Plastid DNA has been proven to be exchanged through the graft union. Entire nuclear genomes are also known to cross the graft junction through plasmodesmata. Graft hybridisation is explained by horizontal gene transfer, DNA transformation, and the long-distance transport of mRNA and small RNAs.
Examples
Graft hybridisation in eudicots
This technique has been demonstrated in Nicotiana, as well as in Solanum.
Graft hybridisation in monocots
The successful creation of an intergeneric graft hybrid of Sorghum and Zea has been demonstrated.
Hereditary changes of Triticum through graft hybridisation (vegetative hybridisation) have also been recorded.
Significance
Hybridisation through grafting has the potential to create economically significant hybrid plants. Graft hybridisation is a simple and practical method for breeding woody plants, particularly helpful for overcoming reproductive isolation and difficulties due to highly heterozygous genotypes.
History
This process was first discussed by Charles Dar
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What traits are those that are inherited unchanged in a hybridization?
A. recessive traits
B. dominant traits
C. mutations
D. alleles
Answer:
|
|
sciq-9622
|
multiple_choice
|
What is a coil of wire with electric current flowing through it called?
|
[
"hydraulic valve",
"carrier valve",
"tectonic valve",
"a solenoid"
] |
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: 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 2:::
In electromagnetism and electronics, electromotive force (also electromotance, abbreviated emf, denoted or ) is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical transducers provide an emf by converting other forms of energy into electrical energy. Other electrical equipment also produce an emf, such as batteries, which convert chemical energy, and generators, which convert mechanical energy. This energy conversion is achieved by physical forces applying physical work on electric charges. However, electromotive force itself is not a physical force, and ISO/IEC standards have deprecated the term in favor of source voltage or source tension instead (denoted ).
An electronic–hydraulic analogy may view emf as the mechanical work done to water by a pump, which results in a pressure difference (analogous to voltage).
In electromagnetic induction, emf can be defined around a closed loop of a conductor as the electromagnetic work that would be done on an elementary electric charge (such as an electron) if it travels once around the loop.
For two-terminal devices modeled as a Thévenin equivalent circuit, an equivalent emf can be measured as the open-circuit voltage between the two terminals. This emf can drive an electric current if an external circuit is attached to the terminals, in which case the device becomes the voltage source of that circuit.
Although an emf gives rise to a voltage and can be measured as a voltage and may sometimes informally be called a "voltage", they are not the same phenomenon (see ).
Overview
Devices that can provide emf include electrochemical cells, thermoelectric devices, solar cells, photodiodes, electrical generators, inductors, transformers and even Van de Graaff generators. In nature, emf is generated when magnetic field fluctuations occur through a surface. For example, the shifting of the Earth's magnetic field during a geomagnetic storm induces currents in an electr
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The ampere-turn (symbol A⋅t) is the MKS (metre–kilogram–second) unit of magnetomotive force (MMF), represented by a direct current of one ampere flowing in a single-turn loop in a vacuum. "Turns" refers to the winding number of an electrical conductor composing an inductor.
For example, a current of flowing through a coil of 10 turns produces an MMF of .
The corresponding physical quantity is N⋅I, the product of the number of turns, N, and the current, I; it has been used in industry, specifically, US-based coil-making industries.
By maintaining the same current and increasing the number of loops or turns of the coil, the strength of the magnetic field increases because each loop or turn of the coil sets up its own magnetic field. The magnetic field unites with the fields of the other loops to produce the field around the entire coil, making the total magnetic field stronger.
The strength of the magnetic field is not linearly related to the ampere-turns when a magnetic material is used as a part of the system. Also, the material within the magnet carrying the magnetic flux "saturates" at some point, after which adding more ampere-turns has little effect.
The ampere-turn corresponds to gilberts, the corresponding CGS unit.
In Thomas Edison's laboratory Francis Upton was the lead mathematician. Trained with Helmholtz in Germany, he used weber as the name of the unit of current, modified to ampere later:
When conducting his investigations, Upton always noted the Weber turns and with his other data had all that was necessary to put the results of his work in proper form.
He discovered that a Weber turn (that is, an ampere turn) was a constant factor, a given number of which always produced the same effect magnetically.
See also
Inductance
Solenoid
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 coil of wire with electric current flowing through it called?
A. hydraulic valve
B. carrier valve
C. tectonic valve
D. a solenoid
Answer:
|
|
sciq-4858
|
multiple_choice
|
What are the preserved remains of animals, plants, and other organisms called?
|
[
"basalt",
"skulls",
"rocks",
"fossils"
] |
D
|
Relavent Documents:
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Trace fossils are classified in various ways for different purposes. Traces can be classified taxonomically (by morphology), ethologically (by behavior), and toponomically, that is, according to their relationship to the surrounding sedimentary layers. Except in the rare cases where the original maker of a trace fossil can be identified with confidence, phylogenetic classification of trace fossils is an unreasonable proposition.
Taxonomic classification
The taxonomic classification of trace fossils parallels the taxonomic classification of organisms under the International Code of Zoological Nomenclature. In trace fossil nomenclature a Latin binomial name is used, just as in animal and plant taxonomy, with a genus and specific epithet. However, the binomial names are not linked to an organism, but rather just a trace fossil. This is due to the rarity of association between a trace fossil and a specific organism or group of organisms. Trace fossils are therefore included in an ichnotaxon separate from Linnaean taxonomy. When referring to trace fossils, the terms ichnogenus and ichnospecies parallel genus and species respectively.
The most promising cases of phylogenetic classification are those in which similar trace fossils show details complex enough to deduce the makers, such as bryozoan borings, large trilobite trace fossils such as Cruziana, and vertebrate footprints. However, most trace fossils lack sufficiently complex details to allow such classification.
Ethologic classification
The Seilacherian System
Adolf Seilacher was the first to propose a broadly accepted ethological basis for trace fossil classification. He recognized that most trace fossils are created by animals in one of five main behavioural activities, and named them accordingly:
Cubichnia are the traces of organisms left on the surface of a soft sediment. This behaviour may simply be resting as in the case of a starfish, but might also evidence the hiding place of prey, or even the ambus
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Thanatocoenosis (from Greek language thanatos - death and koinos - common) are all the embedded fossils at a single discovery site. This site may be referred to as a "death assemblage". Such groupings are composed of fossils of organisms which may not have been associated during life, often originating from different habitats. Examples include marine fossils having been brought together by a water current or animal bones having been deposited by a predator. A site containing thanatocoenosis elements can also lose clarity in its faunal history by more recent intruding factors such as burrowing microfauna or stratigraphic disturbances born from anthropogenic methods.
This term differs from a related term, biocoenosis, which refers to an assemblage in which all organisms within the community interacted and lived together in the same habitat while alive. A biocoenosis can lead to a thanatocoenosis if disrupted significantly enough to have its dead/fossilized matter scattered. A death community/thanatocoenosis is developed by multiple taphonomic processes (those being ones relating to the different ways in which organismal remains pass through strata and are decomposed and preserved) that are generally categorized into two groups: biostratinomy and diagenesis. As a whole, thanatocoenoses are divided into two categories as well: autochthonous and allochthonous.
Death assemblages and thanatocoenoses can provide insight into the process of early-stage fossilization, as well as information about the species within a given ecosystem. The study of taphonomy can aid in furthering the understanding of the ecological past of species and their fossil records if used in conjunction with research on death assemblages from modern ecosystems.
History
The term "thanatocoenosis" was originally created by Erich Wasmund in 1926, and he was the first to define both the similarities and contrasts between these death communities and biocoenoses. Due to confusion between some distinctions
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A zoological specimen is an animal or part of an animal preserved for scientific use.
Various uses are: to verify the identity of a (species), to allow study, increase public knowledge of zoology.
Zoological specimens are extremely diverse. Examples are bird and mammal study skins, mounted specimens, skeletal material, casts, pinned insects, dried material, animals preserved in liquid preservatives, and microscope slides.
Natural history museums are repositories of zoological specimens
Study skins
Bird and mammal specimens are conserved as dry study skins, a form of taxidermy. The skin is removed from the animal's carcass, treated with absorbents, and filled with cotton or polyester batting (In the past plant fibres or sawdust were used). Bird specimens have a long, thin, wooden dowel wrapped in batting at their center. The dowel is often intentionally longer than the bird's body and exits at the animal's vent. This exposed dowel provides a place to handle the bird without disturbing the feathers. Mammal study skins do not normally utilize wooden dowels, instead preparators use wire to support the legs and tail of mammals. Labels are attached to a leg of the specimen with thread or string. Heat and chemicals are sometimes used to aid the drying of study skins.
Skeletal Preparations (Osteology)
Osteological collections consist of cleaned, complete and partial skeletons, crania of Vertebrates, mainly birds and mammals. They are used in studies of comparative anatomy and to identify bones from archaeological sites. Human bones are used in medical and forensic studies.
Molluscs
In museum collections it is common for the dry material to greatly exceed the amount of material that is preserved in alcohol. The shells minus their soft parts are kept in card trays within drawers or in glass tubes, often as lots (a lot is a collection of a single species taken from a single locality on a single occasion). Shell collections sometimes suffer from Byne's disease which also
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Archaeobiology, the study of the biology of ancient times through archaeological materials, is a subspecialty of archaeology. It can be seen as a blanket term for paleobotany, animal osteology, zooarchaeology, microbiology, and many other sub-disciplines. Specifically, plant and animal remains are also called ecofacts. Sometimes these ecofacts can be left by humans and sometimes they can be naturally occurring. Archaeobiology tends to focus on more recent finds, so the difference between archaeobiology and palaeontology is mainly one of date: archaeobiologists typically work with more recent, non-fossilised material found at archaeological sites. Only very rarely are archaeobiological excavations performed at sites with no sign of human presence.
Flora and Fauna in Archaeology
The prime interest of paleobotany is to reconstruct the vegetation that people in the past would have encountered in a particular place and time. Plant studies have always been overshadowed by faunal studies because bones are more conspicuous than plant remains when excavating. Collection of plant remains could everything including pollen, soil, diatoms, wood, plant remains and phytoliths. Phytoliths are sediments and diatoms are water deposits. Each plant remain can tell the archaeologist different things about the environment during a certain time period. Animal remains were the first evidence used by 19th century archaeologists. Today, archaeologists use faunal remains as a guide to the environment. It helps archaeologists understand whether the fauna were present naturally or through activities of carnivores or people. Archaeologists deal with macrofauna and microfauna. Microfauna are better indicators of climate and environmental change than larger species. These can be as small as a bug or as big as a fish or bird. Macrofauna helps archaeologists build a picture of past human diet.
Bacteria and Protists in Archaeology
Bacteria and Protists form two separate kingdoms, but both are fa
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The paleopedological record is, essentially, the fossil record of soils. The paleopedological record consists chiefly of paleosols buried by flood sediments, or preserved at geological unconformities, especially plateau escarpments or sides of river valleys. Other fossil soils occur in areas where volcanic activity has covered the ancient soils.
Problems of recognition
After burial, soil fossils tend to be altered by various chemical and physical processes. These include:
Decomposition of organic matter that was once present in the old soil. This hinders the recognition of vegetation that was in the soil when it was present.
Oxidation of iron from Fe2+ to Fe3+ by O2 as the former soil becomes dry and more oxygen enters the soil.
Drying out of hydrous ferric oxides to anhydrous oxides - again due to the presence of more available O2 in the dry environment.
The keys to recognising fossils of various soils include:
Tubular structures that branch and thin irregularly downward or show the anatomy of fossilised root traces
Gradational alteration down from a sharp lithological contact like that between land surface and soil horizons
Complex patterns of cracks and mineral replacements like those of soil clods (peds) and planar cutans.
Classification
Soil fossils are usually classified by USDA soil taxonomy. With the exception of some exceedingly old soils which have a clayey, grey-green horizon that is quite unlike any present soil and clearly formed in the absence of O2, most fossil soils can be classified into one of the twelve orders recognised by this system. This is usually done by means of X-ray diffraction, which allows the various particles within the former soils to be analysed so that it can be seen to which order the soils correspond.
Other methods for classifying soil fossils rely on geochemical analysis of the soil material, which allows the minerals in the soil to be identified. This is only useful where large amounts of the ancient soil are avai
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the preserved remains of animals, plants, and other organisms called?
A. basalt
B. skulls
C. rocks
D. fossils
Answer:
|
|
sciq-1737
|
multiple_choice
|
What type of energy is used when a roller coaster runs downhill?
|
[
"residual energy",
"vibrational energy",
"kinetic energy",
"proportional 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
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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
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Engineering mathematics is a branch of applied mathematics concerning mathematical methods and techniques that are typically used in engineering and industry. Along with fields like engineering physics and engineering geology, both of which may belong in the wider category engineering science, engineering mathematics is an interdisciplinary subject motivated by engineers' needs both for practical, theoretical and other considerations outside their specialization, and to deal with constraints to be effective in their work.
Description
Historically, engineering mathematics consisted mostly of applied analysis, most notably: differential equations; real and complex analysis (including vector and tensor analysis); approximation theory (broadly construed, to include asymptotic, variational, and perturbative methods, representations, numerical analysis); Fourier analysis; potential theory; as well as linear algebra and applied probability, outside of analysis. These areas of mathematics were intimately tied to the development of Newtonian physics, and the mathematical physics of that period. This history also left a legacy: until the early 20th century subjects such as classical mechanics were often taught in applied mathematics departments at American universities, and fluid mechanics may still be taught in (applied) mathematics as well as engineering departments.
The success of modern numerical computer methods and software has led to the emergence of computational mathematics, computational science, and computational engineering (the last two are sometimes lumped together and abbreviated as CS&E), which occasionally use high-performance computing for the simulation of phenomena and the solution of problems in the sciences and engineering. These are often considered interdisciplinary fields, but are also of interest to engineering mathematics.
Specialized branches include engineering optimization and engineering statistics.
Engineering mathematics in tertiary educ
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of energy is used when a roller coaster runs downhill?
A. residual energy
B. vibrational energy
C. kinetic energy
D. proportional energy
Answer:
|
|
sciq-2708
|
multiple_choice
|
Which measure indicates the number of electrons in a given sublevel?
|
[
"superscripts",
"mole",
"subscripts",
"coefficients"
] |
A
|
Relavent Documents:
Document 0:::
The subatomic scale is the domain of physical size that encompasses objects smaller than an atom. It is the scale at which the atomic constituents, such as the nucleus containing protons and neutrons, and the electrons in their orbitals, become apparent.
The subatomic scale includes the many thousands of times smaller subnuclear scale, which is the scale of physical size at which constituents of the protons and neutrons - particularly quarks - become apparent.
See also
Astronomical scale the opposite end of the spectrum
Subatomic particles
Document 1:::
The elementary charge, usually denoted by , is a fundamental physical constant, defined as the electric charge carried by a single proton or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 .
In the SI system of units, the value of the elementary charge is exactly defined as = coulombs, or 160.2176634 zeptocoulombs (zC). Since the 2019 redefinition of SI base units, the seven SI base units are defined by seven fundamental physical constants, of which the elementary charge is one.
In the centimetre–gram–second system of units (CGS), the corresponding quantity is .
Robert A. Millikan and Harvey Fletcher's oil drop experiment first directly measured the magnitude of the elementary charge in 1909, differing from the modern accepted value by just 0.6%. Under assumptions of the then-disputed atomic theory, the elementary charge had also been indirectly inferred to ~3% accuracy from blackbody spectra by Max Planck in 1901 and (through the Faraday constant) at order-of-magnitude accuracy by Johann Loschmidt's measurement of the Avogadro number in 1865.
As a unit
In some natural unit systems, such as the system of atomic units, e functions as the unit of electric charge. The use of elementary charge as a unit was promoted by George Johnstone Stoney in 1874 for the first system of natural units, called Stoney units. Later, he proposed the name electron for this unit. At the time, the particle we now call the electron was not yet discovered and the difference between the particle electron and the unit of charge electron was still blurred. Later, the name electron was assigned to the particle and the unit of charge e lost its name. However, the unit of energy electronvolt (eV) is a remnant of the fact that the elementary charge was once called electron.
In other natural unit systems, the unit of charge is defined as with the result that
where is the fine-structure constant, is the speed of light, is
Document 2:::
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The debye (D) is another unit of measurement used in atomic physics and chemistry.
Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.
Elementary definition
Often in physics the dimensions of a massive object can be ignored and can be treated as a pointlike object, i.e. a point particle. Point particles with electric charge are referred to as point charges. Two point charges, one with charge and the other one with charge separated by a distance , constitute an electric dipole (a simple case of an electric multipole). For this case, the electric dipole moment has a magnitude and is directed from the negative charge to the positive one. Some authors may split in half and use since this quantity is the distance between either charge and the center of the dipole, leading to a factor of two in the definition.
A stronger mathematical definition is to use vector algebra, since a quantity with magnitude and direction, like the dipole moment of two point charges, can be expressed in vector form where is the displacement vector pointing from the negative charge to the positive charge. The electric dipole moment vector also points from the negative charge to the positive charge. With this definition the dipole direction tends to align itself with an external electric field (and note that the electric flux lines produced by the charges of the dipole itself, which point from positive charge to negative charge then tend to oppose the flux lines of the external field). Note that this sign convention is used in physics, while the opposite sign convention for th
Document 3:::
In physical chemistry, there are numerous quantities associated with chemical compounds and reactions; notably in terms of amounts of substance, activity or concentration of a substance, and the rate of reaction. This article uses SI units.
Introduction
Theoretical chemistry requires quantities from core physics, such as time, volume, temperature, and pressure. But the highly quantitative nature of physical chemistry, in a more specialized way than core physics, uses molar amounts of substance rather than simply counting numbers; this leads to the specialized definitions in this article. Core physics itself rarely uses the mole, except in areas overlapping thermodynamics and chemistry.
Notes on nomenclature
Entity refers to the type of particle/s in question, such as atoms, molecules, complexes, radicals, ions, electrons etc.
Conventionally for concentrations and activities, square brackets [ ] are used around the chemical molecular formula. For an arbitrary atom, generic letters in upright non-bold typeface such as A, B, R, X or Y etc. are often used.
No standard symbols are used for the following quantities, as specifically applied to a substance:
the mass of a substance m,
the number of moles of the substance n,
partial pressure of a gas in a gaseous mixture p (or P),
some form of energy of a substance (for chemistry enthalpy H is common),
entropy of a substance S
the electronegativity of an atom or chemical bond χ.
Usually the symbol for the quantity with a subscript of some reference to the quantity is used, or the quantity is written with the reference to the chemical in round brackets. For example, the mass of water might be written in subscripts as mH2O, mwater, maq, mw (if clear from context) etc., or simply as m(H2O). Another example could be the electronegativity of the fluorine-fluorine covalent bond, which might be written with subscripts χF-F, χFF or χF-F etc., or brackets χ(F-F), χ(FF) etc.
Neither is standard. For the purpose of this a
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which measure indicates the number of electrons in a given sublevel?
A. superscripts
B. mole
C. subscripts
D. coefficients
Answer:
|
|
sciq-6087
|
multiple_choice
|
During the early paleozoic, the amount of carbon dioxide in the atmosphere compared to today was?
|
[
"none",
"the same",
"much lower",
"much greater"
] |
D
|
Relavent Documents:
Document 0:::
The start of the Cambrian period is marked by "fluctuations" in a number of geochemical records, including Strontium, Sulfur and Carbon isotopic excursions. While these anomalies are difficult to interpret, a number of possibilities have been put forward. They probably represent changes on a global scale, and as such may help to constrain possible causes of the Cambrian explosion.
