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ai2_arc-249
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multiple_choice
|
Two layers of sedimentary rock are exposed on the side of a hill. Only one of the layers has fossils. The lack of fossils in one layer of sedimentary rock is most likely due to
|
[
"changing environments.",
"volcanic activity.",
"changing rates of erosion.",
"evaporation of sea water."
] |
A
|
Relavent Documents:
Document 0:::
The geologic record in stratigraphy, paleontology and other natural sciences refers to the entirety of the layers of rock strata. That is, deposits laid down by volcanism or by deposition of sediment derived from weathering detritus (clays, sands etc.). This includes all its fossil content and the information it yields about the history of the Earth: its past climate, geography, geology and the evolution of life on its surface. According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other. They harden over time to become a solidified (competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events.
Correlating the rock record
At a certain locality on the Earth's surface, the rock column provides a cross section of the natural history in the area during the time covered by the age of the rocks. This is sometimes called the rock history and gives a window into the natural history of the location that spans many geological time units such as ages, epochs, or in some cases even multiple major geologic periods—for the particular geographic region or regions. The geologic record is in no one place entirely complete for where geologic forces one age provide a low-lying region accumulating deposits much like a layer cake, in the next may have uplifted the region, and the same area is instead one that is weathering and being torn down by chemistry, wind, temperature, and water. This is to say that in a given location, the geologic record can be and is quite often interrupted as the ancient local environment was converted by geological forces into new landforms and features. Sediment core data at the mouths of large riverine drainage basins, some of which go deep thoroughly support the law of superposition.
However using broadly occurring deposited layers trapped within differently located rock columns, geologists have pieced together a system of units covering most of the geologic time scale
Document 1:::
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
Document 2:::
Stratigraphic paleobiology is a branch of geology that is closely related to paleobiology, sequence stratigraphy and sedimentology. Stratigraphic paleobiology studies how the fossil record is altered by sedimentological processes and how this affects biostratigraphy and paleobiological interpretations of the fossil record.
Topic and key concepts
Patzkowsky and Holland (2012) define stratigraphic paleobiology as follows:
"[Stratigraphic paleobiology] is built on the premise that the distribution of fossil taxa in time and space is controlled not only by processes of evolution, ecology, and environmental change, but also by the stratigraphic processes that govern where and when sediment that might contain fossils is deposited and preserved. Teasing apart the effects of these two suites of processes to understand the history of life on Earth is the essence of stratigraphic paleobiology."
Large parts of stratigraphic paleobiology rely on sequence stratigraphy. This is since within a sequence, many parameters such as depositional conditions, (non)preservation, and facies change deterministically. This sequence stratigraphic background alone, without any changes in ecology or any evolutionary processes, creates a baseline of constant change in the number of fossils and taxa that are preserved. One example for this are maximum flooding surfaces, which commonly display large accumulations of shells and an increased number of first fossil occurrences and last fossil occurrences. This is however not necessary linked to any change in ecology or an extinction event, but can be generated by the low deposition rates during the maximum flooding surface alone.
See also
Range offset
Depositional resolution
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
A 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.
Two layers of sedimentary rock are exposed on the side of a hill. Only one of the layers has fossils. The lack of fossils in one layer of sedimentary rock is most likely due to
A. changing environments.
B. volcanic activity.
C. changing rates of erosion.
D. evaporation of sea water.
Answer:
|
|
sciq-4101
|
multiple_choice
|
Light reactions occur during which stage of photosynthesis?
|
[
"intermediate stage",
"third stage",
"final stage",
"first stage"
] |
D
|
Relavent Documents:
Document 0:::
The evolution of photosynthesis refers to the origin and subsequent evolution of photosynthesis, the process by which light energy is used to assemble sugars from carbon dioxide and a hydrogen and electron source such as water. The process of photosynthesis was discovered by Jan Ingenhousz, a Dutch-born British physician and scientist, first publishing about it in 1779.
The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen rather than water. There are three major metabolic pathways by which photosynthesis is carried out: C3 photosynthesis, C4 photosynthesis, and CAM photosynthesis. C3 photosynthesis is the oldest and most common form. A C3 plant uses the Calvin cycle for the initial steps that incorporate into organic material. A C4 plant prefaces the Calvin cycle with reactions that incorporate into four-carbon compounds. A CAM plant uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. C4 and CAM plants have special adaptations that save water.
Origin
Available evidence from geobiological studies of Archean (>2500 Ma) sedimentary rocks indicates that life existed 3500 Ma. Fossils of what are thought to be filamentous photosynthetic organisms have been dated at 3.4 billion years old, consistent with recent studies of photosynthesis. Early photosynthetic systems, such as those from green and purple sulfur and green and purple nonsulfur bacteria, are thought to have been anoxygenic, using various molecules as electron donors. Green and purple sulfur bacteria are thought to have used hydrogen and hydrogen sulfide as electron and hydrogen donors. Green nonsulfur bacteria used various amino and other organic acids. Purple nonsulfur bacteria used a variety of nonspecific organic and inorganic molecules. It is suggested that photosynthesis likely originated at low-wavelength geothermal light from acidic hydrothermal vents, Zn-tetrapyrroles w
Document 1:::
Stroma, in botany, refers to the colorless fluid surrounding the grana within the chloroplast.
Within the stroma are grana (stacks of thylakoid), the sub-organelles where photosynthesis is started before the chemical changes are completed in the stroma.
Photosynthesis occurs in two stages. In the first stage, light-dependent reactions capture the energy of light and use it to make the energy-storage molecules ATP and NADPH. During the second stage, the light-independent reactions use these products to fix carbon by capturing and reducing carbon dioxide.
The series of biochemical redox reactions which take place in the stroma are collectively called the Calvin cycle or light-independent reactions. There are three phases: carbon fixation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration.
The stroma is also the location of chloroplast DNA and chloroplast ribosomes, and thus also the location of molecular processes including chloroplast DNA replication, and transcription/translation of some chloroplast proteins.
See also
Granum
Document 2:::
The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. The Calvin cycle is present in all photosynthetic eukaryotes and also many photosynthetic bacteria. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes. These reactions take the products (ATP and NADPH) of light-dependent reactions and perform further chemical processes on them. The Calvin cycle uses the chemical energy of ATP and reducing power of NADPH from the light dependent reactions to produce sugars for the plant to use. These substrates are used in a series of reduction-oxidation reactions to produce sugars in a step-wise process; there is no direct reaction that converts several molecules of to a sugar. There are three phases to the light-independent reactions, collectively called the Calvin cycle: carboxylation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration.
Though it is called the "dark reaction", the Calvin cycle does not actually occur in the dark or during night time. This is because the process requires NADPH, which is short-lived and comes from the light-dependent reactions. In the dark, plants instead release sucrose into the phloem from their starch reserves to provide energy for the plant. The Calvin cycle thus happens when light is available independent of the kind of photosynthesis (C3 carbon fixation, C4 carbon fixation, and Crassulacean Acid Metabolism (CAM)); CAM plants store malic acid in their vacuoles every night and release it by day to make this process work.
Coupling to other metabolic pathways
The reactions of the Calvin cycle are closely coupled to the thylakoid electron transport chain as the energy required to reduce the carbon dioxide is provided by NADPH produced during the light de
Document 3:::
In botany, a light curve shows the photosynthetic response of leaf tissue or algal communities to varying light intensities. The shape of the curve illustrates the principle of limiting factors; in low light levels, the rate of photosynthesis is limited by the concentration of chlorophyll and the efficiency of the light-dependent reactions, but in higher light levels it is limited by the efficiency of RuBisCo and the availability of carbon dioxide. The point on the curve where these two differing slopes meet is called the light saturation point and is where the light-dependent reactions are producing more ATP and NADPH than can be utilized by the light-independent reactions. Since photosynthesis is also limited by ambient carbon dioxide levels, light curves are often repeated at several different constant carbon dioxide concentrations.
Document 4:::
Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by photons. It is defined as the interaction of one or more photons with one target molecule.
Photodissociation is not limited to visible light. Any photon with sufficient energy can affect the chemical bonds of a chemical compound. Since a photon's energy is inversely proportional to its wavelength, electromagnetic radiations with the energy of visible light or higher, such as ultraviolet light, X-rays, and gamma rays can induce such reactions.
Photolysis in photosynthesis
Photolysis is part of the light-dependent reaction or light phase or photochemical phase or Hill reaction of photosynthesis. The general reaction of photosynthetic photolysis can be given in terms of photons as:
The chemical nature of "A" depends on the type of organism. Purple sulfur bacteria oxidize hydrogen sulfide () to sulfur (S). In oxygenic photosynthesis, water () serves as a substrate for photolysis resulting in the generation of diatomic oxygen (). This is the process which returns oxygen to Earth's atmosphere. Photolysis of water occurs in the thylakoids of cyanobacteria and the chloroplasts of green algae and plants.
Energy transfer models
The conventional semi-classical model describes the photosynthetic energy transfer process as one in which excitation energy hops from light-capturing pigment molecules to reaction center molecules step-by-step down the molecular energy ladder.
The effectiveness of photons of different wavelengths depends on the absorption spectra of the photosynthetic pigments in the organism. Chlorophylls absorb light in the violet-blue and red parts of the spectrum, while accessory pigments capture other wavelengths as well. The phycobilins of red algae absorb blue-green light which penetrates deeper into water than red light, enabling them to photosynthesize in deep waters. Each absorbed photon causes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Light reactions occur during which stage of photosynthesis?
A. intermediate stage
B. third stage
C. final stage
D. first stage
Answer:
|
|
sciq-643
|
multiple_choice
|
By breaking down wastes and remains of dead organisms, decomposers perform what function in an ecosystem?
|
[
"recycling",
"reproduction",
"symbiosis",
"collecting"
] |
A
|
Relavent Documents:
Document 0:::
Decomposers are organisms that break down dead or decaying organisms; they carry out decomposition, a process possible by only certain kingdoms, such as fungi. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores ingest and digest dead matter internally, while decomposers directly absorb nutrients through external chemical and biological processes. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they are unable to absorb nutrients without ingesting them.
Fungi
The primary decomposer of litter in many ecosystems is fungi. Unlike bacteria, which are unicellular organisms and are decomposers as well, most saprotrophic fungi grow as a branching network of hyphae. While bacteria are restricted to growing and feeding on the exposed surfaces of organic matter, fungi can use their hyphae to penetrate larger pieces of organic matter, below the surface. Additionally, only wood-decay fungi have evolved the enzymes necessary to decompose lignin, a chemically complex substance found in wood. These two factors make fungi the primary decomposers in forests, where litter has high concentrations of lignin and often occurs in large pieces. Fungi decompose organic matter by releasing enzymes to break down the decaying material, after which they absorb the nutrients in the decaying material. Hyphae are used to break down matter and absorb nutrients and are also used in reproduction. When two compatible fungi hyphae grow close to each other, they will then fuse together for reproduction, and form another fungus.
See also
Chemotroph
Micro-animals
Microorganism
Document 1:::
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated "soil organic matter". The detritus of aquatic ecosystems is organic substances that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow".
Theory
The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which organic matter is decomposed, occurs in several phases. Micro- and macro-organisms that feed on it rapidly consume and absorb materials such as proteins, lipids, and sugars that are low in molecular weight, while other compounds such as complex carbohydrates are decomposed more slowly. The decomposing microorganisms degrade the organic materials so as to gain the resources they require for their survival and reproduction. Accordingly, simultaneous to microorganisms' decomposition of the materials of dead plants and animals is their assimilation of decomposed compounds to construct more of their biomass (i.e. to grow their own bodies). When microorganisms die, fine organic particles are produced, and if small animals that feed on microorganisms eat these particles they collect inside the intestines of the consumers, and change shape into large pellets of dung. As a result of this process, most of the materials of dead organisms disappear and are not visible and recognizable in any form, but are pres
Document 2:::
Microbiology of decomposition is the study of all microorganisms involved in decomposition, the chemical and physical processes during which organic matter is broken down and reduced to its original elements.
Decomposition microbiology can be divided into two fields of interest, namely the decomposition of plant materials and the decomposition of cadavers and carcasses.
The decomposition of plant materials is commonly studied in order to understand the cycling of carbon within a given environment and to understand the subsequent impacts on soil quality. Plant material decomposition is also often referred to as composting. The decomposition of cadavers and carcasses has become an important field of study within forensic taphonomy.
Decomposition microbiology of plant materials
The breakdown of vegetation is highly dependent on oxygen and moisture levels. During decomposition, microorganisms require oxygen for their respiration. If anaerobic conditions dominate the decomposition environment, microbial activity will be slow and thus decomposition will be slow. Appropriate moisture levels are required for microorganisms to proliferate and to actively decompose organic matter. In arid environments, bacteria and fungi dry out and are unable to take part in decomposition. In wet environments, anaerobic conditions will develop and decomposition can also be considerably slowed down. Decomposing microorganisms also require the appropriate plant substrates in order to achieve good levels of decomposition. This usually translates to having appropriate carbon to nitrogen ratios (C:N). The ideal composting carbon-to-nitrogen ratio is thought to be approximately 30:1. As in any microbial process, the decomposition of plant litter by microorganisms will also be dependent on temperature. For example, leaves on the ground will not undergo decomposition during the winter months where snow cover occurs as temperatures are too low to sustain microbial activities.
Decomposition mi
Document 3:::
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 4:::
Necrophages are organisms that obtain nutrients by consuming decomposing dead animal biomass, such as the muscle and soft tissue of carcasses and corpses. The term derives from Greek , meaning 'dead', and , meaning 'to eat.' Mainly, necrophages are species within the phylum Arthropoda; however, other animals, such as gastropods and Accipitrimorphae birds have been noted to engage in necrophagy.
Necrophages play a critical role in the study of forensic entomology, as certain Arthropoda, such as Diptera larvae, engage in myiasis and colonization of the human body.
Invertebrates
Diptera
Members of the order Diptera, such as Nematocera, Calliphoridae, Sacrophagidae, and Muscidae, as well as semi-aquatic Diptera larvae, such as Simuliidae and Chironomidae, are the most common necrophages within the Animalia kingdom. Diptera species play a critical role in forensic entomology, as they tend to colonize the human body during the early floating phase of decomposition. The flies utilize the submerged corpse as a source of food as well as an attachment site. Notably, Diptera do not specifically colonize and feed on human carcasses. Diptera species, such as Musca domestica and Chloroprocta idioidea have been observed feeding on the carcasses of other mammalian carcasses, including the Mona monkey, the European rabbit, and the Giant cane rat, as well as fish carrion. The carcass' appeal is characterized by the putridness of the odour it emits; thus, the olfactory system of Diptera species plays a role in their food selectivity. In addition, the diversity and abundance of Diptera species vary both spatially and temporally. Necrophagous Diptera, such as Calliphora vicina, tend to be concentrated in urban areas and rare in more rural areas. However, some researchers oppose this notion and claim anthropogenic impacts are negligible regarding species richness. Temporally, the necrophagous Diptera are observed in higher abundances in the summer season than the winter season. The p
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
By breaking down wastes and remains of dead organisms, decomposers perform what function in an ecosystem?
A. recycling
B. reproduction
C. symbiosis
D. collecting
Answer:
|
|
sciq-1280
|
multiple_choice
|
Which theory describes the benzene molecule and other planar aromatic hydrocarbon molecules as hexagonal rings of sp2-hybridized carbon atoms with the unhybridized p orbital of each carbon atom perpendicular to the plane of the ring?
|
[
"valence bond theory",
"molecular orbital theory",
"hybrid orbital theory",
"covalent bond theory"
] |
A
|
Relavent Documents:
Document 0:::
A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and is formed between one hybridized orbital from each of the carbon atoms. In ethane, the orbitals are sp3-hybridized orbitals, but single bonds formed between carbon atoms with other hybridizations do occur (e.g. sp2 to sp2). In fact, the carbon atoms in the single bond need not be of the same hybridization. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond.
Chains and branching
Carbon is one of the few elements that can form long chains of its own atoms, a property called catenation. This coupled with the strength of the carbon–carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements of life, so carbon compounds have their own field of study: organic chemistry.
Branching is also common in C−C skeletons. Carbon atoms in a molecule are categorized by the number of carbon neighbors they have:
A primary carbon has one carbon neighbor.
A secondary carbon has two carbon neighbors.
A tertiary carbon has three carbon neighbors.
A quaternary carbon has four carbon neighbors.
In "structurally complex organic molecules", it is the three-dimensional orientation of the carbon–carbon bonds at quaternary loci which dictates the shape of the molecule. Further, quaternary loci are found in many biologically active small molecules, such as cortisone and morphine.
Synthesis
Carbon–carbon bond-forming reactions are organic reactions in which a new carbon–carbon bond is formed. They are important in th
Document 1:::
In chemistry, orbital hybridisation (or hybridization) is the concept of mixing atomic orbitals to form new hybrid orbitals (with different energies, shapes, etc., than the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds in valence bond theory. For example, in a carbon atom which forms four single bonds the valence-shell s orbital combines with three valence-shell p orbitals to form four equivalent sp3 mixtures in a tetrahedral arrangement around the carbon to bond to four different atoms. Hybrid orbitals are useful in the explanation of molecular geometry and atomic bonding properties and are symmetrically disposed in space. Usually hybrid orbitals are formed by mixing atomic orbitals of comparable energies.
History and uses
Chemist Linus Pauling first developed the hybridisation theory in 1931 to explain the structure of simple molecules such as methane (CH4) using atomic orbitals. Pauling pointed out that a carbon atom forms four bonds by using one s and three p orbitals, so that "it might be inferred" that a carbon atom would form three bonds at right angles (using p orbitals) and a fourth weaker bond using the s orbital in some arbitrary direction. In reality, methane has four C-H bonds of equivalent strength. The angle between any two bonds is the tetrahedral bond angle of 109°28' (around 109.5°). Pauling supposed that in the presence of four hydrogen atoms, the s and p orbitals form four equivalent combinations which he called hybrid orbitals. Each hybrid is denoted sp3 to indicate its composition, and is directed along one of the four C-H bonds. This concept was developed for such simple chemical systems, but the approach was later applied more widely, and today it is considered an effective heuristic for rationalizing the structures of organic compounds. It gives a simple orbital picture equivalent to Lewis structures.
Hybridisation theory is an integral part of organic chemistry, one of the most compelling exampl
Document 2:::
In chemistry, the carbon-hydrogen bond ( bond) is a chemical bond between carbon and hydrogen atoms that can be found in many organic compounds. This bond is a covalent, single bond, meaning that carbon shares its outer valence electrons with up to four hydrogens. This completes both of their outer shells, making them stable.
Carbon–hydrogen bonds have a bond length of about 1.09 Å (1.09 × 10−10 m) and a bond energy of about 413 kJ/mol (see table below). Using Pauling's scale—C (2.55) and H (2.2)—the electronegativity difference between these two atoms is 0.35. Because of this small difference in electronegativities, the bond is generally regarded as being non-polar. In structural formulas of molecules, the hydrogen atoms are often omitted. Compound classes consisting solely of bonds and bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as hydrocarbons.
In October 2016, astronomers reported that the very basic chemical ingredients of life—the carbon-hydrogen molecule (CH, or methylidyne radical), the carbon-hydrogen positive ion () and the carbon ion ()—are the result, in large part, of ultraviolet light from stars, rather than in other ways, such as the result of turbulent events related to supernovae and young stars, as thought earlier.
Bond length
The length of the carbon-hydrogen bond varies slightly with the hybridisation of the carbon atom. A bond between a hydrogen atom and an sp2 hybridised carbon atom is about 0.6% shorter than between hydrogen and sp3 hybridised carbon. A bond between hydrogen and sp hybridised carbon is shorter still, about 3% shorter than sp3 C-H. This trend is illustrated by the molecular geometry of ethane, ethylene and acetylene.
Reactions
The C−H bond in general is very strong, so it is relatively unreactive. In several compound classes, collectively called carbon acids, the C−H bond can be sufficiently acidic for proton removal. Unactivated C−H bonds are found in alkanes and are no
Document 3:::
Walsh diagrams, often called angular coordinate diagrams or correlation diagrams, are representations of calculated orbital binding energies of a molecule versus a distortion coordinate (bond angles), used for making quick predictions about the geometries of small molecules. By plotting the change in molecular orbital levels of a molecule as a function of geometrical change, Walsh diagrams explain why molecules are more stable in certain spatial configurations (e.g. why water adopts a bent conformation).
A major application of Walsh diagrams is to explain the regularity in structure observed for related molecules having identical numbers of valence electrons (e.g. why H2O and H2S look similar), and to account for how molecules alter their geometries as their number of electrons or spin state changes. Additionally, Walsh diagrams can be used to predict distortions of molecular geometry from knowledge of how the LUMO (Lowest Unoccupied Molecular Orbital) affects the HOMO (Highest Occupied Molecular Orbital) when the molecule experiences geometrical perturbation.
Walsh's rule for predicting shapes of molecules states that a molecule will adopt a structure that best provides the most stability for its HOMO. If a particular structural change does not perturb the HOMO, the closest occupied molecular orbital governs the preference for geometrical orientation.
History
Walsh diagrams were first introduced by A.D. Walsh, a British chemistry professor at the University of Dundee, in a series of ten papers in one issue of the Journal of the Chemical Society. Here, he aimed to rationalize the shapes adopted by polyatomic molecules in the ground state as well as in excited states, by applying theoretical contributions made by Mulliken. Specifically, Walsh calculated and explained the effect of changes in the shape of a molecule on the energy of molecular orbitals. Walsh diagrams are an illustration of such dependency, and his conclusions are what are referred to as the "
Document 4:::
Prismane or 'Ladenburg benzene' is a polycyclic hydrocarbon with the formula C6H6. It is an isomer of benzene, specifically a valence isomer. Prismane is far less stable than benzene. The carbon (and hydrogen) atoms of the prismane molecule are arranged in the shape of a six-atom triangular prism—this compound is the parent and simplest member of the prismanes class of molecules. Albert Ladenburg proposed this structure for the compound now known as benzene. The compound was not synthesized until 1973.
History
In the mid 19th century, investigators proposed several possible structures for benzene which were consistent with its empirical formula, C6H6, which had been determined by combustion analysis. The first, which was proposed by Kekulé in 1865, later proved to be closest to the true structure of benzene. This structure inspired several others to draw structures that were consistent with benzene's empirical formula; for example, Ladenburg proposed prismane, Dewar proposed Dewar benzene, and Koerner and Claus proposed Claus' benzene. Some of these structures would be synthesized in the following years. Prismane, like the other proposed structures for benzene, is still often cited in the literature, because it is part of the historical struggle toward understanding the mesomeric structures and resonance of benzene. Some computational chemists still research the differences between the possible isomers of C6H6.
Properties
Prismane is a colourless liquid at room temperature. The deviation of the carbon-carbon bond angle from 109° to 60° in a triangle leads to a high ring strain, reminiscent of that of cyclopropane but greater. The compound is explosive, which is unusual for a hydrocarbon. Due to this ring strain, the bonds have a low bond energy and break at a low activation energy, which makes synthesis of the molecule difficult; Woodward and Hoffmann noted that prismane's thermal rearrangement to benzene is symmetry-forbidden, comparing it to "an angry tiger una
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which theory describes the benzene molecule and other planar aromatic hydrocarbon molecules as hexagonal rings of sp2-hybridized carbon atoms with the unhybridized p orbital of each carbon atom perpendicular to the plane of the ring?
A. valence bond theory
B. molecular orbital theory
C. hybrid orbital theory
D. covalent bond theory
Answer:
|
|
ai2_arc-1101
|
multiple_choice
|
A mutation that occurs in an organism that reproduces sexually will most likely affect the traits of the offspring if the mutation
|
[
"is located in the cells of the nervous system.",
"alters DNA in a gamete of the parent.",
"alters the behavior of the organisms.",
"is located near the locus of a chromosome."
] |
B
|
Relavent Documents:
Document 0:::
Mutation frequency and mutation rates are highly correlated to each other. Mutation frequencies test are cost effective in laboratories however; these two concepts provide vital information in reference to accounting for the emergence of mutations on any given germ line.
There are several test utilized in measuring the chances of mutation frequency and rates occurring in a particular gene pool. Some of the test are as follows:
Avida Digital Evolution Platform
Fluctuation Analysis
Mutation frequency and rates provide vital information about how often a mutation may be expressed in a particular genetic group or sex. Yoon et., 2009 suggested that as sperm donors ages increased the sperm mutation frequencies increased. This reveals the positive correlation in how males are most likely to contribute to genetic disorders that reside within X-linked recessive chromosome.
There are additional factors affecting mutation frequency and rates involving evolutionary influences. Since, organisms may pass mutations to their offspring incorporating and analyzing the mutation frequency and rates of a particular species may provide a means to adequately comprehend its longevity
Aging
The time course of spontaneous mutation frequency from middle to late adulthood was measured in four different tissues of the mouse. Mutation frequencies in the cerebellum (90% neurons) and male germ cells were lower than in liver and adipose tissue. Furthermore, the mutation frequencies increased with age in liver and adipose tissue, whereas in the cerebellum and male germ cells the mutation frequency remained constant
Dietary restricted rodents live longer and are generally healthier than their ad libitum fed counterparts. No changes were observed in the spontaneous chromosomal mutation frequency of dietary restricted mice (aged 6 and 12 months) compared to ad libitum fed control mice. Thus dietary restriction appears to have no appreciable effect on spontaneous mutation in chromosomal
Document 1:::
A germline mutation, or germinal mutation, is any detectable variation within germ cells (cells that, when fully developed, become sperm and ova). Mutations in these cells are the only mutations that can be passed on to offspring, when either a mutated sperm or oocyte come together to form a zygote. After this fertilization event occurs, germ cells divide rapidly to produce all of the cells in the body, causing this mutation to be present in every somatic and germline cell in the offspring; this is also known as a constitutional mutation. Germline mutation is distinct from somatic mutation.
Germline mutations can be caused by a variety of endogenous (internal) and exogenous (external) factors, and can occur throughout zygote development. A mutation that arises only in germ cells can result in offspring with a genetic condition that is not present in either parent; this is because the mutation is not present in the rest of the parents' body, only the germline.
When mutagenesis occurs
Germline mutations can occur before fertilization and during various stages of zygote development. When the mutation arises will determine the effect it has on offspring. If the mutation arises in either the sperm or the oocyte before development, then the mutation will be present in every cell in the individual's body. A mutation that arises soon after fertilization, but before germline and somatic cells are determined, then the mutation will be present in a large proportion of the individual's cell with no bias towards germline or somatic cells, this is also called a gonosomal mutation. A mutation that arises later in zygote development will be present in a small subset of either somatic or germline cells, but not both.
Causes
Endogenous factors
A germline mutation often arises due to endogenous factors, like errors in cellular replication and oxidative damage. This damage is rarely repaired imperfectly, but due to the high rate of germ cell division, can occur frequently.
Endog
Document 2:::
In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It is a characteristic that would not be observed naturally in a specimen. The term mutant is also applied to a virus with an alteration in its nucleotide sequence whose genome is in the nuclear genome. The natural occurrence of genetic mutations is integral to the process of evolution. The study of mutants is an integral part of biology; by understanding the effect that a mutation in a gene has, it is possible to establish the normal function of that gene.
Mutants arise by mutation
Mutants arise by mutations occurring in pre-existing genomes as a result of errors of DNA replication or errors of DNA repair. Errors of replication often involve translesion synthesis by a DNA polymerase when it encounters and bypasses a damaged base in the template strand. A DNA damage is an abnormal chemical structure in DNA, such as a strand break or an oxidized base, whereas a mutation, by contrast, is a change in the sequence of standard base pairs. Errors of repair occur when repair processes inaccurately replace a damaged DNA sequence. The DNA repair process microhomology-mediated end joining is particularly error-prone.
Etymology
Although not all mutations have a noticeable phenotypic effect, the common usage of the word "mutant" is generally a pejorative term, only used for genetically or phenotypically noticeable mutations. Previously, people used the word "sport" (related to spurt) to refer to abnormal specimens. The scientific usage is broader, referring to any organism differing from the wild type. The word finds its origin in the Latin term mūtant- (stem of mūtāns), which means "to change".
Mutants should not be confused with organisms born with developmental abnormalities, which are caused by errors during morphogenesis. In a devel
Document 3:::
A somatic mutation is a change in the DNA sequence of a somatic cell of a multicellular organism with dedicated reproductive cells; that is, any mutation that occurs in a cell other than a gamete, germ cell, or gametocyte. Unlike germline mutations, which can be passed on to the descendants of an organism, somatic mutations are not usually transmitted to descendants. This distinction is blurred in plants, which lack a dedicated germline, and in those animals that can reproduce asexually through mechanisms such as budding, as in members of the cnidarian genus Hydra.
While somatic mutations are not passed down to an organism's offspring, somatic mutations will be present in all descendants of a cell within the same organism. Many cancers are the result of accumulated somatic mutations.
Fraction of cells affected
The term somatic generally refers to the cells of the body, in contrast to the reproductive (germline) cells, which give rise to the egg or sperm. For example, in mammals, somatic cells make up the internal organs, skin, bones, blood, and connective tissue.
In most animals, separation of germ cells from somatic cells (germline development) occurs during early stages of development. Once this segregation has occurred in the embryo, any mutation outside of the germline cells can not be passed down to an organism's offspring.
However, somatic mutations are passed down to all the progeny of a mutated cell within the same organism. A major section of an organism therefore might carry the same mutation, especially if that mutation occurs at earlier stages of development. Somatic mutations that occur later in an organism's life can be hard to detect, as they may affect only a single cell - for instance, a post-mitotic neuron; improvements in single cell sequencing are therefore an important tool for the study of somatic mutation. Both the nuclear DNA and mitochondrial DNA of a cell can accumulate mutations; somatic mitochondrial mutations have been implicated i
Document 4:::
The Encyclopedia of Genetics () is a print encyclopedia of genetics edited by Sydney Brenner and Jeffrey H. Miller. It has four volumes and 1,700 entries. It is available online at http://www.sciencedirect.com/science/referenceworks/9780122270802.
Genetics
Genetics literature
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A mutation that occurs in an organism that reproduces sexually will most likely affect the traits of the offspring if the mutation
A. is located in the cells of the nervous system.
B. alters DNA in a gamete of the parent.
C. alters the behavior of the organisms.
D. is located near the locus of a chromosome.
Answer:
|
|
sciq-8932
|
multiple_choice
|
What term is used to describe cells without a nucleus?
|
[
"unicellular",
"prokaryotic",
"monophyletic",
"Simple"
] |
B
|
Relavent Documents:
Document 0:::
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
Document 1:::
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 2:::
The nucleoplasm, also known as karyoplasm, is the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. It is enclosed by the nuclear envelope, also known as the nuclear membrane. The nucleoplasm resembles the cytoplasm of a eukaryotic cell in that it is a gel-like substance found within a membrane, although the nucleoplasm only fills out the space in the nucleus and has its own unique functions. The nucleoplasm suspends structures within the nucleus that are not membrane-bound and is responsible for maintaining the shape of the nucleus. The structures suspended in the nucleoplasm include chromosomes, various proteins, nuclear bodies, the nucleolus, nucleoporins, nucleotides, and nuclear speckles.
The soluble, liquid portion of the nucleoplasm is called the karyolymph nucleosol, or nuclear hyaloplasm.
History
The existence of the nucleus, including the nucleoplasm, was first documented as early as 1682 by the Dutch microscopist Leeuwenhoek and was later described and drawn by Franz Bauer. However, the cell nucleus was not named and described in detail until Robert Brown's presentation to the Linnean Society in 1831.
The nucleoplasm, while described by Bauer and Brown, was not specifically isolated as a separate entity until its naming in 1882 by Polish-German scientist Eduard Strasburger, one of the most famous botanists of the 19th century, and the first person to discover mitosis in plants.
Role
Many important cell functions take place in the nucleus, more specifically in the nucleoplasm. The main function of the nucleoplasm is to provide the proper environment for essential processes that take place in the nucleus, serving as the suspension substance for all organelles inside the nucleus, and storing the structures that are used in these processes. 34% of proteins encoded in the human genome are ones that localize to the nucleoplasm. These proteins take part in RNA transcription and gene regulation in the n
Document 3:::
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 4:::
In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
The theory was once universally accepted, but now some biologists consider non-cellular entities such as viruses living organisms, and thus disagree with the first tenet. As of 2021: "expert opinion remains divided roughly a third each between yes, no and don’t know". As there is no universally accepted definition of life, discussion still continues.
History
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 it was believed no one else had seen these. To further support his theory, Matthias Schleiden and Theodor Schwann both also studied cells of both animal and plants. What they discovered were significant differences between the two types of cells. This put forth the idea that cells were not only fundamental to plants, but animals as well.
Microscopes
The discovery of the cell was made possible through the invention of the microscope. In the first century BC, Romans were able to make glass. They discovered that objects appeared to be larger under the glass. The expanded use of lenses in eyeglasses in the 13th century probably led to wider spread use of simple microscopes (magnifying glasses) with limited magnification. Compound microscopes, which combine an objective lens with an eyepiece to view a real image achieving much higher magnification, first appeared in Europe around 1620. In 1665, Robert Hooke used a microscope
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term is used to describe cells without a nucleus?
A. unicellular
B. prokaryotic
C. monophyletic
D. Simple
Answer:
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|
sciq-8298
|
multiple_choice
|
Mollusks such as squid and octopi, which must hunt to survive, possess what complex organs containing millions of neurons?
|
[
"brains",
"tentacles",
"gills",
"hearts"
] |
A
|
Relavent Documents:
Document 0:::
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 1:::
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 2:::
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 3:::
Jennifer M. Li is a Systems Neuroscience & Neuroengineering researcher who is a Max Planck Research Group Leader at the RoLi lab at the Max Planck Institute for Biological Cybernetics. She records and manipulates neural activity in larval zebra fish to research motivation and attention. and has been published in the journal Nature for her work on how the zebra fish brain switches between internal states when foraging for live prey. The RoLi lab has developed a revolutionary microscopy systems that enable whole-brain imaging of freely swimming larval zebra fish. With this technology, Li and Robson aim to investigate natural behaviors in the zebra fish, including spatial navigation, social behavior, feeding, and reward.
Background and education
Jennifer Li received her B.A. in Molecular Biology from Princeton University, where she worked on host-parasite symbiosis and embryonic development in the Wieschaus lab. She received her Ph.D. from Harvard University, where she worked on operant learning and brain-wide neural imaging in the Schier and Engert labs. During her graduate education at Harvard University, Li was a Rowland Junior Fellow in the Rowland Institute at Harvard University. At the Rowland Institute, Li, along with Drew Robson, led their experiment on zebra fish before finishing the project at the Max Planck Institute for Biological Cybernetics.
Career
Jennifer Li and Drew Robson combined brain tracking with a variant of HiLo microscopy to build Differential Illumination Focal Filtering (DIFF) microscopy
Publications
Her most cited publications are:
Misha B Ahrens, Michael B Orger, Drew N Robson, Jennifer M Li, Philipp J Keller, "Whole-brain functional imaging at cellular resolution using light-sheet microscopy" Nature Methods 10 (5), 413-420 (2013)
MB Ahrens, JM Li, MB Orger, DN Robson, AF Schier, F Engert, ... "Brain-wide neuronal dynamics during motor adaptation in zebrafish" Nature 485 (7399), 471-477 (2012)
HM Frydman, JM Li, DN Robson, E Wieschaus,
Document 4:::
The optic glands are endocrine organs in the octopus and squid that play a role in sexual development and senescence. They lie between the brain and optic lobes. The optic gland in female octopuses is associated with their maternal behavior of guarding their eggs without feeding. This self-starvation results in the death of the female octopus before her eggs have hatched. In captivity, some starving females also self-mutilate and entangle their arms in an apparent effort to die even faster.
Removal
Removal of the gland causes the octopus to abandon their eggs and return to feeding. The female octopus then eats further, doubles its weight and doubles its lifespan.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Mollusks such as squid and octopi, which must hunt to survive, possess what complex organs containing millions of neurons?
A. brains
B. tentacles
C. gills
D. hearts
Answer:
|
|
sciq-4304
|
multiple_choice
|
Rna is especially important during synthesis of what?
|
[
"sulfur",
"glucose",
"protein",
"mitochondria"
] |
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:::
Ribozymes (ribonucleic acid enzymes) are RNA molecules that have the ability to catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes. The 1982 discovery of ribozymes demonstrated that RNA can be both genetic material (like DNA) and a biological catalyst (like protein enzymes), and contributed to the RNA world hypothesis, which suggests that RNA may have been important in the evolution of prebiotic self-replicating systems.
The most common activities of natural or in vitro evolved ribozymes are the cleavage (or ligation) of RNA and DNA and peptide bond formation. For example, the smallest ribozyme known (GUGGC-3') can aminoacylate a GCCU-3' sequence in the presence of PheAMP. Within the ribosome, ribozymes function as part of the large subunit ribosomal RNA to link amino acids during protein synthesis. They also participate in a variety of RNA processing reactions, including RNA splicing, viral replication, and transfer RNA biosynthesis. Examples of ribozymes include the hammerhead ribozyme, the VS ribozyme, leadzyme, and the hairpin ribozyme.
Researchers who are investigating the origins of life through the RNA world hypothesis have been working on discovering a ribozyme with the capacity to self-replicate, which would require it to have the ability to catalytically synthesize polymers of RNA. This should be able to happen in prebiotically plausible conditions with high rates of copying accuracy to prevent degradation of information but also allowing for the occurrence of occasional errors during the copying process to allow for Darwinian evolution to proceed.
Attempts have been made to develop ribozymes as therapeutic agents, as enzymes which target defined RNA sequences for cleavage, as biosensors, and for applications in functional genomics and gene discovery.
Discovery
Before the discovery of ribozymes, enzymes—which are defined as catalytic proteins—were the only known biological catal
Document 2:::
This is a list of topics in molecular biology. See also index of biochemistry articles.
Document 3:::
A gene product is the biochemical material, either RNA or protein, resulting from expression of a gene. A measurement of the amount of gene product is sometimes used to infer how active a gene is. Abnormal amounts of gene product can be correlated with disease-causing alleles, such as the overactivity of oncogenes which can cause cancer.
A gene is defined as "a hereditary unit of DNA that is required to produce a functional product". Regulatory elements include:
Promoter region
TATA box
Polyadenylation sequences
Enhancers
These elements work in combination with the open reading frame to create a functional product. This product may be transcribed and be functional as RNA or is translated from mRNA to a protein to be functional in the cell.
RNA products
RNA molecules that do not code for any proteins still maintain a function in the cell. The function of the RNA depends on its classification. These roles include:
aiding protein synthesis
catalyzing reactions
regulating various processes.
Protein synthesis is aided by functional RNA molecules such as tRNA, which helps add the correct amino acid to a polypeptide chain during translation, rRNA, a major component of ribosomes (which guide protein synthesis), as well as mRNA which carry the instructions for creating the protein product.
One type of functional RNA involved in regulation are microRNA (miRNA), which works by repressing translation. These miRNAs work by binding to a complementary target mRNA sequence to prevent translation from occurring. Short-interfering RNA (siRNA) also work by negative regulation of transcription. These siRNA molecules work in RNA-induced silencing complex (RISC) during RNA interference by binding to a target DNA sequence to prevent transcription of a specific mRNA.
Protein products
Proteins are the product of a gene that are formed from translation of a mature mRNA molecule. Proteins contain 4 elements in regards to their structure: primary, secondary, tertiary and quaternary.
Document 4:::
The RNP world is a hypothesized intermediate period in the origin of life characterized by the existence of ribonucleoproteins. The period followed the hypothesized RNA world and ended with the formation of DNA and contemporary proteins. In the RNP world, RNA molecules began to synthesize peptides. These would eventually become proteins which have since assumed most of the diverse functions RNA performed previously. This transition paved the way for DNA to replace RNA as the primary store of genetic information, leading to life as we know it.
Principle of concept
Thomas Cech, in 2009, proposed the existence of the RNP world after his observation of apparent differences in the composition of catalysts in the two most fundamental processes that maintain and express genetic systems. The maintenance process, DNA replication and transcription, is accomplished purely by protein polymerases. The gene expression process, mRNA splicing and protein synthesis, is catalyzed by RNP complexes (the spliceosome and ribosome).
The difference between how these processes catalyze can be reconciled with the RNA world theory. As an older molecule than DNA, RNA had a hybrid RNA-protein-based maintenance system. Our current DNA world could have resulted from the gradual replacement of RNA catalysis machines with proteins. In this view, ribonucleoproteins and nucleotide-based cofactors are relics of an intermediary era, the RNP world.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Rna is especially important during synthesis of what?
A. sulfur
B. glucose
C. protein
D. mitochondria
Answer:
|
|
sciq-837
|
multiple_choice
|
What kind of behavior occurs only after experience or practice and describes most human behaviors?
|
[
"inherited behavior",
"learned behavior",
"practiced behavior",
"innate behavior"
] |
B
|
Relavent Documents:
Document 0:::
Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machines; there is also evidence for some kind of learning in certain plants. Some learning is immediate, induced by a single event (e.g. being burned by a hot stove), but much skill and knowledge accumulate from repeated experiences. The changes induced by learning often last a lifetime, and it is hard to distinguish learned material that seems to be "lost" from that which cannot be retrieved.
Human learning starts at birth (it might even start before in terms of an embryo's need for both interaction with, and freedom within its environment within the womb.) and continues until death as a consequence of ongoing interactions between people and their environment. The nature and processes involved in learning are studied in many established fields (including educational psychology, neuropsychology, experimental psychology, cognitive sciences, and pedagogy), as well as emerging fields of knowledge (e.g. with a shared interest in the topic of learning from safety events such as incidents/accidents, or in collaborative learning health systems). Research in such fields has led to the identification of various sorts of learning. For example, learning may occur as a result of habituation, or classical conditioning, operant conditioning or as a result of more complex activities such as play, seen only in relatively intelligent animals. Learning may occur consciously or without conscious awareness. Learning that an aversive event cannot be avoided or escaped may result in a condition called learned helplessness. There is evidence for human behavioral learning prenatally, in which habituation has been observed as early as 32 weeks into gestation, indicating that the central nervous system is sufficiently developed and primed for learning and memory to occur very early on in development.
Play h
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Evolutionary educational psychology is the study of the relation between inherent folk knowledge and abilities and accompanying inferential and attributional biases as these influence academic learning in evolutionarily novel cultural contexts, such as schools and the industrial workplace. The fundamental premises and principles of this discipline are presented below.
Premises
The premises of evolutionary educational psychology state there are:
(a) aspects of mind and brain that have evolved to draw the individuals’ attention to and facilitate the processing of social (folk psychology), biological (folk biology), physical (folk physics) information patterns that facilitated survival or reproductive outcomes during human evolution (Cosmides & Tooby, 1994; Geary, 2005; Gelman, 1990; Pinker, 1997; Shepard, 1994; Simon, 1956);
(b) although plastic to some degree, these primary abilities are inherently constrained to the extent associated information patterns tended to be consistent across generations and within lifetimes (e.g., Caramazza & Shelton, 1998; Geary & Huffman, 2002);
(c) other aspects of mind and brain evolved to enable the mental generation of potential future social, ecological, or climatic conditions and enable rehearsal of behaviors to cope with variation in these conditions, and are now known as general fluid intelligence, or gF (including skill at everyday reasoning/problem solving; Chiappe & MacDonald, 2005; Geary, 2005; Mithen, 1996); and
(d) children are inherently motivated to learn in folk domains, with the associated attentional and behavioral biases resulting in experiences that automatically and implicitly flesh out and adapt these systems to local conditions (Gelman, 1990; Gelman & Williams, 1998; Gelman, 2003).
Principles
The principles of evolutionary educational psychology represent the foundational assumptions for an evolutionary educational psychology. The gist is knowledge and expertise that is useful in the cultural milieu or ecolo
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Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing innate (inborn) elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to medium length sequence of actions, without variation, are carried out in response to a corresponding clearly defined stimulus.
Any behaviour is instinctive if it is performed without being based upon prior experience (that is, in the absence of learning), and is therefore an expression of innate biological factors. Sea turtles, newly hatched on a beach, will instinctively move toward the ocean. A marsupial climbs into its mother's pouch upon being born. Other examples include animal fighting, animal courtship behaviour, internal escape functions, and the building of nests. Though an instinct is defined by its invariant innate characteristics, details of its performance can be changed by experience; for example, a dog can improve its listening skills by practice.
Instincts are inborn complex patterns of behaviour that exist in most members of the species, and should be distinguished from reflexes, which are simple responses of an organism to a specific stimulus, such as the contraction of the pupil in response to bright light or the spasmodic movement of the lower leg when the knee is tapped. The absence of volitional capacity must not be confused with an inability to modify fixed action patterns. For example, people may be able to modify a stimulated fixed action pattern by consciously recognizing the point of its activation and simply stop doing it, whereas animals without a sufficiently strong volitional capacity may not be able to disengage from their fixed action patterns, once activated.
Instinctual behaviour in humans has been studied.
Early theorists
Jean Henri Fabre
Jean Henri Fabre (1823–1915) is said to be the first person to study small animals (that weren't birds) and insects, and he specifically specialized i
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Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as well as the inanimate physical environment. It is the computed response of the system or organism to various stimuli or inputs, whether internal or external, conscious or subconscious, overt or covert, and voluntary or involuntary.
Taking a behavior informatics perspective, a behavior consists of actor, operation, interactions, and their properties. This can be represented as a behavior vector.
Models
Biology
Although disagreement exists as to how to precisely define behavior in a biological context, one common interpretation based on a meta-analysis of scientific literature states that "behavior is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal or external stimuli".
A broader definition of behavior, applicable to plants and other organisms, is similar to the concept of phenotypic plasticity. It describes behavior as a response to an event or environment change during the course of the lifetime of an individual, differing from other physiological or biochemical changes that occur more rapidly, and excluding changes that are a result of development (ontogeny).
Behaviors can be either innate or learned from the environment.
Behavior can be regarded as any action of an organism that changes its relationship to its environment. Behavior provides outputs from the organism to the environment.
Human behavior
The endocrine system and the nervous system likely influence human behavior. Complexity in the behavior of an organism may be correlated to the complexity of its nervous system. Generally, organisms with more complex nervous systems have a greater capacity to learn new responses and thus adjust their behavior.
Animal behavior
Ethology is the scientifi
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Observational learning is learning that occurs through observing the behavior of others. It is a form of social learning which takes various forms, based on various processes. In humans, this form of learning seems to not need reinforcement to occur, but instead, requires a social model such as a parent, sibling, friend, or teacher with surroundings. Particularly in childhood, a model is someone of authority or higher status in an environment. In animals, observational learning is often based on classical conditioning, in which an instinctive behavior is elicited by observing the behavior of another (e.g. mobbing in birds), but other processes may be involved as well.
Human observational learning
Many behaviors that a learner observes, remembers, and imitates are actions that models display and display modeling, even though the model may not intentionally try to instill a particular behavior. A child may learn to swear, smack, smoke, and deem other inappropriate behavior acceptable through poor modeling. Albert Bandura claims that children continually learn desirable and undesirable behavior through observational learning. Observational learning suggests that an individual's environment, cognition, and behavior all incorporate and ultimately determine how the individual functions and models.
Through observational learning, individual behaviors can spread across a culture through a process called diffusion chain. This basically occurs when an individual first learns a behavior by observing another individual and that individual serves as a model through whom other individuals learn the behavior, and so on.
Culture plays a role in whether observational learning is the dominant learning style in a person or community. Some cultures expect children to actively participate in their communities and are therefore exposed to different trades and roles on a daily basis. This exposure allows children to observe and learn the different skills and practices that are valued i
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of behavior occurs only after experience or practice and describes most human behaviors?
A. inherited behavior
B. learned behavior
C. practiced behavior
D. innate behavior
Answer:
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|
sciq-7139
|
multiple_choice
|
What is a relationship between organisms that strive for the same resources in the same place?
|
[
"antagonistic",
"symbiotic",
"competition",
"parasitic"
] |
C
|
Relavent Documents:
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Any action or influence that species have on each other is considered a biological interaction. These interactions between species can be considered in several ways. One such way is to depict interactions in the form of a network, which identifies the members and the patterns that connect them. Species interactions are considered primarily in terms of trophic interactions, which depict which species feed on others.
Currently, ecological networks that integrate non-trophic interactions are being built. The type of interactions they can contain can be classified into six categories: mutualism, commensalism, neutralism, amensalism, antagonism, and competition.
Observing and estimating the fitness costs and benefits of species interactions can be very problematic. The way interactions are interpreted can profoundly affect the ensuing conclusions.
Interaction characteristics
Characterization of interactions can be made according to various measures, or any combination of them.
Prevalence
Prevalence identifies the proportion of the population affected by a given interaction, and thus quantifies whether it is relatively rare or common. Generally, only common interactions are considered.
Negative/ Positive
Whether the interaction is beneficial or harmful to the species involved determines the sign of the interaction, and what type of interaction it is classified as. To establish whether they are harmful or beneficial, careful observational and/or experimental studies can be conducted, in an attempt to establish the cost/benefit balance experienced by the members.
Strength
The sign of an interaction does not capture the impact on fitness of that interaction. One example of this is of antagonism, in which predators may have a much stronger impact on their prey species (death), than parasites (reduction in fitness). Similarly, positive interactions can produce anything from a negligible change in fitness to a life or death impact.
Relationship in space and time
The rel
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In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species (interspecific interactions). These effects may be short-term, or long-term, both often strongly influence the adaptation and evolution of the species involved. Biological interactions range from mutualism, beneficial to both partners, to competition, harmful to both partners. Interactions can be direct when physical contact is established or indirect, through intermediaries such as shared resources, territories, ecological services, metabolic waste, toxins or growth inhibitors. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship.
Several recent studies have suggested non-trophic species interactions such as habitat modification and mutualisms can be important determinants of food web structures. However, it remains unclear whether these findings generalize across ecosystems, and whether non-trophic interactions affect food webs randomly, or affect specific trophic levels or functional groups.
History
Although biological interactions, more or less individually, were studied earlier, Edward Haskell (1949) gave an integrative approach to the thematic, proposing a classification of "co-actions", later adopted by biologists as "interactions". Close and long-term interactions are described as symbiosis; symbioses that are mutually beneficial are called mutualistic.
The term symbiosis was subject to a century-long debate about whether it should specifically denote mutualism, as in lichens or in parasites that benefit themselves. This debate created two different classifications for biotic interactions, one based on the time (long-term and short-term interactions), and other based on the magnitud of interaction force (competition/mutualism) or effect of individual fitness, accordi
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Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences reduced fitness, and exploitation, or parasitism, in which one species benefits at the expense of the other.
The term mutualism was introduced by Pierre-Joseph van Beneden in his 1876 book Animal Parasites and Messmates to mean "mutual aid among species".
Mutualism is often conflated with two other types of ecological phenomena: cooperation and symbiosis. Cooperation most commonly refers to increases in fitness through within-species (intraspecific) interactions, although it has been used (especially in the past) to refer to mutualistic interactions, and it is sometimes used to refer to mutualistic interactions that are not obligate. Symbiosis involves two species living in close physical contact over a long period of their existence and may be mutualistic, parasitic, or commensal, so symbiotic relationships are not always mutualistic, and mutualistic interactions are not always symbiotic. Despite a different definition between mutualistic interactions and symbiosis, mutualistic and symbiosis have been largely used interchangeably in the past, and confusion on their use has persisted.
Mutualism plays a key part in ecology and evolution. For example, mutualistic interactions are vital for terrestrial ecosystem function as about 80% of land plants species rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements. As another example, the estimate of tropical rainforest plants with seed dispersal mutualisms with animals ranges
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The hypothesis or paradigm of Mutualism Parasitism Continuum postulates that compatible host-symbiont associations can occupy a broad continuum of interactions with different fitness outcomes for each member.
At one end of the continuum lies obligate mutualism where both host and symbiont benefit from the interaction and are dependent on it for survival. At the other end of the continuum highly parasitic interactions can occur, where one member gains a fitness benefit at the expense of the others survival. Between these extremes many different types of interaction are possible.
The degree of change between mutualism or parasitism varies depending on the availability of resources, where there is environmental stress generated by few resources, symbiotic relationships are formed while in environments where there is an excess of resources, biological interactions turn to competition and parasitism.
Classically the transmission mode of the symbiont can also be important in predicting where on the mutualism-parasitism-continuum an interaction will sit. Symbionts that are vertically transmitted (inherited symbionts) frequently occupy mutualism space on the continuum, this is due to the aligned reproductive interests between host and symbiont that are generated under vertical transmission. In some systems increases in the relative contribution of horizontal transmission can drive selection for parasitism.
Studies of this hypothesis have focused on host-symbiont models of plants and fungi, and also of animals and microbes.
See also
Red King Hypothesis
Red Queen Hypothesis
Black Queen Hypothesis
Biological interaction
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Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resources in an ecosystem (e.g. food or living space). This can be contrasted with mutualism, a type of symbiosis. Competition between members of the same species is called intraspecific competition.