The chemical signature may be related to continental break-up, the end of a "global glaciation", or a catastrophic drop in productivity caused by a mass extinction just before the beginning of the Cambrian.
Isotopes
Isotopes are different forms of elements; they have a different number of neutrons in the nucleus, meaning they have very similar chemical properties, but different mass. The weight difference means that some isotopes are discriminated against in chemical processes – for example, plants find it easier to incorporate the lighter 12C than heavy 13C. Other isotopes are only produced as a result of the radioactive decay of other elements, such as 87Sr, the daughter isotope of 87Rb. Rb, and therefore 87Sr, is common in the crust, so abundance of 87Sr in a sample of sediment (relative to 86Sr) is related to the amount of sediment which originated in the crust, as opposed to from the oceans.
The ratios of three major isotopes, 87Sr / 86Sr, 34S / 32S and 13C / 12C, undergo dramatic fluctuations around the beginning of the Cambrian.
Carbon isotopes
Carbon has 2 stable isotopes, carbon-12 (12C) and carbon-13 (13C). The ratio between the two is denoted , and represents a number of factors.
Because organic matter preferentially takes up the lighter 12C, an increase in productivity increases the of the rest of the system, and vice versa. Some carbon reservoirs are very isotopically light: for instance, biogenic methane, produced by bacterial decomposition, has a of −60‰ – vast, when 1‰ is a large fluctuation! An injection of carbon from one of these reservoirs could therefore
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Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (), which causes ocean acidification as atmospheric levels increase.
It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.025%. Burning fossil fuels is the primary cause of these increased concentrations and also the primary cause of climate change.
Its concentration in Earth's pre-industrial atmosphere since late in the Precambrian was regulated by organisms and geological phenomena. Plants, algae and cyanobacteria use energy from sunlight to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis, which produces oxygen as a waste product. In turn, oxygen is consumed and is released as waste by all aerobic organisms when they metabolize organic compounds to produce energy by respiration. is released from organic materials when they decay or combust, such as in forest fires. Since plants require for photosynthesis, and humans and animals depend on plants for food, is necessary for the survival of life on earth.
Carbon dioxide is 53% more dense than dry air, but is long lived and thoroughly mixes in the atmosphere. About half of excess emissions to the atmosphere are absorbed by land and ocean carbon sinks. These sinks can become saturated and are volatile, as decay and wildfires result i
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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
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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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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.
During the early paleozoic, the amount of carbon dioxide in the atmosphere compared to today was?
A. none
B. the same
C. much lower
D. much greater
Answer:
|
|
sciq-488
|
multiple_choice
|
An antigen is a molecule that reacts with some component of the what response?
|
[
"hormones",
"immune",
"digestion",
"fight or flight"
] |
B
|
Relavent Documents:
Document 0:::
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response.
Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungi, and bacteria.
Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are antigen-specific, meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react to bind more than one antigen. The reaction between an antigen and an antibody is called the antigen-antibody reaction.
Antigen can originate either from within the body ("self-protein" or "self antigens") or from the external environment ("non-self"). The immune system identifies and attacks "non-self" external antigens. Antibodies usually do not react with self-antigens due to negative selection of T cells in the thymus and B cells in the bone marrow. The diseases in which antibodies react with self antigens and damage the body's own cells are called autoimmune diseases.
Vaccines are examples of antigens in an immunogenic form, which are intentionally administered to a recipient to induce the memory function of the adaptive immune system towards antigens of the pathogen invading that recipient. The vaccine for seasonal influenza is a common example.
Etymology
Paul Ehrlich coined the term antibody () in his side-chain theory at the end of the 19th century. In 1899, Ladislas Deutsch (László Detr
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Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal. It may be wanted or unwanted:
Wanted immunogenicity typically relates to vaccines, where the injection of an antigen (the vaccine) provokes an immune response against the pathogen, protecting the organism from future exposure. Immunogenicity is a central aspect of vaccine development.
Unwanted immunogenicity is an immune response by an organism against a therapeutic antigen. This reaction leads to production of anti-drug-antibodies (ADAs), inactivating the therapeutic effects of the treatment and potentially inducing adverse effects.
A challenge in biotherapy is predicting the immunogenic potential of novel protein therapeutics. For example, immunogenicity data from high-income countries are not always transferable to low-income and middle-income countries. Another challenge is considering how the immunogenicity of vaccines changes with age. Therefore, as stated by the World Health Organization, immunogenicity should be investigated in a target population since animal testing and in vitro models cannot precisely predict immune response in humans.
Antigenicity is the capacity of a chemical structure (either an antigen or hapten) to bind specifically with a group of certain products that have adaptive immunity: T cell receptors or antibodies (a.k.a. B cell receptors). Antigenicity was more commonly used in the past to refer to what is now known as immunogenicity, and the two are still often used interchangeably. However, strictly speaking, immunogenicity refers to the ability of an antigen to induce an adaptive immune response. Thus an antigen might bind specifically to a T or B cell receptor, but not induce an adaptive immune response. If the antigen does induce a response, it is an 'immunogenic antigen', which is referred to as an immunogen.
Antigenic immunogenic potency
Many lipids and nucleic acids are relatively s
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An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion).
To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety.
In contrast, the remainder of the antibody is relatively constant. In mammals, antibodies occur in a few variants, which define the antibody's class or isotype: IgA, IgD, IgE, IgG, and IgM.
The constant region at the trunk of the antibody includes sites involved in interactions with other components of the immune system. The class hence determines the function triggered by an antibody after binding to an antigen, in addition to some structural features.
Antibodies from different classes also differ in where they are released in the body and at what stage of an immune response.
Together with B and T cells, antibodies comprise the most important part of the adaptive immune system.
They occur in two forms: one that is attached to a B cell, and the other, a soluble form, that is unattached and found in extracellular fluids such as blood plasma.
Initially, all antibodies are of the first form, attached to the surface of a B cell – these are then referred to as B-cell receptors (BCR).
After an antigen binds to a BCR, the B cell activates to proliferate and differentiate into either plasma cells,
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Polyclonal B cell response is a natural mode of immune response exhibited by the adaptive immune system of mammals. It ensures that a single antigen is recognized and attacked through its overlapping parts, called epitopes, by multiple clones of B cell.
In the course of normal immune response, parts of pathogens (e.g. bacteria) are recognized by the immune system as foreign (non-self), and eliminated or effectively neutralized to reduce their potential damage. Such a recognizable substance is called an antigen. The immune system may respond in multiple ways to an antigen; a key feature of this response is the production of antibodies by B cells (or B lymphocytes) involving an arm of the immune system known as humoral immunity. The antibodies are soluble and do not require direct cell-to-cell contact between the pathogen and the B-cell to function.
Antigens can be large and complex substances, and any single antibody can only bind to a small, specific area on the antigen. Consequently, an effective immune response often involves the production of many different antibodies by many different B cells against the same antigen. Hence the term "polyclonal", which derives from the words poly, meaning many, and clones from Greek klōn, meaning sprout or twig; a clone is a group of cells arising from a common "mother" cell. The antibodies thus produced in a polyclonal response are known as polyclonal antibodies. The heterogeneous polyclonal antibodies are distinct from monoclonal antibody molecules, which are identical and react against a single epitope only, i.e., are more specific.
Although the polyclonal response confers advantages on the immune system, in particular, greater probability of reacting against pathogens, it also increases chances of developing certain autoimmune diseases resulting from the reaction of the immune system against native molecules produced within the host.
Humoral response to infection
Diseases which can be transmitted from one organism to
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Immunopathology is a branch of medicine that deals with immune responses associated with disease. It includes the study of the pathology of an organism, organ system, or disease with respect to the immune system, immunity, and immune responses. In biology, it refers to damage caused to an organism by its own immune response, as a result of an infection. It could be due to mismatch between pathogen and host species, and often occurs when an animal pathogen infects a human (e.g. avian flu leads to a cytokine storm which contributes to the increased mortality rate).
Types of Immunity
In all vertebrates, there are two different kinds of immunities: Innate and Adaptive immunity. Innate immunity is used to fight off non-changing antigens and is therefore considered nonspecific. It is usually a more immediate response than the adaptive immune system, usually responding within minutes to hours. It is composed of physical blockades such as the skin, but also contains nonspecific immune cells such as dendritic cells, macrophages, and basophils. The second form of immunity is Adaptive immunity. This form of immunity requires recognition of the foreign antigen before a response is produced. Once the antigen is recognized, a specific response is produced in order to destroy the specific antigen. Because of its tailored response characteristic, adaptive immunity is considered to be specific immunity. A key part of adaptive immunity that separates it from innate is the use of memory to combat the antigen in the future. When the antigen is originally introduced, the organism does not have any receptors for the antigen so it must generate them from the first time the antigen is present. The immune system then builds a memory of that antigen, which enables it to recognize the antigen quicker in the future and be able to combat it quicker and more efficiently. The more the system is exposed to the antigen, the quicker it will build up its responsiveness. Nested within Adaptive immu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
An antigen is a molecule that reacts with some component of the what response?
A. hormones
B. immune
C. digestion
D. fight or flight
Answer:
|
|
sciq-6853
|
multiple_choice
|
The effect of gravity on circulation means that it is harder to get blood up from the legs as the body takes on this?
|
[
"vertical orientation",
"frontal orientation",
"horizontal orientation",
"dorsal orientation"
] |
A
|
Relavent Documents:
Document 0:::
The Parallel Walk Test is a quick and simple quantitative measuring tool for balance during walking and could be a useful tool in clinical settings for assessing balance before and after treatments and to discriminate high fall risk potential.
Description
The test takes 3-5 minutes and consists of walking 6 meters between 2 parallel lines measured 8”, 12” and 15” across in width. The test is scored based on number of stepping errors, i.e. stepping on a line (+1) or stepping over a line (+2), where a higher score denotes decrease performance and total time to perform walk. A warm-up walk of 20m can be performed as well as 1 practice walk.
Lateral movement
It was created to address the significance lateral movement, during walking, has to balance and fall risk and is based on research that indicated increased lateral movement during walking corresponds to decrease dynamic stability. Saunders, et.al., proposed in 1953 an inverted pendulum model to describe normal and pathological walking. They described six "determinants" of walking that control the body's center of gravity, they reasoned that normal walking controls the center of gravity while pathological walking will demonstrate excessive movement of the center of gravity. One of the "determinants" is the lateral movement of the pelvis and excessive movement at the pelvis can be corrected by the position of the foot and leg. Using the inverted pendulum model, MacKinnon and Winter found, to make sure balance was preserved, the center of mass should pass medial to the supporting foot. Current research has shown that testing balance function under narrow stance conditions provides adequate difficulty to help reveal insufficiency in balance control that could increase the risk of falls and that differences between fallers and non-fallers were most pronounced for measures related to lateral stability. Instability during walking is primarily in the mediolateral direction and decrease in mediolateral stability ha
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The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and from Latin vascula meaning vessels). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms cardiovascular system and vascular system interchangeably with the circulatory system.
The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Some invertebrates such as arthropods have an open circulatory system. Diploblasts such as sponges, and comb jellies lack a circulatory system.
Blood is a fluid consisting of plasma, red blood cells, white blood cells, and platelets; it is circulated around the body carrying oxygen and nutrients to the tissues and collecting and disposing of waste materials. Circulated nutrients include proteins and minerals and other components include hemoglobin, hormones, and gases such as oxygen and carbon dioxide. These substances provide nourishment, help the immune system to fight diseases, and help maintain homeostasis by stabilizing temperature and natural pH.
In vertebrates, the lymphatic system is complementary to the circulatory system. The lymphatic system carries excess plasma (filtered from the circulatory system capillaries as interstitial fluid between cells) away from the body tissues via accessory routes that return excess fluid back to blood circulation as lymph. The lymphatic system is a subsystem that is essential for the functioning of the bloo
Document 2:::
Locomotor effects of shoes are the way in which the physical characteristics or components of shoes influence the locomotion neuromechanics of a person. Depending on the characteristics of the shoes, the effects are various, ranging from alteration in balance and posture, muscle activity of different muscles as measured by electromyography (EMG), and the impact force. There are many different types of shoes that exist, such as running, walking, loafers, high heels, sandals, slippers, work boots, dress shoes, and many more. However, a typical shoe will be composed of an insole, midsole, outsole, and heels, if any. In an unshod condition, where one is without any shoes, the locomotor effects are primarily observed in the heel strike patterns and resulting impact forces generated on the ground.
Insoles and inserts
The foot provides the sensory information to the central nervous system through cutaneous afferent feedback, which originates from the special mechanoreceptors within the plantar surface of the foot. This afferent feedback has a strong influence on postural stability and balance correction during standing and walking. Since sensory feedback from the foot may be influenced by the interaction of the foot with the insole surface, different types of insoles and shoe inserts have been used to try to enhance postural stability.
Textured inserts
Textured Inserts are regular shoe inserts that have a raised textured surface on the side that acts to provide enhanced mechanical contact and pressure on the plantar surface of the feet. Providing a textured surface of the shoe insert leads to significant changes during gait in ankle joint kinematics and in EMG amplitude of ankle flexor and extensor muscles. Textured inserts mostly affect ankle motion in the sagittal plane, where plantar flexion of the foot is increased. As for muscle activity, textured inserts decrease the activation of soleus and tibialis anterior muscles during standing and walking.
Insoles w
Document 3:::
Venous return is the rate of blood flow back to the heart. It normally limits cardiac output.
Superposition of the cardiac function curve and venous return curve is used in one hemodynamic model.
Physiology
Venous return (VR) is the flow of blood back to the heart. Under steady-state conditions, venous return must equal cardiac output (Q), when averaged over time because the cardiovascular system is essentially a closed loop. Otherwise, blood would accumulate in either the systemic or pulmonary circulations. Although cardiac output and venous return are interdependent, each can be independently regulated.
The circulatory system is made up of two circulations (pulmonary and systemic) situated in series between the right ventricle (RV) and left ventricle (LV). Balance is achieved, in large part, by the Frank–Starling mechanism. For example, if systemic venous return is suddenly increased (e.g., changing from upright to supine position), right ventricular preload increases leading to an increase in stroke volume and pulmonary blood flow. The left ventricle experiences an increase in pulmonary venous return, which in turn increases left ventricular preload and stroke volume by the Frank–Starling mechanism. In this way, an increase in venous return can lead to a matched increase in cardiac output.
Venous return curve
Hemodynamically, venous return (VR) to the heart from the venous vascular beds is determined by a pressure gradient (venous pressure - right atrial pressure) and venous resistance (RV). Therefore, increases in venous pressure or decreases in right atrial pressure or venous resistance will lead to an increase in venous return, except when changes are brought about by altered body posture. Although the above relationship is true for the hemodynamic factors that determine the flow of blood from the veins back to the heart, it is important not to lose sight of the fact that blood flow through the entire systemic circulation represents both the cardiac
Document 4:::
In the field of biomechanics, the lines of non-extension are notional lines running across the human body along which body movement causes neither stretching or contraction. Discovered by Arthur Iberall in work beginning in the 1940s, as part of research into space suit design, they have been further developed by Dava Newman in the development of the Space Activity Suit.
They were originally mapped by Iberall by drawing a series of circles over a portion of the body and then watching their deformations as the wearer walked around or performed various tasks. The circles deform into ellipses as the skin stretches over the moving musculature, and these deformations were recorded. After a huge number of such measurements the data is then examined to find all of the possible deformations of the circles, and more importantly, the non-moving points on them where the original circle and the deformed ellipse intersect (at four points per circle). By mapping these points over the entire body, a series of lines are produced.
These lines may then be used to direct the placement of tension elements in a spacesuit to enable constant suit pressure regardless of the motion of the body.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The effect of gravity on circulation means that it is harder to get blood up from the legs as the body takes on this?
A. vertical orientation
B. frontal orientation
C. horizontal orientation
D. dorsal orientation
Answer:
|
|
sciq-11323
|
multiple_choice
|
What methods allow scientists to add to scientific knowledge and gain a better understanding of the world?
|
[
"slow investigations",
"early investigations",
"close investigations",
"through investigations"
] |
D
|
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:::
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 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
Document 3:::
A scholar is a person who is a researcher or has expertise in an academic discipline. A scholar can also be an academic, who works as a professor, teacher, or researcher at a university. An academic usually holds an advanced degree or a terminal degree, such as a master's degree or a doctorate (PhD). Independent scholars and public intellectuals work outside of the academy yet may publish in academic journals and participate in scholarly public discussion.
Definitions
In contemporary English usage, the term scholar sometimes is equivalent to the term academic, and describes a university-educated individual who has achieved intellectual mastery of an academic discipline, as instructor and as researcher. Moreover, before the establishment of universities, the term scholar identified and described an intellectual person whose primary occupation was professional research. In 1847, minister Emanuel Vogel Gerhart spoke of the role of the scholar in society:
Gerhart argued that a scholar can not be focused on a single discipline, contending that knowledge of multiple disciplines is necessary to put each into context and to inform the development of each:
A 2011 examination outlined the following attributes commonly accorded to scholars as "described by many writers, with some slight variations in the definition":
Scholars may rely on the scholarly method or scholarship, a body of principles and practices used by scholars to make their claims about the world as valid and trustworthy as possible, and to make them known to the scholarly public. It is the methods that systemically advance the teaching, research, and practice of a given scholarly or academic field of study through rigorous inquiry. Scholarship is creative, can be documented, can be replicated or elaborated, and can be and is peer-reviewed through various methods.
Role in society
Scholars have generally been upheld as creditable figures of high social standing, who are engaged in work important to society.
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What methods allow scientists to add to scientific knowledge and gain a better understanding of the world?
A. slow investigations
B. early investigations
C. close investigations
D. through investigations
Answer:
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|
sciq-6644
|
multiple_choice
|
Light with the shortest wavelength appears as what color?
|
[
"green",
"red",
"blue",
"violet"
] |
D
|
Relavent Documents:
Document 0:::
A colorimeter is a device used in colorimetry that measures the absorbance of particular wavelengths of light by a specific solution. It is commonly used to determine the concentration of a known solute in a given solution by the application of the Beer–Lambert law, which states that the concentration of a solute is proportional to the absorbance.
Construction
The essential parts of a colorimeter are:
a light source (often an ordinary low-voltage filament lamp);
an adjustable aperture;
a set of colored filters;
a cuvette to hold the working solution;
a detector (usually a photoresistor) to measure the transmitted light;
a meter to display the output from the detector.
In addition, there may be:
a voltage regulator, to protect the instrument from fluctuations in mains voltage;
a second light path, cuvette and detector. This enables comparison between the working solution and a "blank", consisting of pure solvent, to improve accuracy.
There are many commercialized colorimeters as well as open source versions with construction documentation for education and for research.
Filters
Changeable optics filters are used in the colorimeter to select the wavelength which the solute absorbs the most, in order to maximize accuracy. The usual wavelength range is from 400 to 700 nm. If it is necessary to operate in the ultraviolet range then some modifications to the colorimeter are needed. In modern colorimeters the filament lamp and filters may be replaced by several (light-emitting diode) of different colors.
Cuvettes
In a manual colorimeter the cuvettes are inserted and removed by hand. An automated colorimeter (as used in an AutoAnalyzer) is fitted with a flowcell through which solution flows continuously.
Output
The output from a colorimeter may be displayed by an analogue or digital meter and may be shown as transmittance (a linear scale from 0 to 100%) or as absorbance (a logarithmic scale from zero to infinity). The useful range of the absorbance scale is
Document 1:::
In physics, monochromatic radiation is electromagnetic radiation with a single constant frequency. When that frequency is part of the visible spectrum (or near it) the term monochromatic light is often used. Monochromatic light is perceived by the human eye as a spectral color.
When monochromatic radiation propagates through vacuum or a homogeneous transparent medium, it has a single constant wavelength.
Practical monochromaticity
No radiation can be totally monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence). In practice, "monochromatic" radiation — even from lasers or spectral lines — always consists of components with a range of frequencies of non-zero width.
Generation
Monochromatic radiation can be produced by a number of methods. Isaac Newton observed that a beam of light from the sun could be spread out by refraction into a fan of light with varying colors; and that if a beam of any particular color was isolated from that fan, it behaved as "pure" light that could not be decomposed further.
When atoms of a chemical element in gaseous state are subjected to an electric current, to suitable radiation, or to high enough temperature, they emit a light spectrum with a set of discrete spectral lines (monochromatic components), that are characteristic of the element. This phenomenon is the basis of the science of spectroscopy, and is exploited in fluorescent lamps and the so-called neon signs.
A laser is a device that generates monochromatic and coherent radiation through a process of stimulated emission.
Properties and uses
When monochromatic radiation is made to interfere with itself, the result can be visible and stable interference fringes that can be used to measure very small distances, or large distances with very high accuracy. The current definition of the metre is based on this technique.
In the technique of spectroscopic analysis, a mat
Document 2:::
Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different frequencies independently of light intensity. Color perception is a part of the larger visual system and is mediated by a complex process between neurons that begins with differential stimulation of different types of photoreceptors by light entering the eye. Those photoreceptors then emit outputs that are propagated through many layers of neurons and then ultimately to the brain. Color vision is found in many animals and is mediated by similar underlying mechanisms with common types of biological molecules and a complex history of evolution in different animal taxa. In primates, color vision may have evolved under selective pressure for a variety of visual tasks including the foraging for nutritious young leaves, ripe fruit, and flowers, as well as detecting predator camouflage and emotional states in other primates.
Wavelength
Isaac Newton discovered that white light after being split into its component colors when passed through a dispersive prism could be recombined to make white light by passing them through a different prism. The visible light spectrum ranges from about 380 to 740 nanometers. Spectral colors (colors that are produced by a narrow band of wavelengths) such as red, orange, yellow, green, cyan, blue, and violet can be found in this range. These spectral colors do not refer to a single wavelength, but rather to a set of wavelengths: red, 625–740 nm; orange, 590–625 nm; yellow, 565–590 nm; green, 500–565 nm; cyan, 485–500 nm; blue, 450–485 nm; violet, 380–450 nm.
Wavelengths longer or shorter than this range are called infrared or ultraviolet, respectively. Humans cannot generally see these wavelengths, but other animals may.
Hue detection
Sufficient differences in wavelength cause a difference in the perceived hue; the just-noticeable difference in wavelength varies from about 1 nm in the blue-green and yellow wavelengths t
Document 3:::
In visual physiology, adaptation is the ability of the retina of the eye to adjust to various levels of light. Natural night vision, or scotopic vision, is the ability to see under low-light conditions. In humans, rod cells are exclusively responsible for night vision as cone cells are only able to function at higher illumination levels. Night vision is of lower quality than day vision because it is limited in resolution and colors cannot be discerned; only shades of gray are seen. In order for humans to transition from day to night vision they must undergo a dark adaptation period of up to two hours in which each eye adjusts from a high to a low luminescence "setting", increasing sensitivity hugely, by many orders of magnitude. This adaptation period is different between rod and cone cells and results from the regeneration of photopigments to increase retinal sensitivity. Light adaptation, in contrast, works very quickly, within seconds.
Efficiency
The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of 1,000. What enables the wider reach is that the eye adapts its definition of what is black.
The eye takes approximately 20–30 minutes to fully adapt from bright sunlight to complete darkness and becomes 10,000 to 1,000,000 times more sensitive than at full daylight. In this process, the eye's perception of color changes as well (this is called the Purkinje effect). However, it takes approximately five minutes for the eye to adapt from darkness to bright sunlight. This is due to cones obtaining more sensitivity when first entering the dark for the first five minutes but the rods taking over after five or more minutes. Cone cells are able to regain maximum retinal sensitivity in 9
Document 4:::
On the coloured light of the binary stars and some other stars of the heavens or in the original German is a treatise by Christian Doppler (1842) in which he postulated his principle that the observed frequency changes if either the source or the observer is moving, which later has been coined the Doppler effect. The original German text can be found in wikisource. The following annotated summary serves as a companion to that original.
Title
The title "" (On the coloured light of the binary stars and some other stars of the heavens - Attempt at a general theory including Bradley's theorem as an integral part) specifies the purpose: describe the hypothesis of the Doppler effect, use it to explain the colours of binary stars, and establish a relation with Bradley's stellar aberration.
Content
§ 1 In which Doppler reminds the readers that light is a wave, and that there is debate as to whether it is a transverse wave, with aether particles oscillating perpendicular to the propagation direction. Proponents claim this is necessary to explain polarised light, whereas opponents object to implications for the aether. Doppler doesn't choose sides, although the issue returns in § 6.
§ 2 Doppler observes that colour is a manifestation of the frequency of the light wave, in the eye of the beholder. He describes his principle that a frequency shift occurs when the source or the observer moves. A ship meets waves at a faster rate when sailing against the waves than when sailing along with them. The same goes for sound and light.
§ 3 Doppler derives his equations for the frequency shift, in two cases:
§ 4 Doppler provides imaginary examples of large and small frequency shifts for sound:
§ 5 Doppler provides imaginary examples of large and small frequency shifts for light from stars. Velocities are expressed in Meilen/s, and the light speed has a rounded value of 42000 Meilen/s. Doppler assumes that 458 THz (extreme red) and 727 THz (extreme violet) are the borders of the v
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Light with the shortest wavelength appears as what color?
A. green
B. red
C. blue
D. violet
Answer:
|
|
sciq-4367
|
multiple_choice
|
What was first discovered in songbirds that produce new neurons while learning songs?
|
[
"proteins",
"homeostasis",
"Brain Cord",
"neurogenesis"
] |
D
|
Relavent Documents:
Document 0:::
The following are two lists of animals ordered by the size of their nervous system. The first list shows number of neurons in their entire nervous system, indicating their overall neural complexity. The second list shows the number of neurons in the structure that has been found to be representative of animal intelligence. The human brain contains 86 billion neurons, with 16 billion neurons in the cerebral cortex.
Scientists are engaged in counting, quantification, in order to find answers to the question in the strategy of neuroscience and intelligence of "self-knowledge": how the evolution of a set of components and parameters (~1011 neurons, ~1014 synapses) of a complex system could lead to the phenomenon of the appearance of intelligence in the biological species "sapiens".
Overview
Neurons are the cells that transmit information in an animal's nervous system so that it can sense stimuli from its environment and behave accordingly. Not all animals have neurons; Trichoplax and sponges lack nerve cells altogether.
Neurons may be packed to form structures such as the brain of vertebrates or the neural ganglions of insects.
The number of neurons and their relative abundance in different parts of the brain is a determinant of neural function and, consequently, of behavior.
Whole nervous system
All numbers for neurons (except Caenorhabditis and Ciona), and all numbers for synapses (except Ciona) are estimations.
List of animal species by forebrain (cerebrum or pallium) neuron number
The question of what physical characteristic of an animal makes an animal intelligent has varied over the centuries. One early speculation was brain size (or weight, which provides the same ordering.) A second proposal was brain-to-body-mass ratio, and a third was encephalization quotient, sometimes referred to as EQ. The current best predictor is number of neurons in the forebrain, based on Herculano-Houzel's improved neuron counts. It accounts most accurately for variations
Document 1:::
The Leibniz Institute for Neurobiology (short LIN) is a German research institute of neuroscience in Magdeburg, focusing on learning, memory and neural plasticity. The institute was founded in 1992 and belongs to the Leibniz Association.
Notes and references
External links
Neuroscience research centers in Germany
Leibniz Association
1992 establishments in Germany
1985 establishments in East Germany
Document 2:::
Constance Scharff (born 1959) is a German zoologist and neuroethologist and Professor at the Free University of Berlin. She is particularly notable for her research on birdsong, neurogenesis and regeneration.
Early life and education
Scharff went to school in Lübeck, Germany and moved to Marburg, Germany, to study biology in 1979. She went on to study experimental neurobiology and neuroethology at Adelphi university in New York with Carol Diakow. From 1984, she worked with Fernando Nottebohm at Rockefeller University where she earned her degree of Ph.D. Studying bird song, the researchers were involved in a series of studies that showed the generation of new neurons in the adult brain. These findings contradicted the then-established view that the brain was equipped with a fixed number of neurons at the time of birth. She moved to Paris in 1991, where she worked at the Institut d'Embryology Cellulaire et Moléculaire. She returned to New York as a postdoctoral associate to work with Nottebohm again in 1994. She was a group leader at the Max Planck institute for Molecular Genetics in Berlin from 2001 to 2005 before she became a professor at the Free University of Berlin in 2005.
Work
Scharff studies birdsong in canaries and zebra finches. Here, her work is concerned with mechanisms of learning in acoustic communication and the neural pathways that control it. Further, her work focusses on the control of neuronal regeneration and replacement in adult birds. She was also involved in the decoding of the zebra finch genome. Her research suggested an important role of the gene FOXP2 in sound learning in both birds and humans, leading to a potential better understanding of hereditary disorders of speech.
Since 2012, Scharff is a member of the Berlin-Brandenburg Academy of Sciences and Humanities.
In 2019 she became a member of the German Academy of Sciences Leopoldina.
Personal life
Scharff has two daughters with microbiologist Arturo Zychlinsky.
Document 3:::
Adult neurogenesis is the process in which new neurons are born and subsequently integrate into functional brain circuits after birth and into adulthood. Avian species including songbirds are among vertebrate species that demonstrate particularly robust adult neurogenesis throughout their telencephalon, in contrast with the more limited neurogenic potential that are observed in adult mammals after birth. Adult neurogenesis in songbirds is observed in brain circuits that underlie complex specialized behavior, including the song control system and the hippocampus. The degree of postnatal and adult neurogenesis in songbirds varies between species, shows sexual dimorphism, fluctuates seasonally, and depends on hormone levels, cell death rates, and social environment. The increased extent of adult neurogenesis in birds compared to other vertebrates, especially in circuits that underlie complex specialized behavior, makes birds an excellent animal model to study this process and its functionality. Methods used in research to track adult neurogenesis in birds include the use of thymidine analogues and identifying endogenous markers of neurogenesis. Historically, the discovery of adult neurogenesis in songbirds substantially contributed to establishing the presence of adult neurogenesis and to progressing a line of research tightly associated with many potential clinical applications.
Mechanism
General mechanism
New neurons are born on the walls of the lateral ventricles (ventricular zone) and migrate to their destination where they integrate into the existing circuits. Neurogenesis occurs throughout the ventricular zone, but proliferation is especially high in specific locations in the lateral wall of the ventricle. Radial glia, a subset of vimentin-expressing glial cells that are the adult neural stem cells, reside in the dorsal and ventral ventricular zone and extend long processes that permeate the neural tissue. Radial glia asymmetrically divide to give rise to new
Document 4:::
Neuroecology studies ways in which the structure and function of the brain results from adaptations to a specific habitat and niche.
It integrates the multiple disciplines of neuroscience, which examines the biological basis of cognitive and emotional processes, such as perception, memory, and decision-making, with the field of ecology, which studies the relationship between living organisms and their physical environment.
In biology, the term 'adaptation' signifies the way evolutionary processes enhance an organism's fitness to survive within a specific ecological context. This fitness includes the development of physical, cognitive, and emotional adaptations specifically suited to the environmental conditions in which the organism or phenotype lives, and in which its species or genotype evolves.
Neuroecology concentrates specifically on neurological adaptations, particularly those of the brain. The purview of this study encompasses two areas. Firstly, neuroecology studies how the physical structure and functional activity of neural networks in a phenotype is influenced by characteristics of the environmental context. This includes the way social stressors, interpersonal relationships, and physical conditions precipitate persistent alterations in the individual brain, providing the neural correlates of cognitive and emotional responses. Secondly, neuroecology studies how neural structure and activity common to a genotype is determined by natural selection of traits that benefit survival and reproduction in a specific environment.
See also
Evolutionary ecology
Evolutionary psychology
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What was first discovered in songbirds that produce new neurons while learning songs?
A. proteins
B. homeostasis
C. Brain Cord
D. neurogenesis
Answer:
|
|
sciq-5464
|
multiple_choice
|
Different feeding "positions" in a food chain or web are associated with what kinds of levels?
|
[
"autotrophic",
"heptic",
"benthic",
"trophic"
] |
D
|
Relavent Documents:
Document 0:::
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 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 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 3:::
Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin vorare, meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγεῖν (), meaning "to eat".
Evolutionary history
The evolution of feeding is varied with some feeding strategies evolving several times in independent lineages. In terrestrial vertebrates, the earliest forms were large amphibious piscivores 400 million years ago. While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, other tetrapods (carnivory), and later, plants (herbivory). Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation (in contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials).
Evolutionary adaptations
The specialization of organisms towards specific food sources is one of the major causes of evolution of form and function, such as:
mouth parts and teeth, such as in whales, vampire bats, leeches, mosquitos, predatory animals such as felines and fishes, etc.
distinct forms of beaks in birds, such as in hawks, woodpeckers, pelicans, hummingbirds, parrots, kingfishers, etc.
specialized claws and other appendages, for apprehending or killing (including fingers in primates)
changes in body colour for facilitating camouflage, disguise, setting up traps for preys, etc.
changes in the digestive system, such as the system of stomachs of herbivores, commensalism and symbiosis
Classification
By mode of ingestion
There are many modes of feeding that animals exhibit, including:
Filter feeding: obtaining nutrients from particles suspended in water
Deposit feeding: obtaining nutrients from particles suspended in soil
Fluid feeding: obtaining nutrients by consuming other organisms' fluids
Bulk feeding: obtaining nutrients by eating all of an organism.
Ram feeding and suction feeding: in
Document 4:::
Heterotrophic nutrition is a mode of nutrition in which organisms depend upon other organisms for food to survive. They can't make their own food like Green plants. Heterotrophic organisms have to take in all the organic substances they need to survive.
All animals, certain types of fungi, and non-photosynthesizing plants are heterotrophic. In contrast, green plants, red algae, brown algae, and cyanobacteria are all autotrophs, which use photosynthesis to produce their own food from sunlight. Some fungi may be saprotrophic, meaning they will extracellularly secrete enzymes onto their food to be broken down into smaller, soluble molecules which can diffuse back into the fungus.
Description
All eukaryotes except for green plants and algae are unable to manufacture their own food: They obtain food from other organisms. This mode of nutrition is also known as heterotrophic nutrition.
All heterotrophs (except blood and gut parasites) have to convert solid food into soluble compounds which are capable of being absorbed (digestion). Then the soluble products of digestion for the organism are being broken down for the release of energy (respiration). All heterotrophs depend on autotrophs for their nutrition. Heterotrophic organisms have only four types of nutrition.
Footnotes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Different feeding "positions" in a food chain or web are associated with what kinds of levels?
A. autotrophic
B. heptic
C. benthic
D. trophic
Answer:
|
|
sciq-10945
|
multiple_choice
|
What are a group of protists whose monophyly is well supported by molecular systematics?
|
[
"mycetozoa",
"sporozoans",
"euglenozoa",
"alveolates"
] |
D
|
Relavent Documents:
Document 0:::
Marine protists are defined by their habitat as protists that live in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. Life originated as marine single-celled prokaryotes (bacteria and archaea) and later evolved into more complex eukaryotes. Eukaryotes are the more developed life forms known as plants, animals, fungi and protists. Protists are the eukaryotes that cannot be classified as plants, fungi or animals. They are mostly single-celled and microscopic. The term protist came into use historically as a term of convenience for eukaryotes that cannot be strictly classified as plants, animals or fungi. They are not a part of modern cladistics because they are paraphyletic (lacking a common ancestor for all descendants).
Most protists are too small to be seen with the naked eye. They are highly diverse organisms currently organised into 18 phyla, but not easy to classify. Studies have shown high protist diversity exists in oceans, deep sea-vents and river sediments, suggesting large numbers of eukaryotic microbial communities have yet to be discovered. There has been little research on mixotrophic protists, but recent studies in marine environments found mixotrophic protists contribute a significant part of the protist biomass. Since protists are eukaryotes (and not prokaryotes) they possess within their cell at least one nucleus, as well as organelles such as mitochondria and Golgi bodies. Many protist species can switch between asexual reproduction and sexual reproduction involving meiosis and fertilization.
In contrast to the cells of prokaryotes, the cells of eukaryotes are highly organised. Plants, animals and fungi are usually multi-celled and are typically macroscopic. Most protists are single-celled and microscopic. But there are exceptions. Some single-celled marine protists are macroscopic. Some marine slime molds have unique life cycles that involve switching between unicellular, colonial, and
Document 1:::
A protist ( ) or protoctist is any eukaryotic organism that is not an animal, plant, or fungus. Protists do not form a natural group, or clade, but an artificial grouping of several independent clades that evolved from the last eukaryotic common ancestor.
Protists were historically regarded as a separate taxonomic kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroups, such as Archaeplastida (which includes plants), SAR, Obazoa (which includes fungi and animals), Amoebozoa and Excavata.
Protists represent an extremely large genetic and ecological diversity in all environments, including extreme habitats. Their diversity, larger than for all other eukaryotes, has only been discovered in recent decades through the study of environmental DNA, and is still in the process of being fully described. They are present in all ecosystems as important components of the biogeochemical cycles and trophic webs. They exist abundantly and ubiquitously in a variety of forms that evolved multiple times independently, such as free-living algae, amoebae and slime moulds, or as important parasites. Together, they compose an amount of biomass that doubles that of animals. They exhibit varied types of nutrition (such as phototrophy, phagotrophy or osmotrophy), sometimes combining them (in mixotrophy). They present unique adaptations not present in multicellular animals, fungi or land plants. The study of protists is termed protistology.
Definition
There is not a single accepted definition of what protists are. As a paraphyletic assemblage of diverse biological groups, they have historically been regarded as a catch-all taxon that includes any eukaryotic organism (i.e., living beings whose cells possess a nucleus) that is not an animal, a land plant or a dikaryon fung
Document 2:::
Ultrastructural identity is a concept in biology. It asserts that evolutionary lineages of eukaryotes in general and protists in particular can be distinguished by complements and arrangements of cellular organelles. These ultrastructural components can be visualized by electron microscopy.
The concept emerged following the application of electron microscopy to protists.
Protists
Early ultrastructural studies revealed that many previously accepted groupings of protists based on optical microscopy included organisms with differing cellular organelles. Those groups included amoebae, flagellates, heliozoa, radiolaria, sporozoa, slime molds, and chromophytic algae. They were deemed likely to be polyphyletic, and their inclusion in efforts to assemble a phylogenetic tree would cause confusion. As an example of this work, German cell biologist Christian Bardele established unexpected diversity with the simply organized heliozoa. His work made it evident that heliozoa were not monophyletic and subsequent studies revealed that the heliozoa was composed of seven types of organisms: actinophryids, centrohelids, ciliophryids, desmothoracids, dimporphids, gymnosphaerids and taxopodids.