If a tree species in a dense forest grows taller than surrounding tree species, it is able to absorb more of the incoming sunlight. However, less sunlight is then available for the trees that are shaded by the taller tree, thus interspecific competition. Leopards and lions can also be in interspecific competition, since both species feed on the same prey, and can be negatively impacted by the presence of the other because they will have less food.
Competition is only one of many interacting biotic and abiotic factors that affect community structure. Moreover, competition is not always a straightforward, direct, interaction. Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area. If the resource cannot support both populations, then lowered fecundity, growth, or survival may result in at least one species. Interspecific competition has the potential to alter populations, communities and the evolution of interacting species. On an individual organism level, competition can occur as interference or exploitative competition.
Types
All of the types described here can also apply to intraspecific competition, that is, competition among individuals within a species. Also, any specific example of interspecific competition can be described in terms of both a mechanism (e.g., resource or interference) and an outcome (symmetric or asymmetric).
Based on mechanism
Exploitative competition, also referred to as resource competition, is a form of competition in which one species consumes and either reduces or more efficiently uses a shared limiting resource and therefore depletes the availab
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a relationship between organisms that strive for the same resources in the same place?
A. antagonistic
B. symbiotic
C. competition
D. parasitic
Answer:
|
|
sciq-3146
|
multiple_choice
|
Asthma affects what tiny branches into which the bronchi are divided?
|
[
"platelets",
"cilia",
"macrophages",
"bronchioles"
] |
D
|
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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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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Lung receptors sense irritation or inflammation in the bronchi and alveoli.
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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)
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This list of life sciences comprises the branches of science that involve the scientific study of life – such as microorganisms, plants, and animals including human beings. This science is one of the two major branches of natural science, the other being physical science, which is concerned with non-living matter. Biology is the overall natural science that studies life, with the other life sciences as its sub-disciplines.
Some life sciences focus on a specific type of organism. For example, zoology is the study of animals, while botany is the study of plants. Other life sciences focus on aspects common to all or many life forms, such as anatomy and genetics. Some focus on the micro-scale (e.g. molecular biology, biochemistry) other on larger scales (e.g. cytology, immunology, ethology, pharmacy, ecology). Another major branch of life sciences involves understanding the mindneuroscience. Life sciences discoveries are helpful in improving the quality and standard of life and have applications in health, agriculture, medicine, and the pharmaceutical and food science industries. For example, it has provided information on certain diseases which has overall aided in the understanding of human health.
Basic life science branches
Biology – scientific study of life
Anatomy – study of form and function, in plants, animals, and other organisms, or specifically in humans
Astrobiology – the study of the formation and presence of life in the universe
Bacteriology – study of bacteria
Biotechnology – study of combination of both the living organism and technology
Biochemistry – study of the chemical reactions required for life to exist and function, usually a focus on the cellular level
Bioinformatics – developing of methods or software tools for storing, retrieving, organizing and analyzing biological data to generate useful biological knowledge
Biolinguistics – the study of the biology and evolution of language.
Biological anthropology – the study of humans, non-hum
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Asthma affects what tiny branches into which the bronchi are divided?
A. platelets
B. cilia
C. macrophages
D. bronchioles
Answer:
|
|
sciq-9379
|
multiple_choice
|
What is the outermost part of the sun's atmosphere called?
|
[
"rays",
"particles",
"corona",
"ultraviolet"
] |
C
|
Relavent Documents:
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Limb darkening is an optical effect seen in stars (including the Sun) and planets, where the central part of the disk appears brighter than the edge, or limb. Its understanding offered early solar astronomers an opportunity to construct models with such gradients. This encouraged the development of the theory of radiative transfer.
Basic theory
Optical depth, a measure of the opacity of an object or part of an object, combines with effective temperature gradients inside the star to produce limb darkening. The light seen is approximately the integral of all emission along the line of sight modulated by the optical depth to the viewer (i.e. 1/e times the emission at 1 optical depth, 1/e2 times the emission at 2 optical depths, etc.). Near the center of the star, optical depth is effectively infinite, causing approximately constant brightness. However, the effective optical depth decreases with increasing radius due to lower gas density and a shorter line of sight distance through the star, producing a gradual dimming, until it becomes zero at the apparent edge of the star.
The effective temperature of the photosphere also decreases with increasing distance from the center of the star. The radiation emitted from a gas is approximately black-body radiation, the intensity of which is proportional to the fourth power of the temperature. Therefore, even in line of sight directions where the optical depth is effectively infinite, the emitted energy comes from cooler parts of the photosphere, resulting in less total energy reaching the viewer.
The temperature in the atmosphere of a star does not always decrease with increasing height. For certain spectral lines, the optical depth is greatest in regions of increasing temperature. In this scenario, the phenomenon of "limb brightening" is seen instead. In the Sun, the existence of a temperature minimum region means that limb brightening should start to dominate at far-infrared or radio wavelengths. Above the lower atmosphe
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Solar radio emission refers to radio waves that are naturally produced by the Sun, primarily from the lower and upper layers of the atmosphere called the chromosphere and corona, respectively. The Sun produces radio emissions through four known mechanisms, each of which operates primarily by converting the energy of moving electrons into electromagnetic radiation. The four emission mechanisms are thermal bremsstrahlung (braking) emission, gyromagnetic emission, plasma emission, and electron-cyclotron maser emission. The first two are incoherent mechanisms, which means that they are the summation of radiation generated independently by many individual particles. These mechanisms are primarily responsible for the persistent "background" emissions that slowly vary as structures in the atmosphere evolve. The latter two processes are coherent mechanisms, which refers to special cases where radiation is efficiently produced at a particular set of frequencies. Coherent mechanisms can produce much larger brightness temperatures (intensities) and are primarily responsible for the intense spikes of radiation called solar radio bursts, which are byproducts of the same processes that lead to other forms of solar activity like solar flares and coronal mass ejections.
History and observations
Radio emission from the Sun was first reported in the scientific literature by Grote Reber in 1944. Those were observations of 160 MHz frequency (2 meters wavelength) microwave emission emanating from the chromosphere. However, the earliest known observation was in 1942 during World War II by British radar operators who detected an intense low-frequency solar radio burst; that information was kept secret as potentially useful in evading enemy radar, but was later described in a scientific journal after the war. One of the most significant discoveries from early solar radio astronomers such as Joseph Pawsey was that the Sun produces much more radio emission than expected from standard blac
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Aeronomy is the scientific study of the upper atmosphere of the Earth and corresponding regions of the atmospheres of other planets. It is a branch of both atmospheric chemistry and atmospheric physics. Scientists specializing in aeronomy, known as aeronomers, study the motions and chemical composition and properties of the Earth's upper atmosphere and regions of the atmospheres of other planets that correspond to it, as well as the interaction between upper atmospheres and the space environment. In atmospheric regions aeronomers study, chemical dissociation and ionization are important phenomena.
History
The mathematician Sydney Chapman introduced the term aeronomy to describe the study of the Earth's upper atmosphere in 1946 in a letter to the editor of Nature entitled "Some Thoughts on Nomenclature." The term became official in 1954 when the International Union of Geodesy and Geophysics adopted it. "Aeronomy" later also began to refer to the study of the corresponding regions of the atmospheres of other planets.
Branches
Aeronomy can be divided into three main branches: terrestrial aeronomy, planetary aeronomy, and comparative aeronomy.
Terrestrial aeronomy
Terrestrial aeronomy focuses on the Earth's upper atmosphere, which extends from the stratopause to the atmosphere's boundary with outer space and is defined as consisting of the mesosphere, thermosphere, and exosphere and their ionized component, the ionosphere. Terrestrial aeronomy contrasts with meteorology, which is the scientific study of the Earth's lower atmosphere, defined as the troposphere and stratosphere. Although terrestrial aeronomy and meteorology once were completely separate fields of scientific study, cooperation between terrestrial aeronomers and meteorologists has grown as discoveries made since the early 1990s have demonstrated that the upper and lower atmospheres have an impact on one another's physics, chemistry, and biology.
Terrestrial aeronomers study atmospheric tides and upper-
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:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the outermost part of the sun's atmosphere called?
A. rays
B. particles
C. corona
D. ultraviolet
Answer:
|
|
sciq-6204
|
multiple_choice
|
Where does oxygen enter the blood?
|
[
"in the lungs",
"in the veins",
"in the liver",
"in the heart"
] |
A
|
Relavent Documents:
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In respiratory physiology, the oxygen cascade describes the flow of oxygen from air to mitochondria, where it is consumed in aerobic respiration to release energy. Oxygen flows from areas with high partial pressure of oxygen (PO2, also known as oxygen tension) to areas of lower PO2.
Air is typically around 21% oxygen, and at sea level, the PO2 of air is typically around 159 mmHg. Humidity dilutes the concentration of oxygen in air. As air is inhaled into the lungs, it mixes with water and exhaust gasses including CO2, further diluting the oxygen concentration and lowering the PO2. As oxygen continues to flow down the concentration gradient from areas of higher concentration to areas of lower concentration, it must pass through barriers such as the alveoli walls, capillary walls, capillary blood plasma, red blood cell membrane, interstitial space, other cell membranes, and cell cytoplasm. The partial pressure of oxygen drops across each barrier.
Table
Table 1 gives the example of a typical oxygen cascade for skeletal muscle of a healthy, adult male at rest who is breathing air at atmospheric pressure at sea level. Actual values in a person may vary widely due to ambient conditions, health status, tissue type, and metabolic demands.
See also
Alveolar–arterial gradient
Alveolar gas equation
Blood gas tension
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The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs. In the lungs the blood is oxygenated and returned to the left atrium to complete the circuit.
The other division of the circulatory system is the systemic circulation that begins with receiving the oxygenated blood from the pulmonary circulation into the left atrium. From the atrium the oxygenated blood enters the left ventricle where it is pumped out to the rest of the body, returning as deoxygenated blood back to the pulmonary circulation.
The blood vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary veins.
A separate circulatory circuit known as the bronchial circulation supplies oxygenated blood to the tissue of the larger airways of the lung.
Structure
De-oxygenated blood leaves the heart, goes to the lungs, and then enters back into the heart. De-oxygenated blood leaves through the right ventricle through the pulmonary artery. From the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve) into the right ventricle. Blood is then pumped from the right ventricle through the pulmonary valve and into the pulmonary artery.
Lungs
The pulmonary arteries carry deoxygenated blood to the lungs, where carbon dioxide is released and oxygen is picked up during respiration. Arteries are further divided into very fine capillaries which are extremely thin-walled. The pulmonary veins return oxygenated blood to the left atrium of the heart.
Veins
Oxygenated blood leaves the lungs through pulmonary veins, which return it to the left part of the heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. From the left ventricle, the blood passes through the aortic valve to the
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In acid base physiology, the Davenport diagram is a graphical tool, developed by Horace W. Davenport, that allows a clinician or investigator to describe blood bicarbonate concentrations and blood pH following a respiratory and/or metabolic acid-base disturbance. The diagram depicts a three-dimensional surface describing all possible states of chemical equilibria between gaseous carbon dioxide, aqueous bicarbonate and aqueous protons at the physiologically complex interface of the alveoli of the lungs and the alveolar capillaries. Although the surface represented in the diagram is experimentally determined, the Davenport diagram is rarely used in the clinical setting, but allows the investigator to envision the effects of physiological changes on blood acid-base chemistry. For clinical use there are two recent innovations: an Acid-Base Diagram which provides Text Descriptions for the abnormalities and a High Altitude Version that provides text descriptions appropriate for the altitude.
Derivation
When a sample of blood is exposed to air, either in the alveoli of the lung or in an in vitro laboratory experiment, carbon dioxide in the air rapidly enters into equilibrium with carbon dioxide derivatives and other species in the aqueous solution. Figure 1 illustrates the most important equilibrium reactions of carbon dioxide in blood relating to acid-base physiology:
Note that in this equation, the HB/B- buffer system represents all non-bicarbonate buffers present in the blood, such as hemoglobin in its various protonated and deprotonated states. Because many different non-bicarbonate buffers are present in human blood, the final equilibrium state reached at any given pCO2 is highly complex and cannot be readily predicted using theory alone. By depicting experimental results, the Davenport diagram provides a simple approach to describing the behavior of this complex system.
Figure 2 shows a Davenport diagram as commonly depicted in textbooks and the literature. To un
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An oxygen bar is an establishment, or part of one, that sells oxygen for recreational use. Individual scents may be added to enhance the experience. The flavors in an oxygen bar come from bubbling oxygen through bottles containing aromatic solutions before it reaches the nostrils: most bars use food-grade particles to produce the scent, but some bars use aroma oils.
History
In 1776, Thomas Henry, an apothecary and Fellow of the Royal Society of England speculated tongue in cheek that Joseph Priestley’s newly discovered dephlogisticated air (now called oxygen) might become "as fashionable as French wine at the fashionable taverns". He did not expect, however, that tavern goers would "relish calling for a bottle of Air, instead of Claret."
Another early reference to the recreational use of oxygen is found in Jules Verne's 1870 novel Around the Moon. In this work, Verne states:
Modeled after the "air stations" in polluted downtown Tokyo and Beijing, the first oxygen bar (the O2 Spa Bar) opened in Toronto, Canada, in 1996. The trend continued in North America and by the late 1990s, bars were in use in New York, California, Florida, Las Vegas and the Rocky Mountain region. Customers in these bars breathe oxygen through a plastic nasal cannula inserted into their nostrils. Oxygen bars can now be found in many venues such as nightclubs, salons, spas, health clubs, resorts, tanning salons, restaurants, coffee houses, bars, airports, ski chalets, yoga studios, chiropractors, and casinos. They can also be found at trade shows, conventions and corporate meetings, as well as at private parties and promotional events.
Provision of oxygen
Oxygen bar guests pay about one U.S. dollar per minute to inhale a percentage of oxygen greater than the normal atmospheric content of 20.9% oxygen. This oxygen is gathered from the ambient air by an industrial (non-medical) oxygen concentrator and inhaled through a nasal cannula for up to about 20 minutes.
The machines used by oxygen ba
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Oxygen saturation is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 97–100 percent. If the level is below 90 percent, it is considered low and called hypoxemia. Arterial blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules () enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation.
Definition
In medicine, oxygen saturation, commonly referred to as "sats", measures the percentage of hemoglobin binding sites in the bloodstream occupied by oxygen. At low partial pressures of oxygen, most hemoglobin is deoxygenated. At around 90% (the value varies according to the clinical context) oxygen saturation increases according to an oxygen-hemoglobin dissociation curve and approaches 100% at partial oxygen pressures of >11 kPa. A pulse oximeter relies on the light absorption characteristics of saturated hemoglobin to give an indication of oxygen saturation.
Physiology
The body maintains a stable level of oxygen saturation for the most part by chemical processes of aerobic metabolism associated with breathing. Using the respiratory system, red blood cells, specifically the hemoglobin, gather oxygen in the lungs and distribute it to the rest of the body. The needs of the body's blood oxygen may fluctuate such as during exercise when more oxygen is required or when living at higher altitudes. A blood cell is said to be "saturated" when carrying a norma
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where does oxygen enter the blood?
A. in the lungs
B. in the veins
C. in the liver
D. in the heart
Answer:
|
|
sciq-2806
|
multiple_choice
|
What is the comparison of two factors within a population?
|
[
"hypothesis",
"curve",
"correlation",
"variable"
] |
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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Test equating traditionally refers to the statistical process of determining comparable scores on different forms of an exam. It can be accomplished using either classical test theory or item response theory.
In item response theory, equating is the process of placing scores from two or more parallel test forms onto a common score scale. The result is that scores from two different test forms can be compared directly, or treated as though they came from the same test form. When the tests are not parallel, the general process is called linking. It is the process of equating the units and origins of two scales on which the abilities of students have been estimated from results on different tests. The process is analogous to equating degrees Fahrenheit with degrees Celsius by converting measurements from one scale to the other. The determination of comparable scores is a by-product of equating that results from equating the scales obtained from test results.
Purpose
Suppose that Dick and Jane both take a test to become licensed in a certain profession. Because the high stakes (you get to practice the profession if you pass the test) may create a temptation to cheat, the organization that oversees the test creates two forms. If we know that Dick scored 60% on form A and Jane scored 70% on form B, do we know for sure which one has a better grasp of the material? What if form A is composed of very difficult items, while form B is relatively easy? Equating analyses are performed to address this very issue, so that scores are as fair as possible.
Equating in item response theory
In item response theory, person "locations" (measures of some quality being assessed by a test) are estimated on an interval scale; i.e., locations are estimated in relation to a unit and origin. It is common in educational assessment to employ tests in order to assess different groups of students with the intention of establishing a common scale by equating the origins, and when appropri
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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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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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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the comparison of two factors within a population?
A. hypothesis
B. curve
C. correlation
D. variable
Answer:
|
|
sciq-6437
|
multiple_choice
|
When vertebrate animals metabolize ammonia what is the primary byproduct that is produced?
|
[
"proteins",
"urea",
"carbon monoxide",
"dioxide"
] |
B
|
Relavent Documents:
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Metabolic wastes or excrements are substances left over from metabolic processes (such as cellular respiration) which cannot be used by the organism (they are surplus or toxic), and must therefore be excreted. This includes nitrogen compounds, water, CO2, phosphates, sulphates, etc. Animals treat these compounds as excretes. Plants have metabolic pathways which transforms some of them (primarily the oxygen compounds) into useful substances..
All the metabolic wastes are excreted in a form of water solutes through the excretory organs (nephridia, Malpighian tubules, kidneys), with the exception of CO2, which is excreted together with the water vapor throughout the lungs. The elimination of these compounds enables the chemical homeostasis of the organism.
Nitrogen wastes
The nitrogen compounds through which excess nitrogen is eliminated from organisms are called nitrogenous wastes () or nitrogen wastes. They are ammonia, urea, uric acid, and creatinine. All of these substances are produced from protein metabolism. In many animals, the urine is the main route of excretion for such wastes; in some, it is the feces.
Ammonotelism
Ammonotelism is the excretion of ammonia and ammonium ions. Ammonia (NH3) forms with the oxidation of amino groups.(-NH2), which are removed from the proteins when they convert into carbohydrates. It is a very toxic substance to tissues and extremely soluble in water. Only one nitrogen atom is removed with it. A lot of water is needed for the excretion of ammonia, about 0.5 L of water is needed per 1 g of nitrogen to maintain ammonia levels in the excretory fluid below the level in body fluids to prevent toxicity. Thus, the marine organisms excrete ammonia directly into the water and are called ammonotelic. Ammonotelic animals include crustaceans, platyhelminths, cnidarians, poriferans, echinoderms, and other aquatic invertebrates.
Ureotelism
The excretion of urea is called ureotelism. Land animals, mainly amphibians and mammals, convert
Document 1:::
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3(aq). Although the name ammonium hydroxide suggests an alkali with the composition , it is actually impossible to isolate samples of NH4OH. The ions and OH− do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions.
Basicity of ammonia in water
In aqueous solution, ammonia deprotonates a small fraction of the water to give ammonium and hydroxide according to the following equilibrium:
NH3 + H2O + OH−.
In a 1 M ammonia solution, about 0.42% of the ammonia is converted to ammonium, equivalent to pH = 11.63
because [] = 0.0042 M, [OH−] = 0.0042 M, [NH3] = 0.9958 M, and pH = 14 + log10[OH−] = 11.62. The base ionization constant is
Kb = = 1.77.
Saturated solutions
Like other gases, ammonia exhibits decreasing solubility in solvent liquids as the temperature of the solvent increases. Ammonia solutions decrease in density as the concentration of dissolved ammonia increases. At , the density of a saturated solution is 0.88 g/ml and contains 35.6% ammonia by mass, 308 grams of ammonia per litre of solution, and has a molarity of approximately 18 mol/L. At higher temperatures, the molarity of the saturated solution decreases and the density increases. Upon warming of saturated solutions, ammonia gas is released.
Applications
In contrast to anhydrous ammonia, aqueous ammonia finds few non-niche uses outside of cleaning agents.
Household cleaner
Diluted (1–3%) ammonia is also an ingredient of numerous cleaning agents, including many window cleaning formulas. Because aqueous ammonia is a gas dissolved in water, as the water evaporates from a window, the gas evaporates also, leaving the window streak-free.
In addition to use as an ingredient in cleansers with other cleansing ingredients,
Document 2:::
In chemistry, ammonolysis (/am·mo·nol·y·sis/) is the process of splitting ammonia into NH2- + H+. Ammonolysis reactions can be conducted with organic compounds to produce amines (molecules containing a nitrogen atom with a lone pair, :N), or with inorganic compounds to produce nitrides. This reaction is analogous to hydrolysis in which water molecules are split. Similar to water, liquid ammonia also undergoes auto-ionization, {2 NH3 ⇌ NH4+ + NH2- }, where the rate constant is k = 1.9 × 10-38.
Organic compounds such as alkyl halides, hydroxyls (hydroxyl nitriles and carbohydrates), carbonyl (aldehydes/ketones/esters/alcohols), and sulfur (sulfonyl derivatives) can all undergo ammonolysis in liquid ammonia.
Organic synthesis
Mechanism: ammonolysis of esters
This mechanism is similar to the hydrolysis of esters, the ammonia attacks the electrophilic carbonyl carbon forming a tetrahedral intermediate. The reformation of the C-O double bond ejects the ester. The alkoxide deprotonates the ammonia forming an alcohol and amide as products.
Of haloalkanes
On heating a haloalkane and concentrated ammonia in a sealed tube with ethanol, a series of amines are formed along with their salts. The tertiary amine is usually the major product.
{NH3 ->[\ce{RX}] RNH2 ->[\ce{RX}] R2NH ->[\ce{RX}] R3N ->[\ce{RX}] R4N+}
This is known as Hoffmann's ammonolysis.
Of alcohols
Alcohols can also undergo ammonolysis when in the presence of ammonia. An example is the conversion of phenol to aniline, catalyzed by stannic chloride.
ROH + NH3 A ->[\ce{TnCl4}] RNH2 + H2O
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The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems.
The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle. Human modification of the global nitrogen cycle can negatively affect the natural environment system and also human health.
Processes
Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, ammonium (), nitrite (), nitrate (), nitrous oxide (), nitric oxide (NO) or inorganic nitrogen gas (). Organic nitrogen may be in the form of a living organism, humus or in the intermediate products of organic matter decomposition. The processes in the nitrogen cycle is to transform nitrogen from one form to another. Many of those processes are carried out by microbes, either in their effort to harvest energy or to accumulate nitrogen in a form needed for their growth. For example, the nitrogenous wastes in animal urine are broken down by nitrifying bacteria in the soil to be used by plants. The diagram alongside shows how these processes fit together to form the nitrogen cycle.
Nitrogen fixation
The conversion of nitrogen gas () into nitrates
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Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (N2O) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of N2O emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems.
History of anthropogenic nitrogen inputs
Approximately 78% of earth's atmosphere is N gas (N2), which is an inert compound and biologically unavailable to most organisms. In order to be utilized in most biological processes, N2 must be converted to reactive nitrogen (Nr), which includes inorganic reduced forms (NH3 and NH4+), inorganic oxidized forms (NO, NO2, HNO3, N2O, and NO3−), and organic compounds (urea, amines, and proteins). N2 has a strong triple bond, and so a significant amount of energy (226 kcal mol−1) is required to convert N2 to Nr. Prior to industrial processes, the only sources of such energy were solar radiation and electrical discharges. Utilizing a large amount of metabolic energy and the enzyme nitrogenase, some bacteria and cyanobacteria convert atmospheric N2 to NH3, a process known as biological nitrogen fixation (BNF). The anthropogenic analogue to BNF is the Haber-Bosch process, in which H2 is reacted with atmospheric N2 at high temperatures and pressures to produce NH3. Lastly, N2 is converted to NO by energy from lightning, which is negligible in current temperate ecosystems, or by fossil fuel combustion.
Until 1850, natural BNF, cultivation-induced BNF (e.g., planting of leguminous crops), and incorporated organic matter wer
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When vertebrate animals metabolize ammonia what is the primary byproduct that is produced?
A. proteins
B. urea
C. carbon monoxide
D. dioxide
Answer:
|
|
ai2_arc-528
|
multiple_choice
|
Directions Read the information about wind erosion then answer the question. Wind can cause erosion that changes the surface of the Earth. Wind erosion can have negative effects on the environment by removing soil and polluting the air during dust storms. What is one way to prevent wind erosion?
|
[
"People can drive off-road bikes across the desert.",
"Ranchers can let their cattle graze in areas with little plant growth.",
"Construction workers can wet the ground before driving on it or digging.",
"Farmers can remove all plant material in the soil between planting seasons."
] |
C
|
Relavent Documents:
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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 1:::
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)
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Vegetation and slope stability are interrelated by the ability of the plant life growing on slopes to both promote and hinder the stability of the slope. The relationship is a complex combination of the type of soil, the rainfall regime, the plant species present, the slope aspect, and the steepness of the slope. Knowledge of the underlying slope stability as a function of the soil type, its age, horizon development, compaction, and other impacts is a major underlying aspect of understanding how vegetation can alter the stability of the slope. There are four major ways in which vegetation influences slope stability: wind throwing, the removal of water, mass of vegetation (surcharge), and mechanical reinforcement of roots.
Wind throwing
Wind throw is the toppling of a tree due to the force of the wind, this exposes the root plate and adjacent soil beneath the tree and influences slope stability. Wind throw is factor when considering one tree on a slope, however it is of lesser importance when considering general slope stability for a body of trees as the wind forces involved represent a smaller percentage of the potential disturbing forces and the trees which are in the centre of the group will be sheltered by those on the outside.
Removal of water
Vegetation influences slope stability by removing water through transpiration. Transpiration is the vaporisation of liquid water contained in plant tissue and the vapour removal to the air. Water is drawn up from the roots and transported through the plant up to the leaves.
The major effect of transpiration is the reduction of soil pore water pressures which counteracts the loss of strength which occurs through wetting, this is most readily seen as a loss of moisture around trees. However it is not easy to rely on tree and shrub roots to remove water from slopes and consequently help ensure slope stability. The ability to transpire in wet conditions is severely reduced and therefore any increase in soil strength
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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
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A buffer strip is an area of land maintained in permanent vegetation that helps to control air quality, soil quality, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by slowing down surface runoff that could enter the local surface waters. The root systems of the planted vegetation in these buffers hold soil particles together which alleviate the soil of wind erosion and stabilize stream banks providing protection against substantial erosion and landslides. Farmers can also use buffer strips to square up existing crop fields to provide safety for equipment while also farming more efficiently.
Buffer strips can have several different configurations of vegetation found on them varying from simply grass to combinations of grass, trees, and shrubs. Areas with diverse vegetation provide more protection from nutrient and pesticide flow and at the same time provide better biodiversity amongst plants and animals.
Many country, state, and local governments provide financial incentives for conservation programs such as buffer strips because they help stabilize the environment, help reduce nitrogen emissions to water and soil loss by wind erosion, while simultaneously providing substantial environmental co-benefits, even when the land is being used. Buffer strips not only stabilize the land but can also provide a visual demonstration that land is under stewardship.
Types
Buffers within fields
A grassed waterway reduces soil erosion and captures most nutrients and pesticides that would normally wash out of crop fields and into major waters. These waterways help to carry surface water at a non-erosive velocity to an area where it will have a stable outlet. Outlets must be adequate enough to allow water to drain without ponding or flooding the area being protected, while also preventing erosion of the water into the outlet which ca
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Directions Read the information about wind erosion then answer the question. Wind can cause erosion that changes the surface of the Earth. Wind erosion can have negative effects on the environment by removing soil and polluting the air during dust storms. What is one way to prevent wind erosion?
A. People can drive off-road bikes across the desert.
B. Ranchers can let their cattle graze in areas with little plant growth.
C. Construction workers can wet the ground before driving on it or digging.
D. Farmers can remove all plant material in the soil between planting seasons.
Answer:
|
|
sciq-7699
|
multiple_choice
|
The normal response of the respiratory system to elevated ph is to increase the amount of what in the blood?
|
[
"co2",
"acid",
"glucose",
"red blood cells"
] |
A
|
Relavent Documents:
Document 0:::
In acid base physiology, the Davenport diagram is a graphical tool, developed by Horace W. Davenport, that allows a clinician or investigator to describe blood bicarbonate concentrations and blood pH following a respiratory and/or metabolic acid-base disturbance. The diagram depicts a three-dimensional surface describing all possible states of chemical equilibria between gaseous carbon dioxide, aqueous bicarbonate and aqueous protons at the physiologically complex interface of the alveoli of the lungs and the alveolar capillaries. Although the surface represented in the diagram is experimentally determined, the Davenport diagram is rarely used in the clinical setting, but allows the investigator to envision the effects of physiological changes on blood acid-base chemistry. For clinical use there are two recent innovations: an Acid-Base Diagram which provides Text Descriptions for the abnormalities and a High Altitude Version that provides text descriptions appropriate for the altitude.
Derivation
When a sample of blood is exposed to air, either in the alveoli of the lung or in an in vitro laboratory experiment, carbon dioxide in the air rapidly enters into equilibrium with carbon dioxide derivatives and other species in the aqueous solution. Figure 1 illustrates the most important equilibrium reactions of carbon dioxide in blood relating to acid-base physiology:
Note that in this equation, the HB/B- buffer system represents all non-bicarbonate buffers present in the blood, such as hemoglobin in its various protonated and deprotonated states. Because many different non-bicarbonate buffers are present in human blood, the final equilibrium state reached at any given pCO2 is highly complex and cannot be readily predicted using theory alone. By depicting experimental results, the Davenport diagram provides a simple approach to describing the behavior of this complex system.
Figure 2 shows a Davenport diagram as commonly depicted in textbooks and the literature. To un
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:::
Intracellular pH (pHi) is the measure of the acidity or basicity (i.e., pH) of intracellular fluid. The pHi plays a critical role in membrane transport and other intracellular processes. In an environment with the improper pHi, biological cells may have compromised function. Therefore, pHi is closely regulated in order to ensure proper cellular function, controlled cell growth, and normal cellular processes. The mechanisms that regulate pHi are usually considered to be plasma membrane transporters of which two main types exist — those that are dependent and those that are independent of the concentration of bicarbonate (). Physiologically normal intracellular pH is most commonly between 7.0 and 7.4, though there is variability between tissues (e.g., mammalian skeletal muscle tends to have a pHi of 6.8–7.1). There is also pH variation across different organelles, which can span from around 4.5 to 8.0. pHi can be measured in a number of different ways.
Homeostasis
Intracellular pH is typically lower than extracellular pH due to lower concentrations of HCO3−. A rise of extracellular (e.g., serum) partial pressure of carbon dioxide (pCO2) above 45 mmHg leads to formation of carbonic acid, which causes a decrease of pHi as it dissociates:
H2O + CO2 H2CO3 H+ + HCO3–
Since biological cells contain fluid that can act as a buffer, pHi can be maintained fairly well within a certain range. Cells adjust their pHi accordingly upon an increase in acidity or basicity, usually with the help of CO2 or HCO3– sensors present in the membrane of the cell. These sensors can permit H+ to pass through the cell membrane accordingly, allowing for pHi to be interrelated with extracellular pH in this respect.
Major intracellular buffer systems include those involving proteins or phosphates. Since the proteins have acidic and basic regions, they can serve as both proton donors or acceptors in order to maintain a relatively stable intracellular pH. In the case of a phosphate buffer, subs
Document 3:::
The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It optimizes respiration by preferentially distributing oxygen stores to the heart and brain, enabling submersion for an extended time.
The diving reflex is exhibited strongly in aquatic mammals, such as seals, otters, dolphins, and muskrats, and exists as a lesser response in other animals, including human babies up to 6 months old (see infant swimming), and diving birds, such as ducks and penguins. Adult humans generally exhibit a mild response, the dive-hunting Sama-Bajau people being a notable outlier.
The diving reflex is triggered specifically by chilling and wetting the nostrils and face while breath-holding, and is sustained via neural processing originating in the carotid chemoreceptors. The most noticeable effects are on the cardiovascular system, which displays peripheral vasoconstriction, slowed heart rate, redirection of blood to the vital organs to conserve oxygen, release of red blood cells stored in the spleen, and, in humans, heart rhythm irregularities. Although aquatic animals have evolved profound physiological adaptations to conserve oxygen during submersion, the apnea and its duration, bradycardia, vasoconstriction, and redistribution of cardiac output occur also in terrestrial animals as a neural response, but the effects are more profound in natural divers.
Physiological response
When the face is submerged and water fills the nostrils, sensory receptors sensitive to wetness within the nasal cavity and other areas of the face supplied by the fifth (V) cranial nerve (the trigeminal nerve) relay the information to the brain. The tenth (X) cranial nerve, (the vagus nerve) – part of the autonomic nervous system – then produces bradycardia and other neural pathways elicit peripheral vasoconstriction, restri
Document 4:::
When we sleep, our breathing changes due to normal biological processes that affect both our respiratory and muscular systems.
Physiology
Sleep Onset
Breathing changes as we transition from wakefulness to sleep. These changes arise due to biological changes in the processes that regulate our breathing. When we fall asleep, minute ventilation (the amount of air that we breathe per minute) reduces due to decreased metabolism.
Non-REM (NREM) Sleep
During NREM sleep, we move through three sleep stages, with each progressively deeper than the last. As our sleep deepens, our minute ventilation continues to decrease, reducing by 13% in the second NREM stage and by 15% in the third. For example, a study of 19 healthy adults revealed that the minute ventilation in NREM sleep was 7.18 liters/minute compared to 7.66 liters/minute when awake.
Ribcage & Abdominal Muscle Contributions
Rib cage contribution to ventilation increases during NREM sleep, mostly by lateral movement, and is detected by an increase in EMG amplitude during breathing. Diaphragm activity is little increased or unchanged and abdominal muscle activity is slightly increased during these sleep stages.
Upper Airway Resistance
Airway resistance increases by about 230% during NREM sleep. Elastic and flow resistive properties of the lung do not change during NREM sleep. The increase in resistance comes primarily from the upper airway in the retro-epiglottic region. Tonic activity of the pharyngeal dilator muscles of the upper airway decreases during the NREM sleep, contributing to the increased resistance, which is reflected in increased esophageal pressure swings during sleep. The other ventilatory muscles compensate for the increased resistance, and so the airflow decreases much less than the increase in resistance.
Arterial Blood Gases
The Arterial blood gasses pCO2 increases by 3-7mmHg, pO2 drops by 3-9mmHg and SaO2 drops by 2% or less. These changes occur despite a reduced metabolic rate, reflected by a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The normal response of the respiratory system to elevated ph is to increase the amount of what in the blood?
A. co2
B. acid
C. glucose
D. red blood cells
Answer:
|
|
sciq-8719
|
multiple_choice
|
What type of organism is used to produce alcoholic beverages and bread?
|
[
"bacteria",
"yeast",
"larvae",
"insects"
] |
B
|
Relavent Documents:
Document 0:::
The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology
In general the field of microbiology can be divided in the more fundamental branch (pure microbiology) and the applied microbiology (biotechnology). In the more fundamental field the organisms are studied as the subject itself on a deeper (theoretical) level.
Applied microbiology refers to the fields where the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms itself are often not studied as such, but applied to sustain certain processes.
Pure microbiology
Bacteriology: the study of bacteria
Mycology: the study of fungi
Protozoology: the study of protozoa
Phycology/algology: the study of algae
Parasitology: the study of parasites
Immunology: the study of the immune system
Virology: the study of viruses
Nematology: the study of nematodes
Microbial cytology: the study of microscopic and submicroscopic details of microorganisms
Microbial physiology: the study of how the microbial cell functions biochemically. Includes the study of microbial growth, microbial metabolism and microbial cell structure
Microbial pathogenesis: the study of pathogens which happen to be microbes
Microbial ecology: the relationship between microorganisms and their environment
Microbial genetics: the study of how genes are organized and regulated in microbes in relation to their cellular functions Closely related to the field of molecular biology
Cellular microbiology: a discipline bridging microbiology and cell biology
Evolutionary microbiology: the study of the evolution of microbes. This field can be subdivided into:
Micr
Document 1:::
List of Useful Microorganisms Used In preparation Of Food And Beverage
See also
Fermentation (food)
Food microbiology
Document 2:::
In food processing, fermentation is the conversion of carbohydrates to alcohol or organic acids using microorganisms—yeasts or bacteria—under anaerobic (oxygen-free) conditions. Fermentation usually implies that the action of microorganisms is desired. The science of fermentation is known as zymology or zymurgy.
The term "fermentation" sometimes refers specifically to the chemical conversion of sugars into ethanol, producing alcoholic drinks such as wine, beer, and cider. However, similar processes take place in the leavening of bread (CO2 produced by yeast activity), and in the preservation of sour foods with the production of lactic acid, such as in sauerkraut and yogurt.
Other widely consumed fermented foods include vinegar, olives, and cheese. More localised foods prepared by fermentation may also be based on beans, grain, vegetables, fruit, honey, dairy products, and fish.
History and prehistory
Brewing and winemaking
Natural fermentation precedes human history. Since ancient times, humans have exploited the fermentation process. The earliest archaeological evidence of fermentation is 13,000-year-old residues of a beer, with the consistency of gruel, found in a cave near Haifa in Israel. Another early alcoholic drink, made from fruit, rice, and honey, dates from 7000 to 6600 BC, in the Neolithic Chinese village of Jiahu, and winemaking dates from ca. 6000 BC, in Georgia, in the Caucasus area. Seven-thousand-year-old jars containing the remains of wine, now on display at the University of Pennsylvania, were excavated in the Zagros Mountains in Iran. There is strong evidence that people were fermenting alcoholic drinks in Babylon ca. 3000 BC, ancient Egypt ca. 3150 BC, pre-Hispanic Mexico ca. 2000 BC, and Sudan ca. 1500 BC.
Discovery of the role of yeast
The French chemist Louis Pasteur founded zymology, when in 1856 he connected yeast to fermentation.
When studying the fermentation of sugar to alcohol by yeast, Pasteur concluded that the fermentation wa
Document 3:::
Zymology, also known as zymurgy, is an applied science that studies the biochemical process of fermentation and its practical uses. Common topics include the selection of fermenting yeast and bacteria species and their use in brewing, wine making, fermenting milk, and the making of other fermented foods.
Fermentation
Fermentation can be simply defined, in this context, as the conversion of sugar molecules into ethanol and carbon dioxide by yeast.
Fermentation practices have led to the discovery of ample microbial and antimicrobial cultures on fermented foods and products.
History
French chemist Louis Pasteur was the first 'zymologist' when in 1857 he connected yeast to fermentation. Pasteur originally defined fermentation as "respiration without air".
Pasteur performed careful research and concluded:
The German Eduard Buchner, winner of the 1907 Nobel Prize in chemistry, later determined that fermentation was actually caused by a yeast secretion, which he termed 'zymase'.
The research efforts undertaken by the Danish Carlsberg scientists greatly accelerated understanding of yeast and brewing. The Carlsberg scientists are generally acknowledged as having jump-started the entire field of molecular biology.
Products
All alcoholic drinks including beer, cider, kombucha, kvass, mead, perry, tibicos, wine, pulque, hard liquors (brandy, rum, vodka, sake, schnapps), and soured by-products including vinegar and alegar
Yeast leavened breads including sourdough, salt-rising bread, and others
Cheese and some dairy products including kefir and yogurt
Chocolate
Dishes including fermented fish, such as garum, surströmming, and Worcestershire sauce
Some vegetables such as kimchi, some types of pickles (most are not fermented though), and sauerkraut
A wide variety of fermented edibles made from soy beans, including fermented bean paste, nattō, tempeh, and soya sauce
Notes
Document 4:::
Industrial microbiology is a branch of biotechnology that applies microbial sciences to create industrial products in mass quantities, often using microbial cell factories. There are multiple ways to manipulate a microorganism in order to increase maximum product yields. Introduction of mutations into an organism may be accomplished by introducing them to mutagens. Another way to increase production is by gene amplification, this is done by the use of plasmids, and vectors. The plasmids and/ or vectors are used to incorporate multiple copies of a specific gene that would allow more enzymes to be produced that eventually cause more product yield. The manipulation of organisms in order to yield a specific product has many applications to the real world like the production of some antibiotics, vitamins, enzymes, amino acids, solvents, alcohol and daily products. Microorganisms play a big role in the industry, with multiple ways to be used. Medicinally, microbes can be used for creating antibiotics in order to treat infection. Microbes can also be used for the food industry as well. Microbes are very useful in creating some of the mass produced products that are consumed by people. The chemical industry also uses microorganisms in order to synthesize amino acids and organic solvents. Microbes can also be used in an agricultural application for use as a biopesticide instead of using dangerous chemicals and or inoculants to help plant proliferation.
Medical application
The medical application to industrial microbiology is the production of new drugs synthesized in a specific organism for medical purposes. Production of antibiotics is necessary for the treatment of many bacterial infections. Some natural occurring antibiotics and precursors, are produced through a process called fermentation. The microorganisms grow in a liquid media where the population size is controlled in order to yield the greatest amount of product. In this environment nutrient, pH, temperature, an
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of organism is used to produce alcoholic beverages and bread?
A. bacteria
B. yeast
C. larvae
D. insects
Answer:
|
|
sciq-7734
|
multiple_choice
|
When did we learn there was a hole in the ozone layer?
|
[
"1950s",
"1990's",
"1980s",
"1970s"
] |
C
|
Relavent Documents:
Document 0:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 1:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 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:::
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 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.
When did we learn there was a hole in the ozone layer?
A. 1950s
B. 1990's
C. 1980s
D. 1970s
Answer:
|
|
sciq-3339
|
multiple_choice
|
In physics, the number of waves that pass a fixed point in a given amount time is referred to as what ?
|
[
"creation frequency",
"wave count",
"wave frequency",
"combination frequency"
] |
C
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
A wavenumber–frequency diagram is a plot displaying the relationship between the wavenumber (spatial frequency) and the frequency (temporal frequency) of certain phenomena. Usually frequencies are placed on the vertical axis, while wavenumbers are placed on the horizontal axis.
In the atmospheric sciences, these plots are a common way to visualize atmospheric waves.
In the geosciences, especially seismic data analysis, these plots also called f–k plot, in which energy density within a given time interval is contoured on a frequency-versus-wavenumber basis. They are used to examine the direction and apparent velocity of seismic waves and in velocity filter design.
Origins
In general, the relationship between wavelength , frequency , and the phase velocity of a sinusoidal wave is:
Using the wavenumber () and angular frequency () notation, the previous equation can be rewritten as
On the other hand, the group velocity is equal to the slope of the wavenumber–frequency diagram:
Analyzing such relationships in detail often yields information on the physical properties of the medium, such as density, composition, etc.
See also
Dispersion relation
Document 2:::
In the physical sciences, the wavenumber (or wave number), also known as repetency, is the spatial frequency of a wave, measured in cycles per unit distance (ordinary wavenumber) or radians per unit distance (angular wavenumber). It is analogous to temporal frequency, which is defined as the number of wave cycles per unit time (ordinary frequency) or radians per unit time (angular frequency).
In multidimensional systems, the wavenumber is the magnitude of the wave vector. The space of wave vectors is called reciprocal space. Wave numbers and wave vectors play an essential role in optics and the physics of wave scattering, such as X-ray diffraction, neutron diffraction, electron diffraction, and elementary particle physics. For quantum mechanical waves, the wavenumber multiplied by the reduced Planck's constant is the canonical momentum.
Wavenumber can be used to specify quantities other than spatial frequency. For example, in optical spectroscopy, it is often used as a unit of temporal frequency assuming a certain speed of light.
Definition
Wavenumber, as used in spectroscopy and most chemistry fields, is defined as the number of wavelengths per unit distance, typically centimeters (cm−1):
where λ is the wavelength. It is sometimes called the "spectroscopic wavenumber". It equals the spatial frequency.
For example, a wavenumber in inverse centimeters can be converted to a frequency in gigahertz by multiplying by 29.9792458 cm/ns (the speed of light, in centimeters per nanosecond); conversely, an electromagnetic wave at 29.9792458 GHz has a wavelength of 1 cm in free space.
In theoretical physics, a wave number, defined as the number of radians per unit distance, sometimes called "angular wavenumber", is more often used:
When wavenumber is represented by the symbol , a frequency is still being represented, albeit indirectly. As described in the spectroscopy section, this is done through the relationship , where s is a frequency in hertz. This is done for con
Document 3:::
In mathematics, physics, and engineering, spatial frequency is a characteristic of any structure that is periodic across position in space. The spatial frequency is a measure of how often sinusoidal components (as determined by the Fourier transform) of the structure repeat per unit of distance.
The SI unit of spatial frequency is the reciprocal metre (m-1), although cycles per meter (c/m) is also common. In image-processing applications, spatial frequency is often expressed in units of cycles per millimeter (c/mm) or also line pairs per millimeter (LP/mm).
In wave propagation, the spatial frequency is also known as wavenumber. Ordinary wavenumber is defined as the reciprocal of wavelength and is commonly denoted by or sometimes :
Angular wavenumber , expressed in radian per metre (rad/m), is related to ordinary wavenumber and wavelength by
Visual perception
In the study of visual perception, sinusoidal gratings are frequently used to probe the capabilities of the visual system, such as contrast sensitivity. In these stimuli, spatial frequency is expressed as the number of cycles per degree of visual angle. Sine-wave gratings also differ from one another in amplitude (the magnitude of difference in intensity between light and dark stripes), orientation, and phase.
Spatial-frequency theory
The spatial-frequency theory refers to the theory that the visual cortex operates on a code of spatial frequency, not on the code of straight edges and lines hypothesised by Hubel and Wiesel on the basis of early experiments on V1 neurons in the cat. In support of this theory is the experimental observation that the visual cortex neurons respond even more robustly to sine-wave gratings that are placed at specific angles in their receptive fields than they do to edges or bars. Most neurons in the primary visual cortex respond best when a sine-wave grating of a particular frequency is presented at a particular angle in a particular location in the visual field. (However, a
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In physics, the number of waves that pass a fixed point in a given amount time is referred to as what ?
A. creation frequency
B. wave count
C. wave frequency
D. combination frequency
Answer:
|
|
sciq-8544
|
multiple_choice
|
When the energy of the earthquake reaches shore, it forms a huge wave called?
|
[
"a tidal wave",
"a tsunami",
"a typhoon",
"a surge"
] |
B
|
Relavent Documents:
Document 0:::
Wave loading is most commonly the application of a pulsed or wavelike load to a material or object. This is most commonly used in the analysis of piping, ships, or building structures which experience wind, water, or seismic disturbances.
Examples of wave loading
Offshore storms and pipes: As large waves pass over shallowly buried pipes, water pressure increases above it. As the trough approaches, pressure over the pipe drops and this sudden and repeated variation in pressure can break pipes. The difference in pressure for a wave with wave height of about 10 m would be equivalent to one atmosphere (101.3 kPa or 14.7 psi) pressure variation between crest and trough and repeated fluctuations over pipes in relatively shallow environments could set up resonance vibrations within pipes or structures and cause problems.
Engineering oil platforms: The effects of wave-loading are a serious issue for engineers designing oil platforms, which must contend with the effects of wave loading, and have devised a number of algorithms to do so.
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This list of rogue waves compiles incidents of known and likely rogue waves – also known as freak waves, monster waves, killer waves, and extreme waves. These are dangerous and rare ocean surface waves that unexpectedly reach at least twice the height of the tallest waves around them, and are often described by witnesses as "walls of water". They occur in deep water, usually far out at sea, and are a threat even to capital ships , ocean liners and land structures such as lighthouses.
In addition to the incidents listed below, it has also been suggested that these types of waves may be responsible for the loss of several low-flying United States Coast Guard helicopters on search and rescue missions.
Background
Anecdotal evidence from mariners' testimonies and incidents of wave damage to ships have long suggested rogue waves occurred; however, their scientific measurement was positively confirmed only following measurements of the Draupner wave, a rogue wave at the Draupner platform, in the North Sea on 1 January 1995. During this event, minor damage was inflicted on the platform, confirming that the reading was valid.
In modern oceanography, rogue waves are defined not as the biggest possible waves at sea, but instead as extreme sized waves for a given sea state.
Many of these encounters are only reported in the media, and are not examples of open ocean rogue waves. Often a huge wave is loosely and incorrectly denoted as a rogue wave. Extremely large waves offer an explanation for the otherwise-inexplicable disappearance of many ocean-going vessels. However, the claim is contradicted by information held by Lloyd's Register. One of the very few cases where evidence suggests a freak wave incident is the 1978 loss of the freighter . This claim, however, is contradicted by other sources, which maintain that, over a time period from 1969 to 1994 alone, rogue waves were responsible for the complete loss of 22 supertankers, often with their entire crew. In 2007, resear
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In elastodynamics, Love waves, named after Augustus Edward Hough Love, are horizontally polarized surface waves. The Love wave is a result of the interference of many shear waves (S-waves) guided by an elastic layer, which is welded to an elastic half space on one side while bordering a vacuum on the other side. In seismology, Love waves (also known as Q waves (Quer: German for lateral)) are surface seismic waves that cause horizontal shifting of the Earth during an earthquake. Augustus Edward Hough Love predicted the existence of Love waves mathematically in 1911. They form a distinct class, different from other types of seismic waves, such as P-waves and S-waves (both body waves), or Rayleigh waves (another type of surface wave). Love waves travel with a lower velocity than P- or S- waves, but faster than Rayleigh waves. These waves are observed only when there is a low velocity layer overlying a high velocity layer/ sub–layers.
Description
The particle motion of a Love wave forms a horizontal line perpendicular to the direction of propagation (i.e. are transverse waves). Moving deeper into the material, motion can decrease to a "node" and then alternately increase and decrease as one examines deeper layers of particles. The amplitude, or maximum particle motion, often decreases rapidly with depth.
Since Love waves travel on the Earth's surface, the strength (or amplitude) of the waves decrease exponentially with the depth of an earthquake. However, given their confinement to the surface, their amplitude decays only as , where represents the distance the wave has travelled from the earthquake. Surface waves therefore decay more slowly with distance than do body waves, which travel in three dimensions. Large earthquakes may generate Love waves that travel around the Earth several times before dissipating.
Since they decay so slowly, Love waves are the most destructive outside the immediate area of the focus or epicentre of an earthquake. They are what mo
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Branched flow refers to a phenomenon in wave dynamics, that produces a tree-like pattern involving successive mostly forward scattering events by smooth obstacles deflecting traveling rays or waves. Sudden and significant momentum or wavevector changes are absent, but accumulated small changes can lead to large momentum changes. The path of a single ray is less important than the environs around a ray, which rotate, compress, and stretch around in an area preserving way. Even more revealing are groups, or manifolds of neighboring rays extending over significant zones. Starting rays out from a point but varying their direction over a range, one to the next, or from different points along a line all with the same initial directions are examples of a manifold. Waves have analogous launching conditions, such as a point source spraying in many directions, or an extended plane wave heading on one direction. The ray bending or refraction leads to characteristic structure in phase space and nonuniform distributions in coordinate space that look somehow universal and resemble branches in trees or stream beds. The branches taken on non-obvious paths through the refracting landscape that are indirect and nonlocal results of terrain already traversed. For a given refracting landscape, the branches will look completely different depending on the initial manifold.
Examples
Two-dimensional electron gas
Branched flow was first identified in experiments with a two-dimensional electron gas. Electrons flowing from a quantum point contact were scanned using a scanning probe microscope. Instead of usual diffraction patterns, the electrons flowed forming branching strands that persisted for several correlation lengths of the background potential.
Ocean dynamics
Focusing of random waves in the ocean can also lead to branched flow. The fluctuation in the depth of the ocean floor can be described as a random potential. A tsunami wave propagating in such medium will form branches which
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In oceanography, a tidal resonance occurs when the tide excites one of the resonant modes of the ocean.
The effect is most striking when a continental shelf is about a quarter wavelength wide. Then an incident tidal wave can be reinforced by reflections between the coast and the shelf edge, the result producing a much higher tidal range at the coast.
Famous examples of this effect are found in the Bay of Fundy, where the world's highest tides are reportedly found, and in the Bristol Channel. Less well known is Leaf Bay, part of Ungava Bay near the entrance of Hudson Strait (Canada), which has tides similar to those of the Bay of Fundy. Other resonant regions with large tides include the Patagonian Shelf and on the continental shelf of northwest Australia.
Most of the resonant regions are also responsible for large fractions of the total amount of tidal energy dissipated in the oceans. Satellite altimeter data shows that the M2 tide dissipates approximately 2.5 TW, of which 261 GW is lost in the Hudson Bay complex, 208 GW on the European Shelves (including the Bristol Channel), 158 GW on the North-west Australian Shelf, 149 GW in the Yellow Sea and 112 GW on the Patagonian Shelf.
Scale of the resonances
The speed of long waves in the ocean is given, to a good approximation, by , where g is the acceleration of gravity and h is the depth of the ocean.
For a typical continental shelf with a depth of 100 m, the speed is approximately 30 m/s. So if the tidal period is 12 hours, a quarter wavelength shelf will have a width of about 300 km.