A critical advance was made by British phycologist David Hibberd. He demonstrated that two types of chromophytic algae, previously presumed to be closely related, had different organizations that were revealed by electron microscopy. The number and organization of locomotor organelles differed (chrysophyte - two flagella; haptophyte - two flagella and haponema), the surfaces of which differed (chrysophyte - with tripartite flagellar hairs now regarded as apomorphic for stramenopiles; haptophyte - naked), as did the transitional zone between axoneme and basal body (chrysophyte with helix); as did flagellar anchorage systems; presence or absence of embellishments on the cell surface (chrysophyte - naked; haptophyte - with scales), plastids especially eyespot, location and functions of dictyosom
Document 3:::
A protist is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor, the last eukaryotic common ancestor, the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like algae, invertebrates and protozoans, the grouping is used for convenience.
Many protists have neither hard parts nor resistant spores, and their fossils are extremely rare or unknown. Examples of such groups include the apicomplexans, most ciliates, some green algae (the Klebsormidiales), choanoflagellates, oomycetes, brown algae, yellow-green algae, Excavata (e.g., euglenids). Some of these have been found preserved in amber (fossilized tree resin) or under unusual conditions (e.g., Paleoleishmania, a kinetoplastid).
Others are relatively common in the fossil record, as the diatoms, golden algae, haptophytes (coccoliths), silicoflagellates, tintinnids (ciliates), dinoflagellates, green algae, red algae, heliozoans, radiolarians, foraminiferans, ebriids and testate amoebae (euglyphids, arcellaceans). Some are used as paleoecological indicators to reconstruct ancient environments.
More probable eukaryote fossils begin to appear at about 1.8 billion years ago, the acritarchs, spherical fossils of likely algal protists. Another possible representative of early fossil eukaryotes are the Gabonionta.
Modern classifications
Systematists today do not treat Protista as a formal taxon, but the term "protist" is still commonly used for convenience in two ways. The most popular contemporary definition is a phylogenetic one, that identifies a paraphyletic group: a protist is any eukaryote that is not an animal, (land) plant, or (true) fungus; this definition excludes many unicellular groups, like the Microsporidia (fungi), many C
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Currently, the addition of many lineages of newly discovered protists (such as Telonemia, Picozoa, Hemimastigophora, Rigifilida...) and the use of phylogenomic analyses have brought a new, more accurate supergroup model. These are the current supergroups of eukaryotes:
TSAR, constituted by Telonemia and the SAR clade (Stramenopiles, Alveolata and Rhizaria). It is estimated to occupy up to half of all eukaryotic diversity, since it includes multiple major groups such as diatoms, dinoflagellates, seaweeds, ciliates, foraminiferans, radiolarians, and the apicomplexan and oomycete parasites. It essentially contains the majority of "Chromalveolata".
Haptista (also treated as a phylum), previously in "Chromalveolata", comprising the haptophyte algae and centrohelids.
Cryptista (also treated as a phylum), previously in "Chromalveolata", comprising the cryptomonads, katablepharids and the enigmatic Palpitomonas.
Archaeplastida (also treated as a kingdom), con
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are a group of protists whose monophyly is well supported by molecular systematics?
A. mycetozoa
B. sporozoans
C. euglenozoa
D. alveolates
Answer:
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|
sciq-1445
|
multiple_choice
|
What system carries messages from sense organs and internal organs to the central nervous system?
|
[
"respiratory system",
"sensitive nervous system",
"auxiliary nervous system",
"peripheral nervous system"
] |
D
|
Relavent Documents:
Document 0:::
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
Document 1:::
The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways, and parts of the brain involved in sensory perception and interoception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, balance and visceral sensation. Sense organs are transducers that convert data from the outer physical world to the realm of the mind where people interpret the information, creating their perception of the world around them.
The receptive field is the area of the body or environment to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field. Receptive fields have been identified for the visual system, auditory system and somatosensory system.
Stimulus
Organisms need information to solve at least three kinds of problems: (a) to maintain an appropriate environment, i.e., homeostasis; (b) to time activities (e.g., seasonal changes in behavior) or synchronize activities with those of conspecifics; and (c) to locate and respond to resources or threats (e.g., by moving towards resources or evading or attacking threats). Organisms also need to transmit information in order to influence another's behavior: to identify themselves, warn conspecifics of danger, coordinate activities, or deceive.
Sensory systems code for four aspects of a stimulus; type (modality), intensity, location, and duration. Arrival time of a sound pulse and phase differences of continuous sound are used for sound localization. Certain receptors are sensitive to certain types of stimuli (for example, different mechanoreceptors respond best to different kinds of touch stimuli, like sharp or blunt objects). Receptors send impulses in certain patterns to send information about the intensity of a stimul
Document 2:::
Cutaneous innervation refers to an area of the skin which is supplied by a specific cutaneous nerve.
Dermatomes are similar; however, a dermatome only specifies the area served by a spinal nerve. In some cases, the dermatome is less specific (when a spinal nerve is the source for more than one cutaneous nerve), and in other cases it is more specific (when a cutaneous nerve is derived from multiple spinal nerves.)
Modern texts are in agreement about which areas of the skin are served by which nerves, but there are minor variations in some of the details. The borders designated by the diagrams in the 1918 edition of Gray's Anatomy are similar, but not identical, to those generally accepted today.
Importance of the peripheral nervous system
The peripheral nervous system (PNS) is divided into the somatic nervous system, the autonomic nervous system, and the enteric nervous system. However, it is the somatic nervous system, responsible for body movement and the reception of external stimuli, which allows one to understand how cutaneous innervation is made possible by the action of specific sensory fibers located on the skin, as well as the distinct pathways they take to the central nervous system. The skin, which is part of the integumentary system, plays an important role in the somatic nervous system because it contains a range of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury.
Importance of the central nervous system
The central nervous system (CNS) works with the peripheral nervous system in cutaneous innervation. The CNS is responsible for processing the information it receives from the cutaneous nerves that detect a given stimulus, and then identifying the kind of sensory inputs which project to a specific region of the primary somatosensory cortex.
The role of nerve endings on the surface of the skin
Groups of nerve terminals located in the different layers of the skin are categorized depending on whether the skin
Document 3:::
Body reactivity is usually understood as the body's ability to react in a proper way to influence the environment. Resistance of an organism is its stability under the influence of pathogenic factors. The body reactivity can range from homeostasis to a fight or flight response. Ultimately, they are all governed by the nervous system.
Nervous system divisions
The central nervous system (CNS) consists of parts that are encased by the bones of the skull and spinal column: the brain and spinal cord. The peripheral nervous system (PNS) is found outside those bones and consists of the nerves and most of the sensory organs.
Central nervous system
The CNS can be divided into the brain and spinal cord. The CNS processes many different kinds of incoming sensory information. It is also the source of thoughts, emotions, and memories. Most signals that stimulate muscles to contract and glands to secrete originate in the CNS. The spinal cord and spinal nerves contribute to homeostasis by providing quick reflexive responses to many stimuli. The spinal cord is the pathway for sensory input to the brain and motor output from the brain. The brain is responsible for integrating most sensory information and coordinating body function, both consciously and unconsciously.
Peripheral nervous system
The PNS can be divided into the autonomic and somatic nervous system. The autonomic nervous system can be divided into the parasympathetic, sympathetic, and enteric nervous system. The sympathetic nervous system regulates the “fight or flight” responses. The parasympathetic nervous system regulates the “rest and digest” responses. The enteric nervous system innervates the viscera (gastrointestinal tract, pancreas, and gall bladder). The somatic nervous system consists of peripheral nerve fibers that send sensory information to the central nervous system and motor nerve fibers that project to skeletal muscle. The somatic nervous system engages in voluntary reactions, and the autonomic nervous
Document 4:::
In anatomy and zoology, the cortex (: cortices) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices.
Etymology
The word is of Latin origin and means bark, rind, shell or husk.
Notable examples
The renal cortex, between the renal capsule and the renal medulla; assists in ultrafiltration
The adrenal cortex, situated along the perimeter of the adrenal gland; mediates the stress response through the production of various hormones
The thymic cortex, mainly composed of lymphocytes; functions as a site for somatic recombination of T cell receptors, and positive selection
The cerebral cortex, the outer layer of the cerebrum, plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness.
Cortical bone is the hard outer layer of bone; distinct from the spongy, inner cancellous bone tissue
Ovarian cortex is the outer layer of the ovary and contains the follicles.
The lymph node cortex is the outer layer of the lymph node.
Cerebral cortex
The cerebral cortex is typically described as comprising three parts: the sensory, motor, and association areas. These sensory areas receive and process information from the senses. The senses of vision, audition, and touch are served by the primary visual cortex, the primary auditory cortex, and primary somatosensory cortex. The cerebellar cortex is the thin gray surface layer of the cerebellum, consisting of an outer molecular layer or stratum moleculare, a single layer of Purkinje cells (the ganglionic layer), and an inner granular layer or stratum granulosum. The cortex is the outer surface of the cerebrum and is composed of gray matter.
The motor areas are located in both hemispheres of the cerebral cortex. Two areas of the cortex are commonly referred to as motor: the primary motor cortex, which executes v
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What system carries messages from sense organs and internal organs to the central nervous system?
A. respiratory system
B. sensitive nervous system
C. auxiliary nervous system
D. peripheral nervous system
Answer:
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scienceQA-10039
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multiple_choice
|
Select the fish.
|
[
"horned frog",
"cassowary",
"Amazon tree boa",
"tiger shark"
] |
D
|
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 cassowary is a bird. It has feathers, two wings, and a beak.
Cassowaries have wings, but they cannot fly! They can run very fast.
A horned frog is an amphibian. It has moist skin and begins its life in water.
Frogs live near water or in damp places. Most frogs lay their eggs in water.
A tiger shark is a fish. It lives underwater. It has fins, not limbs.
Tiger sharks are nocturnal. This means that they are active mostly at night.
|
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:::
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. As of 2022, 2.16 million living animal species have been described—of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are around 7.77 million animal species. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and the chordates, the latter including the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on ad
Document 3:::
A fish (: fish or fishes) is an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. Fish can acoustically communicate with each other, most often in the context of feeding, aggression or courtship.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., cusk-eels and snailfish), although no species has yet been documented in the deepest 25% of the ocean. With 34,300 described species, fish exhibit greater species diversity than any other group of vertebrates.
Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean (in aquaculture). They are also caught by recreational
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the fish.
A. horned frog
B. cassowary
C. Amazon tree boa
D. tiger shark
Answer:
|
sciq-351
|
multiple_choice
|
What material comprises the sun and other stars, as well as lightning and the northern lights?
|
[
"aurora",
"gas",
"gamma",
"plasma"
] |
D
|
Relavent Documents:
Document 0:::
The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM stops at the heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum, or consisting of "aether".
Composition and physical characteristics
The interplanetary medium includes interplanetary dust, cosmic rays, and hot plasma from the solar wind. The density of the interplanetary medium is very low, decreasing in inverse proportion to the square of the distance from the Sun. It is variable, and may be affected by magnetic fields and events such as coronal mass ejections. Typical particle densities in the interplanetary medium are about 5-40 particles/cm, but exhibit substantial variation. In the vicinity of the Earth, it contains about 5 particles/cm, but values as high as 100 particles/cm have been observed.
The temperature of the interplanetary medium varies through the solar system. Joseph Fourier estimated that interplanetary medium must have temperatures comparable to those observed at Earth's poles, but on faulty grounds: lacking modern estimates of atmospheric heat transport, he saw no other means to explain the relative consistency of earth's climate. A very hot interplanetary medium remained a minor position among geophysicists as late as 1959, when Chapman proposed a temperature on the order of 10000 K, but observation in Low Earth orbit of the exosphere soon contradicted his position. In fact, both Fourier and Chapman's final predictions were correct: because the interplanetary medium is so rarefied, it does not exhibit thermodynamic equilibrium. Instead, different components have different temperatures. The solar wind exhibits temperatures consistent with Chapman's estimate in cislunar space, and dust particles near Earth's
Document 1:::
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,
Document 2:::
K-type main-sequence stars, also known as orange dwarfs, may be candidates for supporting extraterrestrial life. These stars are known as "Goldilocks stars" as they emit enough radiation in the non-UV ray spectrum to provide a temperature that allows liquid water to exist on the surface of a planet; they also remain stable in the main sequence longer than the Sun by burning their hydrogen slower, allowing more time for life to form on a planet around a K-type main-sequence star. The planet's habitable zone, ranging from 0.1–0.4 to 0.3–1.3 astronomical units (AU), depending on the size of the star, is often far enough from the star so as not to be tidally locked to the star, and to have a sufficiently low solar flare activity not to be lethal to life. In comparison, red dwarf stars have too much solar activity and quickly tidally lock the planets in their habitable zones, making them less suitable for life. The odds of complex life arising may be better on planets around K-type main-sequence stars than around Sun-like stars, given the suitable temperature and extra time available for it to evolve. Some planets around K-type main-sequence stars are potential candidates for extraterrestrial life.
Habitable zone
A K-type star's habitable zone approximately ranges between 0.1–0.4 to 0.3–1.3 AU from the star. Here, exoplanets will receive only a relatively small amount of ultraviolet radiation, especially so towards the outer edge. This is favorable to support life, as it means that there is enough radiated energy to allow liquid water to exist on the surface, but not so much, especially ionizing radiation, as to destroy life.
The habitable zone is also very stable, lasting for most of the K-type main-sequence star's main sequence phase and with little instability of luminosity during that phase.
Potentially habitable planets
The super-Earth HD 40307 g around the K2.5V star HD 40307 orbits in the CHZ, although it has a reasonably elliptical orbit (e=0.22). There may
Document 3:::
Heliophysics (from the prefix "helio", from Attic Greek hḗlios, meaning Sun, and the noun "physics": the science of matter and energy and their interactions) is the physics of the Sun and its connection with the Solar System. NASA defines heliophysics as "(1) the comprehensive new term for the science of the Sun - Solar System Connection, (2) the exploration, discovery, and understanding of Earth's space environment, and (3) the system science that unites all of the linked phenomena in the region of the cosmos influenced by a star like our Sun."
Heliophysics concentrates on the Sun's effects on Earth and other bodies within the Solar System, as well as the changing conditions in space. It is primarily concerned with the magnetosphere, ionosphere, thermosphere, mesosphere, and upper atmosphere of the Earth and other planets. Heliophysics combines the science of the Sun, corona, heliosphere and geospace, and encompasses a wide variety of astronomical phenomena, including "cosmic rays and particle acceleration, space weather and radiation, dust and magnetic reconnection, nuclear energy generation and internal solar dynamics, solar activity and stellar magnetic fields, aeronomy and space plasmas, magnetic fields and global change", and the interactions of the Solar System with the Milky Way Galaxy.
Term “heliophysics” (Russian: “гелиофизика”) was widely used in Russian-language scientific literature. The Great Soviet Encyclopedia third edition (1969—1978) defines “Heliophysics” as “[…] a division of astrophysics that studies physics of the Sun". In 1990, the Higher Attestation Commission, responsible for the advanced academic degrees in Soviet Union and later in Russia and the Former Soviet Union, established a new specialty “Heliophysics and physics of solar system”. In English-language scientific literature prior to about 2002, the term heliophysics was sporadically used to describe the study of the "physics of the Sun". As such it was a direct translation from th
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What material comprises the sun and other stars, as well as lightning and the northern lights?
A. aurora
B. gas
C. gamma
D. plasma
Answer:
|
|
ai2_arc-561
|
multiple_choice
|
The structures found in a living cell can be compared to the parts of a factory that produces cars. Which part of the factory is most similar to the nucleus of a living cell?
|
[
"a conveyor belt that transports materials",
"a storage bin that holds the pieces needed to assemble a car",
"the computer room that controls the assembly process",
"the generator that provides energy for the factory"
] |
D
|
Relavent Documents:
Document 0:::
Cellular components are the complex biomolecules and structures of which cells, and thus living organisms, are composed. Cells are the structural and functional units of life. The smallest organisms are single cells, while the largest organisms are assemblages of trillions of cells. DNA, double stranded macromolecule that carries the hereditary information of the cell and found in all living cells; each cell carries chromosome(s) having a distinctive DNA sequence.
Examples include macromolecules such as proteins and nucleic acids, biomolecular complexes such as a ribosome, and structures such as membranes, and organelles. While the majority of cellular components are located within the cell itself, some may exist in extracellular areas of an organism.
Cellular components may also be called biological matter or biological material. Most biological matter has the characteristics of soft matter, being governed by relatively small energies. All known life is made of biological matter. To be differentiated from other theoretical or fictional life forms, such life may be called carbon-based, cellular, organic, biological, or even simply living – as some definitions of life exclude hypothetical types of biochemistry.
See also
Cell (biology)
Cell biology
Biomolecule
Organelle
Tissue (biology)
External links
https://web.archive.org/web/20130918033010/http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_cell3.htm
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The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane, and contains many macromolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites. The term comes from the Latin word meaning 'small room'.
Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell.
Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms.
The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology.
Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
Discovery
With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as i
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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
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The Michigan Life Sciences Corridor (MLSC) is a $1 billion biotechnology initiative in the U.S. state of Michigan.
The MLSC invests in biotech research at four Michigan institutions: the University of Michigan in Ann Arbor; Michigan State University in East Lansing; Wayne State University in Detroit; and the Van Andel Institute in Grand Rapids.
The Michigan Economic Development Corporation administers the program. It began in 1999 with money from the state's settlement with the tobacco industry. When the program's funds distributions are completed in 2019, the goal is that the investments in high tech research will have notably expanded the state's economic base.
History
In 1998, the State of Michigan, along with 45 other states, reached the $8.5 billion Tobacco Master Settlement Agreement, a settlement with the U.S. tobacco industry. Former Governor John Engler created the Michigan Life Sciences Corridor in 1999 when he signed Public Act 120 of 1999. The bill appropriated money from the state's settlement with the tobacco industry to fund biotech research at four of Michigan's largest research institutions.
Under the management of the Michigan Economic Development Corporation, the MLSC allocated $1 billion over the course of 20 years, including $50 million in 1999 to fund research on aging. The following year, the MLSC awarded $100 million to 63 Michigan universities. In 2002, Governor Jennifer Granholm incorporated the MLSC into the Michigan Technology Tri-Corridor, adding funding for homeland security and alternative fuel research.
In 2009, the University of Michigan added a 30-building, North Campus Research Complex by acquiring the former Pfizer pharmaceutical corporation facility.
A BioEnterprise Midwest Healthcare Venture report found that Michigan attracted $451.8 million in new biotechnology venture capital investments from 2005 to 2009.
See also
University Research Corridor
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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.
The structures found in a living cell can be compared to the parts of a factory that produces cars. Which part of the factory is most similar to the nucleus of a living cell?
A. a conveyor belt that transports materials
B. a storage bin that holds the pieces needed to assemble a car
C. the computer room that controls the assembly process
D. the generator that provides energy for the factory
Answer:
|
|
sciq-4389
|
multiple_choice
|
Crossing charges is one method for obtaining what?
|
[
"superscripts",
"subscripts",
"notations",
"hybrids"
] |
B
|
Relavent Documents:
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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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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
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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 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:::
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.
Crossing charges is one method for obtaining what?
A. superscripts
B. subscripts
C. notations
D. hybrids
Answer:
|
|
sciq-9651
|
multiple_choice
|
What is the most important factor in determining the type of soil that forms in a particular area?
|
[
"landscape",
"altitude",
"climate",
"migration"
] |
C
|
Relavent Documents:
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A soil type is a taxonomic unit in soil science. All soils that share a certain set of well-defined properties form a distinctive soil type. Soil type is a technical term of soil classification, the science that deals with the systematic categorization of soils. Every soil of the world belongs to a certain soil type. Soil type is an abstract term. In nature, you will not find soil types. You will find soils that belong to a certain soil type.
In hierarchical soil classification systems, soil types mostly belong to the higher or intermediate level. A soil type can normally be subdivided into subtypes, and in many systems several soil types can be combined to entities of higher category. However, in the first classification system of the United States (Whitney, 1909), the soil type was the lowest level and the mapping unit.
For the definition of soil types, some systems use primarily such characteristics that are the result of soil-forming processes (pedogenesis). An example is the German soil systematics. Other systems combine characteristics resulting from soil-forming processes and characteristics inherited from the parent material. Examples are the World Reference Base for Soil Resources (WRB) and the USDA soil taxonomy. Other systems do not ask whether the properties are the result of soil formation or not. An example is the Australian Soil Classification.
A convenient way to define a soil type is referring to soil horizons. However, this is not always possible because some very initial soils may not even have a clear development of horizons. For other soils, it may be more convenient to define the soil type just referring to some properties common to the whole soil profile. For example, WRB defines the Arenosols by their sand content. Many soils are more or less strongly influenced by human activities. This is reflected by the definition of many soil types in various classification systems.
Because soil type is a very general and widely used term, many soi
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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
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The Polish Soil Classification () is a soil classification system used to describe, classify and organize the knowledge about soils in Poland.
Overview
Presented below the 5th edition of Polish Soil Classification was published by Soil Science Society of Poland in 2011 and was in use to 2019 when 6th edition of Polish Soil Classification was published. Previous ones were published in 1956, 1959, 1974 and 1989, and they, following Dokuchaiev's ideas, were relied mostly on the natural's criteria (quality) like soil forming processes and soil morphological features (4th edition was transient because diagnostic soil horizons appeared there). 5th edition of classification, where it was possible, was built on quantitative criteria, like quantitative described diagnostic horizons, diagnostic materials and diagnostic properties. Soil forming processes are not a part of classification but the relationship between the processes and their morphological effects was taken into account during creating differentiating criteria of diagnostic horizons, materials and properties. The classification derives much of international systems: USDA soil taxonomy (1999) and World Reference Base for Soil Resources - WRB (2006).
Polish soil science intellectual tradition has always maintained a balance between genetical-geographic approach (typical for the Russian scientific school) and substantional-geological-petrographic approach (characteristic for Western Europe). Multilateral look at the soil manifested, in all editions of classification, that each soil was described by three types of characteristics:
Genetical genesis described by type of soil – based on diagnostic horizons, materials and properties,
Geological origin of bedrock described by what might be literally translated as "kind" or "sort" of soil,
Soil texture described of what might be literally translated as "class" or "species" of soil.
The Polish Soil Classification has a hierarchical construction. Type of soil is
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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
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Soil classification deals with the systematic categorization of soils based on distinguishing characteristics as well as criteria that dictate choices in use.
Overview
Soil classification is a dynamic subject, from the structure of the system, to the definitions of classes, to the application in the field. Soil classification can be approached from the perspective of soil as a material and soil as a resource.
Inscriptions at the temple of Horus at Edfu outline a soil classification used by Tanen to determine what kind of temple to build at which site. Ancient Greek scholars produced a number of classification based on several different qualities of the soil.
Engineering
Geotechnical engineers classify soils according to their engineering properties as they relate to use for foundation support or building material. Modern engineering classification systems are designed to allow an easy transition from field observations to basic predictions of soil engineering properties and behaviors.
The most common engineering classification system for soils in North America is the Unified Soil Classification System (USCS). The USCS has three major classification groups: (1) coarse-grained soils (e.g. sands and gravels); (2) fine-grained soils (e.g. silts and clays); and (3) highly organic soils (referred to as "peat"). The USCS further subdivides the three major soil classes for clarification. It distinguishes sands from gravels by grain size, classifying some as "well-graded" and the rest as "poorly-graded". Silts and clays are distinguished by the soils' Atterberg limits, and thus the soils are separated into "high-plasticity" and "low-plasticity" soils. Moderately organic soils are considered subdivisions of silts and clays and are distinguished from inorganic soils by changes in their plasticity properties (and Atterberg limits) on drying. The European soil classification system (ISO 14688) is very similar, differing primarily in coding and in adding an "intermediate-p
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the most important factor in determining the type of soil that forms in a particular area?
A. landscape
B. altitude
C. climate
D. migration
Answer:
|
|
sciq-6326
|
multiple_choice
|
The force exerted by a diving board is conservative, provided the internal friction is this?
|
[
"significant",
"static",
"negligible",
"intrinsic"
] |
C
|
Relavent Documents:
Document 0:::
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.
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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 2:::
In physics, a conservative force is a force with the property that the total work done in moving a particle between two points is independent of the path taken. Equivalently, if a particle travels in a closed loop, the total work done (the sum of the force acting along the path multiplied by the displacement) by a conservative force is zero.
A conservative force depends only on the position of the object. If a force is conservative, it is possible to assign a numerical value for the potential at any point and conversely, when an object moves from one location to another, the force changes the potential energy of the object by an amount that does not depend on the path taken, contributing to the mechanical energy and the overall conservation of energy. If the force is not conservative, then defining a scalar potential is not possible, because taking different paths would lead to conflicting potential differences between the start and end points.
Gravitational force is an example of a conservative force, while frictional force is an example of a non-conservative force.
Other examples of conservative forces are: force in elastic spring, electrostatic force between two electric charges, and magnetic force between two magnetic poles. The last two forces are called central forces as they act along the line joining the centres of two charged/magnetized bodies. A central force is conservative if and only if it is spherically symmetric.
Informal definition
Informally, a conservative force can be thought of as a force that conserves mechanical energy. Suppose a particle starts at point A, and there is a force F acting on it. Then the particle is moved around by other forces, and eventually ends up at A again. Though the particle may still be moving, at that instant when it passes point A again, it has traveled a closed path. If the net work done by F at this point is 0, then F passes the closed path test. Any force that passes the closed path test for all possible close
Document 3:::
Surface force denoted fs is the force that acts across an internal or external surface element in a material body.
Normal forces and shear forces between objects are types of surface force. All cohesive forces and contact forces between objects are considered as surface forces.
Surface force can be decomposed into two perpendicular components: normal forces and shear forces. A normal force acts normally over an area and a shear force acts tangentially over an area.
Equations for surface force
Surface force due to pressure
, where f = force, p = pressure, and A = area on which a uniform pressure acts
Examples
Pressure related surface force
Since pressure is , and area is a ,
a pressure of over an area of will produce a surface force of .
See also
Body force
Contact force
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The force exerted by a diving board is conservative, provided the internal friction is this?
A. significant
B. static
C. negligible
D. intrinsic
Answer:
|
|
sciq-2754
|
multiple_choice
|
What is the name of the order that salamanders belong to?
|
[
"oronthalic",
"aneuploid",
"platyhelminth",
"urodela"
] |
D
|
Relavent Documents:
Document 0:::
Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families.
What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely.
The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consistent naming schemes. Orders of plants, fungi, and algae use the suffix (e.g. Dictyotales). Orders of birds and fishes use the Latin suffix meaning 'having the form of' (e.g. Passeriformes), but orders of mammals and invertebrates are not so consistent (e.g. Artiodactyla, Actiniaria, Primates).
Hierarchy of ranks
Zoology
For some clades covered by the International Code of Zoological Nomenclature, several additional classifications are sometimes used, although not all of these are officially recognized.
In their 1997 classification of mammals, McKenna and Bell used two extra levels between superorder and order: grandorder and mirorder. Michael Novacek (1986) inserted them at the same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others.
Botany
In botany, the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ran
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There are several taxons named amphibia. These include:
Amphibia (class), classis Amphibia, the amphibians
Species
Species with the specific epithet 'amphibia'
Rorippa amphibia (R. amphibia), a plant
Persicaria amphibia (P. amphibia), a plant
Neritina amphibia (N. amphibia), a snail
Aranea amphibia (A. amphibia), a spider
See also
Amphibian (disambiguation)
Amphibia (disambiguation)
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Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. As of 2022, 2.16 million living animal species have been described—of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are around 7.77 million animal species. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and the chordates, the latter including the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on ad
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In biology, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system of biological classification (taxonomy) consists of species, genus, family, order, class, phylum, kingdom, and domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics.
A given rank subsumes less general categories under it, that is, more specific descriptions of life forms. Above it, each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of traits or features from common ancestors. The rank of any species and the description of its genus is basic; which means that to identify a particular organism, it is usually not necessary to specify ranks other than these first two.
Consider a particular species, the red fox, Vulpes vulpes: the specific name or specific epithet vulpes (small v) identifies a particular species in the genus Vulpes (capital V) which comprises all the "true" foxes. Their close relatives are all in the family Canidae, which includes dogs, wolves, jackals, and all foxes; the next higher major rank, the order Carnivora, includes caniforms (bears, seals, weasels, skunks, raccoons and all those mentioned above), and feliforms (cats, civets, hyenas, mongooses). Carnivorans are one group of the hairy, warm-blooded, nursing members of the class Mammalia, which are classified among animals with backbones in the phylum Chordata, and with them among all animals in the kingdom Animalia. Finally, at the highest rank all of these are grouped together with all other organisms possessing cell nuclei in the domain Eukarya.
The International Code of Zoological Nomenclature defines rank as: "The level, for nomenclatural purposes, of a taxon in a taxonomic hierarchy (
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Molluscs
Ancylus fluviatilis
Aylacostoma species
Lymnaea ovata
Amphibians
Neurergus strauchii, a newt from Turkey
Pach
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the name of the order that salamanders belong to?
A. oronthalic
B. aneuploid
C. platyhelminth
D. urodela
Answer:
|
|
sciq-11327
|
multiple_choice
|
The term ion applies to entire molecules that are?
|
[
"electrically charged",
"positively charged protons",
"neutrally charged",
"magnetic"
] |
A
|
Relavent Documents:
Document 0:::
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons.
A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds.
Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.
History of discovery
The word ion was coined from Greek neuter present participle of ienai (), meaning "to go". A cation is something that moves down ( pronounced kato, meaning "down") and an anion is something that moves up (, meaning "up"). They are so called because ions move toward the electrode of opposite charge. This term was introduced (after a suggestion by the English polymath William Whewell) by English physicist and chemist Michael Faraday in 1834 for the then-unknown species that goes from one electrode to the other through an aqueous medium. Faraday did not know the nature of these species, but he knew that since metals dissolved into and entered a solution at one electrode and new metal came forth from a solution at the other electrode; that some kind of
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In physics, a charged particle is a particle with an electric charge. It may be an ion, such as a molecule or atom with a surplus or deficit of electrons relative to protons. It can also be an electron or a proton, or another elementary particle, which are all believed to have the same charge (except antimatter). Another charged particle may be an atomic nucleus devoid of electrons, such as an alpha particle.
A plasma is a collection of charged particles, atomic nuclei and separated electrons, but can also be a gas containing a significant proportion of charged particles.
Charged particles are labeled as either positive (+) or negative (-). Only the existence of two "types" of charges are known, and the designations themselves are arbitrarily named. Nothing is inherent to a positively charged particle that makes it "positive", and the same goes for negatively charged particles.
Examples
Positively charged particles
protons and atomic nuclei
positrons (antielectrons)
alpha particles
positive charged pions
cations
Negatively charged particles
electrons
antiprotons
muons
tauons
negative charged pions
anions
Particles without an electric charge
neutrons
photons
neutrinos
neutral pions
z boson
higgs boson
atoms
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In physics, a charge carrier is a particle or quasiparticle that is free to move, carrying an electric charge, especially the particles that carry electric charges in electrical conductors. Examples are electrons, ions and holes. The term is used most commonly in solid state physics. In a conducting medium, an electric field can exert force on these free particles, causing a net motion of the particles through the medium; this is what constitutes an electric current.
The electron and the proton are the elementary charge carriers, each carrying one elementary charge (e), of the same magnitude and opposite sign.
In conductors
In conducting media, particles serve to carry charge:
In many metals, the charge carriers are electrons. One or two of the valence electrons from each atom are able to move about freely within the crystal structure of the metal. The free electrons are referred to as conduction electrons, and the cloud of free electrons is called a Fermi gas. Many metals have electron and hole bands. In some, the majority carriers are holes.
In electrolytes, such as salt water, the charge carriers are ions, which are atoms or molecules that have gained or lost electrons so they are electrically charged. Atoms that have gained electrons so they are negatively charged are called anions, atoms that have lost electrons so they are positively charged are called cations. Cations and anions of the dissociated liquid also serve as charge carriers in melted ionic solids (see e.g. the Hall–Héroult process for an example of electrolysis of a melted ionic solid). Proton conductors are electrolytic conductors employing positive hydrogen ions as carriers.
In a plasma, an electrically charged gas which is found in electric arcs through air, neon signs, and the sun and stars, the electrons and cations of ionized gas act as charge carriers.
In a vacuum, free electrons can act as charge carriers. In the electronic component known as the vacuum tube (also called valve), the mobil
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In physics and chemistry, ionization energy (IE) (American English spelling), ionisation energy (British English spelling) is the minimum energy required to remove the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule. The first ionization energy is quantitatively expressed as
X(g) + energy ⟶ X+(g) + e−
where X is any atom or molecule, X+ is the resultant ion when the original atom was stripped of a single electron, and e− is the removed electron. Ionization energy is positive for neutral atoms, meaning that the ionization is an endothermic process. Roughly speaking, the closer the outermost electrons are to the nucleus of the atom, the higher the atom's ionization energy.
In physics, ionization energy is usually expressed in electronvolts (eV) or joules (J). In chemistry, it is expressed as the energy to ionize a mole of atoms or molecules, usually as kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol).
Comparison of ionization energies of atoms in the periodic table reveals two periodic trends which follow the rules of Coulombic attraction:
Ionization energy generally increases from left to right within a given period (that is, row).
Ionization energy generally decreases from top to bottom in a given group (that is, column).
The latter trend results from the outer electron shell being progressively farther from the nucleus, with the addition of one inner shell per row as one moves down the column.
The nth ionization energy refers to the amount of energy required to remove the most loosely bound electron from the species having a positive charge of (n − 1). For example, the first three ionization energies are defined as follows:
1st ionization energy is the energy that enables the reaction X ⟶ X+ + e−
2nd ionization energy is the energy that enables the reaction X+ ⟶ X2+ + e−
3rd ionization energy is the energy that enables the reaction X2+ ⟶ X3+ + e−
The most notable influences that determine ionization ener
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The protonosphere is a layer of the Earth's atmosphere (or any planet with a similar atmosphere) where the dominant components are atomic hydrogen and ionic hydrogen (protons). It is the outer part of the ionosphere, and extends to the interplanetary medium. Hydrogen dominates in the outermost layers because it is the lightest gas, and in the heterosphere, mixing is not strong enough to overcome differences in constituent gas densities. Charged particles are created by incoming ionizing radiation, mostly from solar radiation.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The term ion applies to entire molecules that are?
A. electrically charged
B. positively charged protons
C. neutrally charged
D. magnetic
Answer:
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|
sciq-3645
|
multiple_choice
|
What layer of soil, essential for farming, has the highest proportion of organic material?
|
[
"humus",
"bedrock",
"topsoil",
"subsoil"
] |
C
|
Relavent Documents:
Document 0:::
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
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Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.
Description
Topsoil is composed of mineral particles and organic matter and usually extends to a depth of 5-10 inches (13–25 cm). Together these make a substrate capable of holding water and air which encourages biological activity.
There are generally a high concentration of roots in topsoil since this is where plants obtain most of their vital nutrients. It also plays host to significant bacterial, fungal and entomological activity without which soil quality would degrade and become less suitable for plants. Bacteria and fungi can be essential in facilitating nutrient exchange with plants and in breaking down organic matter into a form that roots can absorb. Insects also play important roles in breaking down material and aerating and rotating the soil. Many species directly contribute to the health of the soil resulting in stronger plants. A healthy topsoil layer is a very rich microbiome that hosts a wide array of species.
Organic matter provides nutrition for living organisms and varies in quantity between different soils with the strength of the soil structure decreasing when more is present. It condenses and settles over time in different ways depending upon conditions such as beneath roadbeds and foundations vs uncovered and exposed to the elements. The structure becomes affected once the soil is dehydrated. Dehydrated topsoil volume substantially decreases and may suffer wind erosion.
Production
Topsoil is naturally produced in the process of soil formation or pedogenesis. Natural topsoil is mined and conditioned for human use and makes up the bulk of commercial topsoil available. The current rate of use and erosion outpaces soil generation.
It is possible to create artificial topsoil which supports some of the engineering or biological uses of topsoil. More traditional examples of
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Bulk soil is soil outside the rhizosphere that is not penetrated by plant roots. The bulk soil is like an ecosystem, it is made up of many things such as: nutrients, ions, soil particles, and root exudates. There are many different interactions that occur between all the members of the bulk soil. Natural organic compounds are much lower in bulk soil than in the rhizosphere. Furthermore, bulk soil inhabitants are generally smaller than identical species in the rhizosphere. The main two aspects of bulk soil are its chemistry and microbial community composition.
Chemistry of bulk soil
Soil is made up of layers called soil horizons, these make up a vertical soil profile. There are five master horizons O, A, E, B, and C. The O horizon contains organic matter, A is considered the topsoil, E is present or absent depending on the type of soil and conditions, B is the subsoil, and C is unconsolidated rock. There are many chemical interactions and properties that are in all the soil. Chemical properties of the bulk soil are organic matter, carbon, nutrient content, cation-exchange capacity (CEC), free ions (cations or anions), pH, and base saturation and organisms. These can impact many chemical processes such as nutrient cycling, soil formation, biological activity, and erosion.
Microbial communities
Soil is composed of a diverse community of microbes such as: fungi, bacteria, archaea, viruses and microfauna. There are microbes in the bulk soil and the rhizosphere, the variation of microbes increases in the bulk soil and the abundance of microbes increases in the rhizosphere. Some microbes can form symbioses with plants that are beneficial or pathogenic. All these microbes have a special role in many soil processes such as soil formation, organic matter decomposition, nutrient cycling. For example, there are microbes in the rhizosphere (on the plant) that can break down nitrogen, and microbes out in the bulk can break down nitrogen as well. Both have different factors
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Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality. It also refers to the soil's ability to supply plant/crop nutrients in the right quantities and qualities over a sustained period of time. A fertile soil has the following properties:
The ability to supply essential plant nutrients and water in adequate amounts and proportions for plant growth and reproduction; and
The absence of toxic substances which may inhibit plant growth e.g Fe2+ which leads to nutrient toxicity.