With a narrower shelf, there is still a resonance but it is mismatched to the frequency of the tides and so has less effect on tidal amplitudes. However the effect is still enough to partly explain why tides along a coast lying behind a continental shelf are often higher than at offshore islands in the deep ocean (one of the additional partial explanations being Green's law). Resonances also generate strong tidal currents and
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When the energy of the earthquake reaches shore, it forms a huge wave called?
A. a tidal wave
B. a tsunami
C. a typhoon
D. a surge
Answer:
|
|
sciq-7764
|
multiple_choice
|
The name of the cation comes first, followed by the name of the anion, in what kind of compound?
|
[
"covalent bonds",
"ionic compound",
"magnetic compound",
"localized compound"
] |
B
|
Relavent Documents:
Document 0:::
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry (informally called the Blue Book). Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
To avoid long and tedious names in normal communication, the official IUPAC naming recommendations are not always followed in practice, except when it is necessary to give an unambiguous and absolute definition to a compound. IUPAC names can sometimes be simpler than older names, as with ethanol, instead of ethyl alcohol. For relatively simple molecules they can be more easily understood than non-systematic names, which must be learnt or looked over. However, the common or trivial name is often substantially shorter and clearer, and so preferred. These non-systematic names are often derived from an original source of the compound. Also, very long names may be less clear than structural formulas.
Basic principles
In chemistry, a number of prefixes, suffixes and infixes are used to describe the type and position of the functional groups in the compound.
The steps for naming an organic compound are:
Identification of the parent hydride parent hydrocarbon chain. This chain must obey the following rules, in order of precedence:
It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, unlike halogen substituents. If more than one functional group is present, the one with highest group precedence should be used.
It should have the maximum number of multiple bonds.
It should have the maximum length.
It should have the maximum number of substituents or branches cited as prefixes
It should have the ma
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Steudel R 2020, Chemistry of the Non-metals: Syntheses - Structures - Bonding - Applications, in collaboration with D Scheschkewitz, Berlin, Walter de Gruyter, . ▲
An updated translation of the 5th German edition of 2013, incorporating the literature up to Spring 2019. Twenty-three nonmetals, including B, Si, Ge, As, Se, Te, and At but not Sb (nor Po). The nonmetals are identified on the basis of their electrical conductivity at absolute zero putatively being close to zero, rather than finite as in the case of metals. That does not work for As however, which has the electronic structure of a semimetal (like Sb).
Halka M & Nordstrom B 2010, "Nonmetals", Facts on File, New York,
A reading level 9+ book covering H, C, N, O, P, S, Se. Complementary books by the same authors examine (a) the post-transition metals (Al, Ga, In, Tl, Sn, Pb and Bi) and metalloids (B, Si, Ge, As, Sb, Te and Po); and (b) the halogens and noble gases.
Woolins JD 1988, Non-Metal Rings, Cages and Clusters, John Wiley & Sons, Chichester, .
A more advanced text that covers H; B; C, Si, Ge; N, P, As, Sb; O, S, Se and Te.
Steudel R 1977, Chemistry of the Non-metals: With an Introduction to Atomic Structure and Chemical Bonding, English edition by FC Nachod & JJ Zuckerman, Berlin, Walter de Gruyter, . ▲
Twenty-four nonmetals, including B, Si, Ge, As, Se, Te, Po and At.
Powell P & Timms PL 1974, The Chemistry of the Non-metals, Chapman & Hall, London, . ▲
Twenty-two nonmetals including B, Si, Ge, As and Te. Tin and antimony are shown as being intermediate between metals and nonmetals; they are later shown as either metals or nonmetals. Astatine is counted as a metal.
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Stannide ions,
Some examples of stannide Zintl ions are listed below. Some of them contain 2-centre 2-electron bonds (2c-2e), others are "electron deficient" and bonding sometimes can be described using polyhedral skeletal electron pair theory (Wade's rules) where the number of valence electrons contributed by each tin atom is considered to be 2 (the s electrons do not contribute). There are some examples of silicide and plumbide ions with similar structures, for example tetrahedral , the chain anion (Si2−)n, and .
Sn4− found for example in Mg2Sn.
, tetrahedral with 2c-2e bonds e.g. in CsSn.
, tetrahedral closo-cluster with 10 electrons (2n + 2).
(Sn2−)n zig-zag chain polymeric anion with 2c-2e bonds found for example in BaSn.
closo-
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[()2]x+ [(Xn−)x/n · y]x-,
where Xn− is the intercalating anion (or anions).
Most commonly, = Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+ or Zn2+, and is another trivalent cation, possibly of the same element. Fixed-composition phases have been shown to exist over the rang
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Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons. It often, but not always, involves some chemical bonding.
In some cases, the associations can be quite strong—for example, the protein streptavidin and the vitamin biotin have a dissociation constant (reflecting the ratio between bound and free biotin) on the order of 10−14—and so the reactions are effectively irreversible. The result of molecular binding is sometimes the formation of a molecular complex in which the attractive forces holding the components together are generally non-covalent, and thus are normally energetically weaker than covalent bonds.
Molecular binding occurs in biological complexes (e.g., between pairs or sets of proteins, or between a protein and a small molecule ligand it binds) and also in abiologic chemical systems, e.g. as in cases of coordination polymers and coordination networks such as metal-organic frameworks.
Types
Molecular binding can be classified into the following types:
Non-covalent – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
Reversible covalent – a chemical bond is formed, however the free energy difference separating the noncovalently-bonded reactants from bonded product is near equilibrium and the activation barrier is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
Irreversible covalent – a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such that the reverse reaction does not take place.
Bound molecules are sometimes called a "molecular complex"—the term generally refers to non-covalent associations. Non-covalent interactions can effectively become irreversible; for example, tight binding inhibitors of enzymes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The name of the cation comes first, followed by the name of the anion, in what kind of compound?
A. covalent bonds
B. ionic compound
C. magnetic compound
D. localized compound
Answer:
|
|
sciq-7357
|
multiple_choice
|
An experiment generates what to support a hypothesis?
|
[
"study",
"falsehoods",
"evidence",
"reason"
] |
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:::
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:::
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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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.
An experiment generates what to support a hypothesis?
A. study
B. falsehoods
C. evidence
D. reason
Answer:
|
|
sciq-10776
|
multiple_choice
|
What occurs when light interacts with our atmosphere?
|
[
"eclipse",
"rayleigh scattering",
"rainbow formation",
"prism effect"
] |
B
|
Relavent Documents:
Document 0:::
Atmospheric optical phenomena include:
Afterglow
Airglow
Alexander's band, the dark region between the two bows of a double rainbow.
Alpenglow
Anthelion
Anticrepuscular rays
Aurora
Auroral light (northern and southern lights, aurora borealis and aurora australis)
Belt of Venus
Brocken Spectre
Circumhorizontal arc
Circumzenithal arc
Cloud iridescence
Crepuscular rays
Earth's shadow
Earthquake lights
Glories
Green flash
Halos, of Sun or Moon, including sun dogs
Haze
Heiligenschein or halo effect, partly caused by the opposition effect
Ice blink
Light pillar
Lightning
Mirages (including Fata Morgana)
Monochrome Rainbow
Moon dog
Moonbow
Nacreous cloud/Polar stratospheric cloud
Rainbow
Subsun
Sun dog
Tangent arc
Tyndall effect
Upper-atmospheric lightning, including red sprites, Blue jets, and ELVES
Water sky
See also
Document 1:::
Atmospheric optics ray tracing codes - this article list codes for light scattering using ray-tracing technique to study atmospheric optics phenomena such as rainbows and halos. Such particles can be large raindrops or hexagonal ice crystals. Such codes are one of many approaches to calculations of light scattering by particles.
Geometric optics (ray tracing)
Ray tracing techniques can be applied to study light scattering by spherical and non-spherical particles under the condition that the size of a particle is much larger than the wavelength of light. The light can be considered as collection of separate rays with width of rays much larger than the wavelength but smaller than a particle. Rays hitting the particle undergoes reflection, refraction and diffraction. These rays exit in various directions with different amplitudes and phases. Such ray tracing techniques are used to describe optical phenomena such as rainbow of halo on hexagonal ice crystals for large particles.
Review of several mathematical techniques is provided in series of publications.
The 46° halo was first explained as being caused by refractions through ice crystals in 1679 by the French physicist Edmé Mariotte (1620–1684) in terms of light refraction
Jacobowitz in 1971 was the first to apply the ray-tracing technique to hexagonal ice crystal. Wendling et al. (1979) extended Jacobowitz's work from hexagonal ice particle with infinite length to finite length and combined Monte Carlo technique to the ray-tracing simulations.
Classification
The compilation contains information about the electromagnetic scattering by hexagonal ice crystals, large raindrops, and relevant links and applications.
Codes for light scattering by hexagonal ice crystals
Relevant scattering codes
Discrete dipole approximation codes
Codes for electromagnetic scattering by cylinders
Codes for electromagnetic scattering by spheres
External links
Scatterlib - Google Code repository of light scattering codes
See
Document 2:::
Aeronomy is the scientific study of the upper atmosphere of the Earth and corresponding regions of the atmospheres of other planets. It is a branch of both atmospheric chemistry and atmospheric physics. Scientists specializing in aeronomy, known as aeronomers, study the motions and chemical composition and properties of the Earth's upper atmosphere and regions of the atmospheres of other planets that correspond to it, as well as the interaction between upper atmospheres and the space environment. In atmospheric regions aeronomers study, chemical dissociation and ionization are important phenomena.
History
The mathematician Sydney Chapman introduced the term aeronomy to describe the study of the Earth's upper atmosphere in 1946 in a letter to the editor of Nature entitled "Some Thoughts on Nomenclature." The term became official in 1954 when the International Union of Geodesy and Geophysics adopted it. "Aeronomy" later also began to refer to the study of the corresponding regions of the atmospheres of other planets.
Branches
Aeronomy can be divided into three main branches: terrestrial aeronomy, planetary aeronomy, and comparative aeronomy.
Terrestrial aeronomy
Terrestrial aeronomy focuses on the Earth's upper atmosphere, which extends from the stratopause to the atmosphere's boundary with outer space and is defined as consisting of the mesosphere, thermosphere, and exosphere and their ionized component, the ionosphere. Terrestrial aeronomy contrasts with meteorology, which is the scientific study of the Earth's lower atmosphere, defined as the troposphere and stratosphere. Although terrestrial aeronomy and meteorology once were completely separate fields of scientific study, cooperation between terrestrial aeronomers and meteorologists has grown as discoveries made since the early 1990s have demonstrated that the upper and lower atmospheres have an impact on one another's physics, chemistry, and biology.
Terrestrial aeronomers study atmospheric tides and upper-
Document 3:::
Biometeorology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or shorter (in contrast with bioclimatology).
Examples of relevant processes
Weather events influence biological processes on short time scales. For instance, as the Sun rises above the horizon in the morning, light levels become sufficient for the process of photosynthesis to take place in plant leaves. Later on, during the day, air temperature and humidity may induce the partial or total closure of the stomata, a typical response of many plants to limit the loss of water through transpiration. More generally, the daily evolution of meteorological variables controls the circadian rhythm of plants and animals alike.
Living organisms, for their part, can collectively affect weather patterns. The rate of evapotranspiration of forests, or of any large vegetated area for that matter, contributes to the release of water vapor in the atmosphere. This local, relatively fast and continuous process may contribute significantly to the persistence of precipitations in a given area. As another example, the wilting of plants results in definite changes in leaf angle distribution and therefore modifies the rates of reflection, transmission and absorption of solar light in these plants. That, in turn, changes the albedo of the ecosystem as well as the relative importance of the sensible and latent heat fluxes from the surface to the atmosphere. For an example in oceanography, consider the release of dimethyl sulfide by biological activity in sea water and its impact on atmospheric aerosols.
Human biometeorology
The methods and measurements traditionally used in biometeorology are not different when applied to study the interactions between human bodies and the atmosphere, but some aspects or applications may have been explored more extensively. For instance, wind chill has been investigated to determine th
Document 4:::
ARTS (Atmospheric Radiative Transfer Simulator) is a widely used<ref
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atmospheric radiative transfer simulator for infrared, microwave, and sub-millimeter wavelengths.<ref
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While the model is developed by a community, core development is done by the University of Hamburg and Chalmers University, with previous participation from Luleå University of Technology and University of Bremen.
Whereas most radiative transfer models are developed for a specific instrument, ARTS is one of few models that aims to be generically applicable.<ref
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It is designed from basic physical principles and has been used in a wide range of situations. It supports fully polarised radiative transfer calculations in clear-sky or cloudy conditions in 1-D, 2-D, or 3-D geometries,<ref
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including the calculations of Jacobians.
Cloudy simulations support liquid and ice clouds with particles of varying sizes and shapes<ref
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and supports multiple-scattering simulations.<ref
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Absorption is calculated line-by-line, with continua<ref
name="matz"></ref>
or using a lookup table.<ref
name="lut"></ref>
The user programs ARTS by the means of a simple scripting language.<ref
name="paper" />
ARTS is a physics-based model and therefore much slower than many radiative transfer models that are used operationally and is currently unable to simulate solar, visible, or shortwave radiation.
ARTS has been used at the University of Maryland to assess radiosonde humidity measurements,<ref
name="moradi"></ref>
by the University of Bern for water vapour retrievals,<ref
name="tschanz"></ref>
by the Norwegian University of Science and Technology for Carbon monoxide retrievals above Antarctica,<ref
name="co"></ref>
and by the Japanese space agency JAXA to aid the development of retrievals from JEM/SMILES,<ref
name="jaxa"></ref>
among others. According to the ARTS website ARTS has been used in at least 1
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What occurs when light interacts with our atmosphere?
A. eclipse
B. rayleigh scattering
C. rainbow formation
D. prism effect
Answer:
|
|
sciq-4129
|
multiple_choice
|
What are people called that choose to study science?
|
[
"doctors",
"scientists",
"lab technicians",
"engineers"
] |
B
|
Relavent Documents:
Document 0:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 1:::
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:::
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:::
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 4:::
Science, technology, engineering, and mathematics (STEM) is an umbrella term used to group together the distinct but related technical disciplines of science, technology, engineering, and mathematics. The term is typically used in the context of education policy or curriculum choices in schools. It has implications for workforce development, national security concerns (as a shortage of STEM-educated citizens can reduce effectiveness in this area), and immigration policy, with regard to admitting foreign students and tech workers.
There is no universal agreement on which disciplines are included in STEM; in particular, whether or not the science in STEM includes social sciences, such as psychology, sociology, economics, and political science. In the United States, these are typically included by organizations such as the National Science Foundation (NSF), the Department of Labor's O*Net online database for job seekers, and the Department of Homeland Security. In the United Kingdom, the social sciences are categorized separately and are instead grouped with humanities and arts to form another counterpart acronym HASS (Humanities, Arts, and Social Sciences), rebranded in 2020 as SHAPE (Social Sciences, Humanities and the Arts for People and the Economy). Some sources also use HEAL (health, education, administration, and literacy) as the counterpart of STEM.
Terminology
History
Previously referred to as SMET by the NSF, in the early 1990s the acronym STEM was used by a variety of educators, including Charles E. Vela, the founder and director of the Center for the Advancement of Hispanics in Science and Engineering Education (CAHSEE). Moreover, the CAHSEE started a summer program for talented under-represented students in the Washington, D.C., area called the STEM Institute. Based on the program's recognized success and his expertise in STEM education, Charles Vela was asked to serve on numerous NSF and Congressional panels in science, mathematics, and engineering edu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are people called that choose to study science?
A. doctors
B. scientists
C. lab technicians
D. engineers
Answer:
|
|
scienceQA-10122
|
multiple_choice
|
Select the mammal below.
|
[
"toco toucan",
"green iguana",
"thresher shark",
"sea otter"
] |
D
|
A green iguana is a reptile. It has scaly, waterproof skin.
Iguanas are a type of lizard. Iguanas eat plants and fruit.
A sea otter is a mammal. It has fur and feeds its young milk.
Sea otters have very thick fur. Their fur keeps them warm in cold water.
A toco toucan is a bird. It has feathers, two wings, and a beak.
Toucans have large beaks. A toucan's beak can be half as long as its body.
A thresher shark is a fish. It lives underwater. It has fins, not limbs.
A thresher shark has a long tail. It can use its tail to hit and stun prey.
|
Relavent Documents:
Document 0:::
In zoology, mammalogy is the study of mammals – a class of vertebrates with characteristics such as homeothermic metabolism, fur, four-chambered hearts, and complex nervous systems. Mammalogy has also been known as "mastology," "theriology," and "therology." The archive of number of mammals on earth is constantly growing, but is currently set at 6,495 different mammal species including recently extinct. There are 5,416 living mammals identified on earth and roughly 1,251 have been newly discovered since 2006. The major branches of mammalogy include natural history, taxonomy and systematics, anatomy and physiology, ethology, ecology, and management and control. The approximate salary of a mammalogist varies from $20,000 to $60,000 a year, depending on their experience. Mammalogists are typically involved in activities such as conducting research, managing personnel, and writing proposals.
Mammalogy branches off into other taxonomically-oriented disciplines such as primatology (study of primates), and cetology (study of cetaceans). Like other studies, mammalogy is also a part of zoology which is also a part of biology, the study of all living things.
Research purposes
Mammalogists have stated that there are multiple reasons for the study and observation of mammals. Knowing how mammals contribute or thrive in their ecosystems gives knowledge on the ecology behind it. Mammals are often used in business industries, agriculture, and kept for pets. Studying mammals habitats and source of energy has led to aiding in survival. The domestication of some small mammals has also helped discover several different diseases, viruses, and cures.
Mammalogist
A mammalogist studies and observes mammals. In studying mammals, they can observe their habitats, contributions to the ecosystem, their interactions, and the anatomy and physiology. A mammalogist can do a broad variety of things within the realm of mammals. A mammalogist on average can make roughly $58,000 a year. This dep
Document 1:::
Mammals
Alces alces (Linnaeus, 1758) — Eurasian elk, moose
Axis axis (Erxleben, 1777) — chital, axis deer
Bison bison (Linnaeus, 1758) — American bison, buffalo
Capreolus capreolus (Linnaeus, 1758) — European roe deer, roe deer
Caracal caracal (Schreber, 1776) — caracal
Chinchilla chinchilla (Lichtenstein, 1829) — short-tailed chinchilla
Chiropotes chiropotes (Humboldt, 1811) — red-backed bearded saki
Cricetus cricetus (Linnaeus, 1758) — common hamster, European hamster
Crocuta crocuta (Erxleben, 1777) — spotted hyena
Dama dama (Linnaeus, 1758) — European fallow deer
Feroculus feroculus (Kelaart, 1850) — Kelaart's long-clawed shrew
Gazella gazella (Pallas, 1766) — mountain gazelle
Genetta genetta (Linnaeus, 1758) — common genet
Gerbillus gerbillus (Olivier, 1801) — lesser Egyptian gerbil
Giraffa giraffa (von Schreber, 1784) — southern giraffe
Glis glis (Linnaeus, 1766) — European edible dormouse, European fat dormouse
Gorilla gorilla (Savage, 1847) — western gorilla
Gulo gulo (Linnaeus, 1758) — wolverine
Hoolock hoolock (Harlan, 1834) — western hoolock gibbon
Hyaena hyaena (Linnaeus, 1758) — striped hyena
Indri indri (Gmelin, 1788) — indri
Jaculus jaculus (Linnaeus, 1758) — lesser Egyptian jerboa
Lagurus lagurus (Pallas, 1773) — steppe vole, steppe lemming
Lemmus lemmus (Linnaeus, 1758) — Norway lemming
Lutra lutra (Linnaeus, 1758) — European otter
Lynx lynx (Linnaeus, 1758) — Eurasian lynx
Macrophyllum macrophyllum (Schinz, 1821) — long-legged bat
Marmota marmota (Linnaeus, 1758) — Alpine marmot
Martes martes (Linnaeus, 1758) — European pine marten, pine marten
Meles meles (Linnaeus, 1758) — European badg
Document 2:::
Order Artiodactyla (even-toed ungulates)
Tylopoda (camelids)
Artiofabula (ruminants, pigs, peccaries, whales, and dolphins)
Suina (pigs and peccaries)
Cetruminantia (ruminants, whales, and dolphins)
Suborder Ruminantia (antelope, buffalo, cattle, goats, sheep, deer, giraffes, and chevrotains)
Family Antilocapridae (pronghorn)
Family Bovidae, 135 species (antelope, bison, buffalo, cattle, goats, and sheep)
Family Cervidae, 55~94 species (deer, elk, and moose)
Family Giraffidae, 2 species (giraffes, okapis)
Family Moschidae, 4~7 species (musk deer)
Family Tragulidae, 6~10 species (chevrotains, or mouse deer)
Suborder Whippomorpha (aquatic or semi-aquatic even-toed ungulates)
Infraorder Acodonta
Family Hippopotamidae, 2 species (hippopotamuses)
Infraorder Cetacea (whales, dolphins, and porpoises)
Mysticeti (baleen whales)
Family Balaenidae, 2~4 species (right whales and bowhead whales)
Family Balaenopteridae, 6~9 species (rorquals)
Family Eschrichtiidae, 1 species (gray whale)
Family Neobalaenidae, 1 species (pygmy right whale)
Odontoceti (toothed whales, dolphins, and porpoises)
Superfamily Delphinoidea (dolphins, arctic whales, porpoises, and relatives)
Family Delphinidae, 38 species (dolphins, killer whales, and relatives)
Family Monodontidae, 2 species (beluga and narwhal)
Family Phocoenidae, 6 species (porpoises)
Superfamily Physeteroidea (sperm whales)
Family Kogiidae, 2 species (pygmy and dwarf sperm whales)
Family Physeteridae, 1 species (common sperm whale)
Superfamily Ziphoidea (beaked whales)
Family Ziphidae, 22 species (modern beaked whales)
Superfamily Platanistoidea (river dolphins)
Family Iniidae, 1~3 species (South American river dolphin(s))
Document 3:::
Phylogeny
Phylogenetic analyses of artiodactyls revealed the following relationships:
Classification
Order Artiodactyla (even-toed ungulates)
Suborder Tylopoda (camelids)
Artiofabula (ruminants, pigs, peccaries, whales, and dolphins)
Suborder Suina (pigs and peccaries)
Family Suidae 19 species (pigs)
Family Tayassuidae 4 species (peccaries)
Cetruminantia (ruminants, whales, and dolphins)
Suborder Ruminantia (antelope, buffalo, cattle, goats, sheep, deer, giraffes, and chevrotains)
Family Antilocapridae, 1 species (pronghorn)
Family Bovidae, 135 species (antelope, bison, buffalo, cattle, goats, and sheep)
Family Cervidae, 55 - 94 species (deer, elk, and moose)
Family Giraffidae, 2 species (giraffes, okapis)
Family Moschidae, 4 - 7 species (musk deer)
Family Tragulidae, 6 - 10 species (chevrotains, or mouse deer)
Suborder Whippomorpha (aquatic or semi-aquatic even-toed ungulates)
Infraorder Acodonta
Family Hippopotamidae, 2 species (hippopotamuses)
Infraorder Cetacea (whales, dolphins, and porpoises)
Parvorder Mysticeti (baleen whales)
Family Balaenidae, 2 - 4 species (right whales and bowhead whales)
Family Balaenopteridae, 6 - 9 species (rorquals)
Family Eschrichtiidae, 1 species (gray whale)
Family Neobalaenidae, 1 species (pygmy right whale)
Parvorder Odontoceti (toothed whales, dolphins, and porpoises)
Superfamily Delphinoidea (dolphins, arctic whales, porpoises, and relatives)
Family Del
Document 4:::
Vertebrate zoology is the biological discipline that consists of the study of Vertebrate animals, i.e., animals with a backbone, such as fish, amphibians, reptiles, birds and mammals. Many natural history museums have departments named Vertebrate Zoology. In some cases whole museums bear this name, e.g. the Museum of Vertebrate Zoology at the University of California, Berkeley.
Subdivisions
This subdivision of zoology has many further subdivisions, including:
Ichthyology - the study of fishes.
Mammalogy - the study of mammals.
Chiropterology - the study of bats.
Primatology - the study of primates.
Ornithology - the study of birds.
Herpetology - the study of reptiles.
Batrachology - the study of amphibians.
These divisions are sometimes further divided into more specific specialties.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the mammal below.
A. toco toucan
B. green iguana
C. thresher shark
D. sea otter
Answer:
|
sciq-7838
|
multiple_choice
|
Researchers have identified the receptor proteins for all of the tastes except which?
|
[
"bitter",
"sweet",
"salty",
"acid"
] |
C
|
Relavent Documents:
Document 0:::
A taste receptor or tastant is a type of cellular receptor which facilitates the sensation of taste. When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other locations. Molecules which give a sensation of taste are considered "sapid".
Vertebrate taste receptors are divided into two families:
Type 1, sweet, first characterized in 2001: –
Type 2, bitter, first characterized in 2000: In humans there are 25 known different bitter receptors, in cats there are 12, in chickens there are three, and in mice there are 35 known different bitter receptors.
Visual, olfactive, "sapictive" (the perception of tastes), trigeminal (hot, cool), mechanical, all contribute to the perception of taste. Of these, transient receptor potential cation channel subfamily V member 1 (TRPV1) vanilloid receptors are responsible for the perception of heat from some molecules such as capsaicin, and a CMR1 receptor is responsible for the perception of cold from molecules such as menthol, eucalyptol, and icilin.
Tissue distribution
The gustatory system consists of taste receptor cells in taste buds. Taste buds, in turn, are contained in structures called papillae. There are three types of papillae involved in taste: fungiform papillae, foliate papillae, and circumvallate papillae. (The fourth type - filiform papillae do not contain taste buds). Beyond the papillae, taste receptors are also in the palate and early parts of the digestive system like the larynx and upper esophagus. There are three cranial nerves that innervate the tongue; the vagus nerve, glossopharyngeal nerve, and the facial nerve. The glossopharyngeal nerve and the chorda tympani branch of the facial nerve innervate the TAS1R and TAS2R taste receptors. Next to the taste receptors in on the tongue, the gut epithelium is also equipped with a subtle chemosensory system that communicates the sensory information to several effector systems involved
Document 1:::
The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception stimulated when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue. Taste, along with the sense of smell and trigeminal nerve stimulation (registering texture, pain, and temperature), determines flavors of food and other substances. Humans have taste receptors on taste buds and other areas, including the upper surface of the tongue and the epiglottis. The gustatory cortex is responsible for the perception of taste.
The tongue is covered with thousands of small bumps called papillae, which are visible to the naked eye. Within each papilla are hundreds of taste buds. The exception to this is the filiform papillae that do not contain taste buds. There are between 2000 and 5000 taste buds that are located on the back and front of the tongue. Others are located on the roof, sides and back of the mouth, and in the throat. Each taste bud contains 50 to 100 taste receptor cells.
Taste receptors in the mouth sense the five basic tastes: sweetness, sourness, saltiness, bitterness, and savoriness (also known as savory or umami). Scientific experiments have demonstrated that these five tastes exist and are distinct from one another. Taste buds are able to tell different tastes apart when they interact with different molecules or ions. Sweetness, savoriness, and bitter tastes are triggered by the binding of molecules to G protein-coupled receptors on the cell membranes of taste buds. Saltiness and sourness are perceived when alkali metals or hydrogen ions meet taste buds, respectively.
The basic tastes contribute only partially to the sensation and flavor of food in the mouth—other factors include smell, detected by the olfactory epithelium of the nose; texture, detected through a variety of mechanoreceptors, muscle nerves, etc.; temperature, det
Document 2:::
Taste buds are clusters of taste receptor cells, which are also known as gustatory cells. The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper esophagus, the cheek, and epiglottis. These structures are involved in detecting the five elements of taste perception: saltiness, sourness, bitterness, sweetness and savoriness (umami). A popular myth assigns these different tastes to different regions of the tongue; in fact, these tastes can be detected by any area of the tongue. Via small openings in the tongue epithelium, called taste pores, parts of the food dissolved in saliva come into contact with the taste receptors. These are located on top of the taste receptor cells that constitute the taste buds. The taste receptor cells send information detected by clusters of various receptors and ion channels to the gustatory areas of the brain via the seventh, ninth and tenth cranial nerves.
On average, the human tongue has 2,000-8,000 taste buds. The average lifespan of these is estimated to be 10 days.
Types of papillae
The taste buds on the tongue sit on raised protrusions of the tongue surface called papillae. There are four types of lingual papillae; all except one contain taste buds:
Fungiform papillae - as the name suggests, these are slightly mushroom-shaped if looked at in longitudinal section. These are present mostly at the dorsal surface of the tongue, as well as at the sides. Innervated by facial nerve.
Foliate papillae - these are ridges and grooves towards the posterior part of the tongue found at the lateral borders. Innervated by facial nerve (anterior papillae) and glossopharyngeal nerve (posterior papillae).
Circumvallate papillae - there are only about 10 to 14 of these papillae on most people, and they are present at the back of the oral part of the tongue. They are arranged in a circular-shaped row just in front of the sulcus terminalis of the tongue. They are ass
Document 3:::
The primary gustatory cortex (GC) is a brain structure responsible for the perception of taste. It consists of two substructures: the anterior insula on the insular lobe and the frontal operculum on the inferior frontal gyrus of the frontal lobe. Because of its composition the primary gustatory cortex is sometimes referred to in literature as the AI/FO(Anterior Insula/Frontal Operculum). By using extracellular unit recording techniques, scientists have elucidated that neurons in the AI/FO respond to sweetness, saltiness, bitterness, and sourness, and they code the intensity of the taste stimulus.
Role in the taste pathway
Like the olfactory system, the taste system is defined by its specialized peripheral receptors and central pathways that relay and process taste information. Peripheral taste receptors are found on the upper surface of the tongue, soft palate, pharynx, and the upper part of the esophagus. Taste cells synapse with primary sensory axons that run in the chorda tympani and greater superficial petrosal branches of the facial nerve (cranial nerve VII), the lingual branch of the glossopharyngeal nerve (cranial nerve IX), and the superior laryngeal branch of the vagus nerve (Cranial nerve X) to innervate the taste buds in the tongue, palate, epiglottis, and esophagus respectively. The central axons of these primary sensory neurons in the respective cranial nerve ganglia project to rostral and lateral regions of the nucleus of the solitary tract in the medulla, which is also known as the gustatory nucleus of the solitary tract complex. Axons from the rostral (gustatory) part of the solitary nucleus project to the ventral posterior complex of the thalamus, where they terminate in the medial half of the ventral posterior medial nucleus. This nucleus projects in turn to several regions of the neocortex which includes the gustatory cortex (the frontal operculum and the insula), which becomes activated when the subject is consuming and experiencing t
Document 4:::
The evolution of bitter taste receptors has been one of the most dynamic evolutionary adaptations to arise in multiple species. This phenomenon has been widely studied in the field of evolutionary biology because of its role in the identification of toxins often found on the leaves of inedible plants. A palate more sensitive to these bitter tastes would, theoretically, have an advantage over members of the population less sensitive to these poisonous substances because they would be much less likely to ingest toxic plants. Bitter-taste genes have been found in a variety of species, and the same genes have been well characterized in several common laboratory animals such as primates and mice, as well as in humans. The primary gene responsible for encoding this ability in humans is the TAS2R gene family which contains 25 functional loci as well as 11 pseudogenes. The development of this gene has been well characterized, with proof that the ability evolved before the human migration out of Africa. The gene continues to evolve in the present day.
TAS2R
The bitter taste receptor family, T2R (TAS2R), is encoded on chromosome 7 and chromosome 12. Genes on the same chromosome have shown remarkable similarity with each other, suggesting that the primary mutagenic forces in evolution of TAS2R are duplication events. These events have occurred in at least seven primate species: chimpanzee, human, gorilla, orangutan, rhesus macaque and baboon. The high variety among primate and rodent populations additionally suggests that, while selective constraint on these genes certainly exists, its effect is rather slight.
Members of the T2R family encode alpha subunits of G-protein-coupled receptors, which are involved in intracellular taste transduction, not only on the taste buds but also in the pancreas and gastrointestinal tract. The mechanism of transduction is shown by exposure of the endocrine and gastrointestinal cells containing the receptors to bitter compounds, most famously
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Researchers have identified the receptor proteins for all of the tastes except which?
A. bitter
B. sweet
C. salty
D. acid
Answer:
|
|
sciq-3655
|
multiple_choice
|
What is the name of the protective layer of gases that surrounds the earth and blocks harmful rays from the sun?
|
[
"the atmosphere",
"the corona",
"the coma",
"the protector"
] |
A
|
Relavent Documents:
Document 0:::
The blanketing effect (also referred to as line blanketing or the line-blanketing effect) is the enhancement of the red or infrared regions of a stellar spectrum at the expense of the other regions, with an overall diminishing effect on the whole spectrum. The term originates in a 1928 article by astrophysicist Edward Arthur Milne, where it was used to describe the effects that the astronomical metals in a star's outer regions had on that star's spectrum. The name arose because the absorption lines act as a "blanket", causing the continuum temperature of the spectrum to rise over what it would have been if these lines were not present.
Astronomical metals, which produce most of a star's spectral absorption lines, absorb a fraction of the star's radiant energy (a phenomenon known as the blocking effect) and then re-emit it at a lower frequency as part of the backwarming effect. The combination of both these effects results in the position of stars in a color-color diagram to shift towards redder areas as the proportion of metals in them increases. The blanketing effect is thus highly dependent on the metallicity index of a star, which indicates the fraction of elements other than hydrogen and helium that compose it.
Document 1:::
Aeronomy is the scientific study of the upper atmosphere of the Earth and corresponding regions of the atmospheres of other planets. It is a branch of both atmospheric chemistry and atmospheric physics. Scientists specializing in aeronomy, known as aeronomers, study the motions and chemical composition and properties of the Earth's upper atmosphere and regions of the atmospheres of other planets that correspond to it, as well as the interaction between upper atmospheres and the space environment. In atmospheric regions aeronomers study, chemical dissociation and ionization are important phenomena.
History
The mathematician Sydney Chapman introduced the term aeronomy to describe the study of the Earth's upper atmosphere in 1946 in a letter to the editor of Nature entitled "Some Thoughts on Nomenclature." The term became official in 1954 when the International Union of Geodesy and Geophysics adopted it. "Aeronomy" later also began to refer to the study of the corresponding regions of the atmospheres of other planets.
Branches
Aeronomy can be divided into three main branches: terrestrial aeronomy, planetary aeronomy, and comparative aeronomy.
Terrestrial aeronomy
Terrestrial aeronomy focuses on the Earth's upper atmosphere, which extends from the stratopause to the atmosphere's boundary with outer space and is defined as consisting of the mesosphere, thermosphere, and exosphere and their ionized component, the ionosphere. Terrestrial aeronomy contrasts with meteorology, which is the scientific study of the Earth's lower atmosphere, defined as the troposphere and stratosphere. Although terrestrial aeronomy and meteorology once were completely separate fields of scientific study, cooperation between terrestrial aeronomers and meteorologists has grown as discoveries made since the early 1990s have demonstrated that the upper and lower atmospheres have an impact on one another's physics, chemistry, and biology.
Terrestrial aeronomers study atmospheric tides and upper-
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
In infrared astronomy, the L band is an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).
Electromagnetic spectrum
Infrared imaging
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the name of the protective layer of gases that surrounds the earth and blocks harmful rays from the sun?
A. the atmosphere
B. the corona
C. the coma
D. the protector
Answer:
|
|
sciq-2277
|
multiple_choice
|
What type of joint is the knee joint?
|
[
"pivot joint",
"hinge joint",
"ball joint",
"condyloid joint"
] |
B
|
Relavent Documents:
Document 0:::
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 1:::
In animal anatomy, a pivot joint (trochoid joint, rotary joint or lateral ginglymus) is a type of synovial joint whose movement axis is parallel to the long axis of the proximal bone, which typically has a convex articular surface.
According to one classification system, a pivot joint like the other synovial joint —the hinge joint has one degree of freedom. Note that the degrees of freedom of a joint is not the same as the same as joint's range of motion.
Movements
Pivot joints allow for rotation, which can be external (for example when rotating an arm outward), or internal (as in rotating an arm inward). When rotating the forearm, these movements are typically called pronation and supination. In the standard anatomical position, the forearms are supinated, which means that the palms are facing forward, and the thumbs are pointing away from the body. In contrast, a forearm in pronation would have the palm facing backward and the thumb would be closer to the body, pointing medially.
Examples
Examples of a pivot joint include:
Proximal radioulnar joint
Distal radioulnar joint
Median atlanto-axial joint
In contrast, spherical joints (or ball and socket joints) such as the hip joint permit rotation and all other directional movement, while pivot joints only permit rotation.
Document 2:::
The lateral epicondyle of the femur, smaller and less prominent than the medial epicondyle, gives attachment to the fibular collateral ligament of the knee-joint. Directly below it is a small depression from which a smooth well-marked groove curves obliquely upward and backward to the posterior extremity of the condyle.
Document 3:::
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 4:::
Contusions of both surfaces of the knee joint are known as kissing contusions. These contusions are generally found by magnetic resonance imaging and most cases are associated with ligamentous or meniscal injuries.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of joint is the knee joint?
A. pivot joint
B. hinge joint
C. ball joint
D. condyloid joint
Answer:
|
|
scienceQA-1165
|
multiple_choice
|
What do these two changes have in common?
cooking a pancake
salt and vinegar removing tarnish from a penny
|
[
"Both are caused by cooling.",
"Both are only physical changes.",
"Both are caused by heating.",
"Both are chemical changes."
] |
D
|
Step 1: Think about each change.
Cooking a pancake is a chemical change. Pancakes are made from pancake batter. A cooked pancake is a different type of matter than pancake batter. Pancake batter is wet and slippery. Cooked pancakes are fluffy and can be good to eat!
Salt and vinegar removing tarnish from a penny is a chemical change. The salt and vinegar change the tarnish into a different type of matter that can be easily wiped away. This makes the penny look shiny again.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Cooking is caused by heating. But salt and vinegar removing tarnish from a penny 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 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 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:::
Computer science and engineering (CSE) is an academic program at many universities which comprises computer science classes (e.g. data structures and algorithms) and computer engineering classes (e.g computer architecture). There is no clear division in computing between science and engineering, just like in the field of materials science and engineering. CSE is also a term often used in Europe to translate the name of engineering informatics academic programs. It is offered in both undergraduate as well postgraduate with specializations.
Academic courses
Academic programs vary between colleges, but typically include a combination of topics in computer science, computer engineering, and electrical engineering. Undergraduate courses usually include programming, algorithms and data structures, computer architecture, operating systems, computer networks, parallel computing, embedded systems, algorithms design, circuit analysis and electronics, digital logic and processor design, computer graphics, scientific computing, software engineering, database systems, digital signal processing, virtualization, computer simulations and games programming. CSE programs also include core subjects of theoretical computer science such as theory of computation, numerical methods, machine learning, programming theory and paradigms. Modern academic programs also cover emerging computing fields like image processing, data science, robotics, bio-inspired computing, computational biology, autonomic computing and artificial intelligence. Most CSE programs require introductory mathematical knowledge, hence the first year of study is dominated by mathematical courses, primarily discrete mathematics, mathematical analysis, linear algebra, probability, and statistics, as well as the basics of electrical and electronic engineering, physics, and electromagnetism.
Example universities with CSE majors and departments
APJ Abdul Kalam Technological University
American International University-B
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
cooking a pancake
salt and vinegar removing tarnish from a penny
A. Both are caused by cooling.
B. Both are only physical changes.
C. Both are caused by heating.
D. Both are chemical changes.
Answer:
|
sciq-1606
|
multiple_choice
|
Substances that act as both weak acids and bases are said to be what?
|
[
"hygroscopic",
"atmospheric",
"amphiphilic",
"amphoteric"
] |
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:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 2:::
In chemistry and biochemistry, the Henderson–Hasselbalch equation
relates the pH of a chemical solution of a weak acid to the numerical value of the acid dissociation constant, Ka, of acid and the ratio of the concentrations, of the acid and its conjugate base in an equilibrium.
For example, the acid may be acetic acid
The Henderson–Hasselbalch equation can be used to estimate the pH of a buffer solution by approximating the actual concentration ratio as the ratio of the analytical concentrations of the acid and of a salt, MA.
The equation can also be applied to bases by specifying the protonated form of the base as the acid. For example, with an amine,
Derivation, assumptions and limitations
A simple buffer solution consists of a solution of an acid and a salt of the conjugate base of the acid. For example, the acid may be acetic acid and the salt may be sodium acetate.
The Henderson–Hasselbalch equation relates the pH of a solution containing a mixture of the two components to the acid dissociation constant, Ka of the acid, and the concentrations of the species in solution.
To derive the equation a number of simplifying assumptions have to be made. (pdf)
Assumption 1: The acid, HA, is monobasic and dissociates according to the equations
CA is the analytical concentration of the acid and CH is the concentration the hydrogen ion that has been added to the solution. The self-dissociation of water is ignored. A quantity in square brackets, [X], represents the concentration of the chemical substance X. It is understood that the symbol H+ stands for the hydrated hydronium ion. Ka is an acid dissociation constant.
The Henderson–Hasselbalch equation can be applied to a polybasic acid only if its consecutive pK values differ by at least 3. Phosphoric acid is such an acid.
Assumption 2. The self-ionization of water can be ignored.
This assumption is not, strictly speaking, valid with pH values close to 7, half the value of pKw, the constant for self-ioniz
Document 3:::
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.
Principles of buffering
Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−:
When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increases by less than the amount expected for the quantity of strong acid added.
Similarly, if strong alkali is added to the mixture, the hydrogen ion concentration decreases by less than the amount expected for the quantity of alkali added. In Figure 1, the effect is illustrated by the simulated titration of a weak acid with pKa = 4.7. The relative concentration of undissociated acid is shown in blue, and of its conjugate base in red. The pH changes relatively slowly in the buffer region, pH = pKa ± 1, centered at pH = 4.7, where [HA] = [A−]. The hydrogen ion concentration decreases by less than the amount expected because most of the added hydroxide ion is consumed in the reaction
and only a little is consumed in the neutralization reaction (which is the reaction that results in an increase in pH)
Once the acid is more than 95% deprotonated, the pH rises rapidly because most of the added alkali is consumed in the neutralization reaction.
Buffer capacity
Buffer
Document 4:::
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms reactant and reagent are often used interchangeably, but reactant specifies a substance consumed in the course of a chemical reaction. Solvents, though involved in the reaction mechanism, are usually not called reactants. Similarly, catalysts are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates.
Definitions
Organic chemistry
In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents.
Analytical chemistry
In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by colorimetry. Examples include Fehling's reagent, Millon's reagent, and Tollens' reagent.
Commercial or laboratory preparations
In commercial or laboratory preparations, reagent-grade designates chemical substances meeting standards of purity that ensure the scientific precision and reliability of chemical analysis, chemical reactions or physical testing. Purity standards for reagents are set by organizations such as ASTM International or the American Chemical Society. For instance, reagent-quality water must have very low levels of impurities such as sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity. Laboratory products which are less pure, but still useful and economical for undemanding work, may be designated as technical, practical, or crude grade to distinguish them from reagent versions.
Biology
In t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Substances that act as both weak acids and bases are said to be what?
A. hygroscopic
B. atmospheric
C. amphiphilic
D. amphoteric
Answer:
|
|
sciq-11109
|
multiple_choice
|
What type of sti is characterized by blisters?
|
[
"syphilis",
"gonorrhea",
"genital herpes",
"chlamydia"
] |
C
|
Relavent Documents:
Document 0:::
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs), are infections that are commonly spread by sexual activity, especially vaginal intercourse, anal sex and oral sex. The most prevalent STIs may be carried by a significant fraction of the human population.
Document 1:::
Single Best Answer (SBA or One Best Answer) is a written examination form of multiple choice questions used extensively in medical education.
Structure
A single question is posed with typically five alternate answers, from which the candidate must choose the best answer. This method avoids the problems of past examinations of a similar form described as Single Correct Answer. The older form can produce confusion where more than one of the possible answers has some validity. The newer form makes it explicit that more than one answer may have elements that are correct, but that one answer will be superior.
Prior to the widespread introduction of SBAs into medical education, the typical form of examination was true-false multiple choice questions. But during the 2000s, educators found that SBAs would be superior.
Document 2:::
Catheter-associated urinary tract Infection, or CAUTI, is a urinary tract infection associated with urinary catheter use.
Core prevention
A number of combined practices such as improved hand hygiene, enhanced barrier protection and reduced catheter use when managing incontinence appear to reduce CAUTI. Urinary catheters should be inserted using aseptic technique and sterile equipment (including sterile gloves, drape, sponges, antiseptic and sterile solution), particularly in an acute care setting. Although catheter use should be minimized in all patients, particularly those at higher risk of CAUTI and mortality (e.g. the elderly or those with impaired immunity), a meta analysis suggests there is insufficient evidence to determine the value of different policies for replacing long term urinary catheters on patient outcomes.
Incidence
Bacteria and yeast, including those naturally occurring as part of the human microbiome, can grow within biofilm that forms along the surface of urinary catheters. This leads to infection in the bladder, kidneys, and other organs connected to the urinary tract.
CAUTI can lead to complications such as prostatitis, epididymitis, and orchitis in men, and cystitis, pyelonephritis, gram-negative bacteremia, endocarditis, vertebral osteomyelitis, septic arthritis, endophthalmitis, and meningitis in all patients. Complications associated with CAUTI cause discomfort to the patient, prolonged hospital stay, and increased cost and mortality.
Document 3:::
Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
Document 4:::
Those involved in the care of athletes should be alert to the possibility of getting an infectious disease for the following reasons:
There is the chance, or even the expectation, of contact or collision with another player, or the playing surface, which may be a mat or artificial turf.
The opportunities for skin breaks, obvious or subtle, are present and compromise skin defenses.
Young people congregate in dormitories, locker rooms, showers, etc.
There is the possibility of sharing personal toilet articles.
Equipment, gloves and pads and protective gear, is difficult to sanitize and can become contaminated.
However, in many cases, the chance of infection can be reduced by relatively simple measures.
Herpes gladiatorum
Wrestlers use mats which are abrasive and the potential for a true contagion (Latin contagion-, contagio, from contingere to have contact with) is very real. The herpes simplex virus, type I, is very infectious and large outbreaks have been documented. A major epidemic threatened the 2007 Minnesota high school wrestling season, but was largely contained by instituting an eight-day isolation period during which time competition was suspended. Practices, such as 'weight cutting', which can at least theoretically reduce immunity, might potentiate the risk. In non-epidemic circumstances, herpes gladiatorum affects about 3% of high school wrestlers and 8% of collegiate wrestlers. There is the potential for prevention of infection, or at least containment, with antiviral agents which are effective in reducing the spread to other athletes when given to those who are herpes positive, or who have recurrent herpes gladiatorum.
The NCAA specifies that a wrestler must:
- be free of systemic symptoms (fever, malaise, etc.).
- have developed no new blisters for 72 hours before the examination.
- have no moist lesions; all lesions must be dried and have progressed to a FIRM ADHERENT CRUST.
- have been on appropriate systemic antiviral therapy for at lea
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of sti is characterized by blisters?
A. syphilis
B. gonorrhea
C. genital herpes
D. chlamydia
Answer:
|
|
sciq-4383
|
multiple_choice
|
What is group 16 of the periodic table referred to?
|
[
"dioxide group",
"acid group",
"oxygen group",
"sulfur group"
] |
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:::
Sometimes the Tits group is considered a 17th non-strict simple group of Lie type, or a 27th sporadic group, which would yield a total of 45 finite simple groups.
In science
The atomic number of ruthenium
Astronomy
Messier object M44, a magnitude 4.0 open cluster in the constellation Cancer, also known as the Beehive Cluster
The New General Catalogue object NGC 44, a doubl
Document 2:::
The School of Textile and Clothing industries (ESITH) is a Moroccan engineering school, established in 1996, that focuses on textiles and clothing. It was created in collaboration with ENSAIT and ENSISA, as a result of a public private partnership designed to grow a key sector in the Moroccan economy. The partnership was successful and has been used as a model for other schools.
ESITH is the only engineering school in Morocco that provides a comprehensive program in textile engineering with internships for students at the Canadian Group CTT. Edith offers three programs in industrial engineering: product management, supply chain, and logistics, and textile and clothing
Document 3:::
In chemistry and physics, the iron group refers to elements that are in some way related to iron; mostly in period (row) 4 of the periodic table. The term has different meanings in different contexts.
In chemistry, the term is largely obsolete, but it often means iron, cobalt, and nickel, also called the iron triad; or, sometimes, other elements that resemble iron in some chemical aspects.
In astrophysics and nuclear physics, the term is still quite common, and it typically means those three plus chromium and manganese—five elements that are exceptionally abundant, both on Earth and elsewhere in the universe, compared to their neighbors in the periodic table. Titanium and vanadium are also produced in Type Ia supernovae.
General chemistry
In chemistry, "iron group" used to refer to iron and the next two elements in the periodic table, namely cobalt and nickel. These three comprised the "iron triad". They are the top elements of groups 8, 9, and 10 of the periodic table; or the top row of "group VIII" in the old (pre-1990) IUPAC system, or of "group VIIIB" in the CAS system. These three metals (and the three of the platinum group, immediately below them) were set aside from the other elements because they have obvious similarities in their chemistry, but are not obviously related to any of the other groups. The iron group and its alloys exhibit ferromagnetism.
The similarities in chemistry were noted as one of Döbereiner's triads and by Adolph Strecker in 1859. Indeed, Newlands' "octaves" (1865) were harshly criticized for separating iron from cobalt and nickel. Mendeleev stressed that groups of "chemically analogous elements" could have similar atomic weights as well as atomic weights which increase by equal increments, both in his original 1869 paper and his 1889 Faraday Lecture.
Analytical chemistry
In the traditional methods of qualitative inorganic analysis, the iron group consists of those cations which
have soluble chlorides; and
are not precipitated
Document 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.
What is group 16 of the periodic table referred to?
A. dioxide group
B. acid group
C. oxygen group
D. sulfur group
Answer:
|
|
sciq-8031
|
multiple_choice
|
Teeth in the back of the mouth are used for what?
|
[
"swallowing food",
"cutting food",
"grinding food",
"tearing food"
] |
C
|
Relavent Documents:
Document 0:::
Biting is a common zoological behavior involving the active, rapid closing of the jaw around an object. This behavior is found in toothed animals such as mammals, reptiles, amphibians and fish, but can also exist in arthropods. Myocytic contraction of the muscles of mastication is responsible for generating the force that initiates the preparatory jaw abduction (opening), then rapidly adducts (closes) the jaw and moves the top and bottom teeth towards each other, resulting in the forceful action of a bite.
Biting is one of the main functions in most macro-organisms' life, providing them the ability to forage, hunt, eat, build, play, fight and protect, and much more. Biting may be a form of physical aggression due to predatory or territorial intentions, but can also be a normal activity of an animal as it eats, carries objects, softens and prepares food for its young, removes ectoparasites or irritating foreign objects (e.g. burred plant seeds) from body surface, scratches itself, and grooms other animals.
Animal bites often result in serious punctures, avulsions, fractures, hemorrhages, infections, envenomation and death. In modern human societies, dog bites are the most common types, with children the most common victims and faces the most common targets. Other species that can exhibit such behavior towards human are typically aggressive urban animals such as feral cats, spiders and snakes, micropredators such as vampire bats and hematophagic arthropods (e.g. mosquitoes, fleas, lice, bedbugs and ticks, whose "bites" are actually a form of sting-like puncture rather than true biting), or dangerous wild carnivores such as wolves, big cats, bears, crocodilians and predatory fishes (e.g. sharks, barracudas and piranhas).
Types of teeth
The types of teeth that organisms use to bite vary throughout the animal kingdom. Different types of teeth are seen in herbivores, carnivores, and omnivores as they are adapted over many years to better fit their diets. Carnivores
Document 1:::
Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla (upper jaw) or the mandible (lower jaw) and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.
Humans, like most other mammals, are diphyodont, meaning that they develop two sets of teeth. The first set, deciduous teeth, also called "primary teeth", "baby teeth", or "milk teeth", normally eventually contains 20 teeth. Primary teeth typically start to appear ("erupt") around six months of age and this may be distracting and/or painful for the infant. However, some babies are born with one or more visible teeth, known as neonatal teeth or "natal teeth".
Anatomy
Dental anatomy is a field of anatomy dedicated to the study of tooth structure. The development, appearance, and classification of teeth fall within its field of study, though dental occlusion, or contact between teeth, does not. Dental anatomy is also a taxonomic science as it is concerned with the naming of teeth and their structures. This information serves a practical purpose for dentists, enabling them to easily identify and describe teeth and structures during treatment.