The following properties contribute to soil fertility in most situations:
Sufficient soil depth for adequate root growth and water retention;
Good internal drainage, allowing sufficient aeration for optimal root growth (although some plants, such as rice, tolerate waterlogging);
Topsoil or horizon O is with sufficient soil organic matter for healthy soil structure and soil moisture retention;
Soil pH in the range 5.5 to 7.0 (suitable for most plants but some prefer or tolerate more acid or alkaline conditions);
Adequate concentrations of essential plant nutrients in plant-available forms;
Presence of a range of microorganisms that support plant growth.
In lands used for agriculture and other human activities, maintenance of soil fertility typically requires the use of soil conservation practices. This is because soil erosion and other forms of soil degradation generally result in a decline in quality with respect to one or more of the aspects indicated above.
Soil fertilization
Bioavailable phosphorus (available to soil life) is the element in soil that is most often lacking. Nitrogen and potassium are also needed in substantial amounts. For this reason these three elements are always identified on a commercial fertilizer analysis. For example, a 10-10-15 fertilizer has 10 percent nitrogen, 10 percent available phosphorus (P2O5) and 15 percent water-soluble potassiu
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What layer of soil, essential for farming, has the highest proportion of organic material?
A. humus
B. bedrock
C. topsoil
D. subsoil
Answer:
|
|
sciq-10803
|
multiple_choice
|
Does an increase in temperature speed up or slow down reactions?
|
[
"speed up",
"end reaction",
"slow down",
"remain the same"
] |
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:::
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:::
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:::
Activation energy asymptotics (AEA), also known as large activation energy asymptotics, is an asymptotic analysis used in the combustion field utilizing the fact that the reaction rate is extremely sensitive to temperature changes due to the large activation energy of the chemical reaction.
History
The techniques were pioneered by the Russian scientists Yakov Borisovich Zel'dovich, David A. Frank-Kamenetskii and co-workers in the 30s, in their study on premixed flames and thermal explosions (Frank-Kamenetskii theory), but not popular to western scientists until the 70s. In the early 70s, due to the pioneering work of Williams B. Bush, Francis E. Fendell, Forman A. Williams, Amable Liñán and John F. Clarke, it became popular in western community and since then it was widely used to explain more complicated problems in combustion.
Method overview
In combustion processes, the reaction rate is dependent on temperature in the following form (Arrhenius law),
where is the activation energy, and is the universal gas constant. In general, the condition is satisfied, where is the burnt gas temperature. This condition forms the basis for activation energy asymptotics. Denoting for unburnt gas temperature, one can define the Zel'dovich number and heat release parameter as follows
In addition, if we define a non-dimensional temperature
such that approaching zero in the unburnt region and approaching unity in the burnt gas region (in other words, ), then the ratio of reaction rate at any temperature to reaction rate at burnt gas temperature is given by
Now in the limit of (large activation energy) with , the reaction rate is exponentially small i.e., and negligible everywhere, but non-negligible when . In other words, the reaction rate is negligible everywhere, except in a small region very close to burnt gas temperature, where . Thus, in solving the conservation equations, one identifies two different regimes, at leading order,
Outer convective-diffusive zone
I
Document 4:::
The Hatta number (Ha) was developed by Shirôji Hatta, who taught at Tohoku University. It is a dimensionless parameter that compares the rate of reaction in a liquid film to the rate of diffusion through the film. For a second order reaction (), the maximum rate of reaction assumes that the liquid film is saturated with gas at the interfacial concentration ; thus, the maximum rate of reaction is .
For a reaction order in and order in :
It is an important parameter used in Chemical Reaction Engineering.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Does an increase in temperature speed up or slow down reactions?
A. speed up
B. end reaction
C. slow down
D. remain the same
Answer:
|
|
sciq-6385
|
multiple_choice
|
What property of food is determined by burning the food and measuring the heat released?
|
[
"additives",
"nutrients",
"calories",
"acidity"
] |
C
|
Relavent Documents:
Document 0:::
Food science is the basic science and applied science of food; its scope starts at overlap with agricultural science and nutritional science and leads through the scientific aspects of food safety and food processing, informing the development of food technology.
Food science brings together multiple scientific disciplines. It incorporates concepts from fields such as chemistry, physics, physiology, microbiology, and biochemistry. Food technology incorporates concepts from chemical engineering, for example.
Activities of food scientists include the development of new food products, design of processes to produce these foods, choice of packaging materials, shelf-life studies, sensory evaluation of products using survey panels or potential consumers, as well as microbiological and chemical testing. Food scientists may study more fundamental phenomena that are directly linked to the production of food products and its properties.
Definition
The Institute of Food Technologists defines food science as "the discipline in which the engineering, biological, and physical sciences are used to study the nature of foods, the causes of deterioration, the principles underlying food processing, and the improvement of foods for the consuming public". The textbook Food Science defines food science in simpler terms as "the application of basic sciences and engineering to study the physical, chemical, and biochemical nature of foods and the principles of food processing".
Disciplines
Some of the subdisciplines of food science are described below.
Food chemistry
Food chemistry is the study of chemical processes and interactions of all biological and non-biological components of foods. The biological substances include such items as meat, poultry, lettuce, beer, and milk.
It is similar to biochemistry in its main components such as carbohydrates, lipids, and protein, but it also includes areas such as water, vitamins, minerals, enzymes, food additives, flavors, and colors. This
Document 1:::
Food physical chemistry is considered to be a branch of Food chemistry concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods."
Food physical chemistry concepts are often drawn from rheology, theories of transport phenomena, physical and chemical thermodynamics, chemical bonds and interaction forces, quantum mechanics and reaction kinetics, biopolymer science, colloidal interactions, nucleation, glass transitions, and freezing, disordered/noncrystalline solids.
Techniques utilized range widely from dynamic rheometry, optical microscopy, electron microscopy, AFM, light scattering, X-ray diffraction/neutron diffraction, to MRI, spectroscopy (NMR, FT-NIR/IR, NIRS, ESR and EPR, CD/VCD, Fluorescence, FCS, HPLC, GC-MS, and other related analytical techniques.
Understanding food processes and the properties of foods requires a knowledge of physical chemistry and how it applies to specific foods and food processes. Food physical chemistry is essential for improving the quality of foods, their stability, and food product development. Because food science is a multi-disciplinary field, food physical chemistry is being developed through interactions with other areas of food chemistry and food science, such as food analytical chemistry, food process engineering/food processing, food and bioprocess technology, food extrusion, food quality control, food packaging, food biotechnology, and food microbiology.
Topics in Food physical chemistry
The following are examples of topics in food physical chemistry that are of interest to both the food industry and food science:
Water in foods
Local structure in liquid water
Micro-crystalliz
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Food additives are substances added to food to preserve flavor or enhance its taste, appearance, or other qualities.
Purposes
Additives are used for many purposes but the main uses are:
Acids Food acids are added to make flavors "sharper", and also act as preservatives and antioxidants. Common food acids include vinegar, citric acid, tartaric acid, malic acid, folic acid, fumaric acid, and lactic acid.
Acidity regulators Acidity regulators are used to change or otherwise control the acidity and alkalinity of foods.
Anticaking agents Anticaking agents keep powders such as milk powder from caking or sticking.
Antifoaming agents Antifoaming agents reduce or prevent foaming in foods.
Antioxidants Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food, and can be beneficial to health.
Bulking agents Bulking agents such as starch are additives that increase the bulk of a food without affecting its nutritional value.
Food coloring Colorings are added to food to replace colors lost during preparation, or to make food look more attractive.
Color retention agents In contrast to colorings, color retention agents are used to preserve a food's existing color.
Emulsifiers Emulsifiers allow water and oils to remain mixed together in an emulsion, as in mayonnaise, ice cream, and homogenized milk.
Flavors Flavors are additives that give food a particular taste or smell, and may be derived from natural ingredients or created artificially.
Flavor enhancers Flavor enhancers enhance a food's existing flavors. They may be extracted from natural sources (through distillation, solvent extraction, maceration, among other methods) or created artificially.
Flour treatment agents Flour treatment agents are added to flour to improve its color or its use in baking.
Glazing agents Glazing agents provide a shiny appearance or protective coating to foods.
Humectants Humectants prevent foods from drying out.
Tracer gas Tracer gas allow for pac
Document 3:::
Food chemistry is the study of chemical processes and interactions of all biological and non-biological components of foods. The biological substances include such items as meat, poultry, lettuce, beer, milk as examples. It is similar to biochemistry in its main components such as carbohydrates, lipids, and protein, but it also includes areas such as water, vitamins, minerals, enzymes, food additives, flavors, and colors. This discipline also encompasses how products change under certain food processing techniques and ways either to enhance or to prevent them from happening. An example of enhancing a process would be to encourage fermentation of dairy products with microorganisms that convert lactose to lactic acid; an example of preventing a process would be stopping the browning on the surface of freshly cut apples using lemon juice or other acidulated water.
History of food chemistry
The scientific approach to food and nutrition arose with attention to agricultural chemistry in the works of J. G. Wallerius, Humphry Davy, and others. For example, Davy published Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture (1813) in the United Kingdom which would serve as a foundation for the profession worldwide, going into a fifth edition. Earlier work included that by Carl Wilhelm Scheele, who isolated malic acid from apples in 1785.
Some of the findings of Liebig on food chemistry were translated and published by Eben Horsford in Lowell Massachusetts in 1848.
In 1874 the Society of Public Analysts was formed, with the aim of applying analytical methods to the benefit of the public. Its early experiments were based on bread, milk, and wine.
It was also out of concern for the quality of the food supply, mainly food adulteration and contamination issues that would first stem from intentional contamination to later with chemical food additives by the 1950s. The development of colleges and universities worldwide, most notably in the Un
Document 4:::
Food and biological process engineering is a discipline concerned with applying principles of engineering to the fields of food production and distribution and biology. It is a broad field, with workers fulfilling a variety of roles ranging from design of food processing equipment to genetic modification of organisms. In some respects it is a combined field, drawing from the disciplines of food science and biological engineering to improve the earth's food supply.
Creating, processing, and storing food to support the world's population requires extensive interdisciplinary knowledge. Notably, there are many biological engineering processes within food engineering to manipulate the multitude of organisms involved in our complex food chain. Food safety in particular requires biological study to understand the microorganisms involved and how they affect humans. However, other aspects of food engineering, such as food storage and processing, also require extensive biological knowledge of both the food and the microorganisms that inhabit it. This food microbiology and biology knowledge becomes biological engineering when systems and processes are created to maintain desirable food properties and microorganisms while providing mechanisms for eliminating the unfavorable or dangerous ones.
Concepts
Many different concepts are involved in the field of food and biological process engineering. Below are listed several major ones.
Food science
The science behind food and food production involves studying how food behaves and how it can be improved. Researchers analyze longevity and composition (i.e., ingredients, vitamins, minerals, etc.) of foods, as well as how to ensure food safety.
Genetic engineering
Modern food and biological process engineering relies heavily on applications of genetic manipulation. By understanding plants and animals on the molecular level, scientists are able to engineer them with specific goals in mind.
Among the most notable applications of
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What property of food is determined by burning the food and measuring the heat released?
A. additives
B. nutrients
C. calories
D. acidity
Answer:
|
|
sciq-4342
|
multiple_choice
|
What is the process that ventilates lungs called?
|
[
"photosynthesis",
"breathing",
"reproduction",
"perspiration"
] |
B
|
Relavent Documents:
Document 0:::
Speech science refers to the study of production, transmission and perception of speech. Speech science involves anatomy, in particular the anatomy of the oro-facial region and neuroanatomy, physiology, and acoustics.
Speech production
The production of speech is a highly complex motor task that involves approximately 100 orofacial, laryngeal, pharyngeal, and respiratory muscles. Precise and expeditious timing of these muscles is essential for the production of temporally complex speech sounds, which are characterized by transitions as short as 10 ms between frequency bands and an average speaking rate of approximately 15 sounds per second. Speech production requires airflow from the lungs (respiration) to be phonated through the vocal folds of the larynx (phonation) and resonated in the vocal cavities shaped by the jaw, soft palate, lips, tongue and other articulators (articulation).
Respiration
Respiration is the physical process of gas exchange between an organism and its environment involving four steps (ventilation, distribution, perfusion and diffusion) and two processes (inspiration and expiration). Respiration can be described as the mechanical process of air flowing into and out of the lungs on the principle of Boyle's law, stating that, as the volume of a container increases, the air pressure will decrease. This relatively negative pressure will cause air to enter the container until the pressure is equalized. During inspiration of air, the diaphragm contracts and the lungs expand drawn by pleurae through surface tension and negative pressure. When the lungs expand, air pressure becomes negative compared to atmospheric pressure and air will flow from the area of higher pressure to fill the lungs. Forced inspiration for speech uses accessory muscles to elevate the rib cage and enlarge the thoracic cavity in the vertical and lateral dimensions. During forced expiration for speech, muscles of the trunk and abdomen reduce the size of the thoracic cavity by
Document 1:::
The control of ventilation is the physiological mechanisms involved in the control of breathing, which is the movement of air into and out of the lungs. Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and balancing of carbon dioxide by the body as a whole, or by individual cells in cellular respiration.
The most important function of breathing is the supplying of oxygen to the body and balancing of the carbon dioxide levels. Under most conditions, the partial pressure of carbon dioxide (PCO2), or concentration of carbon dioxide, controls the respiratory rate.
The peripheral chemoreceptors that detect changes in the levels of oxygen and carbon dioxide are located in the arterial aortic bodies and the carotid bodies. Central chemoreceptors are primarily sensitive to changes in the pH of the blood, (resulting from changes in the levels of carbon dioxide) and they are located on the medulla oblongata near to the medullar respiratory groups of the respiratory center.
Information from the peripheral chemoreceptors is conveyed along nerves to the respiratory groups of the respiratory center. There are four respiratory groups, two in the medulla and two in the pons. The two groups in the pons are known as the pontine respiratory group.
Dorsal respiratory group – in the medulla
Ventral respiratory group – in the medulla
Pneumotaxic center – various nuclei of the pons
Apneustic center – nucleus of the pons
From the respiratory center, the muscles of respiration, in particular the diaphragm, are activated to cause air to move in and out of the lungs.
Control of respiratory rhythm
Ventilatory pattern
Breathing is normally an unconscious, involuntary, automatic process. The pattern of motor stimuli during breathing can be divided into an inhalation stage and an exhalation stage. Inhalation shows a sudden, ramped increase in motor discharge to the respiratory muscles (and the pharyngeal constrictor muscles). Before the end of inh
Document 2:::
In physiology, respiration is the movement of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction that's to the environment.
The physiological definition of respiration differs from the biochemical definition, which refers to a metabolic process by which an organism obtains energy (in the form of ATP and NADPH) by oxidizing nutrients and releasing waste products. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the diffusion and transport of metabolites between the organism and the external environment.
Gas exchanges in the lung occurs by ventilation and perfusion. Ventilation refers to the in and out movement of air of the lungs and perfusion is the circulation of blood in the pulmonary capillaries. In mammals, physiological respiration involves respiratory cycles of inhaled and exhaled breaths. Inhalation (breathing in) is usually an active movement that brings air into the lungs where the process of gas exchange takes place between the air in the alveoli and the blood in the pulmonary capillaries. Contraction of the diaphragm muscle cause a pressure variation, which is equal to the pressures caused by elastic, resistive and inertial components of the respiratory system. In contrast, exhalation (breathing out) is usually a passive process, though there are many exceptions: when generating functional overpressure (speaking, singing, humming, laughing, blowing, snorting, sneezing, coughing, powerlifting); when exhaling underwater (swimming, diving); at high levels of physiological exertion (running, climbing, throwing) where more rapid gas exchange is necessitated; or in some forms of breath-controlled meditation. Speaking and singing in humans requires sustained breath control that many mammals are not
Document 3:::
Exhalation (or expiration) is the flow of the breath out of an organism. In animals, it is the movement of air from the lungs out of the airways, to the external environment during breathing.
This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume. As the thoracic diaphragm relaxes during exhalation it causes the tissue it has depressed to rise superiorly and put pressure on the lungs to expel the air. During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostal muscles generate abdominal and thoracic pressure, which forces air out of the lungs.
Exhaled air is 4% carbon dioxide, a waste product of cellular respiration during the production of energy, which is stored as ATP. Exhalation has a complementary relationship to inhalation which together make up the respiratory cycle of a breath.
Exhalation and gas exchange
The main reason for exhalation is to rid the body of carbon dioxide, which is the waste product of gas exchange in humans. Air is brought into the body through inhalation. During this process air is taken in by the lungs. Diffusion in the alveoli allows for the exchange of O2 into the pulmonary capillaries and the removal of CO2 and other gases from the pulmonary capillaries to be exhaled. In order for the lungs to expel air the diaphragm relaxes, which pushes up on the lungs. The air then flows through the trachea then through the larynx and pharynx to the nasal cavity and oral cavity where it is expelled out of the body. Exhalation takes longer than inhalation and it is believed to facilitate better exchange of gases. Parts of the nervous system help to regulate respiration in humans. The exhaled air is not just carbon dioxide; it contains a mixture of other gases. Human breath contains volatile organic compounds (VOCs). These compounds consist of methanol, isoprene, acetone,
Document 4:::
Breathing (spiration or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
All aerobic creatures need oxygen for cellular respiration, which extracts energy from the reaction of oxygen with molecules derived from food and produces carbon dioxide as a waste product. Breathing, or external respiration, brings air into the lungs where gas exchange takes place in the alveoli through diffusion. The body's circulatory system transports these gases to and from the cells, where cellular respiration takes place.
The breathing of all vertebrates with lungs consists of repetitive cycles of inhalation and exhalation through a highly branched system of tubes or airways which lead from the nose to the alveoli. The number of respiratory cycles per minute is the breathing or respiratory rate, and is one of the four primary vital signs of life. Under normal conditions the breathing depth and rate is automatically, and unconsciously, controlled by several homeostatic mechanisms which keep the partial pressures of carbon dioxide and oxygen in the arterial blood constant. Keeping the partial pressure of carbon dioxide in the arterial blood unchanged under a wide variety of physiological circumstances, contributes significantly to tight control of the pH of the extracellular fluids (ECF). Over-breathing (hyperventilation) and under-breathing (hypoventilation), which decrease and increase the arterial partial pressure of carbon dioxide respectively, cause a rise in the pH of ECF in the first case, and a lowering of the pH in the second. Both cause distressing symptoms.
Breathing has other important functions. It provides a mechanism for speech, laughter and similar expressions of the emotions. It is also used for reflexes such as yawning, coughing and sneezing. Animals that cannot thermoregulate by perspiration, because they lack sufficient sweat glands, may
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the process that ventilates lungs called?
A. photosynthesis
B. breathing
C. reproduction
D. perspiration
Answer:
|
|
sciq-8801
|
multiple_choice
|
The cells of what basic plant structure lack chloroplasts?
|
[
"ferns",
"stem",
"leaf",
"root"
] |
D
|
Relavent Documents:
Document 0:::
Plant stem cells
Plant stem cells are innately undifferentiated cells located in the meristems of plants. Plant stem cells serve as the origin of plant vitality, as they maintain themselves while providing a steady supply of precursor cells to form differentiated tissues and organs in plants. Two distinct areas of stem cells are recognised: the apical meristem and the lateral meristem.
Plant stem cells are characterized by two distinctive properties, which are: the ability to create all differentiated cell types and the ability to self-renew such that the number of stem cells is maintained. Plant stem cells never undergo aging process but immortally give rise to new specialized and unspecialized cells, and they have the potential to grow into any organ, tissue, or cell in the body. Thus they are totipotent cells equipped with regenerative powers that facilitate plant growth and production of new organs throughout lifetime.
Unlike animals, plants are immobile. As plants cannot escape from danger by taking motion, they need a special mechanism to withstand various and sometimes unforeseen environmental stress. Here, what empowers them to withstand harsh external influence and preserve life is stem cells. In fact, plants comprise the oldest and the largest living organisms on earth, including Bristlecone Pines in California, U.S. (4,842 years old), and the Giant Sequoia in mountainous regions of California, U.S. (87 meters in height and 2,000 tons in weight). This is possible because they have a modular body plan that enables them to survive substantial damage by initiating continuous and repetitive formation of new structures and organs such as leaves and flowers.
Plant stem cells are also characterized by their location in specialized structures called meristematic tissues, which are located in root apical meristem (RAM), shoot apical meristem (SAM), and vascular system ((pro)cambium or vascular meristem.)
Research and development
Traditionally, plant stem ce
Document 1:::
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
The stem is normally divided into nodes and internodes:
The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaves, conifer cones, or flowers). Adventitious roots may also be produced from the nodes. Vines may produce tendrils from nodes.
The internodes distance one node from another.
The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other structures like leaves or flowers.
In most plants, stems are located above the soil surface, but some plants have underground stems.
Stems have several main functions:
Support for and the elevation of leaves, flowers, and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem.
Storage of nutrients.
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
Photosynthesis.
Stems have two pipe-like tissues called xylem and phloem. The xylem tissue arises from the cell facing inside and transports water by the action of transpiration pull, capillary action, and root pressure. The phloem tissue arises from the cell facing outside and consists of sieve tubes and their companion cells. The function of phloem tissue is to distribute food from photosynthetic tissue to other tissues. The two tissues are separated by cambium, a tis
Document 2:::
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones.
Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the term is generally considered to be unscientific.
Characteristics
Botanists define vascular plants by three primary characteristics:
Vascular plants have vascular tissues which distribute resources through the plant. Two kinds of vascular tissue occur in plants: xylem and phloem. Phloem and xylem are closely associated with one another and are typically located immediately adjacent to each other in the plant. The combination of one xylem and one phloem strand adjacent to each other is known as a vascular bundle. The evolution of vascular tissue in plants allowed them to evolve to larger sizes than non-vascular plants, which lack these specialized conducting tissues and are thereby restricted to relatively small sizes.
In vascular plants, the principal generation or phase is the sporophyte, which produces spores and is diploid (having two sets of chromosomes per cell). (By contrast, the principal generation phase in non-vascular plants is the gametophyte, which produces gametes and is haploid - with
Document 3:::
In contrast to the Cladophorales where nuclei are organized in regularly spaced cytoplasmic domains, the cytoplasm of Bryopsidales exhibits streaming, enabling transportation of organelles, transcripts and nutrients across the plant.
The Sphaeropleales also contain several common freshwat
Document 4:::
Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.
Scope
Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin". There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.
First of all, morphology is comparative, meaning that the morphologist examines structures in many different plants of the same or different species, then draws comparisons and formulates ideas about similarities. When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany.
Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive str
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The cells of what basic plant structure lack chloroplasts?
A. ferns
B. stem
C. leaf
D. root
Answer:
|
|
sciq-6064
|
multiple_choice
|
The coordination sphere consists of the central metal ion or atom plus its attached what?
|
[
"ligands",
"strands",
"molecules",
"subunits"
] |
A
|
Relavent Documents:
Document 0:::
In chemistry, crystallography, and materials science, the coordination number, also called ligancy, of a central atom in a molecule or crystal is the number of atoms, molecules or ions bonded to it. The ion/molecule/atom surrounding the central ion/molecule/atom is called a ligand. This number is determined somewhat differently for molecules than for crystals.
For molecules and polyatomic ions the coordination number of an atom is determined by simply counting the other atoms to which it is bonded (by either single or multiple bonds). For example, [Cr(NH3)2Cl2Br2]− has Cr3+ as its central cation, which has a coordination number of 6 and is described as hexacoordinate. The common coordination numbers are 4, 6 and 8.
Molecules, polyatomic ions and coordination complexes
In chemistry, coordination number, defined originally in 1893 by Alfred Werner, is the total number of neighbors of a central atom in a molecule or ion. The concept is most commonly applied to coordination complexes.
Simple and commonplace cases
The most common coordination number for d-block transition metal complexes is 6. The coordination number does not distinguish the geometry of such complexes, i.e. octahedral vs trigonal prismatic.
For transition metal complexes, coordination numbers range from 2 (e.g., AuI in Ph3PAuCl) to 9 (e.g., ReVII in [ReH9]2−). Metals in the f-block (the lanthanoids and actinoids) can accommodate higher coordination number due to their greater ionic radii and availability of more orbitals for bonding. Coordination numbers of 8 to 12 are commonly observed for f-block elements. For example, with bidentate nitrate ions as ligands, CeIV and ThIV form the 12-coordinate ions [Ce(NO3)6]2− (ceric ammonium nitrate) and [Th(NO3)6]2−. When the surrounding ligands are much smaller than the central atom, even higher coordination numbers may be possible. One computational chemistry study predicted a particularly stable ion composed of a central lead ion coordinated with n
Document 1:::
The coordination geometry of an atom is the geometrical pattern defined by the atoms around the central atom. The term is commonly applied in the field of inorganic chemistry, where diverse structures are observed. The coodination geometry depends on the number, not the type, of ligands bonded to the metal centre as well as their locations. The number of atoms bonded is the coordination number.
The geometrical pattern can be described as a polyhedron where the vertices of the polyhedron are the centres of the coordinating atoms in the ligands.
The coordination preference of a metal often varies with its oxidation state. The number of coordination bonds (coordination number) can vary from two in as high as 20 in .
One of the most common coordination geometries is octahedral, where six ligands are coordinated to the metal in a symmetrical distribution, leading to the formation of an octahedron if lines were drawn between the ligands. Other common coordination geometries are tetrahedral and square planar.
Crystal field theory may be used to explain the relative stabilities of transition metal compounds of different coordination geometry, as well as the presence or absence of paramagnetism, whereas VSEPR may be used for complexes of main group element to predict geometry.
Crystallography usage
In a crystal structure the coordination geometry of an atom is the geometrical pattern of coordinating atoms where the definition of coordinating atoms depends on the bonding model used. For example, in the rock salt ionic structure each sodium atom has six near neighbour chloride ions in an octahedral geometry and each chloride has similarly six near neighbour sodium ions in an octahedral geometry. In metals with the body centred cubic (bcc) structure each atom has eight nearest neighbours in a cubic geometry. In metals with the face centred cubic (fcc) structure each atom has twelve nearest neighbours in a cuboctahedral geometry.
Table of coordination geometries
A table o
Document 2:::
Bioorganometallic chemistry is the study of biologically active molecules that contain carbon directly bonded to metals or metalloids. The importance of main-group and transition-metal centers has long been recognized as important to the function of enzymes and other biomolecules. However, only a small subset of naturally-occurring metal complexes and synthetically prepared pharmaceuticals are organometallic; that is, they feature a direct covalent bond between the metal(loid) and a carbon atom. The first, and for a long time, the only examples of naturally occurring bioorganometallic compounds were the cobalamin cofactors (vitamin B12) in its various forms. In the 21st century, as a result of the discovery of new systems containing carbon–metal bonds in biology, bioorganometallic chemistry is rapidly emerging as a distinct subdiscipline of bioinorganic chemistry that straddles organometallic chemistry and biochemistry. Naturally occurring bioorganometallics include enzymes and sensor proteins. Also within this realm are synthetically prepared organometallic compounds that serve as new drugs and imaging agents (technetium-99m sestamibi) as well as the principles relevant to the toxicology of organometallic compounds (e.g., methylmercury). Consequently, bioorganometallic chemistry is increasingly relevant to medicine and pharmacology.
In cofactors and prosthetic groups
Vitamin B12 is the preeminent bioorganometallic species. Vitamin B12 is actually a collection of related enzyme cofactors, several of which contain cobalt–alkyl bonds, and is involved in biological methylation and 1,2-carbon rearrangement reactions. For a long time since its structure was elucidated by Hodgkin in 1955, it was believed to be the only example of a naturally occurring bioorganometallic system.
Several bioorganometallic enzymes carry out reactions involving carbon monoxide. Carbon monoxide dehydrogenase (CODH) catalyzes the water–gas shift reaction, which provides CO (through a
Document 3:::
In coordination chemistry, denticity () refers to the number of donor groups in a given ligand that bind to the central metal atom in a coordination complex. In many cases, only one atom in the ligand binds to the metal, so the denticity equals one, and the ligand is said to be monodentate (sometimes called unidentate). Ligands with more than one bonded atom are called polydentate or multidentate. The denticity of a ligand is described with the Greek letter κ ('kappa'). For example, κ6-EDTA describes an EDTA ligand that coordinates through 6 non-contiguous atoms.
Denticity is different from hapticity because hapticity refers exclusively to ligands where the coordinating atoms are contiguous. In these cases the η ('eta') notation is used. Bridging ligands use the μ ('mu') notation.
Classes
Polydentate ligands are chelating agents and classified by their denticity. Some atoms cannot form the maximum possible number of bonds a ligand could make. In that case one or more binding sites of the ligand are unused. Such sites can be used to form a bond with another chemical species.
Bidentate (also called didentate) ligands bind with two atoms, an example being ethylenediamine.
Tridentate ligands bind with three atoms, an example being terpyridine. Tridentate ligands usually bind via two kinds of connectivity, called "mer" and "fac." "fac" stands for facial, the donor atoms are arranged on a triangle around one face of the octahedron. "mer" stands for meridian, where the donor atoms are stretched out around one half of the octahedron. Cyclic tridentate ligands such as TACN and 9-ane-S3 bind in a facial manner.
Tetradentate ligands bind with four donor atoms, an example being triethylenetetramine (abbreviated trien). For different central metal geometries there can be different numbers of isomers depending on the ligand's topology and the geometry of the metal center. For octahedral metals, the linear tetradentate trien can bind via three geometries. Tripodal t
Document 4:::
Transition metal thiolate complexes are metal complexes containing thiolate ligands. Thiolates are ligands that can be classified as soft Lewis bases. Therefore, thiolate ligands coordinate most strongly to metals that behave as soft Lewis acids as opposed to those that behave as hard Lewis acids. Most complexes contain other ligands in addition to thiolate, but many homoleptic complexes are known with only thiolate ligands. The amino acid cysteine has a thiol functional group, consequently many cofactors in proteins and enzymes feature cysteinate-metal cofactors.
Synthesis
Metal thiolate complexes are commonly prepared by reactions of metal complexes with thiols (RSH), thiolates (RS−), and disulfides (R2S2). The salt metathesis reaction route is common. In this method, an alkali metal thiolate is treated with a transition metal halide to produce an alkali metal halide and the metal thiolate complex:
LiSC6H5 + CuI → Cu(SC6H5) + LiI
The thiol ligand can also effect protonolysis of anionic ligands, as illustrated by the formation of an organonickel thiolate from nickelocene and ethanethiol:
2 HSC2H5 + 2 Ni(C5H5)2 → [Ni(SC2H5)(C5H5)]2 + 2 C5H6
Regarding their mechanism of formation from thiols, metal thiolate complexes can arise via deprotonation of thiol complexes.
Redox routes
Many thiolate complexes are prepared by redox reactions. Organic disulfides oxidize low valence metals, as illustrated by the oxidation of titanocene dicarbonyl:
Some metal centers are oxidized by thiols, the coproduct being hydrogen gas:
These reactions may proceed by the oxidative addition of the thiol to Fe(0).
Thiols and especially thiolate salts are reducing agents. Consequently, they induce redox reactions with certain transition metals. This phenomenon is illustrated by the synthesis of cuprous thiolates from cupric precursors:
4 HSC6H5 + 2 CuO → 2 Cu(SC6H5) + (C6H5S)2 + 2 H2O
Thiolate clusters of the type [Fe4S4(SR)4]2− occur in iron–sulfur pr
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The coordination sphere consists of the central metal ion or atom plus its attached what?
A. ligands
B. strands
C. molecules
D. subunits
Answer:
|
|
sciq-133
|
multiple_choice
|
By allowing blood levels of a hormone to be regulated within a narrow range, feedback loops contribute to maintaining what state?
|
[
"consciousness",
"hibernation",
"homeostasis",
"hypothesis"
] |
C
|
Relavent Documents:
Document 0:::
Pulsatile secretion is a biochemical phenomenon observed in a wide variety of cell and tissue types, in which chemical products are secreted in a regular temporal pattern. The most common cellular products observed to be released in this manner are intercellular signaling molecules such as hormones or neurotransmitters. Examples of hormones that are secreted pulsatilely include insulin, thyrotropin, TRH, gonadotropin-releasing hormone (GnRH) and growth hormone (GH). In the nervous system, pulsatility is observed in oscillatory activity from central pattern generators. In the heart, pacemakers are able to work and secrete in a pulsatile manner. A pulsatile secretion pattern is critical to the function of many hormones in order to maintain the delicate homeostatic balance necessary for essential life processes, such as development and reproduction. Variations of the concentration in a certain frequency can be critical to hormone function, as evidenced by the case of GnRH agonists, which cause functional inhibition of the receptor for GnRH due to profound downregulation in response to constant (tonic) stimulation. Pulsatility may function to sensitize target tissues to the hormone of interest and upregulate receptors, leading to improved responses. This heightened response may have served to improve the animal's fitness in its environment and promote its evolutionary retention.
Pulsatile secretion in its various forms is observed in:
Hypothalamic-pituitary-gonadal axis (HPG) related hormones
Glucocorticoids
Insulin
Growth hormone
Parathyroid hormone
Neuroendocrine Pulsatility
Nervous system control over hormone release is based in the hypothalamus, from which the neurons that populate the pariventricular and arcuate nuclei originate. These neurons project to the median eminence, where they secrete releasing hormones into the hypophysial portal system connecting the hypothalamus with the pituitary gland. There, they dictate endocrine function via the four Hyp
Document 1:::
In biochemistry, steady state refers to the maintenance of constant internal concentrations of molecules and ions in the cells and organs of living systems. Living organisms remain at a dynamic steady state where their internal composition at both cellular and gross levels are relatively constant, but different from equilibrium concentrations. A continuous flux of mass and energy results in the constant synthesis and breakdown of molecules via chemical reactions of biochemical pathways. Essentially, steady state can be thought of as homeostasis at a cellular level.
Maintenance of steady state
Metabolic regulation achieves a balance between the rate of input of a substrate and the rate that it is degraded or converted, and thus maintains steady state. The rate of metabolic flow, or flux, is variable and subject to metabolic demands. However, in a metabolic pathway, steady state is maintained by balancing the rate of substrate provided by a previous step and the rate that the substrate is converted into product, keeping substrate concentration relatively constant.
Thermodynamically speaking, living organisms are open systems, meaning that they constantly exchange matter and energy with their surroundings. A constant supply of energy is required for maintaining steady state, as maintaining a constant concentration of a molecule preserves internal order and thus is entropically unfavorable. When a cell dies and no longer utilizes energy, its internal composition will proceed toward equilibrium with its surroundings.
In some occurrences, it is necessary for cells to adjust their internal composition in order to reach a new steady state. Cell differentiation, for example, requires specific protein regulation that allows the differentiating cell to meet new metabolic requirements.
ATP
The concentration of ATP must be kept above equilibrium level so that the rates of ATP-dependent biochemical reactions meet metabolic demands. A decrease in ATP will result in a decre
Document 2:::
In physiology, a stimulus is a detectable change in the physical or chemical structure of an organism's internal or external environment. The ability of an organism or organ to detect external stimuli, so that an appropriate reaction can be made, is called sensitivity (excitability). Sensory receptors can receive information from outside the body, as in touch receptors found in the skin or light receptors in the eye, as well as from inside the body, as in chemoreceptors and mechanoreceptors. When a stimulus is detected by a sensory receptor, it can elicit a reflex via stimulus transduction. An internal stimulus is often the first component of a homeostatic control system. External stimuli are capable of producing systemic responses throughout the body, as in the fight-or-flight response. In order for a stimulus to be detected with high probability, its level of strength must exceed the absolute threshold; if a signal does reach threshold, the information is transmitted to the central nervous system (CNS), where it is integrated and a decision on how to react is made. Although stimuli commonly cause the body to respond, it is the CNS that finally determines whether a signal causes a reaction or not.
Types
Internal
Homeostatic imbalances
Homeostatic outbalances are the main driving force for changes of the body. These stimuli are monitored closely by receptors and sensors in different parts of the body. These sensors are mechanoreceptors, chemoreceptors and thermoreceptors that, respectively, respond to pressure or stretching, chemical changes, or temperature changes. Examples of mechanoreceptors include baroreceptors which detect changes in blood pressure, Merkel's discs which can detect sustained touch and pressure, and hair cells which detect sound stimuli. Homeostatic imbalances that can serve as internal stimuli include nutrient and ion levels in the blood, oxygen levels, and water levels. Deviations from the homeostatic ideal may generate a homeostatic emotio
Document 3:::
The insulin transduction pathway is a biochemical pathway by which insulin increases the uptake of glucose into fat and muscle cells and reduces the synthesis of glucose in the liver and hence is involved in maintaining glucose homeostasis. This pathway is also influenced by fed versus fasting states, stress levels, and a variety of other hormones.
When carbohydrates are consumed, digested, and absorbed the pancreas senses the subsequent rise in blood glucose concentration and releases insulin to promote uptake of glucose from the bloodstream. When insulin binds to the insulin receptor, it leads to a cascade of cellular processes that promote the usage or, in some cases, the storage of glucose in the cell. The effects of insulin vary depending on the tissue involved, e.g., insulin is most important in the uptake of glucose by muscle and adipose tissue.
This insulin signal transduction pathway is composed of trigger mechanisms (e.g., autophosphorylation mechanisms) that serve as signals throughout the cell. There is also a counter mechanism in the body to stop the secretion of insulin beyond a certain limit. Namely, those counter-regulatory mechanisms are glucagon and epinephrine. The process of the regulation of blood glucose (also known as glucose homeostasis) also exhibits oscillatory behavior.
On a pathological basis, this topic is crucial to understanding certain disorders in the body such as diabetes, hyperglycemia and hypoglycemia.
Transduction pathway
The functioning of a signal transduction pathway is based on extra-cellular signaling that in turn creates a response that causes other subsequent responses, hence creating a chain reaction, or cascade. During the course of signaling, the cell uses each response for accomplishing some kind of a purpose along the way. Insulin secretion mechanism is a common example of signal transduction pathway mechanism.
Insulin is produced by the pancreas in a region called Islets of Langerhans. In the islets of Langerha
Document 4:::
The insulin concentration in blood increases after meals and gradually returns to basal levels during the next 1–2 hours. However, the basal insulin level is not stable. It oscillates with a regular period of 3-6 min. After a meal the amplitude of these oscillations increases but the periodicity remains constant. The oscillations are believed to be important for insulin sensitivity by preventing downregulation of insulin receptors in target cells. Such downregulation underlies insulin resistance, which is common in type 2 diabetes. It would therefore be advantageous to administer insulin to diabetic patients in a manner mimicking the natural oscillations. The insulin oscillations are generated by pulsatile release of the hormone from the pancreas. Insulin originates from beta cells located in the islets of Langerhans. Since each islet contains up to 2000 beta cells and there are one million islets in the pancreas it is apparent that pulsatile secretion requires sophisticated synchronization both within and among the islets of Langerhans.