The anatomic crown of a tooth is the area covered in enamel above the cementoenamel junction (CEJ) or "neck" of the tooth. Most of the crown is composed of dentin ("dentine" in British English) with the pulp chamber inside. The crown is within bone before eruption. After eruption, it is almost always visible. The anatomic root is found below the CEJ and is covered with cementum. As with the crown, dentin composes most of the root, which normally h
Document 2:::
Changes to the dental morphology and jaw are major elements of hominid evolution. These changes were driven by the types and processing of food eaten. The evolution of the jaw is thought to have facilitated encephalization, speech, and the formation of the uniquely human chin.
Background
Today, humans possess 32 permanent teeth with a dental formula of . This breaks down to two pairs of incisors, one pair of canines, two pairs of premolars, and three pairs of molars on each jaw. In modern day humans, incisors are generally spatulate with a single root while canines are also single rooted but are single cusped and conical. Premolars are bicuspid while molars are multi-cuspid. The upper molars have three roots while the lower molars have two roots.
General patterns of dental morphological evolution throughout human evolution include a reduction in facial prognathism, the presence of a Y5 cusp pattern, the formation of a parabolic palate and the loss of the diastema.
Human teeth are made of dentin and are covered by enamel in the areas that are exposed. Enamel, itself, is composed of hydroxyapatite, a calcium phosphate crystal. The various types of human teeth perform different functions. Incisors are used to cut food, canines are used to tear food, and the premolars and molars are used to crush and grind food.
History
Hominidae
Chimpanzees
According to the theory of evolution, humans evolved from a common ancestor of chimpanzees. Researchers hypothesize that the earliest hominid ancestor would have similar dental morphology to chimpanzees today. Thus, comparisons between chimpanzees and Homo sapiens could be used to identify major differences. Major characterizing features of Pan troglodytes dental morphology include the presence of peripherally located cusps, thin enamel, and strong facial prognathism.
Earliest Hominids
Sahelanthropus tchadensis
Sahelanthropus tchadensis is thought to be one of the earliest species belonging to the human lineage. Fossil
Document 3:::
Oral and maxillofacial pathology refers to the diseases of the mouth ("oral cavity" or "stoma"), jaws ("maxillae" or "gnath") and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin (the skin around the mouth). The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders.
The specialty oral and maxillofacial pathology is concerned with diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial region. It is sometimes considered to be a specialty of dentistry and pathology. Sometimes the term head and neck pathology is used instead, which may indicate that the pathologist deals with otorhinolaryngologic disorders (i.e. ear, nose and throat) in addition to maxillofacial disorders. In this role there is some overlap between the expertise of head and neck pathologists and that of endocrine pathologists.
Diagnosis
The key to any diagnosis is thorough medical, dental, social and psychological history as well as assessing certain lifestyle risk factors that may be involved in disease processes. This is followed by a thorough clinical investigation including extra-oral and intra-oral hard and soft tissues.
It is sometimes the case that a diagnosis and treatment regime are possible to determine from history and examination, however it is good practice to compile a list of differential diagnoses. Differential diagnosis allows for decisions on what further investigations are needed in each case.
There are many types of investigations in diagnosis of oral and maxillofacial diseases, including screening tests, imaging (radiographs, CBCT, CT, MRI, ultrasound) and histopathology (biopsy).
Biopsy
A biopsy is indicated when the patient's clinical presentation, past history or imaging studies do not allow a definitive diagnosis. A biopsy is a surgical procedure that involves the removal of a piece of tissue sample from the livin
Document 4:::
An oral medicine or stomatology doctor/dentist (or stomatologist) has received additional specialized training and experience in the diagnosis and management of oral mucosal abnormalities (growths, ulcers, infection, allergies, immune-mediated and autoimmune disorders) including oral cancer, salivary gland disorders, temporomandibular disorders (e.g.: problems with the TMJ) and facial pain (due to musculoskeletal or neurologic conditions), taste and smell disorders; and recognition of the oral manifestations of systemic and infectious diseases. It lies at the interface between medicine and dentistry. An oral medicine doctor is trained to diagnose and manage patients with disorders of the orofacial region, essentially as a "physician of the mouth".
History
The importance of the mouth in medicine has been recognized since the earliest known medical writings. For example, Hippocrates, Galen and others considered the tongue to be a "barometer" of health, and emphasized the diagnostic and prognostic importance of the tongue. However, oral medicine as a specialization is a relatively new subject area. It used to be termed "stomatology" (-stomato- + -ology).
In some institutions, it is termed "oral medicine and oral diagnosis". American physician and dentist, Thomas E Bond authored the first book on oral and maxillofacial pathology in 1848, entitled "A Practical Treatise on Dental Medicine". The term "oral medicine" was not used again until 1868. Jonathan Hutchinson is also considered the father of oral medicine by some.
Oral medicine grew from a group of New York dentists (primarily periodontists), who were interested in the interactions between medicine and dentistry in the 1940s. Before becoming its own specialty in the United States, oral medicine was historically once a subset of the specialty of periodontics, with many periodontists achieving board certification in oral medicine as well as periodontics.
Scope
Oral medicine is concerned with clinical diagnosis a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Teeth in the back of the mouth are used for what?
A. swallowing food
B. cutting food
C. grinding food
D. tearing food
Answer:
|
|
sciq-9022
|
multiple_choice
|
What forms the small holes found in bread?
|
[
"yeast",
"carbon dioxide gas",
"carbon monoxide gas",
"oxygen"
] |
B
|
Relavent Documents:
Document 0:::
Pores are the air pockets found in leavened bread, where carbon dioxide from the fermentation process creates a network of primarily interconnected void structures. The degree to which pores form are a major determiner in the texture ("crumb") of the bread. Pore size varies between varieties of bread. Sourdough bread is a variety with larger pores. Rye bread has smaller pores and a denser crumb.
See also
Document 1:::
A ferment (also known as bread starter) is a fermentation starter used in indirect methods of bread making. It may also be called mother dough.
A ferment and a longer fermentation in the bread-making process have several benefits: there is more time for yeast, enzyme and, if sourdough, bacterial actions on the starch and proteins in the dough; this in turn improves the keeping time of the baked bread, and it creates greater complexities of flavor. Though ferments have declined in popularity as direct additions of yeast in bread recipes have streamlined the process on a commercial level, ferments of various forms are widely used in artisanal bread recipes and formulas.
Classifications
In general, there are two ferment varieties: sponges, based on baker's yeast, and the starters of sourdough, based on wild yeasts and lactic acid bacteria. There are several kinds of pre-ferment commonly named and used in bread baking. They all fall on a varying process and time spectrum, from a mature mother dough of many generations of age to a first-generation sponge based on a fresh batch of baker's yeast:
Biga and poolish (or pouliche) are terms used in Italian and French baking, respectively, for sponges made with domestic baker's yeast. Poolish is a fairly wet sponge (typically one-to-one, this is made with a one-part-flour-to-one-part-water ratio by weight), and it is called biga liquida, whereas the "normal" biga is usually drier. Bigas can be held longer at their peak than wetter sponges, while a poolish is one known technique to increase a dough's extensibility.
Sourdough starter is likely the oldest, being reliant on organisms present in the grain and local environment. In general, these starters have fairly complex microbiological makeups, the most notable including wild yeasts, lactobacillus, and acetobacteria in symbiotic relationship referred to as a SCOBY. They are often maintained over long periods of time. For example, the Boudin Bakery in San Francisco has used t
Document 2:::
The Chorleywood bread process (CBP) is a method of efficient dough production to make yeasted bread quickly, producing a soft, fluffy loaf. Compared to traditional bread-making processes, CBP uses more yeast, added fats, chemicals, and high-speed mixing to allow the dough to be made with lower-protein wheat, and produces bread in a shorter time. It was developed by Bill Collins, George Elton and Norman Chamberlain of the British Baking Industries Research Association at Chorleywood in 1961. , 80% of bread made in the United Kingdom used the process.
For millennia, bread had been made from wheat flour by manually kneading dough with a raising agent (typically yeast) leaving it to ferment before it was baked. In 1862 a cheaper industrial-scale process was developed by John Dauglish, using water with dissolved carbon dioxide instead of yeast. Dauglish's method, used by the Aerated Bread Company that he set up, dominated commercial bread baking for a century until the yeast-based Chorleywood process was developed.
Some protein is lost during traditional bulk fermentation of bread; this does not occur to the same degree in mechanically developed doughs, allowing CBP to use lower-protein wheat. This feature had an important impact in the United Kingdom where, at the time, few domestic wheat varieties were of sufficient quality to make high-quality bread; the CBP permitted a much greater proportion of lower-protein domestic wheat to be used in the grist.
Description
The Chorleywood bread process allows the use of lower-protein wheats and reduces processing time, the system being able to produce a loaf of bread from flour to sliced and packaged form in about three and a half hours. This is achieved through the addition of Vitamin C, fat, yeast, and intense mechanical working by high-speed mixers, not feasible in a small-scale kitchen.
Flour, water, yeast, salt, and fat (if used) are mixed together, along with minor ingredients common to many bread-making techniques, suc
Document 3:::
In cooking, proofing (also called proving) is a step in the preparation of yeast bread and other baked goods in which the dough is allowed to rest and rise a final time before baking. During this rest period, yeast ferments the dough and produces gases, thereby leavening the dough.
In contrast, proofing or blooming yeast (as opposed to proofing the dough) may refer to the process of first suspending yeast in warm water, a necessary hydration step when baking with active dry yeast. Proofing can also refer to the process of testing the viability of dry yeast by suspending it in warm water with carbohydrates (sugars). If the yeast is still alive, it will feed on the sugar and produce a visible layer of foam on the surface of the water mixture.
Fermentation rest periods are not always explicitly named, and can appear in recipes as "Allow dough to rise." When they are named, terms include "bulk fermentation", "first rise", "second rise", "final proof" and "shaped proof".
Dough processes
The process of making yeast-leavened bread involves a series of alternating work and rest periods. Work periods occur when the dough is manipulated by the baker. Some work periods are called mixing, kneading, and folding, as well as division, shaping, and panning. Work periods are typically followed by rest periods, which occur when dough is allowed to sit undisturbed. Particular rest periods include, but are not limited to, autolyse, bulk fermentation and proofing. Proofing, also sometimes called final fermentation, is the specific term for allowing dough to rise after it has been shaped and before it is baked.
Some breads begin mixing with an autolyse. This refers to a period of rest after the initial mixing of flour and water, a rest period that occurs sequentially before the addition of yeast, salt and other ingredients. This rest period allows for better absorption of water and helps the gluten and starches to align. The autolyse is credited to Raymond Calvel, who recommende
Document 4:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What forms the small holes found in bread?
A. yeast
B. carbon dioxide gas
C. carbon monoxide gas
D. oxygen
Answer:
|
|
sciq-3054
|
multiple_choice
|
In neurons, what often involves gated sodium channels?
|
[
"depolarization",
"excitation",
"fermentation",
"polarization"
] |
A
|
Relavent Documents:
Document 0:::
In electrophysiology, the term gating refers to the opening (activation) or closing (by deactivation or inactivation) of ion channels. This change in conformation is a response to changes in transmembrane voltage.
When ion channels are in a 'closed' (non-conducting) state, they are impermeable to ions and do not conduct electrical current. When ion channels are in their open state, they conduct electrical current by allowing specific types of ions to pass through them, and thus, across the plasma membrane of the cell. Gating is the process by which an ion channel transitions between its open and closed states.
A variety of cellular changes can trigger gating, depending on the ion channel, including changes in voltage across the cell membrane (voltage-gated ion channels), chemicals interacting with the ion channel (ligand-gated ion channels), changes in temperature, stretching or deformation of the cell membrane, addition of a phosphate group to the ion channel (phosphorylation), and interaction with other molecules in the cell (e.g., G proteins). The rate at which any of these gating processes occurs in response to these triggers are known as the kinetics of gating. Some drugs and many ion channel toxins act as 'gating modifiers' of voltage-gated ion channels by changing the kinetics of gating.
The voltage-gated ion channels of the action potential are often described as having four gating processes: activation, deactivation, inactivation, and reactivation (also called 'recovery from inactivation'). Activation is the process of opening the activation gate, which occurs in response to the voltage inside the cell membrane (the membrane potential) becoming more positive with respect to the outside of the cell (depolarization), and 'deactivation' is the opposite process of the activation gate closing in response to the inside of the membrane becoming more negative (repolarization). 'Inactivation' is the closing of the inactivation gate, and occurs in response to the
Document 1:::
Patch-sequencing (patch-seq) is a method designed for tackling specific problems involved in characterizing neurons. As neural tissues are one of the most transcriptomically diverse populations of cells, classifying neurons into cell types in order to understand the circuits they form is a major challenge for neuroscientists. Combining classical classification methods with single cell RNA-sequencing post-hoc has proved to be difficult and slow. By combining multiple data modalities such as electrophysiology, sequencing and microscopy, Patch-seq allows for neurons to be characterized in multiple ways simultaneously. It currently suffers from low throughput relative to other sequencing methods mainly due to the manual labor involved in achieving a successful patch-clamp recording on a neuron. Investigations are currently underway to automate patch-clamp technology which will improve the throughput of patch-seq as well.
Background
History of patch clamp
Patch-seq is a specialized form of the patch clamp recording technique, the gold standard of single cell electrophysiological studies for its millisecond resolution of cellular electrophysiology, its ability to detect currents of specific ions, and perhaps most importantly for its ability to form a voltage clamp on the cell membrane. The technique was originally developed using a small glass tube, pipette, which is rapidly heated and stretched to produce a needle like shape with an opening diameter of 3-5 millimeters. Modern preparations use different tip diameters depending on the intended application. The pipette is filled with a salt bath to conduct ionic currents before being pressed onto a cells surface to form an electrical seal with a high electrical resistance (measured in the unit ohm) which ensures low noise in the recording. While this seal will be of the order of megaohms, it has been found that applying slight suction will result in a seal with a resistance greater than a giga-ohm. The high resis
Document 2:::
In neuroscience, saltatory conduction () is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials. The uninsulated nodes of Ranvier are the only places along the axon where ions are exchanged across the axon membrane, regenerating the action potential between regions of the axon that are insulated by myelin, unlike electrical conduction in a simple circuit.
Mechanism
Myelinated axons only allow action potentials to occur at the unmyelinated nodes of Ranvier that occur between the myelinated internodes. It is by this restriction that saltatory conduction propagates an action potential along the axon of a neuron at rates significantly higher than would be possible in unmyelinated axons (150 m/s compared to 0.5 to 10 m/s). As sodium rushes into the node it creates an electrical force which pushes on the ions already inside the axon. This rapid conduction of electrical signal reaches the next node and creates another action potential, thus refreshing the signal. In this manner, saltatory conduction allows electrical nerve signals to be propagated long distances at high rates without any degradation of the signal. Although the action potential appears to jump along the axon, this phenomenon is actually just the rapid conduction of the signal inside the myelinated portion of the axon.
If the entire surface of an axon were insulated, action potentials could not be regenerated along the axon resulting in signal degradation.
Energy efficiency
In addition to increasing the speed of the nerve impulse, the myelin sheath helps in reducing energy expenditure over the axon membrane as a whole, because the amount of sodium and potassium ions that need to be pumped to bring the concentrations back to the resting state following each action potential is decreased.
Distribution
Saltatory conduction occurs widely in the myelinated nerve fibers of vertebrates, but was later disc
Document 3:::
In electrophysiology, the threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential. In neuroscience, threshold potentials are necessary to regulate and propagate signaling in both the central nervous system (CNS) and the peripheral nervous system (PNS).
Most often, the threshold potential is a membrane potential value between –50 and –55 mV, but can vary based upon several factors. A neuron's resting membrane potential (–70 mV) can be altered to either increase or decrease likelihood of reaching threshold via sodium and potassium ions. An influx of sodium into the cell through open, voltage-gated sodium channels can depolarize the membrane past threshold and thus excite it while an efflux of potassium or influx of chloride can hyperpolarize the cell and thus inhibit threshold from being reached.
Discovery
Initial experiments revolved around the concept that any electrical change that is brought about in neurons must occur through the action of ions. The German physical chemist Walther Nernst applied this concept in experiments to discover nervous excitability, and concluded that the local excitatory process through a semi-permeable membrane depends upon the ionic concentration. Also, ion concentration was shown to be the limiting factor in excitation. If the proper concentration of ions was attained, excitation would certainly occur. This was the basis for discovering the threshold value.
Along with reconstructing the action potential in the 1950s, Alan Lloyd Hodgkin and Andrew Huxley were also able to experimentally determine the mechanism behind the threshold for excitation. It is known as the Hodgkin–Huxley model. Through use of voltage clamp techniques on a squid giant axon, they discovered that excitable tissues generally exhibit the phenomenon that a certain membrane potential must be reached in order to fire an action potential. Since the experiment yielded results through the observation o
Document 4:::
Graded potentials are changes in membrane potential that vary in size, as opposed to being all-or-none. They include diverse potentials such as receptor potentials, electrotonic potentials, subthreshold membrane potential oscillations, slow-wave potential, pacemaker potentials, and synaptic potentials, which scale with the magnitude of the stimulus. They arise from the summation of the individual actions of ligand-gated ion channel proteins, and decrease over time and space. They do not typically involve voltage-gated sodium and potassium channels. These impulses are incremental and may be excitatory or inhibitory. They occur at the postsynaptic dendrite in response to presynaptic neuron firing and release of neurotransmitter, or may occur in skeletal, smooth, or cardiac muscle in response to nerve input. The magnitude of a graded potential is determined by the strength of the stimulus.
EPSPs
Graded potentials that make the membrane potential less negative or more positive, thus making the postsynaptic cell more likely to have an action potential, are called excitatory postsynaptic potentials (EPSPs). Depolarizing local potentials sum together, and if the voltage reaches the threshold potential, an action potential occurs in that cell.
EPSPs are caused by the influx of Na+ or Ca2+ from the extracellular space into the neuron or muscle cell. When the presynaptic neuron has an action potential, Ca2+ enters the axon terminal via voltage-dependent calcium channels and causes exocytosis of synaptic vesicles, causing neurotransmitter to be released. The transmitter diffuses across the synaptic cleft and activates ligand-gated ion channels that mediate the EPSP. The amplitude of the EPSP is directly proportional to the number of synaptic vesicles that were released.
If the EPSP is not large enough to trigger an action potential, the membrane subsequently repolarizes to its resting membrane potential. This shows the temporary and reversible nature of graded potentials.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In neurons, what often involves gated sodium channels?
A. depolarization
B. excitation
C. fermentation
D. polarization
Answer:
|
|
sciq-969
|
multiple_choice
|
Which part of all mammals have the same basic bone structure?
|
[
"forelimbs",
"ankles",
"necks",
"knees"
] |
A
|
Relavent Documents:
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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 1:::
The axial skeleton is the part of the skeleton that consists of the bones of the head and trunk of a vertebrate. In the human skeleton, it consists of 80 bones and is composed of six parts; the skull (22 bones), also the ossicles of the middle ear, the hyoid bone, the rib cage, sternum and the vertebral column. The axial skeleton together with the appendicular skeleton form the complete skeleton. Another definition of axial skeleton is the bones including the vertebrae, sacrum, coccyx, skull, ribs, and sternum.
Structure
Flat bones house the brain and other vital organs. This article mainly deals with the axial skeletons of humans; however, it is important to understand the evolutionary lineage of the axial skeleton. The human axial skeleton consists of 81 different bones. It is the medial core of the body and connects the pelvis to the body, where the appendix skeleton attaches. As the skeleton grows older the bones get weaker with the exception of the skull. The skull remains strong to protect the brain from injury.
In humans, the axial skeleton serves to protect the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs.
Human Skull
The human skull consists of the cranium and the facial bones. The cranium holds and protects the brain in a large space called the cranial vault. The cranium is formed from eight plate-shaped bones which fit together at meeting points (joints) called sutures. In addition there are 14 facial bones which form the lower front part of the skull. Together the 22 bones that compose the skull form additional, smaller spaces besides the cranial vault, such as the cavities for the eyes, the internal ear, the nose, and the mouth. The most important facial bones include the jaw or mandible, the upper jaw or maxilla, the zygomatic or cheek bone, and the nasal bone.
Humans are b
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Many anatomical terms descriptive of bone are defined in anatomical terminology, and are often derived from Greek and Latin. Bone in the human body is categorized into long bone, short bone, flat bone, irregular bone and sesamoid bone.
Types of bone
Long bones
A long bone is one that is cylindrical in shape, being longer than it is wide. However, the term describes the shape of a bone, not its size, which is relative. Long bones are found in the arms (humerus, ulna, radius) and legs (femur, tibia, fibula), as well as in the fingers (metacarpals, phalanges) and toes (metatarsals, phalanges). Long bones function as levers; they move when muscles contract.
Short bones
A short bone is one that is cube-like in shape, being approximately equal in length, width, and thickness. The only short bones in the human skeleton are in the carpals of the wrists and the tarsals of the ankles. Short bones provide stability and support as well as some limited motion.
Flat bones
The term “flat bone” is something of a misnomer because, although a flat bone is typically thin, it is also often curved. Examples include the cranial (skull) bones, the scapulae (shoulder blades), the sternum (breastbone), and the ribs. Flat bones serve as points of attachment for muscles and often protect internal organs. Flat bones do not have a medullary cavity because they are thin.
Irregular bones
An irregular bone is one that does not have an easily classified shape and defies description. These bones tend to have more complex shapes, like the vertebrae that support the spinal cord and protect it from compressive forces. Many facial bones, particularly the ones containing sinuses, are classified as irregular bones.
Sesamoid bones
A sesamoid bone is a small, round bone that, as the name suggests, is shaped like a sesame seed. These bones form in tendons (the sheaths of tissue that connect bones to muscles) where a great deal of pressure is generated in a joint. The sesamoid bones protect tendons
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ABMAP, also known as the Animal Bone Metrical Archive Project, consists of a collection of metric data on the main domestic animals recorded at the University of Southampton, together with the data from some other sources, in particular the Museum of London Archaeology Service (MoLAS). Whilst the data is primarily from England, it is applicable to a wider geographical area. Stored in a neutral archival format, it is freely available for teaching, learning and research.
History of the Project
In the 1990s English Heritage funded a project at the University of Southampton to collect and synthesize metrical data recorded over the past twenty years. The main aim was to assemble the data and ensure that it was kept in a format in which it would be maintained and made accessible.
The Database
The project aimed to collect measurements of the main domestic species found on archaeological sites in England. The database included approximately 25,000 bones, predominantly of cattle and sheep, but also of pig, horse, dog, goat, domestic fowl, and goose. The data set is organized by species, anatomical element, period, and site type.
Sources
Serjeantson, D. (2005). 'Science is Measurement'; ABMAP, a Database of Domestic Animal Bone Measurements. Environmental Archaeology 10 (1): 97-103
External links
ABMAP
Archaeological databases
Zooarchaeology
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which part of all mammals have the same basic bone structure?
A. forelimbs
B. ankles
C. necks
D. knees
Answer:
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sciq-7119
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multiple_choice
|
Each month, starting in puberty, one egg matures and is released from where?
|
[
"ovary",
"uterus",
"testes",
"pollen"
] |
A
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Relavent Documents:
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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 1:::
The germ cell nest (germ-line cyst) forms in the ovaries during their development. The nest consists of multiple interconnected oogonia formed by incomplete cell division. The interconnected oogonia are surrounded by somatic cells called granulosa cells. Later on in development, the germ cell nests break down through invasion of granulosa cells. The result is individual oogonia surrounded by a single layer of granulosa cells. There is also a comparative germ cell nest structure in the developing spermatogonia, with interconnected intracellular cytoplasmic bridges.
Formation of germ cell nests
Prior to meiosis primordial germ cells (PGCs) migrate to the gonads and mitotically divide along the genital ridge in clusters or nests of cells referred to as germline cysts or germ cell nests. The understating of germ cell nest formation is limited. However, invertebrate models, especially drosophila have provided insight into the mechanisms surrounding formation. In females, it is suggested that cysts form from dividing progenitor cells. During this cyst formation, 4 rounds of division with incomplete cytokinesis occur resulting in cystocytes that are joined by intercellular bridges, also known as ring canals.
Rodent PGCs migrate to the gonads and mitotically divide at embryonic day (E) 10.5. It is at this stage they switch from complete to incomplete cytokinesis during the mitotic cycle from E10.5-E14.5. Germ cell nests emerge following consecutive divisions of progenitor cells resulting from cleavage furrows arresting and forming intercellular bridges. The intercellular bridges are crucial in maintaining effective communication. They ensure meiosis begins immediately after the mitotic cyst formation cycle is complete. In females, mitosis will end at E14.5 and meiosis will commence. However, It is possible that germ cells may travel to the gonads and cluster together forming nests after their arrival or form through cellular aggregation.
Function
Most of our understan
Document 2:::
Female sperm storage is a biological process and often a type of sexual selection in which sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, or egg, is fertilized. This process takes place in some species of animals, but not in humans. The site of storage is variable among different animal taxa and ranges from structures that appear to function solely for sperm retention, such as insect spermatheca and bird sperm storage tubules (bird anatomy), to more general regions of the reproductive tract enriched with receptors to which sperm associate before fertilization, such as the caudal portion of the cow oviduct containing sperm-associating annexins. Female sperm storage is an integral stage in the reproductive process for many animals with internal fertilization. It has several documented biological functions including:
Supporting the sperm by: a.) enabling sperm to undergo biochemical transitions, called capacitation and motility hyperactivation, in which they become physiologically capable of fertilizing an oocyte (e.g. mammals) and b.) maintaining sperm viability until an oocyte is ovulated (e.g. insects and mammals).
Decreasing the incidence of polyspermy (e.g. some mammals such as pigs).
Enabling mating, ovulation and/or fertilization to occur at different times or in different environments (e.g. many insects and some amphibians, reptiles, birds and mammals).
Supporting prolonged and sustained female fertility (e.g. some insects).
Having a role influencing offspring sex ratios among some insects possessing a haplodiploid sex-determination system (e.g. ants, bees, wasps and thrips as well as some true bugs and some beetles).
Serving as an arena in which sperm from different mating males compete for access to oocytes, a process called sperm competition, and in which females may preferentially utilize sperm from some males over those of others, called female sperm pref
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In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres are an essential part of blastula formation, and blastocyst formation in mammals.
Human blastomere characteristics
In humans, blastomere formation begins immediately following fertilization and continues through the first week of embryonic development. About 90 minutes after fertilization, the zygote divides into two cells. The two-cell blastomere state, present after the zygote first divides, is considered the earliest mitotic product of the fertilized oocyte. These mitotic divisions continue and result in a grouping of cells called blastomeres. During this process, the total size of the embryo does not increase, so each division results in smaller and smaller cells. When the zygote contains 16 to 32 blastomeres it is referred to as a morula. These are the preliminary stages in the embryo beginning to form. Once this begins, microtubules within the morula's cytosolic material in the blastomere cells can develop into important membrane functions, such as sodium pumps. These pumps allow the inside of the embryo to fill with blastocoelic fluid, which supports the further growth of life.
The blastomere is considered totipotent; that is, blastomeres are capable of developing from a single cell into a fully fertile adult organism. This has been demonstrated through studies and conjectures made with mouse blastomeres, which have been accepted as true for most mammalian blastomeres as well. Studies have analyzed monozygotic twin mouse blastomeres in their two-cell state, and have found that when one of the twin blastomeres is destroyed, a fully fertile adult mouse can still develop. Thus, it can be assumed that since one of the twin cells was totipotent, the destroyed one originally was as well.
Relative blastomere size within the embryo is dependent not only on the stage of the cleavage, but also on the regularity of the cleavage amongst t
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Secondary oocytes are the immature ovum shortly after ovulation, to fertilization, where it turns into an ootid. Thus, the time as a secondary oocyte is measured in days.
Ootid
An ootid is the haploid result of ootidogenesis. In oogenesis, it doesn't really have any significance in itself, since it is very similar to the ovum. However, it fills the purpose as the female counterpart of the male spermatid in spermatogenesis
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Each month, starting in puberty, one egg matures and is released from where?
A. ovary
B. uterus
C. testes
D. pollen
Answer:
|
|
sciq-4845
|
multiple_choice
|
Transport of water and solutes in plants water potential is a measure of the difference in potential energy between a water sample and this?
|
[
"dirty water",
"green water",
"pure water",
"salty water"
] |
C
|
Relavent Documents:
Document 0:::
Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matrix effects such as capillary action (which is caused by surface tension). The concept of water potential has proved useful in understanding and computing water movement within plants, animals, and soil. Water potential is typically expressed in potential energy per unit volume and very often is represented by the Greek letter ψ.
Water potential integrates a variety of different potential drivers of water movement, which may operate in the same or different directions. Within complex biological systems, many potential factors may be operating simultaneously. For example, the addition of solutes lowers the potential (negative vector), while an increase in pressure increases the potential (positive vector). If the flow is not restricted, water will move from an area of higher water potential to an area that is lower potential. A common example is water with dissolved salts, such as seawater or the fluid in a living cell. These solutions have negative water potential, relative to the pure water reference. With no restriction on flow, water will move from the locus of greater potential (pure water) to the locus of lesser (the solution); flow proceeds until the difference in potential is equalized or balanced by another water potential factor, such as pressure or elevation.
Components of water potential
Many different factors may affect the total water potential, and the sum of these potentials determines the overall water potential and the direction of water flow:
where:
is the reference correction,
is the solute or osmotic potential,
is the pressure component,
is the gravimetric component,
is the potential due to humidity, and
is the potential due to matrix effects (e.g., fluid cohesion and surface tension.)
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Water-use efficiency (WUE) refers to the ratio of water used in plant metabolism to water lost by the plant through transpiration. Two types of water-use efficiency are referred to most frequently:
photosynthetic water-use efficiency (also called instantaneous water-use efficiency), which is defined as the ratio of the rate of carbon assimilation (photosynthesis) to the rate of transpiration, and
water-use efficiency of productivity (also called integrated water-use efficiency), which is typically defined as the ratio of biomass produced to the rate of transpiration.
Increases in water-use efficiency are commonly cited as a response mechanism of plants to moderate to severe soil water deficits and have been the focus of many programs that seek to increase crop tolerance to drought. However, there is some question as to the benefit of increased water-use efficiency of plants in agricultural systems, as the processes of increased yield production and decreased water loss due to transpiration (that is, the main driver of increases in water-use efficiency) are fundamentally opposed. If there existed a situation where water deficit induced lower transpirational rates without simultaneously decreasing photosynthetic rates and biomass production, then water-use efficiency would be both greatly improved and the desired trait in crop production.
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Evapotranspiration (ET) is the combined processes which move water from the Earth's surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in agricultural irrigation and water resource management.
Definition of evapotranspiration
Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evapotranspiration are:
Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, solar radiation and wind speed.
Transpiration: the movement of water from root systems, through a plant, and exit into the air as water vapor. This exit occurs through stomata in the plant. Rate of transpiration can be influenced by factors including plant type, soil type, weather conditions and water content, and also cultivation practices.
Evapotranspiration is typically measured in millimeters of water (i.e. volume of water moved per unit area of the Earth's surface) in a set unit of time. Globally, it is estimated that on average between three-fifths and three-quarters of land precipitation is returned to the atmosphere via evapotranspiration.
Evapotranspiration does not, in general, account for other mechanisms which are involved in returning water to the atmosphere, though some of these, such as snow and ice sublimation in regions of high elevation or high latitude, can make a large contribution to atmospheric moisture even under standard conditions.
Factors that impact evapotranspiration levels
Primary factors
Because evaporation and transpiration
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 compensatory root water uptake conductance (Kcomp) () characterizes how a plant compensates its water uptake under heterogeneous water potential.
It controls the root water uptake in a soil where the water potential is not uniform.
See also
Standard Uptake Fraction
Hydraulic conductivity
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Transport of water and solutes in plants water potential is a measure of the difference in potential energy between a water sample and this?
A. dirty water
B. green water
C. pure water
D. salty water
Answer:
|
|
sciq-4809
|
multiple_choice
|
What is the wavelength of light expressed in?
|
[
"nanoseconds",
"vatts",
"millimeters",
"nanometers (nm)"
] |
D
|
Relavent Documents:
Document 0:::
In the physical sciences, the wavenumber (or wave number), also known as repetency, is the spatial frequency of a wave, measured in cycles per unit distance (ordinary wavenumber) or radians per unit distance (angular wavenumber). It is analogous to temporal frequency, which is defined as the number of wave cycles per unit time (ordinary frequency) or radians per unit time (angular frequency).
In multidimensional systems, the wavenumber is the magnitude of the wave vector. The space of wave vectors is called reciprocal space. Wave numbers and wave vectors play an essential role in optics and the physics of wave scattering, such as X-ray diffraction, neutron diffraction, electron diffraction, and elementary particle physics. For quantum mechanical waves, the wavenumber multiplied by the reduced Planck's constant is the canonical momentum.
Wavenumber can be used to specify quantities other than spatial frequency. For example, in optical spectroscopy, it is often used as a unit of temporal frequency assuming a certain speed of light.
Definition
Wavenumber, as used in spectroscopy and most chemistry fields, is defined as the number of wavelengths per unit distance, typically centimeters (cm−1):
where λ is the wavelength. It is sometimes called the "spectroscopic wavenumber". It equals the spatial frequency.
For example, a wavenumber in inverse centimeters can be converted to a frequency in gigahertz by multiplying by 29.9792458 cm/ns (the speed of light, in centimeters per nanosecond); conversely, an electromagnetic wave at 29.9792458 GHz has a wavelength of 1 cm in free space.
In theoretical physics, a wave number, defined as the number of radians per unit distance, sometimes called "angular wavenumber", is more often used:
When wavenumber is represented by the symbol , a frequency is still being represented, albeit indirectly. As described in the spectroscopy section, this is done through the relationship , where s is a frequency in hertz. This is done for con
Document 1:::
In mathematics, physics, and engineering, spatial frequency is a characteristic of any structure that is periodic across position in space. The spatial frequency is a measure of how often sinusoidal components (as determined by the Fourier transform) of the structure repeat per unit of distance.
The SI unit of spatial frequency is the reciprocal metre (m-1), although cycles per meter (c/m) is also common. In image-processing applications, spatial frequency is often expressed in units of cycles per millimeter (c/mm) or also line pairs per millimeter (LP/mm).
In wave propagation, the spatial frequency is also known as wavenumber. Ordinary wavenumber is defined as the reciprocal of wavelength and is commonly denoted by or sometimes :
Angular wavenumber , expressed in radian per metre (rad/m), is related to ordinary wavenumber and wavelength by
Visual perception
In the study of visual perception, sinusoidal gratings are frequently used to probe the capabilities of the visual system, such as contrast sensitivity. In these stimuli, spatial frequency is expressed as the number of cycles per degree of visual angle. Sine-wave gratings also differ from one another in amplitude (the magnitude of difference in intensity between light and dark stripes), orientation, and phase.
Spatial-frequency theory
The spatial-frequency theory refers to the theory that the visual cortex operates on a code of spatial frequency, not on the code of straight edges and lines hypothesised by Hubel and Wiesel on the basis of early experiments on V1 neurons in the cat. In support of this theory is the experimental observation that the visual cortex neurons respond even more robustly to sine-wave gratings that are placed at specific angles in their receptive fields than they do to edges or bars. Most neurons in the primary visual cortex respond best when a sine-wave grating of a particular frequency is presented at a particular angle in a particular location in the visual field. (However, a
Document 2:::
The transmission curve or transmission characteristic is the mathematical function or graph that describes the transmission fraction of an optical or electronic filter as a function of frequency or wavelength. It is an instance of a transfer function but, unlike the case of, for example, an amplifier, output never exceeds input (maximum transmission is 100%). The term is often used in commerce, science, and technology to characterise filters.
The term has also long been used in fields such as geophysics and astronomy to characterise the properties of regions through which radiation passes, such as the ionosphere.
See also
Electronic filter — examples of transmission characteristics of electronic filters
Document 3:::
This article summarizes equations used in optics, including geometric optics, physical optics, radiometry, diffraction, and interferometry.
Definitions
Geometric optics (luminal rays)
General fundamental quantities
Physical optics (EM luminal waves)
There are different forms of the Poynting vector, the most common are in terms of the E and B or E and H fields.
Radiometry
For spectral quantities two definitions are in use to refer to the same quantity, in terms of frequency or wavelength.
Equations
Luminal electromagnetic waves
Geometric optics
Subscripts 1 and 2 refer to initial and final optical media respectively.
These ratios are sometimes also used, following simply from other definitions of refractive index, wave phase velocity, and the luminal speed equation:
where:
ε = permittivity of medium,
μ = permeability of medium,
λ = wavelength of light in medium,
v = speed of light in media.
Polarization
Diffraction and interference
Astrophysics definitions
In astrophysics, L is used for luminosity (energy per unit time, equivalent to power) and F is used for energy flux (energy per unit time per unit area, equivalent to intensity in terms of area, not solid angle). They are not new quantities, simply different names.
See also
Defining equation (physical chemistry)
List of electromagnetism equations
List of equations in classical mechanics
List of equations in gravitation
List of equations in nuclear and particle physics
List of equations in quantum mechanics
List of equations in wave theory
List of relativistic equations
Sources
Further reading
Optics equations
Optics
Equations
Document 4:::
In signal processing, the energy of a continuous-time signal x(t) is defined as the area under the squared magnitude of the considered signal i.e., mathematically
Unit of will be (unit of signal)2.
And the energy of a discrete-time signal x(n) is defined mathematically as
Relationship to energy in physics
Energy in this context is not, strictly speaking, the same as the conventional notion of energy in physics and the other sciences. The two concepts are, however, closely related, and it is possible to convert from one to the other:
where Z represents the magnitude, in appropriate units of measure, of the load driven by the signal.
For example, if x(t) represents the potential (in volts) of an electrical signal propagating across a transmission line, then Z would represent the characteristic impedance (in ohms) of the transmission line. The units of measure for the signal energy would appear as volt2·seconds, which is not dimensionally correct for energy in the sense of the physical sciences. After dividing by Z, however, the dimensions of E would become volt2·seconds per ohm,
which is equivalent to joules, the SI unit for energy as defined in the physical sciences.
Spectral energy density
Similarly, the spectral energy density of signal x(t) is
where X(f) is the Fourier transform of x(t).
For example, if x(t) represents the magnitude of the electric field component (in volts per meter) of an optical signal propagating through free space, then the dimensions of X(f) would become volt·seconds per meter and would represent the signal's spectral energy density (in volts2·second2 per meter2) as a function of frequency f (in hertz). Again, these units of measure are not dimensionally correct in the true sense of energy density as defined in physics. Dividing by Zo, the characteristic impedance of free space (in ohms), the dimensions become joule-seconds per meter2 or, equivalently, joules per meter2 per hertz, which is dimensionally correct in SI
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the wavelength of light expressed in?
A. nanoseconds
B. vatts
C. millimeters
D. nanometers (nm)
Answer:
|
|
sciq-3804
|
multiple_choice
|
Synaptic connections can change over time depending on what?
|
[
"age",
"weight",
"diet",
"activity level"
] |
D
|
Relavent Documents:
Document 0:::
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 1:::
Metaplasticity is a term originally coined by W.C. Abraham and M.F. Bear to refer to the plasticity of synaptic plasticity. Until that time synaptic plasticity had referred to the plastic nature of individual synapses. However this new form referred to the plasticity of the plasticity itself, thus the term meta-plasticity. The idea is that the synapse's previous history of activity determines its current plasticity. This may play a role in some of the underlying mechanisms thought to be important in memory and learning such as long-term potentiation (LTP), long-term depression (LTD) and so forth. These mechanisms depend on current synaptic "state", as set by ongoing extrinsic influences such as the level of synaptic inhibition, the activity of modulatory afferents such as catecholamines, and the pool of hormones affecting the synapses under study. Recently, it has become clear that the prior history of synaptic activity is an additional variable that influences the synaptic state, and thereby the degree, of LTP or LTD produced by a given experimental protocol. In a sense, then, synaptic plasticity is governed by an activity-dependent plasticity of the synaptic state; such plasticity of synaptic plasticity has been termed metaplasticity. There is little known about metaplasticity, and there is much research currently underway on the subject, despite its difficulty of study, because of its theoretical importance in brain and cognitive science. Most research of this type is done via cultured hippocampus cells or hippocampal slices.
Hebbian plasticity
The brain is "plastic", meaning it can be molded and formed. This plasticity is what allows you to learn throughout your lifetime; your synapses change based on your experience. New synapses can be made, old ones destroyed, or existing ones can be strengthened or weakened. The original theory of plasticity is called "Hebbian plasticity", named after Donald Hebb in 1949. A quick but effective summary of Hebbian theory is t
Document 2:::
Developmental plasticity is a general term referring to changes in neural connections during development as a result of environmental interactions as well as neural changes induced by learning. Much like neuroplasticity, or brain plasticity, developmental plasticity is specific to the change in neurons and synaptic connections as a consequence of developmental processes. A child creates most of these connections from birth to early childhood. There are three primary methods by which this may occur as the brain develops, but critical periods determine when lasting changes may form. Developmental plasticity may also be used in place of the term phenotypic plasticity when an organism in an embryonic or larval stage can alter its phenotype based on environmental factors. However, a main difference between the two is that phenotypic plasticity experienced during adulthood can be reversible, whereas traits that are considered developmentally plastic set foundations during early development that remain throughout the life of the organism.
Mechanisms
During development, the central nervous system acquires information via endogenous or exogenous factors as well as learning experiences. In acquiring and storing such information, the plastic nature of the central nervous system allows for the adaptation of existing neural connections in order to accommodate new information and experiences, resulting in developmental plasticity. This form of plasticity that occurs during development is the result of three predominant mechanisms: synaptic and homeostatic plasticity, and learning.
Synaptic plasticity
The underlying principle of synaptic plasticity is that synapses undergo an activity-dependent and selective strengthening or weakening so that new information can be stored. Synaptic plasticity depends on numerous factors including the threshold of the presynaptic stimulus in addition to the relative concentrations of neurotransmitter molecules. Synaptic plasticity has long been
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The neuroscience of aging is the study of the changes in the nervous system that occur with ageing. Aging is associated with many changes in the central nervous system, such as mild atrophy of the cortex that is considered non-pathological. Aging is also associated with many neurological and neurodegenerative disease such as amyotrophic lateral sclerosis, dementia, mild cognitive impairment, Parkinson's disease, and Creutzfeldt–Jakob disease.
Normal structural and neural changes
Neurogenesis occurs very little in adults, only occurring in the hypothalamus and striatum to a small extent in a process called adult neurogenesis. The volume of the brain actually decrease roughly 5% per decade after forty. It is currently unclear why brain volume decreases with age, however, a few causes may include: cell death, decreased cell volume, and changes in synaptic structure. The changes in brain volume is heterogenous across regions with prefrontal cortex receiving the most significant reduction in volume followed in order by the striatum, the temporal lobe, cerebellar vermis, cerebellar hemispheres, and the hippocampus. However, one review found that the amygdala and ventromedial prefrontal cortex remained relatively free of atrophy, which is consistent with the finding of emotional stability occurring with non-pathological aging. Enlargement of the ventricles, sulci and fissures are also common in non-pathological aging.
Changes may also be associated with neuroplasticity, synaptic functionality and voltage gated calcium channels. Increased magnitude of hyperpolarization, possibly a result of dysfunctional calcium regulation, leads to decreased firing rate of neurons and decreased plasticity. This effect is particularly pronounced in the hippocampus of aged animals, and may be an important contributor to age-associated memory deficits. The hyperpolarization of a neuron can be divided into three stages: the fast, medium and slow hyperpolarization. In aged neurons,
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BCM theory, BCM synaptic modification, or the BCM rule, named for Elie Bienenstock, Leon Cooper, and Paul Munro, is a physical theory of learning in the visual cortex developed in 1981.
The BCM model proposes a sliding threshold for long-term potentiation (LTP) or long-term depression (LTD) induction, and states that synaptic plasticity is stabilized by a dynamic adaptation of the time-averaged postsynaptic activity. According to the BCM model, when a pre-synaptic neuron fires, the post-synaptic neurons will tend to undergo LTP if it is in a high-activity state (e.g., is firing at high frequency, and/or has high internal calcium concentrations), or LTD if it is in a lower-activity state (e.g., firing in low frequency, low internal calcium concentrations). This theory is often used to explain how cortical neurons can undergo both LTP or LTD depending on different conditioning stimulus protocols applied to pre-synaptic neurons (usually high-frequency stimulation, or HFS, for LTP, or low-frequency stimulation, LFS, for LTD).
Development
In 1949, Donald Hebb proposed a working mechanism for memory and computational adaption in the brain now called Hebbian learning, or the maxim that cells that fire together, wire together. This notion is foundational in the modern understanding of the brain as a neural network, and though not universally true, remains a good first approximation supported by decades of evidence.
However, Hebb's rule has problems, namely that it has no mechanism for connections to get weaker and no upper bound for how strong they can get. In other words, the model is unstable, both theoretically and computationally. Later modifications gradually improved Hebb's rule, normalizing it and allowing for decay of synapses, where no activity or unsynchronized activity between neurons results in a loss of connection strength. New biological evidence brought this activity to a peak in the 1970s, where theorists formalized various approximations in the theory,
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Synaptic connections can change over time depending on what?
A. age
B. weight
C. diet
D. activity level
Answer:
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sciq-9226
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multiple_choice
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The common carotid artery gives rise to the external and internal carotid arteries. the external carotid artery remains superficial and gives rise to many arteries of this?
|
[
"head",
"back",
"chest",
"stomach"
] |
A
|
Relavent Documents:
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The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain.
In human anatomy, the internal and external carotids arise from the common carotid arteries, where these bifurcate at cervical vertebrae C3 or C4. The internal carotid artery supplies the brain, including the eyes, while the external carotid nourishes other portions of the head, such as the face, scalp, skull, and meninges.
Classification
Terminologia Anatomica in 1998 subdivided the artery into four parts: "cervical", "petrous", "cavernous", and "cerebral". However, in clinical settings, the classification system of the internal carotid artery usually follows the 1996 recommendations by Bouthillier, describing seven anatomical segments of the internal carotid artery, each with a corresponding alphanumeric identifier—C1 cervical, C2 petrous, C3 lacerum, C4 cavernous, C5 clinoid, C6 ophthalmic, and C7 communicating. The Bouthillier nomenclature remains in widespread use by neurosurgeons, neuroradiologists and neurologists.
The segments are subdivided based on anatomical and microsurgical landmarks and surrounding anatomy, more than angiographic appearance of the artery. An alternative embryologic classification system proposed by Pierre Lasjaunias and colleagues is invaluable when it comes to explanation of many internal carotid artery variants. An older clinical classification, based on pioneering work by Fischer, is mainly of historical significance.
The segments of the internal carotid artery are as follows:
Cervical segment, or C1, identical to the commonly used cervical portion
Petrous segment, or C2
Lacerum segment, or C3
C2 and C3 compose the commonly termed petrous portion
Cavernous segment, or C4, almost identical to the commonly used cavernous portion
Clinoid segment, or C5. This segment is not identified in some earlier classifications and lies between the commonly used cavernous portion and cerebral or su
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The common iliac lymph nodes, four to six in number, are grouped behind and on the sides of the common iliac artery, one or two being placed below the bifurcation of the aorta, in front of the fifth lumbar vertebra.
They drain chiefly the hypogastric and external iliac glands, and their efferents pass to the lateral aortic glands.
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Cervical artery dissection is dissection of one of the layers that compose the carotid and vertebral artery in the neck (cervix). They include:
Carotid artery dissection, a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain.
Vertebral artery dissection, a flap-like tear of the inner lining of the vertebral artery that supply blood to the brain and spinal cord.
Cervical dissections can be broadly classified as either "spontaneous" or traumatic. Cervical artery dissections are a significant cause of strokes in young adults.
A dissection typically results in a tear in one of the layers of the arterial wall. The result of this tear is often an intramural hematoma and/or aneurysmal dilation in the arteries leading to the intracranial area.
Signs and symptoms of a cervical artery dissection are often non-specific and can be localized or generalized. There is no specific treatment, although most patients are either given an anti-platelet or anti-coagulation agent to prevent or treat strokes.
Epidemiology
Cervical artery dissection has been noted to be a common cause of young adult strokes, with some sources indicating a prevalence of up to 20% in this young adult population with annual incidence rates between 2.6 and 2.9 per 100,000, although these incidences may be misleading with true incidences being higher because clinical presentations can vary, many being minor or self-limited, and thus these dissections can go undiagnosed. In population-based studies, the peak age of presentation is approximately 45 years with a slight gender predisposition towards males (53-57%).
Cervical arteries, as mentioned above, consist of two pairs of arteries: vertebral and carotid. As such, cervical artery dissection can be further categorized based on the involvement of artery: carotid vs. vertebral, and the location of the dissection: intracranial vs. extracranial.
Causes
The two main causes of cervical artery dissection can be broad
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The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body.
The coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called epicardial (above the epicardium, or the outermost tissue of the heart) and microvascular (close to the endocardium, or the innermost tissue of the heart).
Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coronary arteries can have a serious impact on health, possibly leading to angina, a heart attack, and even death.
Structure
The coronary arteries are mainly composed of the left and right coronary arteries, both of which give off several branches, as shown in the 'coronary artery flow' figure.
Aorta
Left coronary artery
Left anterior descending artery
Left circumflex artery
Posterior descending artery
Ramus or intermediate artery
Right coronary artery
Right marginal artery
Posterior descending artery
The left coronary artery arises from the aorta within the left cusp of the aortic valve and feeds blood to the left side of the heart. It branches into two arteries, the left anterior descending and the left circumflex. The left anterior descending artery perfuses the interventricular septum and anterior wall of the left ventricle. The left circumflex artery perfuses the left ventricular free wall. In approximately 33% of individuals, the left coronary artery gives rise to the posterior descending artery wh
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The ascending pharyngeal artery is an artery of the neck that supplies the pharynx.
Its named branches are the inferior tympanic artery, pharyngeal artery, and posterior meningeal artery. inferior tympanic artery, and the meningeal branches (including the posterior meningeal artery).
Anatomy
The ascending pharyngeal artery is a long and slender vessel.
It is deeply seated in the neck, beneath the other branches of the external carotid and under the stylopharyngeus muscle. It lies just superior to the bifurcation of the common carotid arteries.
Origin
It is the first (and smallest) branch of (the proximal part of) the external carotid artery. It arises from the medial (deep) surface of the vessel.
Course and relations
The artery ascends vertically in between the internal carotid artery and the pharynx to reach the base of the skull.
The artery is crossed by the styloglossus muscle and stylopharyngeus muscle. The longus capitis muscle is situated posterior to the artery.
Branches
The artery most typically bifurcates into embryologically distinct pharyngeal and neuromeningeal trunks.
The pharyngeal trunk usually consists of several branches which supply the middle and inferior pharyngeal constrictor muscles and the stylopharyngeus, ramifying in their substance and in the mucous membranes lining them. These branches are in hemodynamic equilibrium with contributors from the internal maxillary artery. The neuromeningeal trunk classically consists of jugular and hypoglossal divisions, which enter the jugular and hypoglossal foramina to supply regional meningeal and neural structures, being in equilibrium with branches of the vertebral, occipital, posterior meningeal, middle meningeal, and internal carotid arteries (via its caroticotympanic branch, meningohypophyseal, and inferolateral trunks). Also present is the inferior tympanic branch, which ascends towards the middle ear cavity; it is involved in internal carotid artery reconstitution via the "aberrant c
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The common carotid artery gives rise to the external and internal carotid arteries. the external carotid artery remains superficial and gives rise to many arteries of this?
A. head
B. back
C. chest
D. stomach
Answer:
|
|
sciq-8379
|
multiple_choice
|
Prions are slow-acting, virtually indestructible infectious proteins that cause diseases of what vital organ in mammals?
|
[
"liver",
"brain",
"heart",
"lung"
] |
B
|
Relavent Documents:
Document 0:::
The School of Biological Sciences is a School within the Faculty Biology, Medicine and Health at The University of Manchester. Biology at University of Manchester and its precursor institutions has gone through a number of reorganizations (see History below), the latest of which was the change from a Faculty of Life Sciences to the current School.
Academics
Research
The School, though unitary for teaching, is divided into a number of broadly defined sections for research purposes, these sections consist of: Cellular Systems, Disease Systems, Molecular Systems, Neuro Systems and Tissue Systems.
Research in the School is structured into multiple research groups including the following themes:
Cell-Matrix Research (part of the Wellcome Trust Centre for Cell-Matrix Research)
Cell Organisation and Dynamics
Computational and Evolutionary Biology
Developmental Biology
Environmental Research
Eye and Vision Sciences
Gene Regulation and Cellular Biotechnology
History of Science, Technology and Medicine
Immunology and Molecular Microbiology
Molecular Cancer Studies
Neurosciences (part of the University of Manchester Neurosciences Research Institute)
Physiological Systems & Disease
Structural and Functional Systems
The School hosts a number of research centres, including: the Manchester Centre for Biophysics and Catalysis, the Wellcome Trust Centre for Cell-Matrix Research, the Centre of Excellence in Biopharmaceuticals, the Centre for the History of Science, Technology and Medicine, the Centre for Integrative Mammalian Biology, and the Healing Foundation Centre for Tissue Regeneration. The Manchester Collaborative Centre for Inflammation Research is a joint endeavour with the Faculty of Medical and Human Sciences of Manchester University and industrial partners.
Research Assessment Exercise (2008)
The faculty entered research into the units of assessment (UOA) for Biological Sciences and Pre-clinical and Human Biological Sciences. In Biological Sciences 20% of outputs
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Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
Document 2:::
Biology by Team in German Biologie im Team - is the first Austrian biology contest for upper secondary schools.
Students at upper secondary schools who are especially interested in biology can deepen their knowledge and
broaden their competence in experimental biology within the framework of this contest.
Each year, a team of teachers choose modules of key themes on which students work in the form of a voluntary exercise. The evaluation focuses in particular on the practical work, and, since the school year 2004/05, also on teamwork. In April, a two-day closing competition takes place, in which six groups of students from participating schools are given various problems to solve. A jury (persons from the science and corporate communities) evaluate the results and how they are presented.
The concept was developed by a team of teachers in co-operation with the AHS (Academic Secondary Schools) - Department of the Pedagogical Institute in Carinthia.
Since 2008 it is situated at the Science departement of the University College of Teacher Training Carinthia.
The first contest in the school year 2002/03 took place under the motto: Hell is loose in the ground under us.
Other themes included Beautiful but dangerous, www-worldwide water 1 and 2, Expedition forest, Relationship boxes, Mole's view, Biological timetravel, Biology at the University, Ecce Homo, Biodiversity, Death in tin cans, Sex sells, Without a trace, Biologists see more, Quo vadis biology? , Biology without limits?, Diversity instead of simplicity, Grid square, Diversity instead of simplicity 0.2, www-worldwide water 3.The theme for the year 2023/24 is I hear something you don't see.
Till now the following schools were participating:
BG/BRG Mössingerstraße Klagenfurt
Ingeborg-Bachmann-Gymnasium, Klagenfurt
BG/BRG St. Martinerstraße Villach
BG/BRG Peraustraße Villach
International school Carinthia, Velden
Österreichisches Gymnasium Prag
Europagymnasium Klagenfurt
BRG Viktring Klagenfurt
BORG Wo
Document 3:::
This is a list of topics in molecular biology. See also index of biochemistry articles.
Document 4:::
MicrobeLibrary is a permanent collection of over 1400 original peer-reviewed resources for teaching undergraduate microbiology. It is provided by the American Society for Microbiology, Washington DC, United States.
Contents include curriculum activities; images and animations; reviews of books, websites and other resources; and articles from Focus on Microbiology Education, Microbiology Education and Microbe. Around 40% of the materials are free to educators and students, the remainder require a subscription. the service is suspended with the message to:
"Please check back with us in 2017".
External links
MicrobeLibrary
Microbiology
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Prions are slow-acting, virtually indestructible infectious proteins that cause diseases of what vital organ in mammals?
A. liver
B. brain
C. heart
D. lung
Answer:
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|
sciq-9520
|
multiple_choice
|
What takes place in the organelle known as the chloroplast, which distinguishes animal from plant cells?
|
[
"digestion",
"photosynthesis",
"reproduction",
"perspiration"
] |
B
|
Relavent Documents:
Document 0:::
Proteinoplasts (sometimes called proteoplasts, aleuroplasts, and aleuronaplasts) are specialized organelles found only in plant cells. Proteinoplasts belong to a broad category of organelles known as plastids. Plastids are specialized double-membrane organelles found in plant cells. Plastids perform a variety of functions such as metabolism of energy, and biological reactions. There are multiple types of plastids recognized including Leucoplasts, Chromoplasts, and Chloroplasts. Plastids are broken up into different categories based on characteristics such as size, function and physical traits. Chromoplasts help to synthesize and store large amounts of carotenoids. Chloroplasts are photosynthesizing structures that help to make light energy for the plant. Leucoplasts are a colorless type of plastid which means that no photosynthesis occurs here. The colorless pigmentation of the leucoplast is due to not containing the structural components of thylakoids unlike what is found in chloroplasts and chromoplasts that gives them their pigmentation. From leucoplasts stems the subtype, proteinoplasts, which contain proteins for storage. They contain crystalline bodies of protein and can be the sites of enzyme activity involving those proteins. Proteinoplasts are found in many seeds, such as brazil nuts, peanuts and pulses. Although all plastids contain high concentrations of protein, proteinoplasts were identified in the 1960s and 1970s as having large protein inclusions that are visible with both light microscopes and electron microscopes. Other subtypes of Leucoplasts include amyloplast, and elaioplasts. Amyloplasts help to store and synthesize starch molecules found in plants, while elaioplasts synthesize and store lipids in plant cells.
See also
Chloroplast and etioplast
Chromoplast
Leucoplast
Amyloplast
Elaioplast
Document 1:::
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 2:::
Leucoplasts ("formed, molded") are a category of plastid and as such are organelles found in plant cells. They are non-pigmented, in contrast to other plastids such as the chloroplast.
Lacking photosynthetic pigments, leucoplasts are not green and are located in non-photosynthetic tissues of plants, such as roots, bulbs and seeds. They may be specialized for bulk storage of starch, lipid or protein and are then known as amyloplasts, elaioplasts, or proteinoplasts (also called aleuroplasts) respectively. However, in many cell types, leucoplasts do not have a major storage function and are present to provide a wide range of essential biosynthetic functions, including the synthesis of fatty acids such as palmitic acid, many amino acids, and tetrapyrrole compounds such as heme. In general, leucoplasts are much smaller than chloroplasts and have a variable morphology, often described as amoeboid. Extensive networks of stromules interconnecting leucoplasts have been observed in epidermal cells of roots, hypocotyls, and petals, and in callus and suspension culture cells of tobacco. In some cell types at certain stages of development, leucoplasts are clustered around the nucleus with stromules extending to the cell periphery, as observed for proplastids in the root meristem.
Etioplasts, which are pre-granal, immature chloroplasts but can also be chloroplasts that have been deprived of light, lack active pigment and can be considered leucoplasts. After several minutes exposure to light, etioplasts begin to transform into functioning chloroplasts and cease being leucoplasts.
Amyloplasts are of large size and store starch.
Proteinoplasts store proteins and are found in seeds (pulses).
Elaioplasts store fats and oils and are found in seeds. They are also called oleosomes.
Compare
Plastid
Chloroplast and etioplast
Chromoplast
Tannosome
Leucoplast
Amyloplast
Elaioplast
Proteinoplast
External links
Organelles
Plant cells
Plant physiology
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
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In biology, tissue is a historically derived biological organizational level between cells and a complete organ. A tissue is therefore often thought of as an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Biological organisms follow this hierarchy:
Cells < Tissue < Organ < Organ System < Organism
The English word "tissue" derives from the French word "tissu", the past participle of the verb tisser, "to weave".
The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is studied in both plant anatomy and physiology. The classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. Developments in electron microscopy, immunofluorescence, and the use of frozen tissue-sections have enhanced the detail that can be observed in tissues. With these tools, the classical appearances of tissues can be examined in health and disease, enabling considerable refinement of medical diagnosis and prognosis.
Plant tissue
In plant anatomy, tissues are categorized broadly into three tissue systems: the epidermis, the ground tissue, and the vascular tissue.
Epidermis – Cells forming the outer surface of the leaves and of the young plant body.
Vascular tissue – The primary components of vascular tissue are the xylem and phloem. These transport fluids and nutrients internally.
Ground tissue – Ground tissue is less differentiated than other tissues. Ground tissue manufactures nutrients by photosynthesis and stores reserve nutrients.
Plant tissues can also be divided differently into two types:
Meristematic tissues
Permanent tissues.
Meristematic tissue
Meristematic tissue consists of actively dividing cell
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What takes place in the organelle known as the chloroplast, which distinguishes animal from plant cells?
A. digestion
B. photosynthesis
C. reproduction
D. perspiration
Answer:
|
|
sciq-2440
|
multiple_choice
|
What is the name of the process by which plants use energy from sunlight to synthesize carbohydrates?
|
[
"pollination",
"cellular respiration",
"photosynthesis",
"osmosis"
] |
C
|
Relavent Documents:
Document 0:::
Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. This is an active area of biological research that includes the study of the transformation of energy in living organisms and the study of thousands of different cellular processes such as cellular respiration and the many other metabolic and enzymatic processes that lead to production and utilization of energy in forms such as adenosine triphosphate (ATP) molecules. That is, the goal of bioenergetics is to describe how living organisms acquire and transform energy in order to perform biological work. The study of metabolic pathways is thus essential to bioenergetics.
Overview
Bioenergetics is the part of biochemistry concerned with the energy involved in making and breaking of chemical bonds in the molecules found in biological organisms. It can also be defined as the study of energy relationships and energy transformations and transductions in living organisms. The ability to harness energy from a variety of metabolic pathways is a property of all living organisms. Growth, development, anabolism and catabolism are some of the central processes in the study of biological organisms, because the role of energy is fundamental to such biological processes. Life is dependent on energy transformations; living organisms survive because of exchange of energy between living tissues/ cells and the outside environment. Some organisms, such as autotrophs, can acquire energy from sunlight (through photosynthesis) without needing to consume nutrients and break them down. Other organisms, like heterotrophs, must intake nutrients from food to be able to sustain energy by breaking down chemical bonds in nutrients during metabolic processes such as glycolysis and the citric acid cycle. Importantly, as a direct consequence of the First Law of Thermodynamics, autotrophs and heterotrophs participate in a universal metabolic network—by eating autotrophs (plants), heterotrophs ha
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{{DISPLAYTITLE: C3 carbon fixation}}
carbon fixation is the most common of three metabolic pathways for carbon fixation in photosynthesis, the other two being and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into two molecules of 3-phosphoglycerate through the following reaction:
CO2 + H2O + RuBP → (2) 3-phosphoglycerate
This reaction was first discovered by Melvin Calvin, Andrew Benson and James Bassham in 1950. C3 carbon fixation occurs in all plants as the first step of the Calvin–Benson cycle. (In and CAM plants, carbon dioxide is drawn out of malate and into this reaction rather than directly from the air.)
Plants that survive solely on fixation ( plants) tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, carbon dioxide concentrations are around 200 ppm or higher, and groundwater is plentiful. The plants, originating during Mesozoic and Paleozoic eras, predate the plants and still represent approximately 95% of Earth's plant biomass, including important food crops such as rice, wheat, soybeans and barley.
plants cannot grow in very hot areas at today's atmospheric CO2 level (significantly depleted during hundreds of millions of years from above 5000 ppm) because RuBisCO incorporates more oxygen into RuBP as temperatures increase. This leads to photorespiration (also known as the oxidative photosynthetic carbon cycle, or C2 photosynthesis), which leads to a net loss of carbon and nitrogen from the plant and can therefore limit growth.
plants lose up to 97% of the water taken up through their roots by transpiration. In dry areas, plants shut their stomata to reduce water loss, but this stops from entering the leaves and therefore reduces the concentration of in the leaves. This lowers the :O2 ratio and therefore also increases photorespiration. and CAM plants have adaptations that allow them to survive in hot and dry areas, and they can therefore out-compete
Document 2:::
Ecophysiology (from Greek , oikos, "house(hold)"; , physis, "nature, origin"; and , -logia), environmental physiology or physiological ecology is a biological discipline that studies the response of an organism's physiology to environmental conditions. It is closely related to comparative physiology and evolutionary physiology. Ernst Haeckel's coinage bionomy is sometimes employed as a synonym.
Plants
Plant ecophysiology is concerned largely with two topics: mechanisms (how plants sense and respond to environmental change) and scaling or integration (how the responses to highly variable conditions—for example, gradients from full sunlight to 95% shade within tree canopies—are coordinated with one another), and how their collective effect on plant growth and gas exchange can be understood on this basis.
In many cases, animals are able to escape unfavourable and changing environmental factors such as heat, cold, drought or floods, while plants are unable to move away and therefore must endure the adverse conditions or perish (animals go places, plants grow places). Plants are therefore phenotypically plastic and have an impressive array of genes that aid in acclimating to changing conditions. It is hypothesized that this large number of genes can be partly explained by plant species' need to live in a wider range of conditions.
Light
Light is the food of plants, i.e. the form of energy that plants use to build themselves and reproduce. The organs harvesting light in plants are leaves and the process through which light is converted into biomass is photosynthesis. The response of photosynthesis to light is called light response curve of net photosynthesis (PI curve). The shape is typically described by a non-rectangular hyperbola. Three quantities of the light response curve are particularly useful in characterising a plant's response to light intensities. The inclined asymptote has a positive slope representing the efficiency of light use, and is called quantum
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Maintenance respiration (or maintenance energy) refers to metabolism occurring in an organism that is needed to maintain that organism in a healthy, living state. Maintenance respiration contrasts with growth respiration, which is responsible for the synthesis of new structures in growth, nutrient uptake, nitrogen (N) reduction and phloem loading, whereas maintenance respiration is associated with protein and membrane turnover and maintenance of ion concentrations and gradients.
In plants
Maintenance respiration in plants refers to the amount of cellular respiration, measured by the carbon dioxide (CO2) released or oxygen (O2) consumed, during the generation of usable energy (mainly ATP, NADPH, and NADH) and metabolic intermediates used for (i) resynthesis of compounds that undergo renewal (turnover) in the normal process of metabolism (examples are enzymatic proteins, ribonucleic acids, and membrane lipids); (ii) maintenance of chemical gradients of ions and metabolites across cellular membranes that are necessary for cellular integrity and plant health; and (iii) operation of metabolic processes involved in physiological adjustment (i.e., acclimation) to a change in the plant's environment. The metabolic costs of the repair of injury from biotic or abiotic stress may also be considered a part of maintenance respiration.
Maintenance respiration is essential for biological health and growth of plants. It is estimated that about half of the respiration carried out by terrestrial plants during their lifetime is for the support of maintenance processes. Because typically more than half of global terrestrial plant photosynthesis (or gross primary production) is used for plant respiration, more than one quarter of global terrestrial plant photosynthesis is presumably consumed in maintenance respiration.
Maintenance respiration is a key component of most physiologically based mathematical models of plant growth, including models of crop growth and yield and models of
Document 4:::
Photosynthesis systems are electronic scientific instruments designed for non-destructive measurement of photosynthetic rates in the field. Photosynthesis systems are commonly used in agronomic and environmental research, as well as studies of the global carbon cycle.
How photosynthesis systems function
Photosynthesis systems function by measuring gas exchange of leaves. Atmospheric carbon dioxide is taken up by leaves in the process of photosynthesis, where is used to generate sugars in a molecular pathway known as the Calvin cycle. This draw-down of induces more atmospheric to diffuse through stomata into the air spaces of the leaf. While stoma are open, water vapor can easily diffuse out of plant tissues, a process known as transpiration. It is this exchange of and water vapor that is measured as a proxy of photosynthetic rate.
The basic components of a photosynthetic system are the leaf chamber, infrared gas analyzer (IRGA), batteries and a console with keyboard, display and memory. Modern 'open system' photosynthesis systems also incorporate miniature disposable compressed gas cylinder and gas supply pipes. This is because external air has natural fluctuations in and water vapor content, which can introduce measurement noise. Modern 'open system' photosynthesis systems remove the and water vapour by passage over soda lime and Drierite, then add at a controlled rate to give a stable concentration. Some systems are also equipped with temperature control and a removable light unit, so the effect of these environmental variables can also be measured.
The leaf to be analysed is placed in the leaf chamber. The concentrations is measured by the infrared gas analyzer. The IRGA shines infrared light through a gas sample onto a detector. in the sample absorbs energy, so the reduction in the level of energy that reaches the detector indicates the concentration. Modern IRGAs take account of the fact that absorbs energy at similar wavelengths as . Modern IRG
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the name of the process by which plants use energy from sunlight to synthesize carbohydrates?
A. pollination
B. cellular respiration
C. photosynthesis
D. osmosis
Answer:
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sciq-8429
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multiple_choice
|
Behind the pupil, a single lens focuses light on a layer of what?
|
[
"photons",
"electrons",
"chloroplasts",
"photoreceptors"
] |
D
|
Relavent Documents:
Document 0:::
"La dioptrique" (in English "Dioptrique", "Optics", or "Dioptrics"), is a short treatise published in 1637 included in one of the Essays written with Discourse on the Method by René Descartes. In this essay Descartes uses various models to understand the properties of light. This essay is known as Descartes' greatest contribution to optics, as it is the first publication of the Law of Refraction.
First Discourse: On Light
The first discourse captures Descartes' theories on the nature of light. In the first model, he compares light to a stick that allows a blind person to discern his environment through touch. Descartes says:
You have only to consider that the differences which a blind man notes among trees, rocks, water, and similar things through the medium of his stick do not seem less to him than those among red, yellow, green, and all the other colors seem to us; and that nevertheless these differences are nothing other, in all these bodies, than the diverse ways of moving, or of resisting the movements of, this stick.
Descartes' second model on light uses his theory of the elements to demonstrate the rectilinear transmission of light as well as the movement of light through solid objects. He uses a metaphor of wine flowing through a vat of grapes, then exiting through a hole at the bottom of the vat.
Now consider that, since there is no vacuum in Nature as almost all the Philosophers affirm, and since there are nevertheless many pores in all the bodies that we perceive around us, as experiment can show quite clearly, it is necessary that these pores be filled with some very subtle and very fluid material, extending without interruption from the stars and planets to us. Thus, this subtle material being compared with the wine in that vat, and the less fluid or heavier parts, of the air as well as of other transparent bodies, being compared with the bunches of grapes which are mixed in, you will easily understand the following: Just as the parts of this wine..
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Rudolf Karl Lüneburg (30 March 1903, Volkersheim (Bockenem) - 19 August 1949, Great Falls, Montana), after his emigration at first Lueneburg, later Luneburg, sometimes misspelled Luneberg or Lunenberg) was a professor of mathematics and optics at the Dartmouth College Eye Institute. He was born in Germany, received his doctorate at Göttingen, and emigrated to the United States in 1935.
His work included an analysis of the geometry of visual space as expected from physiology and the assumption that the angle of vergence provides a constant measure of distance. From these premises he concluded that near field visual space is hyperbolic.
Bibliography
published in:
Reprint:
See also
Luneburg lens
Luneburg method
1903 births
1949 deaths
Emigrants from Nazi Germany to the United States
Geometers
Optical physicists
Dartmouth College faculty
20th-century German mathematicians
Academic staff of Leiden University
University of Göttingen alumni
New York University faculty
University of Southern California faculty
Brown University faculty
Document 2:::
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
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Retinal mosaic is the name given to the distribution of any particular type of neuron across any particular layer in the retina. Typically such distributions are somewhat regular; it is thought that this is so that each part of the retina is served by each type of neuron in processing visual information.
The regularity of retinal mosaics can be quantitatively studied by modelling the mosaic as a spatial point pattern. This is done by treating each cell as a single point and using spatial statistics such as the Effective Radius, Packing Factor and Regularity Index.
Using adaptive optics, it is nowadays possible to image the photoreceptor mosaic (i.e. the distribution of rods and cones) in living humans, enabling the detailed study of photoreceptor density and arrangement across the retina.
In the fovea (where photoreceptor density is highest) the spacing between adjacent receptors is about 6-8 micrometer. This corresponds to an angular resolution of approximately 0.5 arc minute, effectively the upper limit of human visual acuity.
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A hypercentric or pericentric lens is a lens system where the entrance pupil is located in front of the lens, in the space where an object could be located. This has the result that, in a certain region, objects that are farther away from the lens produce larger images than objects that are closer to the lens, in stark contrast to the behavior of the human eye or any ordinary camera (both entocentric lenses), where farther-away objects always appear smaller.
The geometry of a hypercentric lens can be visualized by imagining a point source of light at the center of the entrance pupil sending rays in all directions. Any point on the object will be imaged to the point on the image plane found by continuing the ray that passes through it, so the shape of the image will be the same as that of the shadow cast by the object from the imaginary point of light. So the closer an object gets to that point (the center of the entrance pupil), the larger its image will be.
This inversion of normal perspectivity can be useful for machine vision. Imagine a six-sided die sitting on a conveyor belt being imaged by a hypercentric lens system directly above, whose entrance pupil is below the conveyor belt. The image of the die would contain the top and all four sides at once, because the bottom of the die appears larger than the top.
See also
Entocentric lens
Telecentric lens
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Behind the pupil, a single lens focuses light on a layer of what?
A. photons
B. electrons
C. chloroplasts
D. photoreceptors
Answer:
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|
sciq-10385
|
multiple_choice
|
What is formed when hot lava cools?
|
[
"mineral crystals",
"magma crystals",
"lava rock",
"hydrogen crystals"
] |
A
|
Relavent Documents:
Document 0:::
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 1:::
Dallol is a unique, terrestrial hydrothermal system around a cinder cone volcano in the Danakil Depression, northeast of the Erta Ale Range in Ethiopia. It is known for its unearthly colors and mineral patterns, and the very acidic fluids that discharge from its hydrothermal springs.
Etymology
The term Dallol was coined by the Afar people and means dissolution or disintegration, describing a landscape of green acid ponds and geysers (pH-values less than 1) and iron oxide, sulfur and salt desert plains. The area somewhat resembles the hot springs areas of Yellowstone National Park.
Description
Dallol mountain has an area of about , and rises about above the surrounding salt plains. A circular depression near the centre is probably a collapsed crater. The southwestern slopes have water-eroded salt canyons, pillars, and blocks. There are numerous saline springs and fields of small fumaroles.
Numerous hot springs discharge brine and acidic liquid here. Small, widespread, temporary geysers produce cones of salt. The Dallol deposits include significant bodies of potash found directly at the surface. The yellow, ochre and brown colourings are the result of the presence of iron and other impurities. Older, inactive springs tend to be dark brown because of oxidation processes.
Formation
It was formed by the intrusion of basaltic magma into Miocene salt deposits and subsequent hydrothermal activity. Phreatic eruptions took place here in 1926, forming Dallol Volcano; numerous other eruption craters dot the salt flats nearby. These craters are the lowest known subaerial volcanic vents in the world, at or more below sea level. In October 2004 the shallow magma chamber beneath Dallol deflated and fed a magma intrusion southwards beneath the rift. The most recent signs of activity occurred in January 2011 in what may have been a degassing event from deep below the surface.
Physical properties
Dallol lies in the evaporitic plain of the Danakil Depression at the Afar Triangle
Document 2:::
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 3:::
Maui Nui is a modern geologists' name given to a prehistoric Hawaiian island and the corresponding modern biogeographic region. Maui Nui is composed of four modern islands: Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe. Administratively, the four modern islands comprise Maui County (and a tiny part of Molokaʻi called Kalawao County). Long after the breakup of Maui Nui, the four modern islands retained plant and animal life similar to each other. Thus, Maui Nui is not only a prehistoric island but also a modern biogeographic region.
Geology
Maui Nui formed and broke up during the Pleistocene Epoch, which lasted from about 2.58 million to 11,700 years ago.
Maui Nui is built from seven shield volcanoes. The three oldest are Penguin Bank, West Molokaʻi, and East Molokaʻi, which probably range from slightly over to slightly less than 2 million years old. The four younger volcanoes are Lāna‘i, West Maui, Kaho‘olawe, and Haleakalā, which probably formed between 1.5 and 2 million years ago.
At its prime 1.2 million years ago, Maui Nui was , 50% larger than today's Hawaiʻi Island. The island of Maui Nui included four modern islands (Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe) and landmass west of Molokaʻi called Penguin Bank, which is now completely submerged.
Maui Nui broke up as rising sea levels flooded the connections between the volcanoes. The breakup was complex because global sea levels rose and fell intermittently during the Quaternary glaciation. About 600,000 years ago, the connection between Molokaʻi and the island of Lāna‘i/Maui/Kahoʻolawe became intermittent. About 400,000 years ago, the connection between Lāna‘i and Maui/Kahoʻolawe also became intermittent. The connection between Maui and Kahoʻolawe was permanently broken between 200,000 and 150,000 years ago. Maui, Lāna‘i, and Molokaʻi were connected intermittently thereafter, most recently about 18,000 years ago during the Last Glacial Maximum.
Today, the sea floor between these four islands is relatively shallow
Document 4:::
Clathrate hydrates, or gas hydrates, clathrates, or hydrates, are crystalline water-based solids physically resembling ice, in which small non-polar molecules (typically gases) or polar molecules with large hydrophobic moieties are trapped inside "cages" of hydrogen bonded, frozen water molecules. In other words, clathrate hydrates are clathrate compounds in which the host molecule is water and the guest molecule is typically a gas or liquid. Without the support of the trapped molecules, the lattice structure of hydrate clathrates would collapse into conventional ice crystal structure or liquid water. Most low molecular weight gases, including , , , , , , , , and , as well as some higher hydrocarbons and freons, will form hydrates at suitable temperatures and pressures. Clathrate hydrates are not officially chemical compounds, as the enclathrated guest molecules are never bonded to the lattice. The formation and decomposition of clathrate hydrates are first order phase transitions, not chemical reactions. Their detailed formation and decomposition mechanisms on a molecular level are still not well understood.
Clathrate hydrates were first documented in 1810 by Sir Humphry Davy who found that water was a primary component of what was earlier thought to be solidified chlorine.
Clathrates have been found to occur naturally in large quantities. Around 6.4 trillion () tonnes of methane is trapped in deposits of methane clathrate on the deep ocean floor. Such deposits can be found on the Norwegian continental shelf in the northern headwall flank of the Storegga Slide. Clathrates can also exist as permafrost, as at the Mallik gas hydrate site in the Mackenzie Delta of northwestern Canadian Arctic. These natural gas hydrates are seen as a potentially vast energy resource and several countries have dedicated national programs to develop this energy resource. Clathrate hydrate has also been of great interest as technology enabler for many applications like seawater desalina
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is formed when hot lava cools?
A. mineral crystals
B. magma crystals
C. lava rock
D. hydrogen crystals
Answer:
|
|
sciq-2982
|
multiple_choice
|
A crow that becomes used to a scarecrow and lands on it is an example of what?
|
[
"adaptation",
"assimilation",
"dissociation",
"habituation"
] |
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:::
Structures built by non-human animals, often called animal architecture, are common in many species. Examples of animal structures include termite mounds, ant hills, wasp and beehives, burrow complexes, beaver dams, elaborate nests of birds, and webs of spiders.
Often, these structures incorporate sophisticated features such as temperature regulation, traps, bait, ventilation, special-purpose chambers and many other features. They may be created by individuals or complex societies of social animals with different forms carrying out specialized roles. These constructions may arise from complex building behaviour of animals such as in the case of night-time nests for chimpanzees, from inbuilt neural responses, which feature prominently in the construction of bird songs, or triggered by hormone release as in the case of domestic sows, or as emergent properties from simple instinctive responses and interactions, as exhibited by termites, or combinations of these. The process of building such structures may involve learning and communication, and in some cases, even aesthetics. Tool use may also be involved in building structures by animals.
Building behaviour is common in many non-human mammals, birds, insects and arachnids. It is also seen in a few species of fish, reptiles, amphibians, molluscs, urochordates, crustaceans, annelids and some other arthropods. It is virtually absent from all the other animal phyla.
Functions
Animals create structures primarily for three reasons:
to create protected habitats, i.e. homes.
to catch prey and for foraging, i.e. traps.
for communication between members of the species (intra-specific communication), i.e. display.
Animals primarily build habitat for protection from extreme temperatures and from predation. Constructed structures raise physical problems which need to be resolved, such as humidity control or ventilation, which increases the complexity of the structure. Over time, through evolution, animals use shelters for ot
Document 2:::
In behavioral ecology, adaptive behavior is any behavior that contributes directly or indirectly to an individual's reproductive success, and is thus subject to the forces of natural selection. Examples include favoring kin in altruistic behaviors, sexual selection of the most fit mate, and defending a territory or harem from rivals.
Conversely, non-adaptive behavior is any behavior that is counterproductive to an individual's survival or reproductive success. Examples might include altruistic behaviors which do not favor kin, adoption of unrelated young, and being a subordinate in a dominance hierarchy.
Adaptations are commonly defined as evolved solutions to recurrent environmental problems of survival and reproduction. Individual differences commonly arise through both heritable and non-heritable adaptive behavior. Both have been proven to be influential in the evolution of species' adaptive behaviors, although non-heritable adaptation remains a controversial subject.
Non-heritable
Populations change through the process of evolution. Each individual in a population has a unique role in their particular environment. This role, commonly known as an ecological niche, is simply how an organism lives in an environment in relation to others. Over successive generations, the organism must adapt to their surrounding conditions in order to develop their niche. An organism's niche will evolve as changes in the external environment occur. The most successful species in nature are those that are able to use adaptive behaviors to build on prior knowledge, thereby increasing their overall knowledge bank. In turn, this will improve their overall survival and reproductive success.
Learning
Many species have the ability to adapt through learning. Organisms will often learn through various psychological and cognitive processes, such as operant and classical conditioning and discrimination memory. This learning process allows organisms to modify their behavior to survive in un
Document 3:::
The difficulty of defining or measuring intelligence in non-human animals makes the subject difficult to study scientifically in birds. In general, birds have relatively large brains compared to their head size. The visual and auditory senses are well developed in most species, though the tactile and olfactory senses are well realized only in a few groups. Birds communicate using visual signals as well as through the use of calls and song. The testing of intelligence in birds is therefore usually based on studying responses to sensory stimuli.
The corvids (ravens, crows, jays, magpies, etc.) and psittacines (parrots, macaws, and cockatoos) are often considered the most intelligent birds, and are among the most intelligent animals in general. Pigeons, finches, domestic fowl, and birds of prey have also been common subjects of intelligence studies.
Studies
Bird intelligence has been studied through several attributes and abilities. Many of these studies have been on birds such as quail, domestic fowl, and pigeons kept under captive conditions. It has, however, been noted that field studies have been limited, unlike those of the apes. Birds in the crow family (corvids) as well as parrots (psittacines) have been shown to live socially, have long developmental periods, and possess large forebrains, all of which have been hypothesized to allow for greater cognitive abilities.
Counting has traditionally been considered an ability that shows intelligence. Anecdotal evidence from the 1960s has suggested that crows can count up to 3. Researchers need to be cautious, however, and ensure that birds are not merely demonstrating the ability to subitize, or count a small number of items quickly. Some studies have suggested that crows may indeed have a true numerical ability. It has been shown that parrots can count up to 6.
Cormorants used by Chinese fishermen were given every eighth fish as a reward, and found to be able to keep count up to 7. E.H. Hoh wrote in Natural Histo
Document 4:::
In ethology and cognitive ethology, the hawk/goose effect refers to a behavior observed in some young birds when another bird flies above them: if the flying bird is a goose, the young birds show no reaction, but if the flying bird is a hawk, the young birds either become more agitated or cower to reduce the danger. The observation that short-necked and long-tailed birds flying overhead caused alarm was noted by Oskar Heinroth. Friedrich Goethe conducted experiments with silhouettes to examine alarm reactions in 1937 and a more systematic study was conducted in the same year by Konrad Lorenz and Nikolaas Tinbergen which is considered one of the classic experiments of ethology.
As part of their introducing experimentalism into animal behavior research they performed experiments in which they made 2-dimensional silhouettes of various bird-like shapes and moved them across the young birds' line of vision. Goose-like shapes were ignored while hawk-like shapes produced the response. Later Tinbergen reported that a single shape that was sort of an abstract composite of the hawk and goose silhouettes could produce the effect if moved in one direction but not the other. A study later confirmed that perception of an object was influenced by the direction of motion because the object in question was considered to be moving forwards in that direction. Initially thought to be an inborn instinct developed from natural selection, it was subsequently shown by others to be socially reinforced by other birds.
Hawk or goose distinguished by direction of movement
Just like what is seen in Tinbergen’s 1951 experiment the same figure is used to represent both the hawk and the goose in most hawk/goose experiments. When moving the figure in one direction, it represents a shape resembling a hawk (short neck long tail) while moving the figure in the opposite direction resembles a goose (long neck short tail). The perceived identity influences how the figure is perceived to move, such t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A crow that becomes used to a scarecrow and lands on it is an example of what?
A. adaptation
B. assimilation
C. dissociation
D. habituation
Answer:
|
|
sciq-8002
|
multiple_choice
|
What is the unique larval form of mollusks called?
|
[
"microfilariae",
"hydra",
"scallop",
"trochophore"
] |
D
|
Relavent Documents:
Document 0:::
The gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and from the land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, land snails and slugs.
The class Gastropoda is a diverse and highly successful class of mollusks within the phylum Mollusca. It contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record.
Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and reproductive adaptations of gastropods vary significantly from one clade or group to another, so stating many generalities for all gastropods is difficult.
The class Gastropoda has an extraordinary diversification of habitats. Representatives live in gardens, woodland, deserts, and on mountains; in small ditches, great rivers, and lakes; in estuaries, mudflats, the rocky intertidal, the sandy subtidal, the abyssal depths of the oceans, including the hydrothermal vents, and numerous other ecological niches, including parasitic ones.
Although the name "snail" can be, and often is, applied to all the members of this class, commonly this word means only those species with an external shell big enough that the soft parts can withdraw completely into it. Those gastropods without a shell, and those with only a very reduced or internal shell, are usually known as slugs; those with a shell into which they can partly but not com
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Pseudoplanktonic organisms are those that attach themselves to planktonic organisms or other floating objects, such as drifting wood, buoyant shells of organisms such as Spirula, or man-made flotsam. Examples include goose barnacles and the bryozoan Jellyella. By themselves these animals cannot float, which contrasts them with true planktonic organisms, such as Velella and the Portuguese Man o' War, which are buoyant. Pseudoplankton are often found in the guts of filtering zooplankters.
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Torsion is a gastropod synapomorphy which occurs in all gastropods during larval development. Torsion is the rotation of the visceral mass, mantle, and shell 180˚ with respect to the head and foot of the gastropod. This rotation brings the mantle cavity and the anus to an anterior position above the head.
In some groups of gastropods (Opisthobranchia) there is a degree of secondary detorsion or rotation towards the original position; this may be only partial detorsion or full detorsion.
The torsion or twisting of the visceral mass of larval gastropods is not the same thing as the spiral coiling of the shell, which is also present in many shelled gastropods.
Development
There are two different developmental stages which cause torsion. The first stage is caused by the development of the asymmetrical velar/foot muscle which has one end attached to the left side of the shell and the other end has fibres attached to the left side of the foot and head. At a certain point in larval development this muscle contracts, causing an anticlockwise rotation of the visceral mass and mantle of roughly 90˚. This process is very rapid, taking from a few minutes to a few hours. After this transformation the second stage of torsion development is achieved by differential tissue growth of the left hand side of the organism compared to the right hand side. This second stage is much slower and rotates the visceral mass and mantle a further 90˚. Detorsion is brought about by reversal of the above phases.
During torsion the visceral mass remains almost unchanged anatomically. There are, however, other important changes to other internal parts of the gastropod. Before torsion the gastropod has an euthyneural nervous system, where the two visceral nerves run parallel down the body. Torsion results in a streptoneural nervous system, where the visceral nerves cross over in a figure of eight fashion. As a result, the parietal ganglions end up at different heights. Because of differences betw
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Milax nigricans is a species of gastropods belonging to the family Milacidae.
The species is found in terrestrial environments.
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The size of oesophageal gland of scaly-foot gastropod Chrysomallon squamiferum (family Peltospiridae within Neomphalina) is about two orders of magnitude over the usual size. The scaly-foot gastropod houses endosymbiotic Bacteria in the oesophageal gland. Chrysomallon squamiferum was thought to be the only species of Peltospiridae, that has enlarged oesophageal gland, but later it was shown that both species Gigantopelta has the oesophageal gland also enlarged. In other peltospirids, the posterior portion of the oesophagus forms a pair of blind mid-oesophageal pouches or gutters extending only to the anterior end o
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the unique larval form of mollusks called?
A. microfilariae
B. hydra
C. scallop
D. trochophore
Answer:
|
|
sciq-2791
|
multiple_choice
|
What is the smallest unit of time commonly based on?
|
[
"millimeter",
"hour",
"minute",
"second"
] |
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:::
The Test of Mathematics for University Admission is a paper-based test sometimes used in the United Kingdom and other countries in Africa and the United States all assess the mathematical thinking and reasoning skills needed for undergraduate mathematics courses or courses featuring mathematics. A number of universities across the world accept the test as an optional part of their application process for mathematics-based courses.
History
The test was developed by Cambridge Assessment Admissions Testing and launched in 2016. It was designed to assess the key skills that students need to succeed on demanding university-level mathematics courses, and assist university mathematics tutors in making admissions decisions.
Durham University and Lancaster University began using the test in 2016, with the University of Warwick, the University of Sheffield and the University of Southampton recognising the test in 2017, and the London School of Economics and Political Science (LSE) and Cardiff University in 2018
Research indicates that the test has good predictive validity, with good correlation between candidates' scores in the test and their performance in their exams at the end of first year university study. There is also correlation between A-level Further Maths performance and performance in the test.
Test format and specification
The Test of Mathematics for University Admission is a paper-based 2 hour and 30 minute long test. It has two papers which are taken consecutively.
Paper 1: Mathematical Thinking
Paper 1 has 20 multiple-choice questions, with 75 minutes allowed to complete the paper. This paper assesses a candidate’s ability to apply their knowledge of mathematics in new situations. It comprises a core set of ideas from Pure Mathematics. These ideas reflect those that would be met early on in a typical A Level Mathematics course: algebra, basic functions, sequences and series, coordinate geometry, trigonometry, exponentials and logarithms, differentiat
Document 2:::
In physics, time is defined by its measurement: time is what a clock reads. In classical, non-relativistic physics, it is a scalar quantity (often denoted by the symbol ) and, like length, mass, and charge, is usually described as a fundamental quantity. Time can be combined mathematically with other physical quantities to derive other concepts such as motion, kinetic energy and time-dependent fields. Timekeeping is a complex of technological and scientific issues, and part of the foundation of recordkeeping.
Markers of time
Before there were clocks, time was measured by those physical processes which were understandable to each epoch of civilization:
the first appearance (see: heliacal rising) of Sirius to mark the flooding of the Nile each year
the periodic succession of night and day, seemingly eternally
the position on the horizon of the first appearance of the sun at dawn
the position of the sun in the sky
the marking of the moment of noontime during the day
the length of the shadow cast by a gnomon
Eventually, it became possible to characterize the passage of time with instrumentation, using operational definitions. Simultaneously, our conception of time has evolved, as shown below.
The unit of measurement of time: the second
In the International System of Units (SI), the unit of time is the second (symbol: ). It is a SI base unit, and has been defined since 1967 as "the duration of [cycles] of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom". This definition is based on the operation of a caesium atomic clock. These clocks became practical for use as primary reference standards after about 1955, and have been in use ever since.
The state of the art in timekeeping
The UTC timestamp in use worldwide is an atomic time standard. The relative accuracy of such a time standard is currently on the order of 10−15 (corresponding to 1 second in approximately 30 million years). The smalle
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An unusual unit of measurement is a unit of measurement that does not form part of a coherent system of measurement, especially because its exact quantity may not be well known or because it may be an inconvenient multiple or fraction of a base unit.
Many of the unusual units of measurements listed here are colloquial measurements, units devised to compare a measurement to common and familiar objects.
Length
Hammer unit
Valve's Source game engine uses the Hammer unit as its base unit of length. This unit refers to Source's official map creation software, Hammer. The exact definition varies from game to game, but a Hammer unit is usually defined as a sixteenth of a foot (16 Hammer units = 1 foot). This means that 1 Hammer unit is equal to exactly .
Rack unit
One rack unit (U) is and is used to measure rack-mountable audiovisual, computing and industrial equipment. Rack units are typically denoted without a space between the number of units and the 'U'. Thus, a 4U server enclosure (case) is high, or more practically, built to occupy a vertical space seven inches high, with sufficient clearance to allow movement of adjacent hardware.
Hand
The hand is a non-SI unit of length equal to exactly . It is normally used to measure the height of horses in some English-speaking countries, including Australia, Canada, Ireland, the United Kingdom, and the United States. It is customary when measuring in hands to use a point to indicate inches (quarter-hands) and not tenths of a hand. For example, 15.1 hands normally means 15 hands, 1 inch (5 ft 1 in), rather than 15 hands.
Light-nanosecond
The light-nanosecond is defined as exactly 29.9792458 cm. It was popularized in information technology as a unit of distance by Grace Hopper as the distance which a photon could travel in one billionth of a second (roughly 30 cm or one foot): "The speed of light is one foot per nanosecond."
Metric feet
A metric foot, defined as ), has been used occasionally in the UK but has never b
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There are four Advanced Placement (AP) Physics courses administered by the College Board as part of its Advanced Placement program: the algebra-based Physics 1 and Physics 2 and the calculus-based Physics C: Mechanics and Physics C: Electricity and Magnetism. All are intended to be at the college level. Each AP Physics course has an exam for which high-performing students may receive credit toward their college coursework.
AP Physics 1 and 2
AP Physics 1 and AP Physics 2 were introduced in 2015, replacing AP Physics B. The courses were designed to emphasize critical thinking and reasoning as well as learning through inquiry. They are algebra-based and do not require any calculus knowledge.
AP Physics 1
AP Physics 1 covers Newtonian mechanics, including:
Unit 1: Kinematics
Unit 2: Dynamics
Unit 3: Circular Motion and Gravitation
Unit 4: Energy
Unit 5: Momentum
Unit 6: Simple Harmonic Motion
Unit 7: Torque and Rotational Motion
Until 2020, the course also covered topics in electricity (including Coulomb's Law and resistive DC circuits), mechanical waves, and sound. These units were removed because they are included in AP Physics 2.
AP Physics 2
AP Physics 2 covers the following topics:
Unit 1: Fluids
Unit 2: Thermodynamics
Unit 3: Electric Force, Field, and Potential
Unit 4: Electric Circuits
Unit 5: Magnetism and Electromagnetic Induction
Unit 6: Geometric and Physical Optics
Unit 7: Quantum, Atomic, and Nuclear Physics
AP Physics C
From 1969 to 1972, AP Physics C was a single course with a single exam that covered all standard introductory university physics topics, including mechanics, fluids, electricity and magnetism, optics, and modern physics. In 1973, the College Board split the course into AP Physics C: Mechanics and AP Physics C: Electricity and Magnetism. The exam was also split into two separate 90-minute tests, each equivalent to a semester-length calculus-based college course. Until 2006, both exams could be taken for a single
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the smallest unit of time commonly based on?
A. millimeter
B. hour
C. minute
D. second
Answer:
|
|
sciq-2888
|
multiple_choice
|
Antacids are bases that neutralize what in the digestive tract?
|
[
"salts",
"hormones",
"acids",
"fats"
] |
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
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This is a list of articles that describe particular biomolecules or types of biomolecules.
A
For substances with an A- or α- prefix such as
α-amylase, please see the parent page (in this case Amylase).
A23187 (Calcimycin, Calcium Ionophore)
Abamectine
Abietic acid
Acetic acid
Acetylcholine
Actin
Actinomycin D
Adenine
Adenosmeme
Adenosine diphosphate (ADP)
Adenosine monophosphate (AMP)
Adenosine triphosphate (ATP)
Adenylate cyclase
Adiponectin
Adonitol
Adrenaline, epinephrine
Adrenocorticotropic hormone (ACTH)
Aequorin
Aflatoxin
Agar
Alamethicin
Alanine
Albumins
Aldosterone
Aleurone
Alpha-amanitin
Alpha-MSH (Melaninocyte stimulating hormone)
Allantoin
Allethrin
α-Amanatin, see Alpha-amanitin
Amino acid
Amylase (also see α-amylase)
Anabolic steroid
Anandamide (ANA)
Androgen
Anethole
Angiotensinogen
Anisomycin
Antidiuretic hormone (ADH)
Anti-Müllerian hormone (AMH)
Arabinose
Arginine
Argonaute
Ascomycin
Ascorbic acid (vitamin C)
Asparagine
Aspartic acid
Asymmetric dimethylarginine
ATP synthase
Atrial-natriuretic peptide (ANP)
Auxin
Avidin
Azadirachtin A – C35H44O16
B
Bacteriocin
Beauvericin
beta-Hydroxy beta-methylbutyric acid
beta-Hydroxybutyric acid
Bicuculline
Bilirubin
Biopolymer
Biotin (Vitamin H)
Brefeldin A
Brassinolide
Brucine
Butyric acid
C
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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 3:::
The metabolome refers to the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The small molecule chemicals found in a given metabolome may include both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics) that are not naturally produced by an organism.
In other words, there is both an endogenous metabolome and an exogenous metabolome. The endogenous metabolome can be further subdivided to include a "primary" and a "secondary" metabolome (particularly when referring to plant or microbial metabolomes). A primary metabolite is directly involved in the normal growth, development, and reproduction. A secondary metabolite is not directly involved in those processes, but usually has important ecological function. Secondary metabolites may include pigments, antibiotics or waste products derived from partially metabolized xenobiotics. The study of the metabolome is called metabolomics.
Origins
The word metabolome appears to be a blending of the words "metabolite" and "chromosome". It was constructed to imply that metabolites are indirectly encoded by genes or act on genes and gene products. The term "metabolome" was first used in 1998 and was likely coined to match with existing biological terms referring to the complete set of genes (the genome), the complete set of proteins (the proteome) and the complete set of transcripts (the transcriptome). The first book on metabolomics was published in 2003. The first journal dedicated to metabolomics (titled simply "Metabolomics") was launched in 2005 and is currently edited by Prof. Roy Goodacre. Some of the m
Document 4:::
Stomachic is a historic term for a medicine that serves to tone the stomach, improving its function and increase appetite. While many herbal remedies claim stomachic effects, modern pharmacology does not have an equivalent term for this type of action.
Herbs with putative stomachic effects include:
Agrimony
Aloe
Anise
Avens (Geum urbanum)
Barberry
Bitterwood (Picrasmaa excelsa)
Cannabis
Cayenne
Centaurium
Cleome
Colombo (herb) (Frasera carolinensis)
Dandelion
Elecampane
Ginseng
Goldenseal
Grewia asiatica (Phalsa or Falsa)
Hops
Holy thistle
Juniper berry
Mint
Mugwort
Oregano
Peach bark
Rhubarb
White mustard seeds
Rose hips
Rue
Sweet flag (Acorus calamus)
Wormwood (Artemisia absinthium)
The purported stomachic mechanism of action of these substances is to stimulate the appetite by increasing the gastric secretions of the stomach; however, the actual therapeutic value of some of these compounds is dubious. Some other important agents used are:
Bitters: used to stimulate the taste buds, thus producing reflex secretion of gastric juices. Quassia, Aristolochia, gentian, and chirata are commonly used.
Alcohol: increases gastric secretion by direct action and also by the reflex stimulation of taste buds.
Miscellaneous compounds: including insulin which increases the gastric secretion by producing hypoglycemia, and histamine, which produces direct stimulation of gastric glands.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Antacids are bases that neutralize what in the digestive tract?
A. salts
B. hormones
C. acids
D. fats
Answer:
|
|
sciq-7860
|
multiple_choice
|
An elastic collision is one that conserves internal energy of what type?
|
[
"potential",
"seismic",
"kinetic",
"thermal"
] |
C
|
Relavent Documents:
Document 0:::
In the context of classical mechanics simulations and physics engines employed within video games, collision response deals with models and algorithms for simulating the changes in the motion of two solid bodies following collision and other forms of contact.
Rigid body contact
Two rigid bodies in unconstrained motion, potentially under the action of forces, may be modelled by solving their equations of motion using numerical integration techniques. On collision, the kinetic properties of two such bodies seem to undergo an instantaneous change, typically resulting in the bodies rebounding away from each other, sliding, or settling into relative static contact, depending on the elasticity of the materials and the configuration of the collision.
Contact forces
The origin of the rebound phenomenon, or reaction, may be traced to the behaviour of real bodies that, unlike their perfectly rigid idealised counterparts, do undergo minor compression on collision, followed by expansion, prior to separation. The compression phase converts the kinetic energy of the bodies into potential energy and to an extent, heat. The expansion phase converts the potential energy back to kinetic energy.
During the compression and expansion phases of two colliding bodies, each body generates reactive forces on the other at the points of contact, such that the sum reaction forces of one body are equal in magnitude but opposite in direction to the forces of the other, as per the Newtonian principle of action and reaction. If the effects of friction are ignored, a collision is seen as affecting only the component of the velocities that are directed along the contact normal and as leaving the tangential components unaffected
Reaction
The degree of relative kinetic energy retained after a collision, termed the restitution, is dependent on the elasticity of the bodies‟ materials. The coefficient of restitution between two given materials is modeled as the ratio of the relative post-collis
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The coefficient of restitution (COR, also denoted by e), is the ratio of the final to initial relative speed between two objects after they collide. It normally ranges from 0 to 1 where 1 would be a perfectly elastic collision. A perfectly inelastic collision has a coefficient of 0, but a 0 value does not have to be perfectly inelastic. It is measured in the Leeb rebound hardness test, expressed as 1000 times the COR, but it is only a valid COR for the test, not as a universal COR for the material being tested.
The value is almost always less than 1 due to initial translational kinetic energy being lost to rotational kinetic energy, plastic deformation, and heat. It can be more than 1 if there is an energy gain during the collision from a chemical reaction, a reduction in rotational energy, or another internal energy decrease that contributes to the post-collision velocity.
The mathematics were developed by Sir Isaac Newton in 1687. It is also known as Newton's experimental law.
Further details
Line of impact – It is the line along which e is defined or in absence of tangential reaction force between colliding surfaces, force of impact is shared along this line between bodies. During physical contact between bodies during impact its line along common normal to pair of surfaces in contact of colliding bodies. Hence e is defined as a dimensionless one-dimensional parameter.
Range of values for e – treated as a constant
e is usually a positive, real number between 0 and 1:
e = 0: This is a perfectly inelastic collision.
0 < e < 1: This is a real-world inelastic collision, in which some kinetic energy is dissipated.
e = 1: This is a perfectly elastic collision, in which no kinetic energy is dissipated, and the objects rebound from one another with the same relative speed with which they approached.e < 0: A COR less than zero would represent a collision in which the separation velocity of the objects has the same direction (sign) as the closing velocity, implyi
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In mechanics and physics, shock is a sudden acceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation.
Shock describes matter subject to extreme rates of force with respect to time. Shock is a vector that has units of an acceleration (rate of change of velocity). The unit g (or g) represents multiples of the standard acceleration of gravity and is conventionally used.
A shock pulse can be characterised by its peak acceleration, the duration, and the shape of the shock pulse (half sine, triangular, trapezoidal, etc.). The shock response spectrum is a method for further evaluating a mechanical shock.
Shock measurement
Shock measurement is of interest in several fields such as
Propagation of heel shock through a runner's body
Measure the magnitude of a shock need to cause damage to an item: fragility.
Measure shock attenuation through athletic flooring
Measuring the effectiveness of a shock absorber
Measuring the shock absorbing ability of package cushioning
Measure the ability of an athletic helmet to protect people
Measure the effectiveness of shock mounts
Determining the ability of structures to resist seismic shock: earthquakes, etc.
Determining whether personal protective fabric attenuates or amplifies shocks
Verifying that a Naval ship and its equipment can survive explosive shocks
Shocks are usually measured by accelerometers but other transducers and high speed imaging are also used. A wide variety of laboratory instrumentation is available; stand-alone shock data loggers are also used.
Field shocks are highly variable and often have very uneven shapes. Even laboratory controlled shocks often have uneven shapes and include short duration spikes; Noise can be reduced by appropriate digital or analog filtering.
Governing test methods and specifications provide detail about the conduct of shock tests. Proper placement of measuring instruments is critical. Fragile items and packaged g
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
In physics, deflection is a change in a moving object's velocity, hence its trajectory, as a consequence of contact (collision) with a surface or the influence of a non-contact force field. Examples of the former include a ball bouncing off the ground or a bat; examples of the latter include a beam of electrons used to produce a picture, or the relativistic bending of light due to gravity.
Deflective efficiency
An object's deflective efficiency can never equal or surpass 100%, for example:
a mirror will never reflect exactly the same amount of light cast upon it, though it may concentrate the light which is reflected into a narrower beam.
on hitting the ground, a ball previously in free-fall (meaning no force other than gravity acted upon it) will never bounce back up to the place where it first started to descend.
This transfer of some energy into heat or other radiation is a consequence of the theory of thermodynamics, where, for every such interaction, some energy must be converted into alternative forms of energy or is absorbed by the deformation of the objects involved in the collision.
See also
Electrostatic deflection
Coriolis effect
Deflection yoke
Impulse
Reflection
Scattering
Collision
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
An elastic collision is one that conserves internal energy of what type?
A. potential
B. seismic
C. kinetic
D. thermal
Answer:
|
|
sciq-3954
|
multiple_choice
|
Bond energy is an indication of the amount of energy needed for what to occur?
|
[
"photosynthesis",
"chemical reaction",
"oxidation",
"physical reaction only"
] |
B
|
Relavent Documents:
Document 0:::
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells, in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.