Mechanism
Pulsatile insulin secretion from individual beta cells is driven by oscillation of the calcium concentration in the cells. In beta cells lacking contact, the periodicity of these oscillations is rather variable (2-10 min). However, within an islet of Langerhans the oscillations become synchronized by electrical coupling between closely located beta cells that are connected by gap junctions, and the periodicity is more uniform (3-6 min).
Pulsatile insulin release from the entire pancreas requires that secretion is synchronized between 1 million islets within a 25 cm long organ. Much like the cardiac pacemaker, the pancreas is connected to cranial nerve 10, and others, but the oscillations are accomplished by intrapancreatic neurons and do not require neural input from the brain. It is not entirely clear which neural factors account for this synchronization but ATP as well as the gasses NO and CO may be involved. The effe
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
By allowing blood levels of a hormone to be regulated within a narrow range, feedback loops contribute to maintaining what state?
A. consciousness
B. hibernation
C. homeostasis
D. hypothesis
Answer:
|
|
sciq-11406
|
multiple_choice
|
Fermat’s principle states that light will always take the path of least amount of?
|
[
"energy",
"resistance",
"time",
"momentum"
] |
C
|
Relavent Documents:
Document 0:::
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 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:::
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 3:::
Applied physics is the application of physics to solve scientific or engineering problems. It is usually considered a bridge or a connection between physics and engineering.
"Applied" is distinguished from "pure" by a subtle combination of factors, such as the motivation and attitude of researchers and the nature of the relationship to the technology or science that may be affected by the work. Applied physics is rooted in the fundamental truths and basic concepts of the physical sciences but is concerned with the utilization of scientific principles in practical devices and systems and with the application of physics in other areas of science and high technology.
Examples of research and development areas
Accelerator physics
Acoustics
Atmospheric physics
Biophysics
Brain–computer interfacing
Chemistry
Chemical physics
Differentiable programming
Artificial intelligence
Scientific computing
Engineering physics
Chemical engineering
Electrical engineering
Electronics
Sensors
Transistors
Materials science and engineering
Metamaterials
Nanotechnology
Semiconductors
Thin films
Mechanical engineering
Aerospace engineering
Astrodynamics
Electromagnetic propulsion
Fluid mechanics
Military engineering
Lidar
Radar
Sonar
Stealth technology
Nuclear engineering
Fission reactors
Fusion reactors
Optical engineering
Photonics
Cavity optomechanics
Lasers
Photonic crystals
Geophysics
Materials physics
Medical physics
Health physics
Radiation dosimetry
Medical imaging
Magnetic resonance imaging
Radiation therapy
Microscopy
Scanning probe microscopy
Atomic force microscopy
Scanning tunneling microscopy
Scanning electron microscopy
Transmission electron microscopy
Nuclear physics
Fission
Fusion
Optical physics
Nonlinear optics
Quantum optics
Plasma physics
Quantum technology
Quantum computing
Quantum cryptography
Renewable energy
Space physics
Spectroscopy
See also
Applied science
Applied mathematics
Engineering
Engineering Physics
High Technology
Document 4:::
The path of least resistance is the physical or metaphorical pathway that provides the least resistance to forward motion by a given object or entity, among a set of alternative paths. The concept is often used to describe why an object or entity takes a given path. The way in which water flows is often given as an example for the idea.
Description
In physics, the "path of least resistance" is a heuristic from folk physics that can sometimes, in very simple situations, describe approximately what happens. It is an approximation of the tendency to the least energy state. Other examples are "what goes up must come down" (gravity) and "heat goes from hot to cold" (second law of thermodynamics). But these simple descriptions are not derived from laws of physics and in more complicated cases these heuristics will fail to give even approximately correct results.
In electrical circuits, for example, the current always follows all available paths, and in some simple cases the "path of least resistance" will take up most of the current, but this will not be generally true in even slightly more complicated circuits. It may seem for example, that if there are three paths of approximately equal resistance, the majority of the current will flow down one of the three paths. However, due to electrons repelling each other, the total path of least resistance is in fact to have approximate equal current flowing through each path. The reason for this is that three paths made of equally conductive wire will have a total resistance that is one-third of the single path. In conclusion, the current is always distributed over all possible paths inversely proportional to their resistance.
The path of least resistance is also used to describe certain human behaviors, although with much less specificity than in the strictly physical sense. In these cases, resistance is often used as a metaphor for personal effort or confrontation; a person taking the path of least resistance avoids these.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Fermat’s principle states that light will always take the path of least amount of?
A. energy
B. resistance
C. time
D. momentum
Answer:
|
|
ai2_arc-468
|
multiple_choice
|
When prehistoric animals died and their soft parts decayed, which product was formed?
|
[
"oil",
"sand",
"coal",
"shale"
] |
A
|
Relavent Documents:
Document 0:::
Biotic material or biological derived material is any material that originates from living organisms. Most such materials contain carbon and are capable of decay.
The earliest life on Earth arose at least 3.5 billion years ago. Earlier physical evidences of life include graphite, a biogenic substance, in 3.7 billion-year-old metasedimentary rocks discovered in southwestern Greenland, as well as, "remains of biotic life" found in 4.1 billion-year-old rocks in Western Australia. Earth's biodiversity has expanded continually except when interrupted by mass extinctions. Although scholars estimate that over 99 percent of all species of life (over five billion) that ever lived on Earth are extinct, there are still an estimated 10–14 million extant species, of which about 1.2 million have been documented and over 86% have not yet been described.
Examples of biotic materials are wood, straw, humus, manure, bark, crude oil, cotton, spider silk, chitin, fibrin, and bone.
The use of biotic materials, and processed biotic materials (bio-based material) as alternative natural materials, over synthetics is popular with those who are environmentally conscious because such materials are usually biodegradable, renewable, and the processing is commonly understood and has minimal environmental impact. However, not all biotic materials are used in an environmentally friendly way, such as those that require high levels of processing, are harvested unsustainably, or are used to produce carbon emissions.
When the source of the recently living material has little importance to the product produced, such as in the production of biofuels, biotic material is simply called biomass. Many fuel sources may have biological sources, and may be divided roughly into fossil fuels, and biofuel.
In soil science, biotic material is often referred to as organic matter. Biotic materials in soil include glomalin, Dopplerite and humic acid. Some biotic material may not be considered to be organic matte
Document 1:::
Phyllocladane is a tricyclic diterpane which is generally found in gymnosperm resins. It has a formula of C20H34 and a molecular weight of 274.4840. As a biomarker, it can be used to learn about the gymnosperm input into a hydrocarbon deposit, and about the age of the deposit in general. It indicates a terrogenous origin of the source rock. Diterpanes, such as Phyllocladane are found in source rocks as early as the middle and late Devonian periods, which indicates any rock containing them must be no more than approximately 360 Ma. Phyllocladane is commonly found in lignite, and like other resinites derived from gymnosperms, is naturally enriched in 13C. This enrichment is a result of the enzymatic pathways used to synthesize the compound.
The compound can be identified by GC-MS. A peak of m/z 123 is indicative of tricyclic diterpenoids in general, and phyllocladane in particular is further characterized by strong peaks at m/z 231 and m/z 189. Presence of phyllocladane and its relative abundance to other tricyclic diterpanes can be used to differentiate between various oil fields.
Document 2:::
A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, it has developed to encompass any constituents, secretions, and metabolites of plants or animals. In context of molecular biology, biogenic substances are referred to as biomolecules. They are generally isolated and measured through the use of chromatography and mass spectrometry techniques. Additionally, the transformation and exchange of biogenic substances can by modelled in the environment, particularly their transport in waterways.
The observation and measurement of biogenic substances is notably important in the fields of geology and biochemistry. A large proportion of isoprenoids and fatty acids in geological sediments are derived from plants and chlorophyll, and can be found in samples extending back to the Precambrian. These biogenic substances are capable of withstanding the diagenesis process in sediment, but may also be transformed into other materials. This makes them useful as biomarkers for geologists to verify the age, origin and degradation processes of different rocks.
Biogenic substances have been studied as part of marine biochemistry since the 1960s, which has involved investigating their production, transport, and transformation in the water, and how they may be used in industrial applications. A large fraction of biogenic compounds in the marine environment are produced by micro and macro algae, including cyanobacteria. Due to their antimicrobial properties they are currently the subject of research in both industrial projects, such as for anti-fouling paints, or in medicine.
History of discovery and classification
During a meeting of the New York Academy of Sciences' Section of Geology and Mineralogy in 1903, geologist Amadeus William Grabau proposed a new rock classification system in his paper 'Discussion of and Suggestions Regarding a New Classification of Rocks'. Within
Document 3:::
Bisnorhopanes (BNH) are a group of demethylated hopanes found in oil shales across the globe and can be used for understanding depositional conditions of the source rock. The most common member, 28,30-bisnorhopane, can be found in high concentrations in petroleum source rocks, most notably the Monterey Shale, as well as in oil and tar samples. 28,30-Bisnorhopane was first identified in samples from the Monterey Shale Formation in 1985. It occurs in abundance throughout the formation and appears in stratigraphically analogous locations along the California coast. Since its identification and analysis, 28,30-bisnorhopane has been discovered in oil shales around the globe, including lacustrine and offshore deposits of Brazil, silicified shales of the Eocene in Gabon, the Kimmeridge Clay Formation in the North Sea, and in Western Australian oil shales.
Chemistry
28,30-bisnorhopane exists in three epimers: 17α,18α21β(H), 17β,18α,21α(H), and 17β,18α,21β(H). During GC-MS, the three epimers coelute at the same time and are nearly indistinguishable. However, mass spectral fragmentation of the 28,30-bisnorhopane is predominantly characterized by m/z 191, 177, and 163. The ratios of 163/191 fragments can be used to distinguish the epimers, where the βαβ orientation has the highest, m/z 163/191 ratio. Further, the D/E ring ratios can be used to create a hierarchy of epimer maturity. From this, it is believed that the ααβ epimer is the first-formed, diagenetically, supported also by its percent dominance in younger shales. 28,30-bisnorhopane is created independently from kerogen, instead derived from bitumen, unbound as free oil-hydrocarbons. As such, as oil generation increases with source maturation, the concentration of 28,30-bisnorhopane decreases. Bisnorhopane may not be a reliable diagnostic for oil maturity due to microbial biodegradation.
Nomenclature
Norhopanes are a family of demethylated hopanes, identical to the methylated hopane structure, minus indicated desmet
Document 4:::
A megabias, or a taphonomic megabias, is a large-scale pattern in the quality of the fossil record that affects paleobiologic analysis at provincial to global levels and at timescales usually exceeding ten million years. It can result from major shifts in intrinsic and extrinsic properties of organisms, including morphology and behaviour in relation to other organisms, or shifts in the global environment, which can cause secular or long-term cyclic changes in preservation.
Introduction
The fossil record exhibits bias at many different levels. At the most basic level, there is a global bias towards biomineralizing organisms, because biomineralized body parts are more resistant to decay and degradation. Due to the principle of uniformitarianism, there is a basic assumption in geology that the formation of rocks has occurred by the same naturalistic processes throughout history, and thus that the reach of such biases remains stable over time. A megabias is a direct contradiction of this, whereby changes occur in large scale paleobiologic patterns. This includes:
Changes in diversity and community structure over tens of millions of years
Variation in the quality of the fossil record between mass and background extinction times
Variation among different climate states, biogeographic provinces, and tectonic settings.
It is generally assumed that the quality of the fossil record decreases globally and across all taxa with increasing age, because more time is available for the diagenesis and destruction of both fossils and enclosing rocks, and thus the term "megabias" is usually used to refer to global trends in preservation. However, it has been noted that the fossil record of some taxa actually improves with greater age. Examples such as this, and other related paleobiological trends, clearly indicate the action of a megabias, but only within one particular taxon. Hence, it is necessary to define four classes of megabias related to the reach of the bias, first defined
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When prehistoric animals died and their soft parts decayed, which product was formed?
A. oil
B. sand
C. coal
D. shale
Answer:
|
|
sciq-10913
|
multiple_choice
|
How is eye color in humans determined?
|
[
"temperature of the womb",
"by the father",
"multiple genes",
"random chance"
] |
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:::
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:::
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:::
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
Document 4:::
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.
How is eye color in humans determined?
A. temperature of the womb
B. by the father
C. multiple genes
D. random chance
Answer:
|
|
sciq-2077
|
multiple_choice
|
What changes from heat or pressure during metamorphism?
|
[
"minerals",
"carbohydrates",
"fossils",
"grains"
] |
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:::
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:::
Metamictisation (sometimes called metamictization or metamiction) is a natural process resulting in the gradual and ultimately complete destruction of a mineral's crystal structure, leaving the mineral amorphous. The affected material is therefore described as metamict.
Certain minerals occasionally contain interstitial impurities of radioactive elements, and it is the alpha radiation emitted from those compounds that is responsible for degrading a mineral's crystal structure through internal bombardment. The effects of metamictisation are extensive: other than negating any birefringence previously present, the process also lowers a mineral's refractive index, hardness, and its specific gravity. The mineral's colour is also affected: metamict specimens are usually green, brown or blackish. Further, metamictisation diffuses the bands of a mineral's absorption spectrum. Curiously and inexplicably, the one attribute which metamictisation does not alter is dispersion. All metamict materials are themselves radioactive, some dangerously so.
An example of a metamict mineral is zircon. The presence of uranium and thorium atoms substituting for zirconium in the crystal structure is responsible for the radiation damage in this case. Unaffected specimens are termed high zircon while metamict specimens are termed low zircon. Other minerals known to undergo metamictisation include allanite, gadolinite, ekanite, thorite and titanite. Ekanite is almost invariably found completely metamict as thorium and uranium are part of its essential chemical composition.
Metamict minerals can have their crystallinity and properties restored through prolonged annealing.
A related phenomenon is the formation of pleochroic halos surrounding minute zircon inclusions within a crystal of biotite or other mineral. The spherical halos are produced by alpha particle radiation from the included uranium- or thorium-bearing species. Such halos can also be found surrounding monazite and other radioacti
Document 3:::
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 4:::
Material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geological origin or biological function. Materials science is the study of materials, their properties and their applications.
Raw materials can be processed in different ways to influence their properties, by purification, shaping or the introduction of other materials. New materials can be produced from raw materials by synthesis.
In industry, materials are inputs to manufacturing processes to produce products or more complex materials.
Historical elements
Materials chart the history of humanity. The system of the three prehistoric ages (Stone Age, Bronze Age, Iron Age) were succeeded by historical ages: steel age in the 19th century, polymer age in the middle of the following century (plastic age) and silicon age in the second half of the 20th century.
Classification by use
Materials can be broadly categorized in terms of their use, for example:
Building materials are used for construction
Building insulation materials are used to retain heat within buildings
Refractory materials are used for high-temperature applications
Nuclear materials are used for nuclear power and weapons
Aerospace materials are used in aircraft and other aerospace applications
Biomaterials are used for applications interacting with living systems
Material selection is a process to determine which material should be used for a given application.
Classification by structure
The relevant structure of materials has a different length scale depending on the material. The structure and composition of a material can be determined by microscopy or spectroscopy.
Microstructure
In engineering, materials can be categorised according to their microscopic structure:
Plastics: a wide range of synthetic or semi-synthetic materials that use polymers as a main ingred
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What changes from heat or pressure during metamorphism?
A. minerals
B. carbohydrates
C. fossils
D. grains
Answer:
|
|
sciq-1049
|
multiple_choice
|
What system, which includes the skin, plays important roles in protection, sensing stimuli and thermoregulation?
|
[
"teleporters system",
"pectins system",
"digestive system",
"integumentary system"
] |
D
|
Relavent Documents:
Document 0:::
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 1:::
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
Document 2:::
A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways. A biological system is not to be confused with a living system, such as a living organism.
Organ and tissue systems
These specific systems are widely studied in human anatomy and are also present in many other animals.
Respiratory system: the organs used for breathing, the pharynx, larynx, bronchi, lungs and diaphragm.
Digestive system: digestion and processing food with salivary glands, oesophagus, stomach, liver, gallbladder, pancreas, intestines, rectum and anus.
Cardiovascular system (heart and circulatory system): pumping and channeling blood to and from the body and lungs with heart, blood and blood vessels.
Urinary system: kidneys, ureters, bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.
Integumentary system: skin, hair, fat, and nails.
Skeletal system: structural support and protection with bones, cartilage, ligaments and tendons.
Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid, parathyroid and adrenals, i.e., adrenal glands.
Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream; includes the lymph and the nodes and vessels. The lymphatic system includes functions including immune responses and development of antibodies.
Immune system: protects the organism from
Document 3:::
Skin temperature is the temperature of the outermost surface of the body. Normal human skin temperature on the trunk of the body varies between 33.5 and 36.9 °C (92.3 and 98.4 °F), though the skin's temperature is lower over protruding parts, like the nose, and higher over muscles and active organs. Recording skin temperature presents extensive difficulties. Although it is not a clear indicator of internal body temperature, skin temperature is significant in assessing the healthy function of skin. Some experts believe the physiological significance of skin temperature has been overlooked, because clinical analysis has favoured measuring temperatures of the mouth, armpit, and/or rectum. Temperatures of these parts typically are consistent with internal body temperature.
Patterns in skin temperature often provide crucial diagnostic data on pathological conditions, ranging from locomotion to vascular diseases. Such information can prove significant to determination of subsequent therapeutic treatments.
Background and interactions
The three primary functions performed by skin are protection, regulation and sensation. Interactions between skin and temperature occur constantly in relation to each of these functions and often hold considerable medical and physiological significance.
The skin is composed of three main layers, the epidermis, dermis and hypodermis, and contains a variety of cells, receptors and junctions which enable performance of a multitude of functions. The capacity of our skin to cope under a range of conditions and at various tissue temperatures, whilst simultaneously delivering these functions, attests to the resilience of the organ.
There are three important aspects of the relationship between skin and temperature:
Thermal sensations can be detected and communicated from localised sensory regions of the skin.
Skin acts as both a medium and means for delivering mechanisms of thermoregulation, including insulation, sweating and control of blood
Document 4:::
The glomus body is not to be confused with the glomus cell which is a kind of chemoreceptor found in the carotid bodies and aortic bodies.
A glomus body (or glomus organ) is a component of the dermis layer of the skin, involved in body temperature regulation. The glomus body is a small arteriovenous anastomosis surrounded by a capsule of connective tissue. Glomus bodies (glomera) are most numerous in the fingers and toes. The role of the glomus body is to shunt blood away (heat transfer) from the skin surface when exposed to cold temperature, thus preventing heat loss, and allowing maximum blood flow to the skin in warm weather to allow heat to dissipate. The glomus body has high sympathetic tone and potentiation leads to near complete vasoconstriction.
Endothelial cells form a single, continuous layer that lines all vascular segments. Junctional complexes keep the endothelial cells together in arteries but are less numerous in veins. The organization of the endothelial cell layer in capillaries can varies greatly, depending on the location.
The arteriovenous shunt of the glomus body is a normal anatomic shunt as opposed to an abnormal arteriovenous fistula. A metarteriole is another type.
See also
Glomus tumor
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What system, which includes the skin, plays important roles in protection, sensing stimuli and thermoregulation?
A. teleporters system
B. pectins system
C. digestive system
D. integumentary system
Answer:
|
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