Much of biochemistry deals with the structures, bonding, functions, and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids. They provide the structure of cells and perform many of the functions associated with life. The chemistry of the cell also depends upon the reactions of small molecules and ions. These can be inorganic (for example, water and metal ions) or organic (for example, the amino acids, which are used to synthesize proteins). The mechanisms used by cells to harness energy from their environment via chemical reactions are known as metabolism. The findings of biochemistry are applied primarily in medicine, nutrition and agriculture. In medicine, biochemists investigate the causes and cures of diseases. Nutrition studies how to maintain health and wellness and also the effects of nutritional deficiencies. In agriculture, biochemists investigate soil and fertilizers, with the goal of improving crop cultivation, crop storage, and pest control. In recent decades, biochemical principles a
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In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.
The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may need coenzymes (e.g. NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via peptide bonds, and DNA molecules, which are composed of nucleotides joined via phosphodiester bonds.
Properties of chemical reactions
Biosynthesis occurs due to a series of chemical reactions. For these reactions to take place, the following elements are necessary:
Precursor compounds: these compounds are the starting molecules or substrates in a reaction. These may also be viewed as the reactants in a given chemical process.
Chemical energy: chemical energy can be found in the form of high energy molecules. These molecules are required for energetically unfavorable reactions. Furthermore, the hydrolysis of these compounds drives a reaction forward. High energy molecules, such as ATP, have three phosphates. Often, the terminal phosphate is split off during hydrolysis and transferred to another molecule.
Catalysts: these may be for example metal ions or coenzymes and they catalyze a reaction by increasing the rate of the reaction and lowering the activation energy.
In the sim
Document 2:::
In chemistry and particularly biochemistry, an energy-rich species (usually energy-rich molecule) or high-energy species (usually high-energy molecule) is a chemical species which reacts, potentially with other species found in the environment, to release chemical energy.
In particular, the term is often used for:
adenosine triphosphate (ATP) and similar molecules called high-energy phosphates, which release inorganic phosphate into the environment in an exothermic reaction with water:
ATP + → ADP + Pi ΔG°' = −30.5 kJ/mol (−7.3 kcal/mol)
fuels such as hydrocarbons, carbohydrates, lipids, proteins, and other organic molecules which react with oxygen in the environment to ultimately form carbon dioxide, water, and sometimes nitrogen, sulfates, and phosphates
molecular hydrogen
monatomic oxygen, ozone, hydrogen peroxide, singlet oxygen and other metastable or unstable species which spontaneously react without further reactants
in particular, the vast majority of free radicals
explosives such as nitroglycerin and other substances which react exothermically without requiring a second reactant
metals or metal ions which can be oxidized to release energy
This is contrasted to species that are either part of the environment (this sometimes includes diatomic triplet oxygen) or do not react with the environment (such as many metal oxides or calcium carbonate); those species are not considered energy-rich or high-energy species.
Alternative definitions
The term is often used without a definition. Some authors define the term "high-energy" to be equivalent to "chemically unstable", while others reserve the term for high-energy phosphates, such as the Great Soviet Encyclopedia which defines the term "high-energy compounds" to refer exclusively to those.
The IUPAC glossary of terms used in ecotoxicology defines a primary producer as an "organism capable of using the energy derived from light or a chemical substance in order to manufacture energy-rich organic compou
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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 4:::
In chemistry, bond cleavage, or bond fission, is the splitting of chemical bonds. This can be generally referred to as dissociation when a molecule is cleaved into two or more fragments.
In general, there are two classifications for bond cleavage: homolytic and heterolytic, depending on the nature of the process. The triplet and singlet excitation energies of a sigma bond can be used to determine if a bond will follow the homolytic or heterolytic pathway. A metal−metal sigma bond is an exception because the bond's excitation energy is extremely high, thus cannot be used for observation purposes.
In some cases, bond cleavage requires catalysts. Due to the high bond-dissociation energy of C−H bonds, around , a large amount of energy is required to cleave the hydrogen atom from the carbon and bond a different atom to the carbon.
Homolytic cleavage
In homolytic cleavage, or homolysis, the two electrons in a cleaved covalent bond are divided equally between the products. This process is also known as homolytic fission or radical fission. The bond-dissociation energy of a bond is the amount of energy required to cleave the bond homolytically. This enthalpy change is one measure of bond strength.
The triplet excitation energy of a sigma bond is the energy required for homolytic dissociation, but the actual excitation energy may be higher than the bond-dissociation energy due to the repulsion between electrons in the triplet state.
Heterolytic cleavage
In heterolytic cleavage, or heterolysis, the bond breaks in such a fashion that the originally-shared pair of electrons remain with one of the fragments. Thus, a fragment gains an electron, having both bonding electrons, while the other fragment loses an electron. This process is also known as ionic fission.
The singlet excitation energy of a sigma bond is the energy required for heterolytic dissociation, but the actual singlet excitation energy may be lower than the bond-dissociation energy of heterolysis as a resu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Bond energy is an indication of the amount of energy needed for what to occur?
A. photosynthesis
B. chemical reaction
C. oxidation
D. physical reaction only
Answer:
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sciq-10512
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multiple_choice
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What are materials that can be magnetized called?
|
[
"Metal material",
"interstitial materials",
"catalytic materials",
"ferromagnetic materials"
] |
D
|
Relavent Documents:
Document 0:::
In classical electromagnetism, magnetization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. Accordingly, physicists and engineers usually define magnetization as the quantity of magnetic moment per unit volume.
It is represented by a pseudovector M. Magnetization can be compared to electric polarization, which is the measure of the corresponding response of a material to an electric field in electrostatics.
Magnetization also describes how a material responds to an applied magnetic field as well as the way the material changes the magnetic field, and can be used to calculate the forces that result from those interactions.
The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. Net magnetization results from the response of a material to an external magnetic field.
Paramagnetic materials have a weak induced magnetization in a magnetic field, which disappears when the magnetic field is removed. Ferromagnetic and ferrimagnetic materials have strong magnetization in a magnetic field, and can be magnetized to have magnetization in the absence of an external field, becoming a permanent magnet. Magnetization is not necessarily uniform within a material, but may vary between different points.
Definition
The magnetization field or M-field can be defined according to the following equation:
Where is the elementary magnetic moment and is the volume element; in other words, the M-field is the distribution of magnetic moments in the region or manifold concerned. This is better illustrated through the following relation:
where m is an ordinary magnetic moment and the triple integral denotes integration over a volume. This makes the M-field completely analogous to the electric polarisation field, or P-field, used to determine the electric dipole moment
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Remanence or remanent magnetization or residual magnetism is the magnetization left behind in a ferromagnetic material (such as iron) after an external magnetic field is removed. Colloquially, when a magnet is "magnetized", it has remanence. The remanence of magnetic materials provides the magnetic memory in magnetic storage devices, and is used as a source of information on the past Earth's magnetic field in paleomagnetism. The word remanence is from remanent + -ence, meaning "that which remains".
The equivalent term residual magnetization is generally used in engineering applications. In transformers, electric motors and generators a large residual magnetization is not desirable (see also electrical steel) as it is an unwanted contamination, for example a magnetization remaining in an electromagnet after the current in the coil is turned off. Where it is unwanted, it can be removed by degaussing.
Sometimes the term retentivity is used for remanence measured in units of magnetic flux density.
Types
Saturation remanence
The default definition of magnetic remanence is the magnetization remaining in zero field after a large magnetic field is applied (enough to achieve saturation). The effect of a magnetic hysteresis loop is measured using instruments such as a vibrating sample magnetometer; and the zero-field intercept is a measure of the remanence. In physics this measure is converted to an average magnetization (the total magnetic moment divided by the volume of the sample) and denoted in equations as Mr. If it must be distinguished from other kinds of remanence, then it is called the saturation remanence or saturation isothermal remanence (SIRM) and denoted by Mrs.
In engineering applications the residual magnetization is often measured using a B-H analyzer, which measures the response to an AC magnetic field (as in Fig. 1). This is represented by a flux density Br. This value of remanence is one of the most important parameters characterizing permanent ma
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The Soft Magnetic Materials Conference, commonly referred to as SMM, is an international conference devoted to all kinds of soft magnetic materials with the emphasis on industrial and applications aspects.
Format and purpose
The SMM is held for three days, every two years, often at the beginning of September in a European country. Each time the SMM has a different logo.
In SMM18 (organised by Wolfson Centre for Magnetics there were 260 participants from over 30 countries. There were 306 scientific papers presented, out of which around 200 are peer reviewed and will be published in Journal of Magnetism and Magnetic Materials, Elsevier at the beginning of 2008.
In the past the SMM proceedings have also been published in IEEE Transactions on Magnetics
or other peer reviewed journals.
The SMM is the largest international conference devoted to soft magnetic materials. It has active participation of the academic world as well as of industry, with a high scientific level of contributed and invited communications.
The main aim of the SMM is to bring together engineers and scientists from universities, research institutions and industry who are active in research, development and industrial applications of the materials. The programme of the conference includes invited lectures by academic and industrial experts, oral presentations and poster sessions for regular contributions.
Scope
Typical topics of the SMM are:
Basic magnetisation processes including domain studies and Barkhausen noise
Magnetisation characterisation and measurement techniques
Losses, magnetostriction and B-H properties
Non-oriented and grain-oriented electrical steels
Novel and special magnetic materials
Fe-Ni, Fe-Co, amorphous and nanocrystalline alloys
Composites, powder cores and ferrites
Power applications (e.g. motors, transformers and actuators)
Sensors, high frequency and electronic applications
Modelling, simulation or prediction of material and device performance
Design of ele
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Biomagnetism is the phenomenon of magnetic fields produced by living organisms; it is a subset of bioelectromagnetism. In contrast, organisms' use of magnetism in navigation is magnetoception and the study of the magnetic fields' effects on organisms is magnetobiology. (The word biomagnetism has also been used loosely to include magnetobiology, further encompassing almost any combination of the words magnetism, cosmology, and biology, such as "magnetoastrobiology".)
The origin of the word biomagnetism is unclear, but seems to have appeared several hundred years ago, linked to the expression "animal magnetism". The present scientific definition took form in the 1970s, when an increasing number of researchers began to measure the magnetic fields produced by the human body. The first valid measurement was actually made in 1963, but the field of research began to expand only after a low-noise technique was developed in 1970. Today the community of biomagnetic researchers does not have a formal organization, but international conferences are held every two years, with about 600 attendees. Most conference activity centers on the MEG (magnetoencephalogram), the measurement of the magnetic field of the brain.
Prominent researchers
David Cohen
John Wikswo
Samuel Williamson
See also
Bioelectrochemistry
Human magnetism
Magnetite
Magnetocardiography
Magnetoception - sensing of magnetic fields by organisms
Magnetoelectrochemistry
Magnetoencephalography
Magnetogastrography
Magnetomyography
SQUID
Notes
Further reading
Williamson SH, Romani GL, Kaufman L, Modena I, editors. Biomagnetism: An Interdisciplinary Approach. 1983. NATO ASI series. New York: Plenum Press.
Cohen, D. Boston and the history of biomagnetism. Neurology and Clinical Neurophysiology 2004; 30: 1.
History of Biomagnetism
Bioelectromagnetics
Magnetism
Document 4:::
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe3O4. It occurs in nature as the mineral magnetite. It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe2O3) which also occurs naturally as the mineral hematite. It contains both Fe2+ and Fe3+ ions and is sometimes formulated as FeO ∙ Fe2O3. This iron oxide is encountered in the laboratory as a black powder. It exhibits permanent magnetism and is ferrimagnetic, but is sometimes incorrectly described as ferromagnetic. Its most extensive use is as a black pigment (see: Mars Black). For this purpose, it is synthesized rather than being extracted from the naturally occurring mineral as the particle size and shape can be varied by the method of production.
Preparation
Heated iron metal interacts with steam to form iron oxide and hydrogen gas.
3Fe + 4H2O->Fe3O4 + 4H2
Under anaerobic conditions, ferrous hydroxide (Fe(OH)2) can be oxidized by water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction:
\underset{ferrous\ hydroxide}{3Fe(OH)2} -> \underset{magnetite}{Fe3O4} + \underset{hydrogen}{H2} + \underset{water}{2H2O}
This works because crystalline magnetite (Fe3O4) is thermodynamically more stable than amorphous ferrous hydroxide (Fe(OH)2 ).
The Massart method of preparation of magnetite as a ferrofluid, is convenient in the laboratory: mix iron(II) chloride and iron(III) chloride in the presence of sodium hydroxide.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are materials that can be magnetized called?
A. Metal material
B. interstitial materials
C. catalytic materials
D. ferromagnetic materials
Answer:
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sciq-4835
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multiple_choice
|
Where do lancelets live?
|
[
"on land",
"deep sea caves",
"shallow ocean water",
"riverbeds"
] |
C
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Relavent Documents:
Document 0:::
One of the marine ecosystems found in the Virgin Islands are the coral reefs. These coral reefs can be located between the islands of St. Croix, St. Thomas, and St. John. These coral reefs have an area of 297.9 km2, along with other marine habitats that are in between. The way these coral reefs grow are by coral larvae swimming freely and attaching themselves to hard surfaces around the islands and start to develop a skeleton on the outside of their skin to protect themselves from predators but also allow a new place for other coral larvae to attach to and grow on. These corals can form into three different structures; fringing reefs, which are reefs that are close to the shore, barrier reefs, which are reefs that are alongside the shore and is separated by deep water, and an atoll reef which is a coral reef that circles a lagoon or body of water.
Distribution
As stated, the coral reefs such as fringing reefs, deep reefs, patch reefs and spur and groove formation are distributed over three islands in the Virgin Islands which are St. Croix (Salt River Bay National Historical Park and Ecological Preserve, Buck Island Reef National Monument), St. Thomas, and St. John (Virgin Islands Coral Reef National Monument). The coral reefs found offshore of St. Thomas and St. John are distributed patchily around the islands. Additionally, a developed barrier reef system surrounds St. Croix along its eastern and southern shores.
Ecology
The coral reefs as well as hard-bottom habitat accounts for 297.9 km2. The coral reefs are home to diverse species. There are over 40 species of scleractinian corals and three species of Millepora. Live scleractinian species are found throughout the Virgin Islands, but mainly around Buck Island, St. Croix and St. John. More specifically based on a survey from 2001-2006, listed are a total of 215 fishes from St. John and 202 from St. Croix. Four species of sea turtles are found within the Virgin Islands. The coral reefs are impacted by freshwa
Document 1:::
External links
https://web.archive.org/web/20100610042626/http://chancellor.utk.edu/professors/horn.shtml
http://web.utk.edu/~shorn/research.htm
Livi
Document 2:::
The Oyster Question: Scientists, Watermen, and the Maryland Chesapeake Bay since 1880 is a 2009 book by Christine Keiner. It examines the conflict between oystermen and scientists in the Chesapeake Bay from the end of the nineteenth century to the present, which includes the period of the so-called "Oyster Wars" and the precipitous decline of the oyster industry at the end of the twentieth century. The book engages the myth of the "Tragedy of the Commons" by examining the often fraught relationship between local politics and conservation science, arguing that for most of the period Maryland's state political system gave rural oystermen more political clout than politicians and the scientists they appointed and allowing oystermen to effectively manage the oyster bed commons. Only towards the end of the twentieth century did reapportionment bring suburban and urban interests more political power, by which time they had latched on to oystermen as elements of the area's heritage and incorporated them and the oysters into broader conservation efforts. An important theme is the "intersection[] of scientific knowledge with experiential knowledge in the context of use," in that Keiner "treats the knowledge of the Chesapeake Bay’s oystermen alongside that of biologists." "Through her analysis, Keiner effectively reframes how environmental historians have analyzed histories of common resources and provides a working model for integrating historical and ecological information to bridge the histories of science and environmental history."
Awards
The book won the 2010 Forum for the History of Science in America Prize. It shared the 2010 Maryland Historical Trust's Heritage Book Award, and received an Honorable Mention for the Frederick Jackson Turner Award from the Organization of American Historians in 2010.
Document 3:::
Espegrend (also known as Espeland) is a marine biological field station located in Bergen, Norway. The station is located close to the airport Flesland, 20 kilometers south of Bergen.
Overview
The Department of Biological Sciences at the University of Bergen has specialized laboratories and research installations in the main campus in downtown Bergen. It is also responsible for the Marine biological field station at Espeland. The Station is located in the Raunefjord, with deep sea fauna easily available. The station has good mesocosm facilities, a research vessel RV Aurelia, and good facilities for benthic and planktonic sampling. Espegrend has a number of specialised facilities. It is well known for is mesocosm facility. Espegrend has very good access to diverse and well described marine habitats and model environments. The station comprises a boarding house, boats, laboratories and basic equipment for marine research.
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The Br. Alfred Shields FSC Marine Biological Station is the marine laboratory of De La Salle University. It is located in Sitio Matuod, Lian, Batangas near Talim Bay and also near Mt. Tikbalang. Most of undergraduate and graduate thesis/researches on marine science of the university are done in this facility. Dr. Wilfredo Roehl Y. Licuanan is the current director of the Station.
History
The marine station was named after Br. Alfred Shields FSC, the founder of DLSU's Biology Department. The land where the station is now located was donated by the Limjoco Family. The Marine Station is in the Municipality of Lian in Batangas, a province in the Southern part of Luzon. The Marine Station is near Talim Bay. It is also near a hill, Mt. Tikbalang.
Facilities
The station has basic laboratory and field facilities. These include SCUBA diving gear, tanks, and compressors as well as snorkels and masks; A small outrigger boat, a dry laboratory, reference collections of common marine organisms, computers and various communications and video equipment. Basic housing facilities for faculty and students are also available including two 10-bed dormitory rooms, and a small kitchen. Freshwater supply is provided from a deep well and a generator is available for emergency power.
Faculty and students
A resident scientist (a faculty member of the Biology Department of the university) may be available to supervise and assist in the day-to-day activities of the station. Common users over the past year are faculty and students of the Departments of Biology and Chemistry, as well as natural science students from De La Salle University-Dasmariñas, University of Santo Tomas, University of the Philippines, and the Ateneo de Manila University.
Research and outreach
Recent research and outreach activities conducted by the MBS include: a marine resource assessment of Cauayan, Negros Occidental, evaluation of coral reef conservation at Maricaban Strait, and various undergraduate and graduate th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where do lancelets live?
A. on land
B. deep sea caves
C. shallow ocean water
D. riverbeds
Answer:
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ai2_arc-557
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multiple_choice
|
Which of these is true when a piece of wood is completely burned in a fire?
|
[
"The change in the wood is reversible.",
"The energy in the wood is destroyed.",
"The change in the wood is physical.",
"The energy in the wood is transformed."
] |
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:::
Wood science, commonly referred to as wood sciences, is a scientific discipline that predominantly investigates elements associated with the formation, composition and macro- and microstructure of wood. It additionally delves into the biological, chemical, physical, and mechanical properties and characteristics of wood, as a natural lignocellulosic material.
A deep understanding of wood plays a pivotal role in various endeavors, such as the processing of wood, the production of wood-based materials like particleboard, fiberboard, OSB, plywood and other materials, as well as the utilization of wood and wood-based materials in construction and a wide array of products, including pulpwood, furniture, engineered wood products such as glued laminated timber, CLT, LVL, PSL, as well as pellets, briquettes, and numerous other products.
History
Initial comprehensive investigations in the field of wood science emerged at the start of the 20th century. The advent of contemporary wood research commenced in 1910, when the Forest Products Laboratory (FPL) was established in Madison, Wisconsin, USA. The Forest Products Laboratory played a fundamental role in wood science providing scientific research on wood and wood products in partnership with academia, industry, local and other institutions in North and South America and worldwide.
In the following years, many wood research institutes came into existence across almost all industrialized nations. A general overview of these institutes and laboratories is shown below:
1913: Institute of Wood and Pulp Chemistry Eberswalde (today's Eberswalde University for Sustainable Development), Germany
1913: Forest Products Laboratory Montreal, Canada
1918: Forest Products Laboratory Vancouver, Canada
1919: Forest Products Laboratory Melbourne, Australia
1923: Forest Products Research Laboratory, Princes Risborough, Great Britain
1929: Institute for Wood Science and Technology, Leningrant, St. Petersburg, USSR
1933: Centre Technique
Document 2:::
A controlled or prescribed (Rx) burn, which can include hazard reduction burning, backfire, swailing or a burn-off, is a fire set intentionally for purposes of forest management, fire suppression, farming, prairie restoration or greenhouse gas abatement. A controlled burn may also refer to the intentional burning of slash and fuels through burn piles. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters.
Hazard reduction or controlled burning is conducted during the cooler months to reduce fuel buildup and decrease the likelihood of serious hotter fires. Controlled burning stimulates the germination of some desirable forest trees, and reveals soil mineral layers which increases seedling vitality, thus renewing the forest. Some cones, such as those of lodgepole pine, sequoia and many chaparral shrubs are pyriscent, meaning heat from fire opens cones to disperse seeds.
In industrialized countries, controlled burning is usually overseen by fire control authorities for regulations and permits.
History
There are two basic causes of wildfires. One is natural, mainly through lightning, and the other is human activity. Controlled burns have a long history in wildland management. Pre-agricultural societies used fire to regulate both plant and animal life. Fire history studies have documented periodic wildland fires ignited by indigenous peoples in North America and Australia. Native Americans frequently used fire to manage natural environments in a way that benefited humans and wildlife, starting low-intensity fires that released nutrients for plants, reduced competition, and consumed excess flammable material that otherwise would eventually fuel high-intensity, catastrophic fires.
Fires, both naturally caused and prescribed, were once part of natural landscapes in many areas. In the US, these practices ended in the early 20th century, when federal fire policies were enacted with the goal of suppressing all fires. S
Document 3:::
Fossil wood, also known as fossilized tree, is wood that is preserved in the fossil record. Over time the wood will usually be the part of a plant that is best preserved (and most easily found). Fossil wood may or may not be petrified, in which case it is known as petrified wood or petrified tree. The study of fossil wood is sometimes called palaeoxylology, with a "palaeoxylologist" somebody who studies fossil wood.
The fossil wood may be the only part of the plant that has been preserved, with the rest of the plant completely unknown: therefore such wood may get a special kind of botanical name. This will usually include "xylon" and a term indicating its presumed (not necessarily certain) affinity, such as Araucarioxylon (wood similar to that of extant Araucaria or some related genus like Agathis or Wollemia), Palmoxylon (wood similar to that of modern Arecaeae), or Castanoxylon (wood similar to that of modern chinkapin or chestnut tree).
Types
Petrified wood
Petrified wood are fossils of wood that have turned to stone through the process of permineralization. All organic materials are replaced with minerals while maintaining the original structure of the wood.
The most notable example is the petrified forest in Arizona.
Mummified wood
Mummified wood are fossils of wood that have not permineralized. They are formed when trees are buried rapidly in dry cold or hot environments. They are valued in paleobotany because they retain original cells and tissues capable of being examined with the same techniques used with extant plants in dendrology.
Notable examples include the mummified forests in Ellesmere Island and Axel Heiberg Island.
Submerged forests
Submerged forests are remains of trees submerged by marine transgression. They are important in determining sea level rise since the last glacial period.
See also
Amber
Dendrochronology
Paleobotany
Xyloid lignite
Document 4:::
Energy flow is the flow of energy through living things within an ecosystem. All living organisms can be organized into producers and consumers, and those producers and consumers can further be organized into a food chain. Each of the levels within the food chain is a trophic level. In order to more efficiently show the quantity of organisms at each trophic level, these food chains are then organized into trophic pyramids. The arrows in the food chain show that the energy flow is unidirectional, with the head of an arrow indicating the direction of energy flow; energy is lost as heat at each step along the way.
The unidirectional flow of energy and the successive loss of energy as it travels up the food web are patterns in energy flow that are governed by thermodynamics, which is the theory of energy exchange between systems. Trophic dynamics relates to thermodynamics because it deals with the transfer and transformation of energy (originating externally from the sun via solar radiation) to and among organisms.
Energetics and the carbon cycle
The first step in energetics is photosynthesis, wherein water and carbon dioxide from the air are taken in with energy from the sun, and are converted into oxygen and glucose. Cellular respiration is the reverse reaction, wherein oxygen and sugar are taken in and release energy as they are converted back into carbon dioxide and water. The carbon dioxide and water produced by respiration can be recycled back into plants.
Energy loss can be measured either by efficiency (how much energy makes it to the next level), or by biomass (how much living material exists at those levels at one point in time, measured by standing crop). Of all the net primary productivity at the producer trophic level, in general only 10% goes to the next level, the primary consumers, then only 10% of that 10% goes on to the next trophic level, and so on up the food pyramid. Ecological efficiency may be anywhere from 5% to 20% depending on how efficient
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which of these is true when a piece of wood is completely burned in a fire?
A. The change in the wood is reversible.
B. The energy in the wood is destroyed.
C. The change in the wood is physical.
D. The energy in the wood is transformed.
Answer:
|
|
sciq-8380
|
multiple_choice
|
What does the male reproductive system consist of?
|
[
"structures that produce ova",
"organs that produce estrogen",
"structures that produce sperm and secrete testosterone",
"structures that collect urine"
] |
C
|
Relavent Documents:
Document 0:::
Reproductive biology includes both sexual and asexual reproduction.
Reproductive biology includes a wide number of fields:
Reproductive systems
Endocrinology
Sexual development (Puberty)
Sexual maturity
Reproduction
Fertility
Human reproductive biology
Endocrinology
Human reproductive biology is primarily controlled through hormones, which send signals to the human reproductive structures to influence growth and maturation. These hormones are secreted by endocrine glands, and spread to different tissues in the human body. In humans, the pituitary gland synthesizes hormones used to control the activity of endocrine glands.
Reproductive systems
Internal and external organs are included in the reproductive system. There are two reproductive systems including the male and female, which contain different organs from one another. These systems work together in order to produce offspring.
Female reproductive system
The female reproductive system includes the structures involved in ovulation, fertilization, development of an embryo, and birth.
These structures include:
Ovaries
Oviducts
Uterus
Vagina
Mammary Glands
Estrogen is one of the sexual reproductive hormones that aid in the sexual reproductive system of the female.
Male reproductive system
The male reproductive system includes testes, rete testis, efferent ductules, epididymis, sex accessory glands, sex accessory ducts and external genitalia.
Testosterone, an androgen, although present in both males and females, is relatively more abundant in males. Testosterone serves as one of the major sexual reproductive hormones in the male reproductive system However, the enzyme aromatase is present in testes and capable of synthesizing estrogens from androgens. Estrogens are present in high concentrations in luminal fluids of the male reproductive tract. Androgen and estrogen receptors are abundant in epithelial cells of the male reproductive tract.
Animal Reproductive Biology
Animal reproduction oc
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The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.
Animals
In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable sexually transmitted diseases.
Most other vertebrates have similar reproductive systems consisting of gonads, ducts, and openings. However, there is a great diversity of physical adaptations as well as reproductive strategies in every group of vertebrates.
Vertebrates
Vertebrates share key elements of their reproductive systems. They all have gamete-producing organs known as gonads. In females, these gonads are then connected by oviducts to an opening to the outside of the body, typically the cloaca, but sometimes to a unique pore such as a vagina or intromittent organ.
Humans
The human reproductive system usually involves internal fertilization by sexual intercourse. During this process, the male inserts their erect penis into the female's vagina and ejaculates semen, which contains sperm. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum. Upon successful fertilization and implantation, gestation of the fetus then occurs within the female's uterus for approximately nine months, this process is known as pregnancy in humans. Gestati
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Fish reproductive organs include testes and ovaries. In most species, gonads are paired organs of similar size, which can be partially or totally fused. There may also be a range of secondary organs that increase reproductive fitness. The genital papilla is a small, fleshy tube behind the anus in some fishes, from which the sperm or eggs are released; the sex of a fish can often be determined by the shape of its papilla.
Anatomy
Testes
Most male fish have two testes of similar size. In the case of sharks, the testes on the right side is usually larger. The primitive jawless fish have only a single testis, located in the midline of the body, although even this forms from the fusion of paired structures in the embryo.
Under a tough membranous shell, the tunica albuginea, the testis of some teleost fish, contains very fine coiled tubes called seminiferous tubules. The tubules are lined with a layer of cells (germ cells) that from puberty into old age, develop into sperm cells (also known as spermatozoa or male gametes). The developing sperm travel through the seminiferous tubules to the rete testis located in the mediastinum testis, to the efferent ducts, and then to the epididymis where newly created sperm cells mature (see spermatogenesis). The sperm move into the vas deferens, and are eventually expelled through the urethra and out of the urethral orifice through muscular contractions.
However, most fish do not possess seminiferous tubules. Instead, the sperm are produced in spherical structures called sperm ampullae. These are seasonal structures, releasing their contents during the breeding season, and then being reabsorbed by the body. Before the next breeding season, new sperm ampullae begin to form and ripen. The ampullae are otherwise essentially identical to the seminiferous tubules in higher vertebrates, including the same range of cell types.
In terms of spermatogonia distribution, the structure of teleosts testes has two types: in the most common, spe
Document 3:::
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:::
This list of related male and female reproductive organs shows how the male and female reproductive organs and the development of the reproductive system are related, sharing a common developmental path. This makes them biological homologues. These organs differentiate into the respective sex organs in males and females.
List
Internal organs
External organs
The external genitalia of both males and females have similar origins. They arise from the genital tubercle that forms anterior to the cloacal folds (proliferating mesenchymal cells around the cloacal membrane). The caudal aspect of the cloacal folds further subdivides into the posterior anal folds and the anterior urethral folds. Bilateral to the urethral fold, genital swellings (tubercles) become prominent. These structures are the future scrotum and labia majora in males and females, respectively.
The genital tubercles of an eight-week-old embryo of either sex are identical. They both have a glans area, which will go on to form the glans clitoridis (females) or glans penis (males), a urogenital fold and groove, and an anal tubercle. At around ten weeks, the external genitalia are still similar. At the base of the glans, there is a groove known as the coronal sulcus or corona glandis. It is the site of attachment of the future prepuce. Just anterior to the anal tubercle, the caudal end of the left and right urethral folds fuse to form the urethral raphe. The lateral part of the genital tubercle (called the lateral tubercle) grows longitudinally and is about the same length in either sex.
Human physiology
The male external genitalia include the penis and the scrotum. The female external genitalia include the clitoris, the labia, and the vaginal opening, which are collectively called the vulva. External genitalia vary widely in external appearance among different people.
One difference between the glans penis and the glans clitoridis is that the glans clitoridis packs nerve endings into a volume only about
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does the male reproductive system consist of?
A. structures that produce ova
B. organs that produce estrogen
C. structures that produce sperm and secrete testosterone
D. structures that collect urine
Answer:
|
|
sciq-8735
|
multiple_choice
|
Which type of joints do not allow any movement of the bones?
|
[
"attached",
"linked",
"fixed",
"fitted"
] |
C
|
Relavent Documents:
Document 0:::
The American Society of Biomechanics (ASB) is a scholarly society that focuses on biomechanics across a variety of academic fields. It was founded in 1977 by a group of scientists and clinicians. The ASB holds an annual conference as an arena to disseminate and learn about the most recent progress in the field, to distribute awards to recognize excellent work, and to engage in public outreach to expand the impact of its members.
Conferences
The society hosts an annual conference that takes place in North America (usually USA). These conferences are periodically joint conferences held in conjunction with the International Society of Biomechanics (ISB), the North American Congress on Biomechanics (NACOB), and the World Congress of Biomechanics (WCB). The annual conference, when not partnered with another conference, receives around 700 to 800 abstract submissions per year, with attendees in approximately the same numbers. The first conference was held in 1977.
Often, work presented at these conferences achieves media attention due to the ‘public interest’ nature of the findings or that new devices are introduced there. Examples include:
the effect of tablet reading on cervical spine posture;
the squeak of the basketball shoe;
‘underwear’ to address back-pain;
recovery after exercise;
exoskeleton boots for joint pain during exercise;
how flamingos stand on one leg.
National Biomechanics Day
The ASB is instrumental in promoting National Biomechanics Day (NBD), which has received international recognition.
In New Zealand, Massey University attracted NZ$48,000 of national funding
through the Unlocking Curious Minds programme to promote National Biomechanics Day, with the aim to engage 1,100 students from lower-decile schools in an experiential learning day focused on the science of biomechanics.
It was first held in 2016 on April 7, and consisted of ‘open house’ visits from middle and high school students to biomechanics research and teaching laboratories a
Document 1:::
The list below describes such skeletal movements as normally are possible in particular joints of the human body. Other animals have different degrees of movement at their respective joints; this is because of differences in positions of muscles and because structures peculiar to the bodies of humans and other species block motions unsuited to their anatomies.
Arm and shoulder
Shoulder
elbow
The major muscles involved in retraction include the rhomboid major muscle, rhomboid minor muscle and trapezius muscle, whereas the major muscles involved in protraction include the serratus anterior and pectoralis minor muscles.
Sternoclavicular and acromioclavicular joints
Elbow
Wrist and fingers
Movements of the fingers
Movements of the thumb
Neck
Spine
Lower limb
Knees
Feet
The muscles tibialis anterior and tibialis posterior invert the foot. Some sources also state that the triceps surae and extensor hallucis longus invert. Inversion occurs at the subtalar joint and transverse tarsal joint.
Eversion of the foot occurs at the subtalar joint. The muscles involved in this include Fibularis longus and fibularis brevis, which are innervated by the superficial fibular nerve. Some sources also state that the fibularis tertius everts.
Dorsiflexion of the foot: The muscles involved include those of the Anterior compartment of leg, specifically tibialis anterior muscle, extensor hallucis longus muscle, extensor digitorum longus muscle, and peroneus tertius. The range of motion for dorsiflexion indicated in the literature varies from 12.2 to 18 degrees. Foot drop is a condition, that occurs when dorsiflexion is difficult for an individual who is walking.
Plantarflexion of the foot: Primary muscles for plantar flexion are situated in the Posterior compartment of leg, namely the superficial Gastrocnemius, Soleus and Plantaris (only weak participation), and the deep muscles Flexor hallucis longus, Flexor digitorum longus and Tibialis posterior. Muscles in the Lateral co
Document 2:::
In animal anatomy, a pivot joint (trochoid joint, rotary joint or lateral ginglymus) is a type of synovial joint whose movement axis is parallel to the long axis of the proximal bone, which typically has a convex articular surface.
According to one classification system, a pivot joint like the other synovial joint —the hinge joint has one degree of freedom. Note that the degrees of freedom of a joint is not the same as the same as joint's range of motion.
Movements
Pivot joints allow for rotation, which can be external (for example when rotating an arm outward), or internal (as in rotating an arm inward). When rotating the forearm, these movements are typically called pronation and supination. In the standard anatomical position, the forearms are supinated, which means that the palms are facing forward, and the thumbs are pointing away from the body. In contrast, a forearm in pronation would have the palm facing backward and the thumb would be closer to the body, pointing medially.
Examples
Examples of a pivot joint include:
Proximal radioulnar joint
Distal radioulnar joint
Median atlanto-axial joint
In contrast, spherical joints (or ball and socket joints) such as the hip joint permit rotation and all other directional movement, while pivot joints only permit rotation.
Document 3:::
In mechanical engineering, a kinematic chain is an assembly of rigid bodies connected by joints to provide constrained motion that is the mathematical model for a mechanical system. As the word chain suggests, the rigid bodies, or links, are constrained by their connections to other links. An example is the simple open chain formed by links connected in series, like the usual chain, which is the kinematic model for a typical robot manipulator.
Mathematical models of the connections, or joints, between two links are termed kinematic pairs. Kinematic pairs model the hinged and sliding joints fundamental to robotics, often called lower pairs and the surface contact joints critical to cams and gearing, called higher pairs. These joints are generally modeled as holonomic constraints. A kinematic diagram is a schematic of the mechanical system that shows the kinematic chain.
The modern use of kinematic chains includes compliance that arises from flexure joints in precision mechanisms, link compliance in compliant mechanisms and micro-electro-mechanical systems, and cable compliance in cable robotic and tensegrity systems.
Mobility formula
The degrees of freedom, or mobility, of a kinematic chain is the number of parameters that define the configuration of the chain.
A system of rigid bodies moving in space has degrees of freedom measured relative to a fixed frame. This frame is included in the count of bodies, so that mobility does not depend on link that forms the fixed frame. This means the degree-of-freedom of this system is , where is the number of moving bodies plus the fixed body.
Joints that connect bodies impose constraints. Specifically, hinges and sliders each impose five constraints and therefore remove five degrees of freedom. It is convenient to define the number of constraints that a joint imposes in terms of the joint's freedom , where . In the case of a hinge or slider, which are one-degree-of-freedom joints, have and therefore .
The
Document 4:::
In anatomy, a biaxial joint is a freely mobile joint that allows movement in two anatomical planes. An example of a biaxial joint is a metacarpophalangeal joint of the hand. The joint allows for movement along one axis to produce bending or straightening of the finger, and movement along a second axis, which allows for spreading of the fingers away from each other and bringing them together.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which type of joints do not allow any movement of the bones?
A. attached
B. linked
C. fixed
D. fitted
Answer:
|
|
sciq-5800
|
multiple_choice
|
Insects are arthropods in which class?
|
[
"lexapoda",
"hexapoda",
"trichina",
"xerophyte"
] |
B
|
Relavent Documents:
Document 0:::
Entomology, the scientific study of insects and closely related terrestrial arthropods, has been impelled by the necessity of societies to protect themselves from insect-borne diseases, crop losses to pest insects, and insect-related discomfort, as well as by people's natural curiosity. This timeline article traces the history of entomology.
Timelines of entomology
Timeline of entomology – prior to 1800
Timeline of entomology – 1800–1850
Timeline of entomology – 1850–1900
Timeline of entomology – post 1900
History of classification
Many different classifications were proposed by early entomologists. It is important to realise that whilst many early names survive, they may be at different levels in the phylogenetic hierarchy. For instance, many families were first published as genera, as for example the genus Mymar, proposed by Alexander Henry Haliday in 1829, is now represented by the family Mymaridae.
History of forensic entomology
See also
European and American voyages of scientific exploration
List of natural history dealers
Document 1:::
This glossary of entomology describes terms used in the formal study of insect species by entomologists.
A–C
A synthetic chlorinated hydrocarbon insecticide, toxic to vertebrates. Though its phytotoxicity is low, solvents in some formulations may damage certain crops. cf. the related Dieldrin, Endrin, Isodrin
D–F
A synthetic chlorinated hydrocarbon insecticide, toxic to vertebrates. cf. the related Aldrin, Endrin, Isodrin
A synthetic chlorinated hydrocarbon insecticide, toxic to vertebrates. Though its phytotoxicity is low, solvents in some formulations may damage certain crops. cf. the related Dieldrin, Aldrin, Isodrin
G–L
A synthetic chlorinated hydrocarbon insecticide, toxic to vertebrates. Though its phytotoxicity is low, solvents in some formulations may damage certain crops. cf. the related Dieldrin, Aldrin, Endrin
M–O
P–R
S–Z
Figures
See also
Anatomical terms of location
Butterfly
Caterpillar
Comstock–Needham system
External morphology of Lepidoptera
Glossary of ant terms
Glossary of spider terms
Glossary of scientific names
Insect wing
Pupa
Document 2:::
Hybrid Insect Micro-Electro-Mechanical Systems (HI-MEMS) is a project of DARPA, a unit of the United States Department of Defense. Created in 2006, the unit's goal is the creation of tightly coupled machine-insect interfaces by placing micro-mechanical systems inside the insects during the early stages of metamorphosis. After implantation, the "insect cyborgs" could be controlled by sending electrical impulses to their muscles. The primary application is surveillance. The project was created with the ultimate goal of delivering an insect within 5 meters of a target located 100 meters away from its starting point. In 2008, a team from the University of Michigan demonstrated a cyborg unicorn beetle at an academic conference in Tucson, Arizona. The beetle was able to take off and land, turn left or right, and demonstrate other flight behaviors. Researchers at Cornell University demonstrated the successful implantation of electronic probes into tobacco hornworms in the pupal stage.
Document 3:::
Insect biodiversity accounts for a large proportion of all biodiversity on the planet—over half of the estimated 1.5 million organism species described are classified as insects.
Species diversity
Estimates of the total number of insect species or those within specific orders are often highly variable. Globally, averages of these predictions estimate there are around 1.5 million beetle species and 5.5 million insect species with around 1 million insect species currently found and described.
Between 950,000–1,000,000 of all described species are insects, so over 50% of all described eukaryotes (1.8 million) are insects (see illustration). With only 950,000 known non-insects, if the actual number of insects is 5.5 million, they may represent over 80% of the total, and with only about 20,000 new species of all organisms being described each year, most insect species likely will remain undescribed, unless species descriptions greatly increase in rate. Of the 24 orders of insects, four dominate in terms of numbers of described species, with at least 670,000 species included in Coleoptera, Diptera, Hymenoptera and Lepidoptera.
The fossil record concerning insects stretches back for hundreds of millions of years. It suggests there are ongoing background levels of both new species appearing and extinctions. Very occasionally, the record also appears to show mass extinctions of insects. The Permian–Triassic extinction event saw the greatest level of insect extinction, with the Cretaceous–Paleogene being the second highest. Insect diversity has recovered after past mass extinctions, due to periods where new species originate with increased frequency, though the recovery can take millions of years.
In the Holocene
Several studies seemed to indicate that some insect populations are in decline in the late 20th and early 21st centuries, and has also been popularized as the windshield phenomenon. For many studies, factors such as abundance, biomass, and species richness are o
Document 4:::
The Phasmid Study Group is a group for professional and amateur entomologists who are interested in the order Phasmatodea, i.e. stick and leaf insects, known as "phasmids", as well as other interested persons. Over 40 species of Phasmid have been named after members of the group. The group includes world experts in the study of phasmids worldwide.
The group was formed in 1980 and has since developed a worldwide membership. It has meetings twice a year at The Natural History Museum, London. It also distributes phasmids, free of charge, to its members.
The group has two publications. Phasmid Studies is issued occasionally and contains scientific papers and longer articles. The Phasmid Study Group's Newsletter is posted to each member twice a year, it contains shorter articles and announcements, and is printed in full colour with many photographs and much information on phasmids.
External links
Phasmid Study Group Website
Phasmatodea
Entomological organizations
Scientific organizations established in 1980
1980 establishments in the United Kingdom
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Insects are arthropods in which class?
A. lexapoda
B. hexapoda
C. trichina
D. xerophyte
Answer:
|
|
scienceQA-2018
|
multiple_choice
|
What do these two changes have in common?
an old sandwich rotting in a trashcan
a piece of apple turning brown
|
[
"Both are only physical changes.",
"Both are caused by heating.",
"Both are caused by cooling.",
"Both are chemical changes."
] |
D
|
Step 1: Think about each change.
A sandwich rotting is a chemical change. The matter in the sandwich breaks down and slowly turns into a different type of matter.
A piece of apple turning brown is a chemical change. The apple reacts with oxygen in the air and turns into a different type of matter.
If you scrape off the brown layer of the apple, the inside is still white. The inside hasn't touched the air. So the chemical change didn't happen to that part of the apple.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Neither change is caused by heating.
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:::
Rancidification is the process of complete or incomplete autoxidation or hydrolysis of fats and oils when exposed to air, light, moisture, or bacterial action, producing short-chain aldehydes, ketones and free fatty acids.
When these processes occur in food, undesirable odors and flavors can result. In processed meats, these flavors are collectively known as warmed-over flavor. In certain cases, however, the flavors can be desirable (as in aged cheeses).
Rancidification can also detract from the nutritional value of food, as some vitamins are sensitive to oxidation. Similar to rancidification, oxidative degradation also occurs in other hydrocarbons, such as lubricating oils, fuels, and mechanical cutting fluids.
Pathways
Five pathways for rancidification are recognized:
Hydrolytic
Hydrolytic rancidity refers to the odor that develops when triglycerides are hydrolyzed and free fatty acids are released. This reaction of lipid with water may require a catalyst (such as a lipase, or acidic or alkaline conditions) leading to the formation of free fatty acids and glycerol. In particular, short-chain fatty acids, such as butyric acid, are malodorous. When short-chain fatty acids are produced, they serve as catalysts themselves, further accelerating the reaction, a form of autocatalysis.
Oxidative
Oxidative rancidity is associated with the degradation by oxygen in the air.
Free-radical oxidation
The double bonds of an unsaturated fatty acid can be cleaved by free-radical reactions involving molecular oxygen. This reaction causes the release of malodorous and highly volatile aldehydes and ketones. Because of the nature of free-radical reactions, the reaction is catalyzed by sunlight. Oxidation primarily occurs with unsaturated fats. For example, even though meat is held under refrigeration or in a frozen state, the poly-unsaturated fat will continue to oxidize and slowly become rancid. The fat oxidation process, potentially resulting in rancidity, begins immediately
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:::
In cooking, proofing (also called proving) is a step in the preparation of yeast bread and other baked goods in which the dough is allowed to rest and rise a final time before baking. During this rest period, yeast ferments the dough and produces gases, thereby leavening the dough.
In contrast, proofing or blooming yeast (as opposed to proofing the dough) may refer to the process of first suspending yeast in warm water, a necessary hydration step when baking with active dry yeast. Proofing can also refer to the process of testing the viability of dry yeast by suspending it in warm water with carbohydrates (sugars). If the yeast is still alive, it will feed on the sugar and produce a visible layer of foam on the surface of the water mixture.
Fermentation rest periods are not always explicitly named, and can appear in recipes as "Allow dough to rise." When they are named, terms include "bulk fermentation", "first rise", "second rise", "final proof" and "shaped proof".
Dough processes
The process of making yeast-leavened bread involves a series of alternating work and rest periods. Work periods occur when the dough is manipulated by the baker. Some work periods are called mixing, kneading, and folding, as well as division, shaping, and panning. Work periods are typically followed by rest periods, which occur when dough is allowed to sit undisturbed. Particular rest periods include, but are not limited to, autolyse, bulk fermentation and proofing. Proofing, also sometimes called final fermentation, is the specific term for allowing dough to rise after it has been shaped and before it is baked.
Some breads begin mixing with an autolyse. This refers to a period of rest after the initial mixing of flour and water, a rest period that occurs sequentially before the addition of yeast, salt and other ingredients. This rest period allows for better absorption of water and helps the gluten and starches to align. The autolyse is credited to Raymond Calvel, who recommende
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 old sandwich rotting in a trashcan
a piece of apple turning brown
A. Both are only physical changes.
B. Both are caused by heating.
C. Both are caused by cooling.
D. Both are chemical changes.
Answer:
|
sciq-8551
|
multiple_choice
|
What is the first step towards wound repair?
|
[
"clotting factors",
"blotting factors",
"hormone factors",
"electrolysis factors"
] |
A
|
Relavent Documents:
Document 0:::
Wound healing refers to a living organism's replacement of destroyed or damaged tissue by newly produced tissue.
In undamaged skin, the epidermis (surface, epithelial layer) and dermis (deeper, connective layer) form a protective barrier against the external environment. When the barrier is broken, a regulated sequence of biochemical events is set into motion to repair the damage. This process is divided into predictable phases: blood clotting (hemostasis), inflammation, tissue growth (cell proliferation), and tissue remodeling (maturation and cell differentiation). Blood clotting may be considered to be part of the inflammation stage instead of a separate stage.
The wound-healing process is not only complex but fragile, and it is susceptible to interruption or failure leading to the formation of non-healing chronic wounds. Factors that contribute to non-healing chronic wounds are diabetes, venous or arterial disease, infection, and metabolic deficiencies of old age.
Wound care encourages and speeds wound healing via cleaning and protection from reinjury or infection. Depending on each patient's needs, it can range from the simplest first aid to entire nursing specialties such as wound, ostomy, and continence nursing and burn center care.
Stages
Hemostasis (blood clotting): Within the first few minutes of injury, platelets in the blood begin to stick to the injured site. They change into an amorphous shape, more suitable for clotting, and they release chemical signals to promote clotting. This results in the activation of fibrin, which forms a mesh and acts as "glue" to bind platelets to each other. This makes a clot that serves to plug the break in the blood vessel, slowing/preventing further bleeding.
Inflammation: During this phase, damaged and dead cells are cleared out, along with bacteria and other pathogens or debris. This happens through the process of phagocytosis, where white blood cells engulf debris and destroy it. Platelet-derived growth factors
Document 1:::
Wound assessment is a component of wound management. As far as may be practical, the assessment is to be accomplished before prescribing any treatment plan. The objective is to collect information about the patient and about the wound, that may be relevant to planning and implementing the treatment.
Wound assessment principles
Wound assessment includes observation of the wound, surveying the patient, as well as identifying relevant clinical data from physical examination and patient's health history. Clinical data recorded during an initial assessment serves as a baseline for prescribing the appropriate treatment.
TIME framework and Triangle of Wound Assessment (TWA)
To assist clinicians in standardizing the wound assessment and preparation of wound bed for treatment, the TIME framework has been developed in 2002 by a group of wound care experts.
The TIME acronym stands for Tissue, Infection/Inflammation, Moisture, and Edge – components that, per the TIME recommendation, should be thoroughly assessed to optimize the treatment. Depending on the clinical findings for each component, TIME recommends certain clinical actions aimed at correcting the issues and facilitating the healing.
A recent global anthropological study has prompted clinicians to review the TIME framework and resulted in a 2016 development of a new comprehensive tool for wound assessment – the Triangle of Wound Assessment (TWA). Based on the study's findings, TWA identifies three zones (wound bed, wound edge, and periwound skin) that must be included in wound assessment to arrive at clinical decisions that will help heal the wound in the most efficient way. TIME framework components are integrated into the assessment of each zone.
The introduction of periwound skin as a component of wound assessment identifies a significant departure from traditional methods; it emphasizes the importance of addressing periwound skin during treatment in the same measure as wound bed and wound edge.
Wound assessm
Document 2:::
Postoperative wounds are those wounds acquired during surgical procedures. Postoperative wound healing occurs after surgery and normally follows distinct bodily reactions: the inflammatory response, the proliferation of cells and tissues that initiate healing, and the final remodeling. Postoperative wounds are different from other wounds in that they are anticipated and treatment is usually standardized depending on the type of surgery performed. Since the wounds are 'predicted' actions can be taken beforehand and after surgery that can reduce complications and promote healing.
Healing sequence
The body responds to postoperative wounds in the same manner as it does to tissue damage acquired in other circumstances. The inflammatory response is designed to create homeostasis. This first step is called the inflammatory stage. The next stage and wound healing is the infiltration of leukocytes and release of cytokines into the tissue. The inflammatory response and the infiltration of leukocytes occur simultaneously. The final stage of postoperative wound healing is called remodeling. Remodeling restores the structure of the tissue and that tissues ability to regain its function.
Diagnosis
Surgical wounds can begin to open between three and five days after surgery. The wound usually appears red and can be accompanied by drainage. Clinicians delay re-opening the wound unless it is necessary due to the potential of other complications. If the surgical wound worsens, or if a rupture of the digestive system is suspected the decision may be to investigate the source of the drainage or infection.
Complications
Wound dehiscence
The rates of a surgical wound opening after surgery has remained constant. When a wound opens after surgery, the hospital stay becomes longer and the medical care becomes more intensive if a surgical wound opens after surgery.
Infection
Infection will complicate healing of surgical wounds and is commonly observed. Most infections are present wit
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β-Neoendorphin is an endogenous opioid peptide with a nonapeptide structure and the amino acid sequence Tyr-Gly-Gly-Phe-Leu-Arg-Lys-Tyr-Pro (YGGFLRKYP).
β-Neoendorphins (β-NEP) have the capability to stimulate wound healing by accelerating keratinocyte migration. This is achieved by β-NEP's activation of mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (ERK 1 and ERK 2); along with the upregulation of matrix metalloproteinase 2 and 9 (MMP-2 and MMP-9). Wound healing by β-NEP results in migration without consequences on proliferation in human keratinocytes.
See also
α-Neoendorphin
Document 4:::
Wound licking is an instinctive response in humans and many other animals to cover an injury or second degree burn with saliva. Dogs, cats, small rodents, horses, and primates all lick wounds. Saliva contains tissue factor which promotes the blood clotting mechanism. The enzyme lysozyme is found in many tissues and is known to attack the cell walls of many gram-positive bacteria, aiding in defense against infection. Tears are also beneficial to wounds due to the lysozyme enzyme. However, there are also infection risks due to bacteria in the mouth.
Mechanism
Oral mucosa heals faster than skin, suggesting that saliva may have properties that aid wound healing. Saliva contains cell-derived tissue factor, and many compounds that are antibacterial or promote healing. Salivary tissue factor, associated with microvesicles shed from cells in the mouth, promotes wound healing through the extrinsic blood coagulation cascade. The enzymes lysozyme and peroxidase, defensins, cystatins and an antibody, IgA, are all antibacterial. Thrombospondin and some other components are antiviral. A protease inhibitor, secretory leukocyte protease inhibitor, is present in saliva and is both antibacterial and antiviral, and a promoter of wound healing. Nitrates that are naturally found in saliva break down into nitric oxide on contact with skin, which will inhibit bacterial growth. Saliva contains growth factors such as epidermal growth factor, VEGF, TGF-β1, leptin, IGF-I, lysophosphatidic acid, hyaluronan and NGF, which all promote healing, although levels of EGF and NGF in humans are much lower than those in rats. In humans, histatins may play a larger role. As well as being growth factors, IGF-I and TGF-α induce antimicrobial peptides. Saliva also contains an analgesic, opiorphin. Licking will also tend to debride the wound and remove gross contamination from the affected area.
In a recent study, scientists have confirmed through several experiments that the protein responsible for healin
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the first step towards wound repair?
A. clotting factors
B. blotting factors
C. hormone factors
D. electrolysis factors
Answer:
|
|
sciq-9921
|
multiple_choice
|
What is a carbon-based compound that is found in living things called?
|
[
"organic compound",
"biological compound",
"biochemical compound",
"genetic compound"
] |
C
|
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
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The molecules that an organism uses as its carbon source for generating biomass are referred to as "carbon sources" in biology. It is possible for organic or inorganic sources of carbon. Heterotrophs must use organic molecules as both are a source of carbon and energy, in contrast to autotrophs, which can use inorganic materials as both a source of carbon and an abiotic source of energy, such as, for instance, inorganic chemical energy or light (photoautotrophs) (chemolithotrophs).
The carbon cycle, which begins with a carbon source that is inorganic, such as carbon dioxide and progresses through the carbon fixation process, includes the biological use of carbon as one of its components.[1]
Types of organism by carbon source
Heterotrophs
Autotrophs
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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.
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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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Glycerol dialkyl glycerol tetraether lipids (GDGTs) are a class of membrane lipids synthesized by archaea and some bacteria, making them useful biomarkers for these organisms in the geological record. Their presence, structure, and relative abundances in natural materials can be useful as proxies for temperature, terrestrial organic matter input, and soil pH for past periods in Earth history. Some structural forms of GDGT form the basis for the TEX86 paleothermometer. Isoprenoid GDGTs, now known to be synthesized by many archaeal classes, were first discovered in extremophilic archaea cultures. Branched GDGTs, likely synthesized by acidobacteriota, were first discovered in a natural Dutch peat sample in 2000.
Chemical structure
The two primary structural classes of GDGTs are isoprenoid (isoGDGT) and branched (brGDGT), which refer to differences in the carbon skeleton structures. Isoprenoid compounds are numbered -0 through -8, with the numeral representing the number of cyclopentane rings present within the carbon skeleton structure. The exception is crenarchaeol, a Nitrososphaerota product with one cyclohexane ring moiety in addition to four cyclopentane rings. Branched GDGTs have zero, one, or two cyclopentane moieties and are further classified based the positioning of their branches. They are numbered with roman numerals and letters, with -I indicating structures with four modifications (i.e. either a branch or a cyclopentane moiety), -II indicating structures with five modifications, and -III indicating structures with six modifications. The suffix a after the roman numeral means one of its modifications is a cyclopentane moiety; b means two modifications are cyclopentane moieties. For example, GDGT-IIb is a compound with three branches and two cyclopentane moieties (a total of five modifications). GDGTs form as monolayers and with ether bonds to glycerol, as opposed to as bilayers and with ester bonds as is the case in eukaryotes and most bacteria.
Biologi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a carbon-based compound that is found in living things called?
A. organic compound
B. biological compound
C. biochemical compound
D. genetic compound
Answer:
|
|
sciq-6013
|
multiple_choice
|
What cycle vital to plants includes a process called denitrification?
|
[
"sedimentation cycle",
"nitrogen cycle",
"carbon cycle",
"photosynthesis"
] |
B
|
Relavent Documents:
Document 0:::
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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{{DISPLAYTITLE: C3 carbon fixation}}
carbon fixation is the most common of three metabolic pathways for carbon fixation in photosynthesis, the other two being and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into two molecules of 3-phosphoglycerate through the following reaction:
CO2 + H2O + RuBP → (2) 3-phosphoglycerate
This reaction was first discovered by Melvin Calvin, Andrew Benson and James Bassham in 1950. C3 carbon fixation occurs in all plants as the first step of the Calvin–Benson cycle. (In and CAM plants, carbon dioxide is drawn out of malate and into this reaction rather than directly from the air.)
Plants that survive solely on fixation ( plants) tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, carbon dioxide concentrations are around 200 ppm or higher, and groundwater is plentiful. The plants, originating during Mesozoic and Paleozoic eras, predate the plants and still represent approximately 95% of Earth's plant biomass, including important food crops such as rice, wheat, soybeans and barley.
plants cannot grow in very hot areas at today's atmospheric CO2 level (significantly depleted during hundreds of millions of years from above 5000 ppm) because RuBisCO incorporates more oxygen into RuBP as temperatures increase. This leads to photorespiration (also known as the oxidative photosynthetic carbon cycle, or C2 photosynthesis), which leads to a net loss of carbon and nitrogen from the plant and can therefore limit growth.
plants lose up to 97% of the water taken up through their roots by transpiration. In dry areas, plants shut their stomata to reduce water loss, but this stops from entering the leaves and therefore reduces the concentration of in the leaves. This lowers the :O2 ratio and therefore also increases photorespiration. and CAM plants have adaptations that allow them to survive in hot and dry areas, and they can therefore out-compete
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Some types of lichen are able to fix nitrogen from the atmosphere. This process relies on the presence of cyanobacteria as a partner species within the lichen. The ability to fix nitrogen enables lichen to live in nutrient-poor environments. Lichen can also extract nitrogen from the rocks on which they grow.
Nitrogen fixation, and hence the abundance of lichen and their host plants, may be decreased by application of nitrogen-based agricultural fertilizer and by atmospheric pollution.
The nitrogen cycle
The nitrogen cycle is one of the Earth's biogeochemical cycles. It involves the conversion of nitrogen into different chemical forms. The main processes of the nitrogen cycle are the fixation, ammonification, nitrification, and denitrification. As one of the macronutrients, nitrogen plays an important role in plant growth. The nitrogen cycle is affected by environmental factors. For example, in the subarctic heath, increase in temperature can cause nitrogen fixation to increase or decrease based on season, while overall climate warming indirectly caused the vegetation change which in turn affected the nitrogen fixation process.
Lichens
Lichens are symbiotic organisms that play an important role in the biogeochemical cycle on Earth. The characteristics of lichens, such as strong resistance to factors such as desiccation, ability to grow and break down rocks allow lichen to grow in different types of environment including highly nitrogen limited area such as subarctic heath. While it does not occur often, formation of akinetes (type of cell formed by cyanobacteria which are resistant to cold and desiccation) was observed in nitrogen fixing lichen. Depending on its partner, lichens derive the carbon and nitrogen from algal and cyanobacteria photobionts (which fixes nitrogen from the air). Lichen fungi can fix nitrogen during the day and night, as long the dark period is not too long.
Nitrogen-fixing and non-nitrogen-fixing lichens
Both nitrogen-fixing lichens and
Document 3:::
A biogeochemical cycle, or more generally a cycle of matter, is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is transformed and cycled by living organisms and through various geological forms and reservoirs, including the atmosphere, the soil and the oceans. It can be thought of as the pathway by which a chemical substance cycles (is turned over or moves through) the biotic compartment and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, lithosphere and hydrosphere.
For example, in the carbon cycle, atmospheric carbon dioxide is absorbed by plants through photosynthesis, which converts it into organic compounds that are used by organisms for energy and growth. Carbon is then released back into the atmosphere through respiration and decomposition. Additionally, carbon is stored in fossil fuels and is released into the atmosphere through human activities such as burning fossil fuels. In the nitrogen cycle, atmospheric nitrogen gas is converted by plants into usable forms such as ammonia and nitrates through the process of nitrogen fixation. These compounds can be used by other organisms, and nitrogen is returned to the atmosphere through denitrification and other processes. In the water cycle, the universal solvent water evaporates from land and oceans to form clouds in the atmosphere, and then precipitates back to different parts of the planet. Precipitation can seep into the ground and become part of groundwater systems used by plants and other organisms, or can runoff the surface to form lakes and rivers. Subterranean water can then seep into the ocean along with river discharges, rich with dissolved and particulate organic matter and other nutrients.
There are bio
Document 4:::
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems.
The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle. Human modification of the global nitrogen cycle can negatively affect the natural environment system and also human health.
Processes
Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, ammonium (), nitrite (), nitrate (), nitrous oxide (), nitric oxide (NO) or inorganic nitrogen gas (). Organic nitrogen may be in the form of a living organism, humus or in the intermediate products of organic matter decomposition. The processes in the nitrogen cycle is to transform nitrogen from one form to another. Many of those processes are carried out by microbes, either in their effort to harvest energy or to accumulate nitrogen in a form needed for their growth. For example, the nitrogenous wastes in animal urine are broken down by nitrifying bacteria in the soil to be used by plants. The diagram alongside shows how these processes fit together to form the nitrogen cycle.
Nitrogen fixation
The conversion of nitrogen gas () into nitrates
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What cycle vital to plants includes a process called denitrification?
A. sedimentation cycle
B. nitrogen cycle
C. carbon cycle
D. photosynthesis
Answer:
|
|
scienceQA-9054
|
multiple_choice
|
Select the liquid.
|
[
"thread",
"milk",
"air inside a tire",
"tortoise shell"
] |
B
|
The air inside a tire is a gas. A gas expands to fill a space. The air in a tire expands to fill all the space inside the tire. If air leaks out, it will expand into the space around the tire.
Thread is a solid that can be bent or tangled. But it still has a size and shape of its own.
A tortoise shell is a solid. A solid has a size and shape of its own. A tortoise shell is made of a solid called keratin, just like your fingernails!
Milk is a liquid. A liquid takes the shape of any container it is in. If you pour milk into a different container, the milk will take the shape of that container. But the milk will still take up the same amount of space.
|
Relavent Documents:
Document 0:::
The Z-tube is an experimental apparatus for measuring the tensile strength of a liquid.
It consists of a Z-shaped tube with open ends, filled with a liquid, and set on top of a spinning table. If the tube were straight, the liquid would immediately fly out one end or the other of the tube as it began to spin. By bending the ends of the tube back towards the center of rotation, a shift of the liquid away from center will result in the water level in one end of the tube rising and thus increasing the pressure in that end of the tube, and consequently returning the liquid to the center of the tube. By measuring the rotational speed and the distance from the center of rotation to the liquid level in the bent ends of the tube, the pressure reduction inside the tube can be calculated.
Negative pressures, (i.e. less than zero absolute pressure, or in other words, tension) have been reported using water processed to remove dissolved gases. Tensile strengths up to 280 atmospheres have been reported for water in glass.
Document 1:::
The water thread experiment is a phenomenon that occurs when two containers of deionized water, placed on an insulator, are connected by a thread, then a high-voltage positive electric charge is applied to one container, and a negative charge to the other. At a critical voltage, an unsupported water liquid bridge is formed between the containers, which will remain even when they are separated. The phenomenon was first reported in 1893 in a public lecture by the British engineer William Armstrong.
The bridge as observed in a typical configuration has a diameter of 1–3 mm so the bridge remains intact when pulled as far as , and remains stable up to 45 minutes. The surface temperature also rises from an initial surface temperature of up to before breakdown.
Experiment
In a typical experiment, two 100 mL beakers are filled with deionized water to roughly 3 mm below the edge of the beaker, and the water exposed to 15 kV direct current, with one beaker turning negative, and the other positive. After building up electric charge, the water then spontaneously rises along the thread over the glass walls and forms a "water bridge" between them. When one beaker is slowly pushed away from the other, the structure remains. When the voltage rises to 25 kV, the structure can be pulled apart as far as . If the thread is very short, then the force of the water may be strong enough to push the thread from the positive glass into the negative glass.
The water generally travels from anode to cathode, but the direction may vary due to the different surface charge that builds up at the water bridge surface, which will generate electrical shear stresses of different signs. The bridge breaks into droplets due to capillary action when the beakers are pulled apart at a critical distance, or the voltage is reduced to a critical value.
The bridge needs clean, deionized water to be formed, and its stability is dramatically reduced as ions are introduced into the liquid (by either adding sa
Document 2:::
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity.
The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube such as a straw, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell.
It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.
Etymology
Capillary comes from the Latin word capillaris, meaning "of or resembling hair." The meaning stems from the tiny, hairlike diameter of a capillary. While capillary is usually used as a noun, the word also is used as an adjective, as in "capillary action," in which a liquid is moved along — even upward, against gravity — as the liquid is attracted to the internal surface of the capillaries.
History
The first recorded observation of capillary action was by Leonardo da Vinci. A former student of Galileo, Niccolò Aggiunti, was said to have investigated capillary action. In 1660, capillary action was still a novelty to the Irish chemist Robert Boyle, when he reported that "some inquisitive French Men" had observed that when a capillary tube was dipped into water, the water would ascend to "some height in the Pipe". Boyle then reported an experiment in which he dipped a capillary tube into red wine and then subjected the tube to a partial vacuum. He found that the vacuum had no observable influence on the height of the liquid in the capillary, so the behavior of liquids in capillary tubes was due to some phenomenon different from that
Document 3:::
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a nearly constant volume independent of pressure. It is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape.
The density of a liquid is usually close to that of a solid, and much higher than that of a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids.
A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Unlike a gas, a liquid maintains a fairly constant density and does not disperse to fill every space of a container.
Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is either gas (as interstellar clouds) or plasma (as stars).
Introduction
Liquid is one of the four primary states of matter, with the others being solid, gas and plasma. A liquid is a fluid. Unlike a solid, the molecules in a liquid have a much greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, allowing a liquid to flow while a solid remains rigid.
A liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, and, if placed in a sealed container, will distribute applied pressure evenly to every surface in the container. If liquid is placed in a bag, it can be squeezed into any shape. Unlike a gas, a liquid is nearly incompressible, meaning that it occupies nearly a constant volume over a wide range of pressures; it does not generally expand to fill available space in a containe
Document 4:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the liquid.
A. thread
B. milk
C. air inside a tire
D. tortoise shell
Answer:
|
sciq-4396
|
multiple_choice
|
There are a series of rules for naming branched alkanes (and, ultimately, for all organic compounds). these rules make up the system of nomenclature for naming what?
|
[
"oxygen molecules",
"non-organic molecules",
"organic molecules",
"typical molecules"
] |
C
|
Relavent Documents:
Document 0:::
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry (informally called the Blue Book). Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
To avoid long and tedious names in normal communication, the official IUPAC naming recommendations are not always followed in practice, except when it is necessary to give an unambiguous and absolute definition to a compound. IUPAC names can sometimes be simpler than older names, as with ethanol, instead of ethyl alcohol. For relatively simple molecules they can be more easily understood than non-systematic names, which must be learnt or looked over. However, the common or trivial name is often substantially shorter and clearer, and so preferred. These non-systematic names are often derived from an original source of the compound. Also, very long names may be less clear than structural formulas.
Basic principles
In chemistry, a number of prefixes, suffixes and infixes are used to describe the type and position of the functional groups in the compound.
The steps for naming an organic compound are:
Identification of the parent hydride parent hydrocarbon chain. This chain must obey the following rules, in order of precedence:
It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, unlike halogen substituents. If more than one functional group is present, the one with highest group precedence should be used.
It should have the maximum number of multiple bonds.
It should have the maximum length.
It should have the maximum number of substituents or branches cited as prefixes
It should have the ma
Document 1:::
This is an index of lists of molecules (i.e. by year, number of atoms, etc.). Millions of molecules have existed in the universe since before the formation of Earth. Three of them, carbon dioxide, water and oxygen were necessary for the growth of life. Although humanity had always been surrounded by these substances, it has not always known what they were composed of.
By century
The following is an index of list of molecules organized by time of discovery of their molecular formula or their specific molecule in case of isomers:
List of compounds
By number of carbon atoms in the molecule
List of compounds with carbon number 1
List of compounds with carbon number 2
List of compounds with carbon number 3
List of compounds with carbon number 4
List of compounds with carbon number 5
List of compounds with carbon number 6
List of compounds with carbon number 7
List of compounds with carbon number 8
List of compounds with carbon number 9
List of compounds with carbon number 10
List of compounds with carbon number 11
List of compounds with carbon number 12
List of compounds with carbon number 13
List of compounds with carbon number 14
List of compounds with carbon number 15
List of compounds with carbon number 16
List of compounds with carbon number 17
List of compounds with carbon number 18
List of compounds with carbon number 19
List of compounds with carbon number 20
List of compounds with carbon number 21
List of compounds with carbon number 22
List of compounds with carbon number 23
List of compounds with carbon number 24
List of compounds with carbon numbers 25-29
List of compounds with carbon numbers 30-39
List of compounds with carbon numbers 40-49
List of compounds with carbon numbers 50+
Other lists
List of interstellar and circumstellar molecules
List of gases
List of molecules with unusual names
See also
Molecule
Empirical formula
Chemical formula
Chemical structure
Chemical compound
Chemical bond
Coordination complex
L
Document 2:::
E–Z configuration, or the E–Z convention, is the IUPAC preferred method of describing the absolute stereochemistry of double bonds in organic chemistry. It is an extension of cis–trans isomer notation (which only describes relative stereochemistry) that can be used to describe double bonds having two, three or four substituents.
Following the Cahn–Ingold–Prelog priority rules (CIP rules), each substituent on a double bond is assigned a priority, then positions of the higher of the two substituents on each carbon are compared to each other. If the two groups of higher priority are on opposite sides of the double bond (trans to each other), the bond is assigned the configuration E (from entgegen, , the German word for "opposite"). If the two groups of higher priority are on the same side of the double bond (cis to each other), the bond is assigned the configuration Z (from zusammen, , the German word for "together").
The letters E and Z are conventionally printed in italic type, within parentheses, and separated from the rest of the name with a hyphen. They are always printed as full capitals (not in lowercase or small capitals), but do not constitute the first letter of the name for English capitalization rules (as in the example above).
Another example: The CIP rules assign a higher priority to bromine than to chlorine, and a higher priority to chlorine than to hydrogen, hence the following (possibly counterintuitive) nomenclature.
For organic molecules with multiple double bonds, it is sometimes necessary to indicate the alkene location for each E or Z symbol. For example, the chemical name of alitretinoin is (2E,4E,6Z,8E)-3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexenyl)nona-2,4,6,8-tetraenoic acid, indicating that the alkenes starting at positions 2, 4, and 8 are E while the one starting at position 6 is Z.
See also
Descriptor (chemistry)
Geometric isomerism
Molecular geometry
Document 3:::
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
Document 4:::
A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and is formed between one hybridized orbital from each of the carbon atoms. In ethane, the orbitals are sp3-hybridized orbitals, but single bonds formed between carbon atoms with other hybridizations do occur (e.g. sp2 to sp2). In fact, the carbon atoms in the single bond need not be of the same hybridization. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond.
Chains and branching
Carbon is one of the few elements that can form long chains of its own atoms, a property called catenation. This coupled with the strength of the carbon–carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements of life, so carbon compounds have their own field of study: organic chemistry.
Branching is also common in C−C skeletons. Carbon atoms in a molecule are categorized by the number of carbon neighbors they have:
A primary carbon has one carbon neighbor.
A secondary carbon has two carbon neighbors.
A tertiary carbon has three carbon neighbors.
A quaternary carbon has four carbon neighbors.
In "structurally complex organic molecules", it is the three-dimensional orientation of the carbon–carbon bonds at quaternary loci which dictates the shape of the molecule. Further, quaternary loci are found in many biologically active small molecules, such as cortisone and morphine.
Synthesis
Carbon–carbon bond-forming reactions are organic reactions in which a new carbon–carbon bond is formed. They are important in th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
There are a series of rules for naming branched alkanes (and, ultimately, for all organic compounds). these rules make up the system of nomenclature for naming what?
A. oxygen molecules
B. non-organic molecules
C. organic molecules
D. typical molecules
Answer:
|
|
sciq-4181
|
multiple_choice
|
What causes acid rain?
|
[
"air pollution",
"carbon dioxide",
"heavy pollution",
"chemicals in waterways"
] |
A
|
Relavent Documents:
Document 0:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 1:::
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:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
Cary Institute of Ecosystem Studies (Cary Institute), formerly known as the Institute of Ecosystem Studies, is an independent, not-for-profit environmental research organization dedicated to the scientific study of the world's ecosystems and the natural and human factors that influence them. The organization is headquartered in Millbrook, NY on a research campus. Areas of expertise include disease ecology, urban ecology, freshwater ecology and provisioning, and forest health.
Details
Cary Institute's research is collaborative and multidisciplinary. Its scientists lead two of the National Science Foundation's Long Term Ecological Research Network sites: the Baltimore Ecosystem Study (Baltimore, MD; focus: urban ecology) and the Hubbard Brook Ecosystem Study (Woodstock, NH; focus: forest and freshwater health). They also play a leadership role in the Global Lake Ecological Observatory Network, an international effort that shares and interprets high resolution sensor data to understand, predict, and communicate the role and response of lakes in a changing global environment.
While working at Hubbard Brook Experimental Forest in the 1960s, Cary Institute founder Gene E. Likens co-discovered acid rain in North America. His longterm studies on precipitation and stream water chemistry were instrumental in shaping the 1990 Clean Air Act amendments. Today, Cary Institute continues to steward the longest continuous data set on acid rain and deposition through its direction of the Hubbard Brook Ecosystem Study.
Cary Institute's grounds have been home to long-term studies on the ecology of tick-borne disease for more than 20 years. Findings underpin The Tick Project, a 5-year study testing interventions with the potential to reduce Lyme disease and protect public health. A three-decade research program on the Hudson River informs sustainable shoreline management, and a synthesis of imported forest pests and pathogens is the basis for Tree-SMART Trade, a national policy init
Document 4:::
Nutrient cycling in the Columbia River Basin involves the transport of nutrients through the system, as well as transformations from among dissolved, solid, and gaseous phases, depending on the element. The elements that constitute important nutrient cycles include macronutrients such as nitrogen (as ammonium, nitrite, and nitrate), silicate, phosphorus, and micronutrients, which are found in trace amounts, such as iron. Their cycling within a system is controlled by many biological, chemical, and physical processes.
The Columbia River Basin is the largest freshwater system of the Pacific Northwest, and due to its complexity, size, and modification by humans, nutrient cycling within the system is affected by many different components. Both natural and anthropogenic processes are involved in the cycling of nutrients. Natural processes in the system include estuarine mixing of fresh and ocean waters, and climate variability patterns such as the Pacific Decadal Oscillation and the El Nino Southern Oscillation (both climatic cycles that affect the amount of regional snowpack and river discharge). Natural sources of nutrients in the Columbia River include weathering, leaf litter, salmon carcasses, runoff from its tributaries, and ocean estuary exchange. Major anthropogenic impacts to nutrients in the basin are due to fertilizers from agriculture, sewage systems, logging, and the construction of dams.
Nutrients dynamics vary in the river basin from the headwaters to the main river and dams, to finally reaching the Columbia River estuary and ocean. Upstream in the headwaters, salmon runs are the main source of nutrients. Dams along the river impact nutrient cycling by increasing residence time of nutrients, and reducing the transport of silicate to the estuary, which directly impacts diatoms, a type of phytoplankton. The dams are also a barrier to salmon migration, and can increase the amount of methane locally produced. The Columbia River estuary exports high rates of n
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What causes acid rain?
A. air pollution
B. carbon dioxide
C. heavy pollution
D. chemicals in waterways
Answer:
|
|
sciq-3813
|
multiple_choice
|
What type of rock contains concentrations of valuable minerals?
|
[
"ores",
"igneous",
"metamorphic",
"sedimentary"
] |
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:::
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 2:::
See also
List of minerals
Document 3:::
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
Document 4:::
Molybdenite is a mineral of molybdenum disulfide, MoS2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum atoms sandwiched between sheets of sulfur atoms. The Mo-S bonds are strong, but the interaction between the sulfur atoms at the top and bottom of separate sandwich-like tri-layers is weak, resulting in easy slippage as well as cleavage planes.
Molybdenite crystallizes in the hexagonal crystal system as the common polytype 2H and also in the trigonal system as the 3R polytype.
Description
Occurrence
Molybdenite occurs in high temperature hydrothermal ore deposits.
Its associated minerals include pyrite, chalcopyrite, quartz, anhydrite, fluorite, and scheelite. Important deposits include the disseminated porphyry molybdenum deposits at Questa, New Mexico and the Henderson and Climax mines in Colorado. Molybdenite also occurs in porphyry copper deposits of Arizona, Utah, and Mexico.
The element rhenium is always present in molybdenite as a substitute for molybdenum, usually in the parts per million (ppm ) range, but often up to 1–2%. High rhenium content results in a structural variety detectable by X-ray diffraction techniques. Molybdenite ores are essentially the only source for rhenium. The presence of the radioactive isotope rhenium-187 and its daughter isotope osmium-187 provides a useful geochronologic dating technique.
Features
Molybdenite is extremely soft with a metallic luster, and is superficially almost identical to graphite, to the point where it is not possible to positively distinguish between the two minerals without scientific equipment. It marks paper in much the same way as graphite. Its distinguishing feature from graphite is its higher specific gravity, as well as its tendency to occur in a matrix.
Uses
Molybdenite is an important ore of molybdenum, and is the most common source of the metal. While
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of rock contains concentrations of valuable minerals?
A. ores
B. igneous
C. metamorphic
D. sedimentary
Answer:
|
|
scienceQA-5121
|
multiple_choice
|
Select the solid.
|
[
"water in a glass",
"handsaw",
"air inside a soccer ball",
"air inside a balloon"
] |
B
|
A handsaw is a solid. A solid has a size and shape of its own. The handle of this handsaw is made of wood, and the blade is made of metal. Both wood and metal are solids.
The air inside a soccer ball is a gas. A gas expands to fill a space. The air fills all the space inside the soccer ball. If air leaks out, it will expand into the space around the ball.
The air inside a balloon is a gas. A gas expands to fill a space. The air inside a balloon expands to fill all the space in the balloon. If the balloon pops, the air will expand to fill a much larger space.
The water in a glass is a liquid. A liquid takes the shape of any container it is in. If you pour water from a glass into a different container, the water will take the shape of that container. But the water will still take up the same amount of space.
|
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 Z-tube is an experimental apparatus for measuring the tensile strength of a liquid.
It consists of a Z-shaped tube with open ends, filled with a liquid, and set on top of a spinning table. If the tube were straight, the liquid would immediately fly out one end or the other of the tube as it began to spin. By bending the ends of the tube back towards the center of rotation, a shift of the liquid away from center will result in the water level in one end of the tube rising and thus increasing the pressure in that end of the tube, and consequently returning the liquid to the center of the tube. By measuring the rotational speed and the distance from the center of rotation to the liquid level in the bent ends of the tube, the pressure reduction inside the tube can be calculated.
Negative pressures, (i.e. less than zero absolute pressure, or in other words, tension) have been reported using water processed to remove dissolved gases. Tensile strengths up to 280 atmospheres have been reported for water in glass.
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:::
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a nearly constant volume independent of pressure. It is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape.
The density of a liquid is usually close to that of a solid, and much higher than that of a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids.
A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Unlike a gas, a liquid maintains a fairly constant density and does not disperse to fill every space of a container.
Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is either gas (as interstellar clouds) or plasma (as stars).
Introduction
Liquid is one of the four primary states of matter, with the others being solid, gas and plasma. A liquid is a fluid. Unlike a solid, the molecules in a liquid have a much greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, allowing a liquid to flow while a solid remains rigid.
A liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, and, if placed in a sealed container, will distribute applied pressure evenly to every surface in the container. If liquid is placed in a bag, it can be squeezed into any shape. Unlike a gas, a liquid is nearly incompressible, meaning that it occupies nearly a constant volume over a wide range of pressures; it does not generally expand to fill available space in a containe
Document 4:::
The self-sealing suction cup is a suction cup that exerts a suction force only when it is in physical contact with an object. Unlike most other suction cups, it does not exert any suction force when it is not in contact with an object. Its grasping ability is achieved entirely through passive means without the use of sensors, valves, or actuators.
It was designed so that, when used as part of a suction cup array, the suction cups that don't come in contact with the object remain sealed. By having only the suction cups that are in direct contact of the object to exhibit suction force, the researchers were able to minimize leak points where air could enter and increase the pressure that each active cup receives, maximizing the suction force. As a result, an array of self-sealing suction cups can grasp and pick up a wide range of object sizes and shapes. This comes in contrast to conventional suction cups that are typically designed for one specific object size and geometry. In addition, suction cups of various sizes have been manufactured, ranging from the palm of a hand to the point of a fingertip.
The self-sealing suction cup was first developed in 2010 by a collaboration of researchers from the U.S. Army Research Laboratory (ARL), the Edgewood Chemical Biological Center at Aberdeen Proving Ground, and the University of Maryland.
Design
The design of the self-sealing suction cup was initially inspired by the suckers of the octopus and its ability to pick up different sized items by individually actuating its suction cups based on the item's size and physical features.
The internal geometry of the self-sealing suction cup was designed to the smallest possible size and features a minimum wall thickness of 1.02 mm, a tube diameter of 1.59 mm, and minimum part spacing of 0.13 mm. The suction cup incorporates a mix of rubber and plastic components, where the cup lip, base, tube, springs, and plug are made out of soft rubber while the cup side, collar, hinges, and fl
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the solid.
A. water in a glass
B. handsaw
C. air inside a soccer ball
D. air inside a balloon
Answer:
|
sciq-8331
|
multiple_choice
|
Which disease does the bacteria salmonella cause in humans?
|
[
"water poisioning",
"food poisoning",
"blood poisoning",
"skin poisoning"
] |
B
|
Relavent Documents:
Document 0:::
The 2012 outbreak of Salmonella took place in 15 places worldwide with over 2,300 strains identified.
In general, the United States alone experiences 1 million cases of salmonellosis per year. In Europe, although there are around 100,000 incidents of salmonellosis reported annually, there has been a steady decrease in cases over the past four years. The exact number of those infected is impossible to know as not all cases are reported. Of these reported cases, some can be classified as foodborne disease outbreaks by the Centers for Disease Control and Prevention (CDC) if "two or more people get the same illness from the same contaminated food or drink" or zoonotic outbreaks if "two or more people get the same illness from the same pet or other animal". In 2012, the various strains or serotypes of the Salmonella bacteria, related to the outbreaks in the United States, infected over 1800 people and killed seven. In Europe, the European Centre for Disease Prevention and Control (ECDC) reported 91,034 cases of Salmonella infection with 65,317 cases related to the 2012 outbreaks. Of those 65,317 cases, there were 61 deaths.
Salmonella bacteria can be found in almost any product or animal that has been exposed to fecal matter. These exposures can occur from crops grown from waste-based fertilizers or from food items handled by infected humans. Salmonellosis is an intestinal disease, meaning that the bacteria must be ingested and processed through the intestines in order for infection to occur. Thus, salmonellosis is commonly spread to humans through ingestion of contaminated food items. It can also be spread through contact with reptiles and birds, usually after the person handles the animal or its environment (without hand-washing immediately) and then touches their mouth or food items. Those infected usually develop symptoms anywhere from 12 to 72 hours after first contact with Salmonella bacteria, and most do not require serious medical attention. This salmonellosis
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Salmonella is a genus of rod-shaped (bacillus) gram-negative bacteria of the family Enterobacteriaceae. The two known species of Salmonella are Salmonella enterica and Salmonella bongori. S. enterica is the type species and is further divided into six subspecies that include over 2,600 serotypes. Salmonella was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon.
Salmonella species are non-spore-forming, predominantly motile enterobacteria with cell diameters between about 0.7 and 1.5 μm, lengths from 2 to 5 μm, and peritrichous flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from oxidation and reduction reactions, using organic sources. They are also facultative anaerobes, capable of generating adenosine triphosphate with oxygen ("aerobically") when it is available, or using other electron acceptors or fermentation ("anaerobically") when oxygen is not available.
Salmonella species are intracellular pathogens, of which certain serotypes cause illness. Most infections are due to the ingestion of food contaminated by feces. Typhoidal Salmonella serotypes can only be transferred between humans and can cause foodborne illness as well as typhoid and paratyphoid fever. Typhoid fever is caused by typhoidal Salmonella invading the bloodstream, as well as spreading throughout the body, invading organs, and secreting endotoxins (the septic form). This can lead to life-threatening hypovolemic shock and septic shock, and requires intensive care including antibiotics.
Nontyphoidal Salmonella serotypes are zoonotic and can be transferred from animals and between humans. They usually invade only the gastrointestinal tract and cause salmonellosis, the symptoms of which can be resolved without antibiotics. However, in sub-Saharan Africa, nontyphoidal Salmonella can be invasive and cause paratyphoid fever, which requires immediate antibiotic treatment.
Taxonomy
The genus Salmonella is part of the fa
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Almost 2,000 people, mostly schoolchildren from the Caraga region of the Philippines, experienced food poisoning after consuming durian, mangosteen, and mango flavored candies in 2015. The Food and Drug Administration of the Philippines confirmed that the sweets were contaminated by staphylococcus bacteria, a bacteria commonly found on human skin. The cause was suspected to be accidental bacterial contamination by vendors, who had repackaged the candy.
Victims
Most of the victims of the food poisoning incident were schoolchildren within the Caraga Region. Victims reported of experiencing symptoms such as diarrhea, dizziness, and stomachache. The cases were reported by at least nine health facilities based in Surigao del Sur, Surigao del Norte and Agusan del Sur. At least 10 people were hospitalized.
The first cases were reported in Cagwait, Surigao del Sur in the morning of July 10.
Food poisoning symptoms were reported in the following towns:
Surigao del Sur
Carrascal
Cagwait
Cortes, Surigao del Sur
Lianga
San Agustin
Madrid
Marihatag
Tago
Tandag
Surigao del Norte
Placer
Surigao City
Agusan del Sur
Bayugan
Response
Acting Mayor Paolo Duterte of Davao City ordered an urgent investigation on July 10 regarding the matter to determine the exact cause of the candy contamination incident.
On July 11, 2015, the Department of Health in the Caraga declared a food poisoning outbreak in the region. Hospitals across the Caraga Region were put into white alert in response to the incident.
Investigation
The Food and Drug Administration (FDA) conducted microbiological tests on the samples of the contaminated candies. The FDA had suspected that the candies were contaminated by E. coli, Salmonella or staphylococcus based on the reported symptoms by victims of the food poisoning incident. They announced that the candy samples tested positive for staphylococcus aureus.
The FDA traced the contaminated candies' origin to two manufacturing facilities in Davao City
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Mycoplasma haemomuris, formerly known as Haemobartonella muris and Bartonella muris, is a Gram-negative bacillus. It is known to cause anemia in rats and mice.
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Escherichia coli O157:H7 is a serotype of the bacterial species Escherichia coli and is one of the Shiga-like toxin–producing types of E. coli. It is a cause of disease, typically foodborne illness, through consumption of contaminated and raw food, including raw milk and undercooked ground beef. Infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea, and to kidney failure; these have been reported to cause the deaths of children younger than five years of age, of elderly patients, and of patients whose immune systems are otherwise compromised.
Transmission is via the fecal–oral route, and most illness has been through distribution of contaminated raw leaf green vegetables, undercooked meat and raw milk.
Signs and symptoms
E. coli O157:H7 infection often causes severe, acute hemorrhagic diarrhea (although nonhemorrhagic diarrhea is also possible) and abdominal cramps. Usually little or no fever is present, and the illness resolves in 5 to 10 days. It can also sometimes be asymptomatic.
In some people, particularly children under five years of age, persons whose immunologies are otherwise compromised, and the elderly, the infection can cause hemolytic–uremic syndrome (HUS), in which the red blood cells are destroyed and the kidneys fail. About 2–7% of infections lead to this complication. In the United States, HUS is the principal cause of acute kidney failure in children, and most cases of HUS are caused by E. coli O157:H7.
Bacteriology
Like the other strains of the E. coli, O157:H7 is gram-negative and oxidase-negative. Unlike many other strains, it does not ferment sorbitol, which provides a basis for clinical laboratory differentiation of the strain. Strains of E. coli that express Shiga and Shiga-like toxins gained that ability via infection with a prophage containing the structural gene coding for the toxin, and nonproducing strains may become infected and produce shiga-like toxins after incubation with shiga toxin positive strains
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which disease does the bacteria salmonella cause in humans?
A. water poisioning
B. food poisoning
C. blood poisoning
D. skin poisoning
Answer:
|
|
sciq-8394
|
multiple_choice
|
What do we call use of electric current to encode information?
|
[
"ferious",
"electronics",
"metals",
"products"
] |
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
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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
Document 2:::
This article details the history of electronics engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".
Electronics engineering as a profession sprang from technological improvements in the telegraph industry during the late 19th century and in the radio and telephone industries during the early 20th century. People gravitated to radio, attracted by the technical fascination it inspired, first in receiving and then in transmitting. Many who went into broadcasting in the 1920s had become "amateurs" in the period before World War I. The modern discipline of electronics engineering was to a large extent born out of telephone-, radio-, and television-equipment development and the large amount of electronic-systems development during World War II of radar, sonar, communication systems, and advanced munitions and weapon systems. In the interwar years, the subject was known as radio engineering. The word electronics began to be used in the 1940s In the late 1950s, the term electronics engineering started to emerge.
Electronic laboratories (Bell Labs, for instance) created and subsidized by large corporations in the industries of radio, television, and telephone equipment, began churning out a series of electronic advances. The electronics industry was revolutionized by the inventions of the first transistor in 1948, the integrated circuit chip in 1959, and the silicon MOSFET (metal–oxide–semiconductor field-effect transistor) in 1959. In the UK, the subject of electronics engineering became distinct from electrical engineering as a university-degree subject around 1960. (Before this time, students of electronics and related subjects like radio and telecommunications had to enroll in the electrical engineering department of the university as no university had departments of electronics. Electrical engineering was the nea
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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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Electronic engineering is a sub-discipline of electrical engineering which emerged in the early 20th century and is distinguished by the additional use of active components such as semiconductor devices to amplify and control electric current flow. Previously electrical engineering only used passive devices such as mechanical switches, resistors, inductors, and capacitors.
It covers fields such as: analog electronics, digital electronics, consumer electronics, embedded systems and power electronics. It is also involved in many related fields, for example solid-state physics, radio engineering, telecommunications, control systems, signal processing, systems engineering, computer engineering, instrumentation engineering, electric power control, photonics and robotics.
The Institute of Electrical and Electronics Engineers (IEEE) is one of the most important professional bodies for electronics engineers in the US; the equivalent body in the UK is the Institution of Engineering and Technology (IET). The International Electrotechnical Commission (IEC) publishes electrical standards including those for electronics engineering.
History and development
Electronics engineering as a profession emerged following the identification of the electron in 1897 and the subsequent invention of the vacuum tube which could amplify and rectify small electrical signals, that inaugurated the field of electronics. Practical applications started with the invention of the diode by Ambrose Fleming and the triode by Lee De Forest in the early 1900s, which made the detection of small electrical voltages such as radio signals from a radio antenna possible with a non-mechanical device. The growth of electronics was rapid. By the early 1920s, commercial radio broadcasting and communications were becoming widespread and electronic amplifiers were being used in such diverse applications as long-distance telephony and the music recording industry.
The discipline was further enhanced by the large a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do we call use of electric current to encode information?
A. ferious
B. electronics
C. metals
D. products
Answer:
|
|
sciq-9969
|
multiple_choice
|
What is the name for the inner lining of the uterus?
|
[
"the endometrium",
"cuticle",
"the uterine shell",
"the epidermis"
] |
A
|
Relavent Documents:
Document 0:::
The vaginal epithelium is the inner lining of the vagina consisting of multiple layers of (squamous) cells. The basal membrane provides the support for the first layer of the epithelium-the basal layer. The intermediate layers lie upon the basal layer, and the superficial layer is the outermost layer of the epithelium. Anatomists have described the epithelium as consisting of as many as 40 distinct layers. The mucus found on the epithelium is secreted by the cervix and uterus. The rugae of the epithelium create an involuted surface and result in a large surface area that covers 360 cm2. This large surface area allows the trans-epithelial absorption of some medications via the vaginal route.
In the course of the reproductive cycle, the vaginal epithelium is subject to normal, cyclic changes, that are influenced by estrogen: with increasing circulating levels of the hormone, there is proliferation of epithelial cells along with an increase in the number of cell layers. As cells proliferate and mature, they undergo partial cornification. Although hormone induced changes occur in the other tissues and organs of the female reproductive system, the vaginal epithelium is more sensitive and its structure is an indicator of estrogen levels. Some Langerhans cells and melanocytes are also present in the epithelium. The epithelium of the ectocervix is contiguous with that of the vagina, possessing the same properties and function. The vaginal epithelium is divided into layers of cells, including the basal cells, the parabasal cells, the superficial squamous flat cells, and the intermediate cells. The superficial cells exfoliate continuously, and basal cells replace the superficial cells that die and slough off from the stratum corneum. Under the stratus corneum is the stratum granulosum and stratum spinosum. The cells of the vaginal epithelium retain a usually high level of glycogen compared to other epithelial tissue in the body. The surface patterns on the cells themselve
Document 1:::
Chorionic villi are villi that sprout from the chorion to provide maximal contact area with maternal blood.
They are an essential element in pregnancy from a histomorphologic perspective, and are, by definition, a product of conception. Branches of the umbilical arteries carry embryonic blood to the villi. After circulating through the capillaries of the villi, blood returns to the embryo through the umbilical vein. Thus, villi are part of the border between maternal and fetal blood during pregnancy.
Structure
Villi can also be classified by their relations:
Floating villi float freely in the intervillous space. They exhibit a bi-layered epithelium consisting of cytotrophoblasts with overlaying syncytium (syncytiotrophoblast).
Anchoring (stem) villi stabilize the mechanical integrity of the placental-maternal interface.
Development
The chorion undergoes rapid proliferation and forms numerous processes, the chorionic villi, which invade and destroy the uterine decidua and at the same time absorb from it nutritive materials for the growth of the embryo. They undergo several stages, depending on their composition.
Until about the end of the second month of pregnancy, the villi cover the entire chorion, and are almost uniform in size—but after then, they develop unequally.
Microanatomy
The bulk of the villi consist of connective tissues that contain blood vessels. Most of the cells in the connective tissue core of the villi are fibroblasts. Macrophages known as Hofbauer cells are also present.
Clinical significance
Use for prenatal diagnosis
In 1983, an Italian biologist named Giuseppe Simoni discovered a new method of prenatal diagnosis using chorionic villi.
Stem cell
Chorionic villi are a rich source of stem cells. Biocell Center, a biotech company managed by Giuseppe Simoni, is studying and testing these types of stem cells. Chorionic stem cells, like amniotic stem cells, are uncontroversial multipotent stem cells.
Infections
Recent studies indicate th
Document 2:::
The uterine horns (cornua of uterus) are the points in the upper uterus where the fallopian tubes exit to meet the ovaries. They are one of the points of attachment for the round ligament of uterus (the other being the mons pubis). They also provide attachment to the ovarian ligament, which is located below the fallopian tube at the back; while the round ligament of uterus is located below the tube at the front.
The uterine horns are far more prominent in other animals (such as cows and cats) than they are in humans. In the cat, implantation of the embryo occurs in one of the two uterine horns, not the body of the uterus itself.
Occasionally, if a fallopian tube does not connect, the uterine horn will fill with blood each month, and a minor one-day surgery will be performed to remove it. Often, people who are born with this have trouble getting pregnant as both ovaries are functional and either may ovulate. The spare egg, that cannot travel the fallopian tube, is absorbed into the body.
Document 3:::
The supravaginal portion of the cervix (also known as the uterine portion of the cervix) is separated in front from the bladder by fibrous tissue (parametrium), which extends also on to its sides and lateralward between the layers of the broad ligaments.
The uterine arteries reach the margins of the cervix in this fibrous tissue, while on either side the ureter runs downward and forward in it at a distance of about 2 cm. from the cervix.
Posteriorly, the supravaginal cervix is covered by peritoneum, which is prolonged below on to the posterior vaginal wall, when it is reflected on to the rectum, forming the recto-uterine pouch.
It is in relation with the rectum, from which it may be separated by coils of small intestine.
Document 4:::
This list of related male and female reproductive organs shows how the male and female reproductive organs and the development of the reproductive system are related, sharing a common developmental path. This makes them biological homologues. These organs differentiate into the respective sex organs in males and females.
List
Internal organs
External organs
The external genitalia of both males and females have similar origins. They arise from the genital tubercle that forms anterior to the cloacal folds (proliferating mesenchymal cells around the cloacal membrane). The caudal aspect of the cloacal folds further subdivides into the posterior anal folds and the anterior urethral folds. Bilateral to the urethral fold, genital swellings (tubercles) become prominent. These structures are the future scrotum and labia majora in males and females, respectively.
The genital tubercles of an eight-week-old embryo of either sex are identical. They both have a glans area, which will go on to form the glans clitoridis (females) or glans penis (males), a urogenital fold and groove, and an anal tubercle. At around ten weeks, the external genitalia are still similar. At the base of the glans, there is a groove known as the coronal sulcus or corona glandis. It is the site of attachment of the future prepuce. Just anterior to the anal tubercle, the caudal end of the left and right urethral folds fuse to form the urethral raphe. The lateral part of the genital tubercle (called the lateral tubercle) grows longitudinally and is about the same length in either sex.
Human physiology
The male external genitalia include the penis and the scrotum. The female external genitalia include the clitoris, the labia, and the vaginal opening, which are collectively called the vulva. External genitalia vary widely in external appearance among different people.
One difference between the glans penis and the glans clitoridis is that the glans clitoridis packs nerve endings into a volume only about
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the name for the inner lining of the uterus?
A. the endometrium
B. cuticle
C. the uterine shell
D. the epidermis
Answer:
|
|
sciq-9715
|
multiple_choice
|
Aids is an infectious disease of which system?
|
[
"muscular",
"immune",
"endocrine",
"digestion"
] |
B
|
Relavent Documents:
Document 0:::
Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
Document 1:::
MicrobeLibrary is a permanent collection of over 1400 original peer-reviewed resources for teaching undergraduate microbiology. It is provided by the American Society for Microbiology, Washington DC, United States.
Contents include curriculum activities; images and animations; reviews of books, websites and other resources; and articles from Focus on Microbiology Education, Microbiology Education and Microbe. Around 40% of the materials are free to educators and students, the remainder require a subscription. the service is suspended with the message to:
"Please check back with us in 2017".
External links
MicrobeLibrary
Microbiology
Document 2:::
AIDS Education and Prevention is a bimonthly peer-reviewed public health journal published by Guilford Press on behalf of the International Society for AIDS Education.
It covers education and prevention of AIDS, including epidemiological studies of risk behaviors. According to the Journal Citation Reports, the journal has a 2021 impact factor of 1.920.
The editor-in-chief is Francisco S. Sy (National Institute on Minority Health and Health Disparities).
Document 3:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 4:::
Medical education is education related to the practice of being a medical practitioner, including the initial training to become a physician (i.e., medical school and internship) and additional training thereafter (e.g., residency, fellowship, and continuing medical education).
Medical education and training varies considerably across the world. Various teaching methodologies have been used in medical education, which is an active area of educational research.
Medical education is also the subject-didactic academic field of educating medical doctors at all levels, including entry-level, post-graduate, and continuing medical education. Specific requirements such as entrustable professional activities must be met before moving on in stages of medical education.
Common techniques and evidence base
Medical education applies theories of pedagogy specifically in the context of medical education. Medical education has been a leader in the field of evidence-based education, through the development of evidence syntheses such as the Best Evidence Medical Education collection, formed in 1999, which aimed to "move from opinion-based education to evidence-based education". Common evidence-based techniques include the Objective structured clinical examination (commonly known as the 'OSCE) to assess clinical skills, and reliable checklist-based assessments to determine the development of soft skills such as professionalism. However, there is a persistence of ineffective instructional methods in medical education, such as the matching of teaching to learning styles and Edgar Dales' "Cone of Learning".
Entry-level education
Entry-level medical education programs are tertiary-level courses undertaken at a medical school. Depending on jurisdiction and university, these may be either undergraduate-entry (most of Europe, Asia, South America and Oceania), or graduate-entry programs (mainly Australia, Philippines and North America). Some jurisdictions and universities provide both u
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Aids is an infectious disease of which system?
A. muscular
B. immune
C. endocrine
D. digestion
Answer:
|
|
sciq-6283
|
multiple_choice
|
The outermost layer of the leaf is the epidermis; it is present on both sides of the leaf and is called the upper and lower epidermis, respectively. botanists call the upper side the adaxial surface (or adaxis) and the lower side this?
|
[
"dorsal surface",
"abaxial surface (or abaxis)",
"anterior surface",
"posterior surface"
] |
B
|
Relavent Documents:
Document 0:::
The epidermis (from the Greek ἐπιδερμίς, meaning "over-skin") is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, and (especially in roots) absorbs water and mineral nutrients. The epidermis of most leaves shows dorsoventral anatomy: the upper (adaxial) and lower (abaxial) surfaces have somewhat different construction and may serve different functions. Woody stems and some other stem structures such as potato tubers produce a secondary covering called the periderm that replaces the epidermis as the protective covering.
Description
The epidermis is the outermost cell layer of the primary plant body. In some older works the cells of the leaf epidermis have been regarded as specialized parenchyma cells, but the established modern preference has long been to classify the epidermis as dermal tissue, whereas parenchyma is classified as ground tissue. The epidermis is the main component of the dermal tissue system of leaves (diagrammed below), and also stems, roots, flowers, fruits, and seeds; it is usually transparent (epidermal cells have fewer chloroplasts or lack them completely, except for the guard cells.)
The cells of the epidermis are structurally and functionally variable. Most plants have an epidermis that is a single cell layer thick. Some plants like Ficus elastica and Peperomia, which have a periclinal cellular division within the protoderm of the leaves, have an epidermis with multiple cell layers. Epidermal cells are tightly linked to each other and provide mechanical strength and protection to the plant. The walls of the epidermal cells of the above-ground parts of plants contain cutin, and are covered with a cuticle. The cuticle reduces water loss to the atmosphere, it is sometimes covered with wax in smooth sheets, granules, p
Document 1:::
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of Eucalyptus, palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll which is essential for photosynthesis as it absorbs light energy from the sun. A leaf with lighter-colored or white patches or edges is called a variegated leaf.
Leaves can have many different shapes, sizes, textures and colors. The broad, flat leaves with complex venation of flowering plants are known as megaphylls and the species that bear them, the majority, as broad-leaved or megaphyllous plants, which also include acrogymnosperms and ferns. In the lycopods, with different evolutionary origins, the leaves are simple (with only a single vein) and are known as microphylls. Some leaves, such as bulb scales, are not above ground. In many aquatic species, the leaves are submerged in water. Succulent plants often have thick juicy leaves, but some leaves are without major photosynthetic function and may be dead at maturity, as in some cataphylls and spines. Furthermore, several kinds of leaf-like structures found in vascular plants are not totally homologous with them. Examples include flattened plant stems called phylloclades and cladodes, and flattened leaf stems
Document 2:::
In biology, a tunica (, ; : tunicae) is a layer, coat, sheath, or similar covering. The word came to English from the Neo-Latin of science and medicine. Its literal sense is about the same as that of the word tunic, with which it is cognate. In biology one of its senses used to be the taxonomic name of a genus of plants, but the nomenclature has been revised and those plants are now included in the genus Petrorhagia.
In modern biology in general, tunica occurs as a technical or anatomical term mainly in botany and zoology. It usually refers to membranous structures that line or cover particular organs. In many such contexts tunica is used interchangeably with tunic according to preference. An organ or organism that has a tunic(a) may be said to be tunicate, as in a tunicate bulb. This adjective tunicate is not to be confused with the noun tunicate, which refers to a member of the subphylum Tunicata.
Botanical and related usages
In botany there are several contexts for the term.
As a general, but not comprehensive, descriptive term in botanical anatomy John Lindley in the 19th century defined tunica as "any loose membranous skin not formed from epidermis".
The apical meristem, in particular in Angiosperms, has an outer layer of cells called the tunica; its role in growth and development differs from that of the inner meristem, or corpus.
Bulbs and corms often have protective outer coverings of dead material. Particularly in fields such as horticulture and taxonomic description, such bulbs and corms are said to be "tunicate" — having tunics. Usually such a tunic is derived from the bases of sacrificial dead leaves, often cataphylls specialised for the purpose and dying in place. Such tunics may be delicate, brittle membranes such as those around the bulbs of onions, but the many variations reflect a wide range of adaptations in various species. Many of the larger Amaryllidaceae in particular, for example Boophone species, accumulate thick layers of rot-resistant le
Document 3:::
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 4:::
In botany, epiblem is a tissue that replaces the epidermis in most roots and in stems of submerged aquatic plants. It is usually located between the epidermis and cortex in the root or stem of a plant.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The outermost layer of the leaf is the epidermis; it is present on both sides of the leaf and is called the upper and lower epidermis, respectively. botanists call the upper side the adaxial surface (or adaxis) and the lower side this?
A. dorsal surface
B. abaxial surface (or abaxis)
C. anterior surface
D. posterior surface
Answer:
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|
sciq-3932
|
multiple_choice
|
What organ breaks down excess amino acids and toxins in the blood?
|
[
"kidney",
"heart",
"liver",
"lungs"
] |
C
|
Relavent Documents:
Document 0:::
In pharmacology the elimination or excretion of a drug is understood to be any one of a number of processes by which a drug is eliminated (that is, cleared and excreted) from an organism either in an unaltered form (unbound molecules) or modified as a metabolite. The kidney is the main excretory organ although others exist such as the liver, the skin, the lungs or glandular structures, such as the salivary glands and the lacrimal glands. These organs or structures use specific routes to expel a drug from the body, these are termed elimination pathways:
Urine
Tears
Perspiration
Saliva
Respiration
Milk
Faeces
Bile
Drugs are excreted from the kidney by glomerular filtration and by active tubular secretion following the same steps and mechanisms as the products of intermediate metabolism. Therefore, drugs that are filtered by the glomerulus are also subject to the process of passive tubular reabsorption. Glomerular filtration will only remove those drugs or metabolites that are not bound to proteins present in blood plasma (free fraction) and many other types of drugs (such as the organic acids) are actively secreted. In the proximal and distal convoluted tubules non-ionised acids and weak bases are reabsorbed both actively and passively. Weak acids are excreted when the tubular fluid becomes too alkaline and this reduces passive reabsorption. The opposite occurs with weak bases. Poisoning treatments use this effect to increase elimination, by alkalizing the urine causing forced diuresis which promotes excretion of a weak acid, rather than it getting reabsorbed. As the acid is ionised, it cannot pass through the plasma membrane back into the blood stream and instead gets excreted with the urine. Acidifying the urine has the same effect for weakly basic drugs.
On other occasions drugs combine with bile juices and enter the intestines. In the intestines the drug will join with the unabsorbed fraction of the administered dose and be eliminated with the faeces
Document 1:::
This is a list of articles that describe particular biomolecules or types of biomolecules.
A
For substances with an A- or α- prefix such as
α-amylase, please see the parent page (in this case Amylase).
A23187 (Calcimycin, Calcium Ionophore)
Abamectine
Abietic acid
Acetic acid
Acetylcholine
Actin
Actinomycin D
Adenine
Adenosmeme
Adenosine diphosphate (ADP)
Adenosine monophosphate (AMP)
Adenosine triphosphate (ATP)
Adenylate cyclase
Adiponectin
Adonitol
Adrenaline, epinephrine
Adrenocorticotropic hormone (ACTH)
Aequorin
Aflatoxin
Agar
Alamethicin
Alanine
Albumins
Aldosterone
Aleurone
Alpha-amanitin
Alpha-MSH (Melaninocyte stimulating hormone)
Allantoin
Allethrin
α-Amanatin, see Alpha-amanitin
Amino acid
Amylase (also see α-amylase)
Anabolic steroid
Anandamide (ANA)
Androgen
Anethole
Angiotensinogen
Anisomycin
Antidiuretic hormone (ADH)
Anti-Müllerian hormone (AMH)
Arabinose
Arginine
Argonaute
Ascomycin
Ascorbic acid (vitamin C)
Asparagine
Aspartic acid
Asymmetric dimethylarginine
ATP synthase
Atrial-natriuretic peptide (ANP)
Auxin
Avidin
Azadirachtin A – C35H44O16
B
Bacteriocin
Beauvericin
beta-Hydroxy beta-methylbutyric acid
beta-Hydroxybutyric acid
Bicuculline
Bilirubin
Biopolymer
Biotin (Vitamin H)
Brefeldin A
Brassinolide
Brucine
Butyric acid
C
Document 2:::
The liver is a major metabolic organ only found in vertebrate animals, which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm and mostly shielded by the lower right rib cage. Its other metabolic roles include carbohydrate metabolism, the production of hormones, conversion and storage of nutrients such as glucose and glycogen, and the decomposition of red blood cells.
The liver is also an accessory digestive organ that produces bile, an alkaline fluid containing cholesterol and bile acids, which emulsifies and aids the breakdown of dietary fat. The gallbladder, a small hollow pouch that sits just under the right lobe of liver, stores and concentrates the bile produced by the liver, which is later excreted to the duodenum to help with digestion. The liver's highly specialized tissue, consisting mostly of hepatocytes, regulates a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex organic molecules, many of which are necessary for normal vital functions. Estimates regarding the organ's total number of functions vary, but is generally cited as being around 500.
It is not known how to compensate for the absence of liver function in the long term, although liver dialysis techniques can be used in the short term. Artificial livers have not been developed to promote long-term replacement in the absence of the liver. , liver transplantation is the only option for complete liver failure.
Structure
The liver is a dark reddish brown, wedge-shaped organ with two lobes of unequal size and shape. A human liver normally weighs approximately and has a width of about . There is considerable size variation between individuals, with the standard reference range for men being and for women . It is both the heaviest int
Document 3:::
The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body. The dual function of excretory systems is the elimination of the waste products of metabolism and to drain the body of used up and broken down components in a liquid and gaseous state. In humans and other amniotes (mammals, birds and reptiles) most of these substances leave the body as urine and to some degree exhalation, mammals also expel them through sweating.
Only the organs specifically used for the excretion are considered a part of the excretory system. In the narrow sense, the term refers to the urinary system. However, as excretion involves several functions that are only superficially related, it is not usually used in more formal classifications of anatomy or function.
As most healthy functioning organs produce metabolic and other wastes, the entire organism depends on the function of the system. Breaking down of one of more of the systems is a serious health condition, for example kidney failure.
Systems
Urinary system
The kidneys are large, bean-shaped organs which are present on each side of the vertebral column in the abdominal cavity. Humans have two kidneys and each kidney is supplied with blood from the renal artery. The kidneys remove from the blood the nitrogenous wastes such as urea, as well as salts and excess water, and excrete them in the form of urine. This is done with the help of millions of nephrons present in the kidney. The filtrated blood is carried away from the kidneys by the renal vein (or kidney vein). The urine from the kidney is collected by the ureter (or excretory tubes), one from each kidney, and is passed to the urinary bladder. The urinary bladder collects and stores the urine until urination. The urine collected in the bladder is passed into the external environment from the body through an opening called
Document 4:::
Renal pathology is a subspecialty of anatomic pathology that deals with the diagnosis and characterization of medical diseases (non-tumor) of the kidneys. In the academic setting, renal pathologists work closely with nephrologists and transplant surgeons, who typically obtain diagnostic specimens via percutaneous renal biopsy. The renal pathologist must synthesize findings from light microscopy, electron microscopy, and immunofluorescence to obtain a definitive diagnosis. Medical renal diseases may affect the glomerulus, the tubules and interstitium, the vessels, or a combination of these compartments.
External links
http://www.renalpathsoc.org/
Renal Pathology Tutorial written by J. Charles Jennette
Pathologist Guide
Anatomical pathology
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What organ breaks down excess amino acids and toxins in the blood?
A. kidney
B. heart
C. liver
D. lungs
Answer:
|
|
sciq-1696
|
multiple_choice
|
In which phase do the chromosomes duplicate?
|
[
"mitosis",
"interphase",
"metaphase",
"prophase"
] |
B
|
Relavent Documents:
Document 0:::
Interkinesis or interphase II is a period of rest that cells of some species enter during meiosis between meiosis I and meiosis II. No DNA replication occurs during interkinesis; however, replication does occur during the interphase I stage of meiosis (See meiosis I). During interkinesis, the spindles of the first meiotic division disassembles and the microtubules reassemble into two new spindles for the second meiotic division. Interkinesis follows telophase I; however, many plants skip telophase I and interkinesis, going immediately into prophase II. Each chromosome still consists of two chromatids. In this stage other organelle number may also increase.
Document 1:::
Interphase is the portion of the cell cycle that is not accompanied by visible changes under the microscope, and includes the G1, S and G2 phases. During interphase, the cell grows (G1), replicates its DNA (S) and prepares for mitosis (G2). A cell in interphase is not simply quiescent. The term quiescent (i.e. dormant) would be misleading since a cell in interphase is very busy synthesizing proteins, copying DNA into RNA, engulfing extracellular material, processing signals, to name just a few activities. The cell is quiescent only in the sense of cell division (i.e. the cell is out of the cell cycle, G0). Interphase is the phase of the cell cycle in which a typical cell spends most of its life. Interphase is the 'daily living' or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other "normal" cell functions.
Interphase was formerly called the resting phase. However, interphase does not describe a cell that is merely resting; rather, the cell is living and preparing for later cell division, so the name was changed. A common misconception is that interphase is the first stage of mitosis, but since mitosis is the division of the nucleus, prophase is actually the first stage.
In interphase, the cell gets itself ready for mitosis or meiosis. Somatic cells, or normal diploid cells of the body, go through mitosis in order to reproduce themselves through cell division, whereas diploid germ cells (i.e., primary spermatocytes and primary oocytes) go through meiosis in order to create haploid gametes (i.e., sperm and ova) for the purpose of sexual reproduction.
Stages of interphase
There are three stages of cellular interphase, with each phase ending when a cellular checkpoint checks the accuracy of the stage's completion before proceeding to the next. The stages of interphase are:
G1 (Gap 1), in which the cell grows and functions normally. During this time, a high a
Document 2:::
Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes. However, in contrast to eukaryotic chromosome segregation, replication and segregation are not temporally separated. Instead segregation occurs progressively following replication.
Mitotic chromatid segregation
During mitosis chromosome segregation occurs routinely as a step in cell division (see mitosis diagram). As indicated in the mitosis diagram, mitosis is preceded by a round of DNA replication, so that each chromosome forms two copies called chromatids. These chromatids separate to opposite poles, a process facilitated by a protein complex referred to as cohesin. Upon proper segregation, a complete set of chromatids ends up in each of two nuclei, and when cell division is completed, each DNA copy previously referred to as a chromatid is now called a chromosome.
Meiotic chromosome and chromatid segregation
Chromosome segregation occurs at two separate stages during meiosis called anaphase I and anaphase II (see meiosis diagram). In a diploid cell there are two sets of homologous chromosomes of different parental origin (e.g. a paternal and a maternal set). During the phase of meiosis labeled “interphase s” in the meiosis diagram there is a round of DNA replication, so that each of the chromosomes initially present is now composed of two copies called chromatids. These chromosomes (paired chromatids) then pair with the homologous chromosome (also paired chromatids) present in the same nucleus (see prophase I in the meiosis diagram). The process of alignment of paired homologous chromosomes is called synapsis (see Synapsis). During synapsis, genetic recombination usually occurs. Some of the recombination even
Document 3:::
A kinetochore (, ) is a disc-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis. The term kinetochore was first used in a footnote in a 1934 Cytology book by Lester W. Sharp and commonly accepted in 1936. Sharp's footnote reads: "The convenient term kinetochore (= movement place) has been suggested to the author by J. A. Moore", likely referring to John Alexander Moore who had joined Columbia University as a freshman in 1932.
Monocentric organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles a single, localized kinetochore. Holocentric organisms, such as nematodes and some plants, assemble a kinetochore along the entire length of a chromosome.
Kinetochores start, control, and supervise the striking movements of chromosomes during cell division. During mitosis, which occurs after the amount of DNA is doubled in each chromosome (while maintaining the same number of chromosomes) in S phase, two sister chromatids are held together by a centromere. Each chromatid has its own kinetochore, which face in opposite directions and attach to opposite poles of the mitotic spindle apparatus. Following the transition from metaphase to anaphase, the sister chromatids separate from each other, and the individual kinetochores on each chromatid drive their movement to the spindle poles that will define the two new daughter cells. The kinetochore is therefore essential for the chromosome segregation that is classically associated with mitosis and meiosis.
Structure of Kinetochore
The kinetochore contains two regions:
an inner kinetochore, which is tightly associated with the centromere DNA and assembled in a specialized form of chromatin that persists t
Document 4:::
Prophase () is the first stage of cell division in both mitosis and meiosis. Beginning after interphase, DNA has already been replicated when the cell enters prophase. The main occurrences in prophase are the condensation of the chromatin reticulum and the disappearance of the nucleolus.
Staining and microscopy
Microscopy can be used to visualize condensed chromosomes as they move through meiosis and mitosis.
Various DNA stains are used to treat cells such that condensing chromosomes can be visualized as the move through prophase.
The giemsa G-banding technique is commonly used to identify mammalian chromosomes, but utilizing the technology on plant cells was originally difficult due to the high degree of chromosome compaction in plant cells. G-banding was fully realized for plant chromosomes in 1990. During both meiotic and mitotic prophase, giemsa staining can be applied to cells to elicit G-banding in chromosomes. Silver staining, a more modern technology, in conjunction with giesma staining can be used to image the synaptonemal complex throughout the various stages of meiotic prophase. To perform G-banding, chromosomes must be fixed, and thus it is not possible to perform on living cells.
Fluorescent stains such as DAPI can be used in both live plant and animal cells. These stains do not band chromosomes, but instead allow for DNA probing of specific regions and genes. Use of fluorescent microscopy has vastly improved spatial resolution.
Mitotic prophase
Prophase is the first stage of mitosis in animal cells, and the second stage of mitosis in plant cells. At the start of prophase there are two identical copies of each chromosome in the cell due to replication in interphase. These copies are referred to as sister chromatids and are attached by DNA element called the centromere. The main events of prophase are: the condensation of chromosomes, the movement of the centrosomes, the formation of the mitotic spindle, and the beginning of nucleoli break down.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In which phase do the chromosomes duplicate?
A. mitosis
B. interphase
C. metaphase
D. prophase
Answer:
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|
sciq-4518
|
multiple_choice
|
Where is most digestion completed?
|
[
"the stomach",
"the cavity",
"the esophagus",
"the duodenum"
] |
D
|
Relavent Documents:
Document 0:::
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small compounds that the body can use.
In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva. Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work, and electrolytes (Na+, K+, Cl−, HCO−3). About 30% of starch is hydrolyzed into disaccharide in the oral cavity (mouth). After undergoing mastication and starch digestion, the food will be in the form of a small, round slurry mass called a bolus. It will then travel down the esophagus and into the stomach by the action of peristalsis. Gastric juice in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and pepsin. In infants and toddlers, gastric juice also contains rennin to digest milk proteins. As the first two chemicals may damage the stomach wall, mucus and bicarbonates are secreted by the stomach. They provide a slimy layer that acts as a shield against the damag
Document 1:::
The gastrointestinal wall of the gastrointestinal tract is made up of four layers of specialised tissue. From the inner cavity of the gut (the lumen) outwards, these are:
Mucosa
Submucosa
Muscular layer
Serosa or adventitia
The mucosa is the innermost layer of the gastrointestinal tract. It surrounds the lumen of the tract and comes into direct contact with digested food (chyme). The mucosa itself is made up of three layers: the epithelium, where most digestive, absorptive and secretory processes occur; the lamina propria, a layer of connective tissue, and the muscularis mucosae, a thin layer of smooth muscle.
The submucosa contains nerves including the submucous plexus (also called Meissner's plexus), blood vessels and elastic fibres with collagen, that stretches with increased capacity but maintains the shape of the intestine.
The muscular layer surrounds the submucosa. It comprises layers of smooth muscle in longitudinal and circular orientation that also helps with continued bowel movements (peristalsis) and the movement of digested material out of and along the gut. In between the two layers of muscle lies the myenteric plexus (also called Auerbach's plexus).
The serosa/adventitia are the final layers. These are made up of loose connective tissue and coated in mucus so as to prevent any friction damage from the intestine rubbing against other tissue. The serosa is present if the tissue is within the peritoneum, and the adventitia if the tissue is retroperitoneal.
Structure
When viewed under the microscope, the gastrointestinal wall has a consistent general form, but with certain parts differing along its course.
Mucosa
The mucosa is the innermost layer of the gastrointestinal tract. It surrounds the cavity (lumen) of the tract and comes into direct contact with digested food (chyme). The mucosa is made up of three layers:
The epithelium is the innermost layer. It is where most digestive, absorptive and secretory processes occur.
The lamina propr
Document 2:::
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 3:::
The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being removed by defecation. The colon is the longest portion of the large intestine, and the terms are often used interchangeably but most sources define the large intestine as the combination of the cecum, colon, rectum, and anal canal. Some other sources exclude the anal canal.
In humans, the large intestine begins in the right iliac region of the pelvis, just at or below the waist, where it is joined to the end of the small intestine at the cecum, via the ileocecal valve. It then continues as the colon ascending the abdomen, across the width of the abdominal cavity as the transverse colon, and then descending to the rectum and its endpoint at the anal canal. Overall, in humans, the large intestine is about long, which is about one-fifth of the whole length of the human gastrointestinal tract.
Structure
The colon of the large intestine is the last part of the digestive system. It has a segmented appearance due to a series of saccules called haustra. It extracts water and salt from solid wastes before they are eliminated from the body and is the site in which the fermentation of unabsorbed material by the gut microbiota occurs. Unlike the small intestine, the colon does not play a major role in absorption of foods and nutrients. About 1.5 litres or 45 ounces of water arrives in the colon each day.
The colon is the longest part of the large intestine and its average length in the adult human is 65 inches or 166 cm (range of 80 to 313 cm) for males, and 61 inches or 155 cm (range of 80 to 214 cm) for females.
Sections
In mammals, the large intestine consists of the cecum (including the appendix), colon (the longest part), rectum, and anal canal.
The four sections of the colon are: the ascending colon, transverse colon, desce
Document 4:::
Digestion chambers are a histologic finding in nerves that are undergoing Wallerian degeneration.
Appearance
Digestion chambers consist of small globular fragments, which represent degenerating myelin sheaths.
See also
Nerve injury
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where is most digestion completed?
A. the stomach
B. the cavity
C. the esophagus
D. the duodenum
Answer:
|
|
sciq-10891
|
multiple_choice
|
The human male and female reproductive cycles are controlled by the interaction of hormones from the hypothalamus and anterior pituitary with hormones from reproductive tissues and organs. in both sexes, the hypothalamus monitors and causes the release of hormones from this?
|
[
"hypothalamus gland",
"thyroid gland",
"anterior pituitary gland",
"pineal gland"
] |
C
|
Relavent Documents:
Document 0:::
Reproductive biology includes both sexual and asexual reproduction.
Reproductive biology includes a wide number of fields:
Reproductive systems
Endocrinology
Sexual development (Puberty)
Sexual maturity
Reproduction
Fertility
Human reproductive biology
Endocrinology
Human reproductive biology is primarily controlled through hormones, which send signals to the human reproductive structures to influence growth and maturation. These hormones are secreted by endocrine glands, and spread to different tissues in the human body. In humans, the pituitary gland synthesizes hormones used to control the activity of endocrine glands.
Reproductive systems
Internal and external organs are included in the reproductive system. There are two reproductive systems including the male and female, which contain different organs from one another. These systems work together in order to produce offspring.
Female reproductive system
The female reproductive system includes the structures involved in ovulation, fertilization, development of an embryo, and birth.
These structures include:
Ovaries
Oviducts
Uterus
Vagina
Mammary Glands
Estrogen is one of the sexual reproductive hormones that aid in the sexual reproductive system of the female.
Male reproductive system
The male reproductive system includes testes, rete testis, efferent ductules, epididymis, sex accessory glands, sex accessory ducts and external genitalia.
Testosterone, an androgen, although present in both males and females, is relatively more abundant in males. Testosterone serves as one of the major sexual reproductive hormones in the male reproductive system However, the enzyme aromatase is present in testes and capable of synthesizing estrogens from androgens. Estrogens are present in high concentrations in luminal fluids of the male reproductive tract. Androgen and estrogen receptors are abundant in epithelial cells of the male reproductive tract.
Animal Reproductive Biology
Animal reproduction oc
Document 1:::
Prenatal Testosterone Transfer (also known as prenatal androgen transfer or prenatal hormone transfer) refers to the phenomenon in which testosterone synthesized by a developing male fetus transfers to one or more developing fetuses within the womb and influences development. This typically results in the partial masculinization of specific aspects of female behavior, cognition, and morphology, though some studies have found that testosterone transfer can cause an exaggerated masculinization in males. There is strong evidence supporting the occurrence of prenatal testosterone transfer in rodents and other litter-bearing species, such as pigs. When it comes to humans, studies comparing dizygotic opposite-sex and same-sex twins suggest the phenomenon may occur, though the results of these studies are often inconsistent.
Mechanisms of transfer
Testosterone is a steroid hormone; therefore it has the ability to diffuse through the amniotic fluid between fetuses. In addition, hormones can transfer among fetuses through the mother's bloodstream.
Consequences of testosterone transfer
During prenatal development, testosterone exposure is directly responsible for masculinizing the genitals and brain structures. This exposure leads to an increase in male-typical behavior.
Animal studies
Most animal studies are performed on rats or mice. In these studies, the amount of testosterone each individual fetus is exposed to depends on its intrauterine position (IUP). Each gestating fetus not at either end of the uterine horn is surrounded by either two males (2M), two females (0M), or one female and one male (1M). Development of the fetus varies widely according to its IUP.
Mice
In mice, prenatal testosterone transfer causes higher blood concentrations of testosterone in 2M females when compared to 1M or 0M females. This has a variety of consequences on later female behavior, physiology, and morphology.
Below is a table comparing physiological, morphological, and behavioral diffe
Document 2:::
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 3:::
Uterine glands or endometrial glands are tubular glands, lined by a simple columnar epithelium, found in the functional layer of the endometrium that lines the uterus. Their appearance varies during the menstrual cycle. During the proliferative phase, uterine glands appear long due to estrogen secretion by the ovaries. During the secretory phase, the uterine glands become very coiled with wide lumens and produce a glycogen-rich secretion known as histotroph or uterine milk. This change corresponds with an increase in blood flow to spiral arteries due to increased progesterone secretion from the corpus luteum. During the pre-menstrual phase, progesterone secretion decreases as the corpus luteum degenerates, which results in decreased blood flow to the spiral arteries. The functional layer of the uterus containing the glands becomes necrotic, and eventually sloughs off during the menstrual phase of the cycle.
They are of small size in the unimpregnated uterus, but shortly after impregnation become enlarged and elongated, presenting a contorted or waved appearance.
Function
Hormones produced in early pregnancy stimulate the uterine glands to secrete a number of substances to give nutrition and protection to the embryo and fetus, and the fetal membranes. These secretions are known as histiotroph, alternatively histotroph, and also as uterine milk. Important uterine milk proteins are glycodelin-A, and osteopontin.
Some secretory components from the uterine glands are taken up by the secondary yolk sac lining the exocoelomic cavity during pregnancy, and may thereby assist in providing fetal nutrition.
Additional images
Document 4:::
The Vandenbergh effect is a phenomenon reported by J.G. Vandenbergh et al. in 1975, in which an early induction of the first estrous cycle in prepubertal female mice occurs as a result of exposure to the pheromone-laden urine of a sexually mature (dominant) male mouse.
Physiologically, the exposure to male urine induces the release of GnRH, which provokes the first estrus. The Vandenbergh effect has also been seen with exposure to adult female mice. When an immature female mouse is exposed to the urine of mature female mouse, estrus is delayed in the prepubertal female. In this situation, GnRH is inhibited and therefore delays puberty in the juvenile female mouse.
The Vandenbergh effect is caused by pheromones found in a male's urine. The male does not have to be present for this effect to take place; the urine alone is sufficient. These pheromones are detected by the vomeronasal organ in the septum of the female's nose. This occurs because the female body will only take the step to begin puberty if there are available mates around. She will not waste energy on puberty if there is no possibility of finding a mate.
In addition to GnRH, exogenous estradiol has recently implicated as having a role in the Vandenbergh effect. Utilizing tritium-labeled estradiol implanted in male mice, researchers have been able to trace the pathways the estradiol takes once transmitted to a female. The estradiol was found in a multitude of regions within the females and appeared to enter her circulation nasally and through the skin. Their findings suggested that some aspects of the Vandenbergh effect as well as the Bruce effect may be related to exogenous estradiol from males.
Additional studies have looked into the validity of estradiol's role in the Vandenbergh effect by means of exogenous estradiol placed in castrated rats. Castrated males were injected with either a control (oil) or estradiol in the oil vehicle. As expected, urinary androgens in the castrated males were below no
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The human male and female reproductive cycles are controlled by the interaction of hormones from the hypothalamus and anterior pituitary with hormones from reproductive tissues and organs. in both sexes, the hypothalamus monitors and causes the release of hormones from this?
A. hypothalamus gland
B. thyroid gland
C. anterior pituitary gland
D. pineal gland
Answer:
|
|
sciq-11222
|
multiple_choice
|
How many sperm does it take to fertilize an egg?
|
[
"1",
"4",
"3",
"2"
] |
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:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 3:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How many sperm does it take to fertilize an egg?
A. 1
B. 4
C. 3
D. 2
Answer:
|
|
sciq-309
|
multiple_choice
|
The name of a spinal cord region corresponds to the level at which spinal nerves pass through the what?
|
[
"notochord",
"synovial fluid",
"lumbar foramina",
"intervertebral foramina"
] |
D
|
Relavent Documents:
Document 0:::
The human brain anatomical regions are ordered following standard neuroanatomy hierarchies. Functional, connective, and developmental regions are listed in parentheses where appropriate.
Hindbrain (rhombencephalon)
Myelencephalon
Medulla oblongata
Medullary pyramids
Arcuate nucleus
Olivary body
Inferior olivary nucleus
Rostral ventrolateral medulla
Caudal ventrolateral medulla
Solitary nucleus (Nucleus of the solitary tract)
Respiratory center-Respiratory groups
Dorsal respiratory group
Ventral respiratory group or Apneustic centre
Pre-Bötzinger complex
Botzinger complex
Retrotrapezoid nucleus
Nucleus retrofacialis
Nucleus retroambiguus
Nucleus para-ambiguus
Paramedian reticular nucleus
Gigantocellular reticular nucleus
Parafacial zone
Cuneate nucleus
Gracile nucleus
Perihypoglossal nuclei
Intercalated nucleus
Prepositus nucleus
Sublingual nucleus
Area postrema
Medullary cranial nerve nuclei
Inferior salivatory nucleus
Nucleus ambiguus
Dorsal nucleus of vagus nerve
Hypoglossal nucleus
Chemoreceptor trigger zone
Metencephalon
Pons
Pontine nuclei
Pontine cranial nerve nuclei
Chief or pontine nucleus of the trigeminal nerve sensory nucleus (V)
Motor nucleus for the trigeminal nerve (V)
Abducens nucleus (VI)
Facial nerve nucleus (VII)
Vestibulocochlear nuclei (vestibular nuclei and cochlear nuclei) (VIII)
Superior salivatory nucleus
Pontine tegmentum
Pontine micturition center (Barrington's nucleus)
Locus coeruleus
Pedunculopontine nucleus
Laterodorsal tegmental nucleus
Tegmental pontine reticular nucleus
Nucleus incertus
Parabrachial area
Medial parabrachial nucleus
Lateral parabrachial nucleus
Subparabrachial nucleus (Kölliker-Fuse nucleus)
Pontine respiratory group
Superior olivary complex
Medial superior olive
Lateral superior olive
Medial nucleus of the trapezoid body
Paramedian pontine reticular formation
Parvocellular reticular nucleus
Caudal pontine reticular nucleus
Cerebellar peduncles
Superior cerebellar peduncle
Middle cerebellar peduncle
Inferior
Document 1:::
The lateral corticospinal tract (also called the crossed pyramidal tract or lateral cerebrospinal fasciculus) is the largest part of the corticospinal tract. It extends throughout the entire length of the spinal cord, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.
Structure
Descending motor pathways carry motor signals from the brain down the spinal cord and to the target muscle or organ. They typically consist of an upper motor neuron and a lower motor neuron. The lateral corticospinal tract is a descending motor pathway that begins in the cerebral cortex, decussates in the pyramids of the lower medulla (also known as the medulla oblongata or the cervicomedullary junction, which is the most posterior division of the brain) and proceeds down the contralateral side of the spinal cord. It is the largest part of the corticospinal tract. It extends throughout the entire length of the medulla spinalis, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.
Function
Axons in the lateral corticospinal tract weave out of the tract and into the anterior horns of the spinal cord. It controls fine movement of ipsilateral limbs (albeit contralateral to the corresponding motor cortex) as it lies distal to the pyramidal decussation. Control of more central axial and girdle muscles comes from the anterior corticospinal tract.
Damage to different parts of the body will cause deficits, depending on whether the damage is above (rostral) or below (caudal) the pyramidal decussation. Damage to the body above the pyramidal decussation will cause contralateral motor deficits. For example, if there is a lesion at the pre-central gyrus in the right cerebral cortex, then the left side of the body will be affected. Whereas damage below the pyramidal decussation will result in ipsilateral motor deficits. For example, spinal
Document 2:::
The lumbar nerves are the five pairs of spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions.
Structure
The lumbar nerves are five spinal nerves which arise from either side of the spinal cord below the thoracic spinal cord and above the sacral spinal cord. They arise from the spinal cord between each pair of lumbar spinal vertebrae and travel through the intervertebral foramina. The nerves then split into an anterior branch, which travels forward, and a posterior branch, which travels backwards and supplies the area of the back.
Posterior divisions
The middle divisions of the posterior branches run close to the articular processes of the vertebrae and end in the multifidus muscle. The outer branches supply the erector spinae muscles.
The nerves give off branches to the skin. These pierce the aponeurosis of the greater trochanter.
Anterior divisions
The anterior divisions of the lumbar nerves () increase in size from above downward.
The anterior divisions communicate with the sympathetic trunk. Near the origin of the divisions, they are joined by gray rami communicantes from the lumbar ganglia of the sympathetic trunk. These rami consist of long, slender branches which accompany the lumbar arteries around the sides of the vertebral bodies, beneath the Psoas major. Their arrangement is somewhat irregular: one ganglion may give rami to two lumbar nerves, or one lumbar nerve may receive rami (branches) from two ganglia. The first and second, and sometimes the third and fourth lumbar nerves are each connected with the lumbar part of the sympathetic trunk by a white ramus communicans.
The nerves pass obliquely outward behind the Psoas major, or between its fasciculi, distributing filaments to it and the Quadratus lumborum.
As the nerves travel forward, they create nervous plexuses. The first three lumbar nerves, and the greater part of the fourth together form the lumbar plexus. The smaller part of the fourth
Document 3:::
A shallow, longitudinal groove separating the developing gray matter into a basal and alar plates along the length of the neural tube. The sulcus limitans extends the length of the spinal cord and through the mesencephalon.
Document 4:::
The most lateral of the bundles of the anterior nerve roots is generally taken as a dividing line that separates the anterolateral system into two parts. These are the anterior funiculus, between the anterior median fissure and the most lateral of the anterior nerve roots, and the lateral funiculus (or lateral column) between the exit of these roots and the posterolateral sulcus.
The lateral funiculus transmits the contralateral corticospinal and spinothalamic tracts. A lateral cutting of the spinal cord results in the transection of both ipsilateral posterior column and lateral funiculus and this produces Brown-Séquard syndrome.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The name of a spinal cord region corresponds to the level at which spinal nerves pass through the what?
A. notochord
B. synovial fluid
C. lumbar foramina
D. intervertebral foramina
Answer:
|
|
sciq-10519
|
multiple_choice
|
What is light that has only a single wavelength called?
|
[
"spectroscopy",
"primary",
"monochromatic",
"fluorescent"
] |
C
|
Relavent Documents:
Document 0:::
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 1:::
The single-particle spectrum is a distribution of a physical quantity such as energy or momentum. The study of particle spectra allows us to see the global picture of particle production.
The spectrum are particles that are in space. This belongs to Raman spectroscopy by Chandrasekhar Venkata Raman. Spectrum particles are nothing but the VIBGYOR rays which are separated by prism or water. For example, a rainbow.
Physical quantities
Document 2:::
In spectroscopy a band head is the abrupt edge of a spectroscopic band. When a band is described as degrading to the violet, it means that for wavelengths above the band head wavelength, the spectrum is dark as the band comes to a sudden stop(just above/after the head), and below the wavelength the brightness of the band weakens gradually. A band that degrades to the red, conversely means that the band head is a lower limit on wavelength for the band, and it fades off toward longer wavelengths, which in visible light is the red end of the spectrum.
If a band spectrum is examined at high resolution it consists of many lines. At a band head the numbers often increase to a limit, or otherwise a series of lines may approach from one side and then reverse at the band head. The lines pile up on top of each other at the band head, and may not be viewed separately. They have become unresolvable.
Double head
Two bands may overlap with the head of one on top of another band or close to each other. This may make a stepped appearance. The two band heads close to each other are called a double head.
Headless band
A headless band fades off at both ends with a maximum somewhere in the band.
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
In 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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is light that has only a single wavelength called?
A. spectroscopy
B. primary
C. monochromatic
D. fluorescent
Answer:
|
|
sciq-4131
|
multiple_choice
|
What is the term for organisms that can maintain a stable body temperature even in the face of large fluctuations in the environmental temperature?
|
[
"pachyderm",
"ectotherms",
"homeotherm",
"endotherms"
] |
D
|
Relavent Documents:
Document 0:::
A stenotherm (from Greek στενός stenos "narrow" and θέρμη therme "heat") is a species or living organism only capable of living or surviving within a narrow temperature range. This type of temperature specialization is often seen in organisms that live in environments where the temperature is relatively stable, such as in deep sea environments or in polar regions.
The opposite of a stenotherm is a eurytherm, an organism that can function at a wide range of different body temperatures. Eurythermic organisms are typically found in environments where the temperature varies more significantly, such as in temperate or tropical regions.
The size, shape, and composition of an organism's body can affect its temperature regulation, with larger organisms tending to have a more stable internal temperature than smaller organisms.
Examples
Chionoecetes opilio is a stenothermic organism, and temperature affects its biology throughout its life history, from embryo to adult. Small changes in temperature (< 2 °C) can increase the duration of egg incubation for C. opilio by a full year.
See also
Ecotope
Document 1:::
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation. The internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology). If the body is unable to maintain a normal temperature and it increases significantly above normal, a condition known as hyperthermia occurs. Humans may also experience lethal hyperthermia when the wet bulb temperature is sustained above for six hours. Work in 2022 established by experiment that a wet-bulb temperature exceeding 30.55°C caused uncompensable heat stress in young, healthy adult humans. The opposite condition, when body temperature decreases below normal levels, is known as hypothermia. It results when the homeostatic control mechanisms of heat within the body malfunction, causing the body to lose heat faster than producing it. Normal body temperature is around 37°C(98.6°F), and hypothermia sets in when the core body temperature gets lower than . Usually caused by prolonged exposure to cold temperatures, hypothermia is usually treated by methods that attempt to raise the body temperature back to a normal range.
It was not until the introduction of thermometers that any exact data on the temperature of animals could be obtained. It was then found that local differences were present, since heat production and heat loss vary considerably in different parts of the body, although the circulation of the blood tends to bring about a mean temperature of the internal parts. Hence it is important to identify the parts of the body that most closely reflect the temperature
Document 2:::
Endothermic organisms known as homeotherms maintain internal temperatures with minimal metabolic regulation within a range of ambient temperatures called the thermal neutral zone (TNZ). Within the TNZ the basal rate of heat production is equal to the rate of heat loss to the environment. Homeothermic organisms adjust to the temperatures within the TNZ through different responses requiring little energy.
Environmental temperatures can cause fluctuations in a homeothermic organism's metabolic rate. This response is due to the energy required to maintain a relatively constant body temperature above ambient temperature by controlling heat loss and heat gain. The degree of this response depends not only on the species, but also on the levels of insulative and metabolic adaptation. Environmental temperatures below the TNZ, the lower critical temperature (LCT), require an organism to increase its metabolic rate to meet the environmental demands for heat. The Regulation about the TNZ requires metabolic heat production when the LCT is reached, as heat is lost to the environment. The organism reaches the LCT when the Ta (ambient temp.) decreases.
When an organism reaches this stage the metabolic rate increases significantly and thermogenesis increases the Tb (body temp.) If the Ta continues to decrease far below the LCT hypothermia occurs. Alternatively, evaporative heat loss for cooling occurs when temperatures above the TNZ, the upper critical zone (UCT), are realized (Speakman and Keijer 2013). When the Ta reaches too far above the UCT, the rate of heat gain and rate of heat production become higher than the rate of heat dissipation (heat loss through evaporative cooling), resulting in hyperthermia.
It can show postural changes where it changes its body shape or moves and exposes different areas to the sun/shade, and through radiation, convection and conduction, heat exchange occurs. Vasomotor responses allow control of the flow of blood between the periphery and the c
Document 3:::
A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures. To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages. These wide ranges of tolerable temperatures are directly derived from the tolerance of a given eurythermal organism's proteins. Extreme examples of eurytherms include Tardigrades (Tardigrada), the desert pupfish (Cyprinodon macularis), and green crabs (Carcinus maenas), however, nearly all mammals, including humans, are considered eurytherms. Eurythermy can be an evolutionary advantage: adaptations to cold temperatures, called cold-eurythemy, are seen as essential for the survival of species during ice ages. In addition, the ability to survive in a wide range of temperatures increases a species' ability to inhabit other areas, an advantage for natural selection.
Eurythermy is an aspect of thermoregulation in organisms. It is in contrast with the idea of stenothermic organisms, which can only operate within a relatively narrow range of ambient temperatures. Through a wide variety of thermal coping mechanisms, eurythermic organisms can either provide or expel heat for themselves in order to survive in cold or hot, respectively, or otherwise prepare themselves for extreme temperatures. Certain species of eurytherm have been shown to have unique protein synthesis processes that differentiate them from relatively stenothermic, but otherwise similar, species.
Examples
Tardigrades, known for their ability to survive in nearly any environment, are extreme examples of eurytherms. Certain species of tardigrade, including Mi. tardigradum, are able to withstand and survive temperatures ranging from –273 °C (near absolute zero) to 150 °C in their anhydrobiotic state.
The desert pupfish, a rare bony fish that occupies places like the Colorado River Delta in Baja California, small ponds in Sonora, Mexico, and drainage sites near the Salton Sea
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An endotherm (from Greek ἔνδον endon "within" and θέρμη thermē "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions instead of relying almost purely on ambient heat. Such internally generated heat is mainly an incidental product of the animal's routine metabolism, but under conditions of excessive cold or low activity an endotherm might apply special mechanisms adapted specifically to heat production. Examples include special-function muscular exertion such as shivering, and uncoupled oxidative metabolism, such as within brown adipose tissue.
Only birds and mammals are extant universally endothermic groups of animals. However, Argentine black and white tegu, leatherback sea turtles, lamnid sharks, tuna and billfishes, cicadas, and winter moths are also endothermic. Unlike mammals and birds, some reptiles, particularly some species of python and tegu, possess seasonal reproductive endothermy in which they are endothermic only during their reproductive season.
In common parlance, endotherms are characterized as "warm-blooded". The opposite of endothermy is ectothermy, although in general, there is no absolute or clear separation between the nature of endotherms and ectotherms.
Origin
Endothermy was thought to have originated towards the end of the Permian Period. One recent study claimed the origin of endothermy within Synapsida (the mammalian lineage) was among Mammaliamorpha, a node calibrated during the Late Triassic period, about 233 million years ago. Another study instead argued that endothermy only appeared later, during the Middle Jurassic, among crown-group mammals.
Evidence for endothermy has been found in basal synapsids ("pelycosaurs"), pareiasaurs, ichthyosaurs, plesiosaurs, mosasaurs, and basal archosauromorphs. Even the earliest amniotes might have been endotherms.
Mechanisms
Generating and conserving heat
Many endotherms have a larger amount
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the term for organisms that can maintain a stable body temperature even in the face of large fluctuations in the environmental temperature?
A. pachyderm
B. ectotherms
C. homeotherm
D. endotherms
Answer:
|
|
sciq-1267
|
multiple_choice
|
Atoms of what element ultimately form in a red supergiant?
|
[
"iron",
"gold",
"coal",
"steel"
] |
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
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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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A red dwarf is the smallest and coolest kind of star on the main sequence. Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighborhood of the Sun. However, as a result of their low luminosity, individual red dwarfs cannot be easily observed. From Earth, not one star that fits the stricter definitions of a red dwarf is visible to the naked eye. Proxima Centauri, the nearest star to the Sun, is a red dwarf, as are fifty of the sixty nearest stars. According to some estimates, red dwarfs make up three-quarters of the stars in the Milky Way.
The coolest red dwarfs near the Sun have a surface temperature of about and the smallest have radii about 9% that of the Sun, with masses about 7.5% that of the Sun. These red dwarfs have spectral types of L0 to L2. There is some overlap with the properties of brown dwarfs, since the most massive brown dwarfs at lower metallicity can be as hot as and have late M spectral types.
Definitions and usage of the term "red dwarf" vary on how inclusive they are on the hotter and more massive end. One definition is synonymous with stellar M dwarfs (M-type main sequence stars), yielding a maximum temperature of and . One includes all stellar M-type main-sequence and all K-type main-sequence stars (K dwarf), yielding a maximum temperature of and . Some definitions include any stellar M dwarf and part of the K dwarf classification. Other definitions are also in use. Many of the coolest, lowest mass M dwarfs are expected to be brown dwarfs, not true stars, and so those would be excluded from any definition of red dwarf.
Stellar models indicate that red dwarfs less than are fully convective. Hence, the helium produced by the thermonuclear fusion of hydrogen is constantly remixed throughout the star, avoiding helium buildup at the core, thereby prolonging the period of fusion. Low-mass red dwarfs therefore develop very slowly, maintaining a constant luminosity and spectral type for trillions of years,
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Sir Isaac Newton Sixth Form is a specialist maths and science sixth form with free school status located in Norwich, owned by the Inspiration Trust. It has the capacity for 480 students aged 16–19. It specialises in mathematics and science.
History
Prior to becoming a Sixth Form College the building functioned as a fire station serving the central Norwich area until August 2011 when it closed down. Two years later the Sixth Form was created within the empty building with various additions being made to the existing structure. The sixth form was ranked the 7th best state sixth form in England by the Times in 2022.
Curriculum
At Sir Isaac Newton Sixth Form, students can study a choice of either Maths, Further Maths, Core Maths, Biology, Chemistry, Physics, Computer Science, Environmental Science or Psychology. Additionally, students can also study any of the subjects on offer at the partner free school Jane Austen College, also located in Norwich and specialising in humanities, Arts and English.
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Atoms of what element ultimately form in a red supergiant?
A. iron
B. gold
C. coal
D. steel
Answer:
|
|
scienceQA-9450
|
multiple_choice
|
Select the vertebrate.
|
[
"saturn butterfly",
"metallic tarantula",
"sunfish",
"weaver ant"
] |
C
|
A saturn butterfly is an insect. Like other insects, a saturn butterfly is an invertebrate. It does not have a backbone. It has an exoskeleton.
A weaver ant is an insect. Like other insects, a weaver ant is an invertebrate. It does not have a backbone. It has an exoskeleton.
A sunfish is a fish. Like other fish, a sunfish is a vertebrate. It has a backbone.
Like other tarantulas, a metallic tarantula is an invertebrate. It does not have a backbone. It has an exoskeleton.
|
Relavent Documents:
Document 0:::
Vertebrate zoology is the biological discipline that consists of the study of Vertebrate animals, i.e., animals with a backbone, such as fish, amphibians, reptiles, birds and mammals. Many natural history museums have departments named Vertebrate Zoology. In some cases whole museums bear this name, e.g. the Museum of Vertebrate Zoology at the University of California, Berkeley.
Subdivisions
This subdivision of zoology has many further subdivisions, including:
Ichthyology - the study of fishes.
Mammalogy - the study of mammals.
Chiropterology - the study of bats.
Primatology - the study of primates.
Ornithology - the study of birds.
Herpetology - the study of reptiles.
Batrachology - the study of amphibians.
These divisions are sometimes further divided into more specific specialties.
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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
Document 2:::
Animals are multicellular eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million in total. Animals range in size from 8.5 millionths of a metre to long and have complex interactions with each other and their environments, forming intricate food webs. The study of animals is called zoology.
Animals may be listed or indexed by many criteria, including taxonomy, status as endangered species, their geographical location, and their portrayal and/or naming in human culture.
By common name
List of animal names (male, female, young, and group)
By aspect
List of common household pests
List of animal sounds
List of animals by number of neurons
By domestication
List of domesticated animals
By eating behaviour
List of herbivorous animals
List of omnivores
List of carnivores
By endangered status
IUCN Red List endangered species (Animalia)
United States Fish and Wildlife Service list of endangered species
By extinction
List of extinct animals
List of extinct birds
List of extinct mammals
List of extinct cetaceans
List of extinct butterflies
By region
Lists of amphibians by region
Lists of birds by region
Lists of mammals by region
Lists of reptiles by region
By individual (real or fictional)
Real
Lists of snakes
List of individual cats
List of oldest cats
List of giant squids
List of individual elephants
List of historical horses
List of leading Thoroughbred racehorses
List of individual apes
List of individual bears
List of giant pandas
List of individual birds
List of individual bovines
List of individual cetaceans
List of individual dogs
List of oldest dogs
List of individual monkeys
List of individual pigs
List of w
Document 3:::
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
Document 4:::
The Cichlid Room Companion (CRC) is a membership-based webpage dedicated to the fishes of the Cichlid family (Cichlidae). The site was launched in May 1996 and offers arguably the most comprehensive authoritative catalogue of cichlids on the web, which is illustrated with more than 25,000 photographs of fishes and 2,000 of habitats, as well as over 300 videos of cichlids and their habitats. It also “offers access to ample information about 253 genera and 2371 species”, a discussion forum as well as many articles about taxonomy, natural history, fish-keeping, field accounts, conservation, and other cichlid related topics; mostly written by citizen scientists and people who specialize in cichlids. The species summaries provided in the form of profiles include taxonomic, distribution and habitat, distribution maps, conservation, natural history, captive maintenance, images, videos, collection records, and an extensive bibliography of the species included and have been prepared by world-class specialists. A document establishes the standards followed in the preparation and maintenance of the cichlid catalogue. The site is administered by its creator and editor, Juan Miguel Artigas-Azas, a naturalist, who is also an aquarist and a nature photographer. In 2008, the American Cichlid Association (ACA) awarded Artigas-Azas the Guy Jordan Retrospective Award, which is the maximum honor that association gives to people who have done extensive contribution to the international cichlid hobby.
Contributions to public understanding of science
In the past decade, the Internet has fundamentally transformed the relationships between the scientific community and society as a whole, as the boundaries between public and private, professionals and hobbyists fade away; allowing for a wider range of participants to engage with science in unprecedented ways. The educational and citizens science task of the CRC has been acknowledged in the formal scientific literature, both as a source of d
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the vertebrate.
A. saturn butterfly
B. metallic tarantula
C. sunfish
D. weaver ant
Answer:
|
sciq-9020
|
multiple_choice
|
What does the kyoto protocol focus on controlling?
|
[
"Helium emissions",
"greenhouse gas emissions",
"carbonate gas emissions",
"Ozone emissions"
] |
B
|
Relavent Documents:
Document 0:::
Directive 2003/30/EC was a European Union directive for promoting the use of biofuels for EU transport. The directive entered into force in May 2003, and stipulated that national measures must be taken by countries across the EU aiming at replacing 5.75% of all transport fossil fuels (petrol and diesel) with biofuels by 2010. The directive also called for an intermediate target of 2% by 31 December 2005. The target of 5.75% was to be met by 31 December 2010. These percentages were to be calculated on the basis of energy content of the fuel and were to apply to petrol and diesel fuel for transport purposes placed on the markets of member states. Member states were encouraged to take on national "indicative" targets in conformity with the overall target.
Directive 2003/30/EC was repealed by Directive 2009/28/EC.
Legislation
COM(2001) 547, Communication of the European Commission of 7 November 2001 on an Action Plan and two Proposals for Directives to foster the use of Alternative Fuels for Transport, starting with the regulatory and fiscal promotion of biofuels
COM(2006) 845, Communication of the European Commission to the Council and the European Parliament: Biofuels Progress Report, that proposes to raise the biofuel target to 10% by 2020.
Related legislation:
Council Directive 2003/96/EC of 27 October 2003 restructuring the Community framework for the taxation of energy products and electricity
COM(2007)18: Proposal for a Directive amending Fuel Quality Directive 98/70/EC (also called Directive relating to the quality of petrol and diesel fuels ), as amended by Directive 2003/17/EC: fuel suppliers should reduce the lifecycle greenhouse gas emissions from transport fuels from 2011 onward, by 1% year.
Results
A 2007 progress report found that biofuel only held a 1% share, not reaching the target of 2% or the combined goals of the member nations, which was 1.4%. The 2010 target was officially replaced when the Directive 2003/30/EC was repealed by Directive
Document 1:::
Climate restoration is the climate change goal and associated actions to restore to levels humans have actually survived long-term, below 300 ppm. This would restore the Earth system generally to a safe state, for the well-being of future generations of humanity and nature. Actions include carbon dioxide removal from the Carbon dioxide in Earth's atmosphere, which, in combination with emissions reductions, would reduce the level of in the atmosphere and thereby reduce the global warming produced by the greenhouse effect of an excess of over its pre-industrial level. Actions also include restoring pre-industrial atmospheric methane levels by accelerating natural methane oxidation.
Climate restoration enhances legacy climate goals (stabilizing earth's climate) to include ensuring the survival of humanity by restoring to levels of the last 6000 years that allowed agriculture and civilization to develop.
Restoration and mitigation
Climate restoration is the goal underlying climate change mitigation, whose actions are intended to "limit the magnitude or rate of long-term climate change". Advocates of climate restoration accept that climate change has already had major negative impacts which threaten the long-term survival of humanity. The current mitigation pathway leaves the risk that conditions will go beyond adaptation and abrupt climate change will be upon us. There is a human moral imperative to maximize the chances of future generations' survival. By promoting the vision of the "survival and flourishing of humanity", with the Earth System restored to a state close to that in which our species and civilization evolved, advocates claim that there is a huge incentive for innovation and investment to ensure that this restoration takes place safely and in a timely fashion. As stated in "The Economist" in November 2017, "in any realistic scenario, emissions cannot be cut fast enough to keep the total stock of greenhouse gases sufficiently small to limit the ris
Document 2:::
Roland Geyer is professor of industrial ecology at the Bren School of Environmental Science and Management, University of California at Santa Barbara. He is a specialist in the ecological impact of plastics.
In March 2021, Geyer wrote in The Guardian that humanity should ban fossil fuels, just at it had earlier banned tetraethyllead (TEL) and chlorofluorocarbons (CFC).
Document 3:::
Debra C. Roberts is a South African scientist and one of the six co-chairs of the Intergovernmental Panel on Climate Change. She was elected co-chair of Working Group II for the sixth assessment in 2015.
She is head of the Sustainable and Resilient City Initiatives Unit in eThekwini Municipality (Durban, South Africa).
Education and career
Roberts has a PhD in Urban Biogeography at the (then) University of Natal, South Africa (1991). After working as a post-doctoral researcher, she joined local government in 1994. She established the Environmental Planning and Climate Protection Department of eThekwini Municipality (Durban, South Africa) which she led from 1994 to 2016. In 2016 she was appointed to establish the Sustainable and Resilient City Initiatives Unit in Durban and is the city’s first Chief Resilience Officer. She is a part time professor at the University of Twente.
IPCC work
She was a lead author of Chapter 8 (Urban Areas) of Working Group II of the IPCC Fifth Assessment Report and was elected as Co-Chair of Working Group II for the IPCC’s sixth assessment cycle in 2015.
She was also a lead author of the IPCC Special Report on Global Warming of 1.5 °C.
Recognition
In 2014, the AfriCAN Climate Consortium gave Roberts their AfriCAN Climate Research Award.
She was the 2016 Barbara Ward Lecturer of the International Institute for Environment and Development. She is an honorary professor of the University of KwaZulu-Natal, and was listed in 2019 by public servant organization Apolitical as one of the 100 most influential people in climate change in the world. She received honorary doctorates from the University of Twente in 2022 and from the University of Cape Town in 2023.
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does the kyoto protocol focus on controlling?
A. Helium emissions
B. greenhouse gas emissions
C. carbonate gas emissions
D. Ozone emissions
Answer:
|
|
sciq-9114
|
multiple_choice
|
When methane burns, what is produced along with carbon dioxide?
|
[
"hydrogen",
"oxygen",
"nitrogen",
"water"
] |
D
|
Relavent Documents:
Document 0:::
Biogas is a gaseous renewable energy source produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester, biodigester or a bioreactor.
The gas composition is primarily methane () and carbon dioxide () and may have small amounts of hydrogen sulfide (), moisture and siloxanes. The gases methane and hydrogen can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for heating purpose, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.
After removal of carbon dioxide and hydrogen sulfide it can be compressed in the same way as natural gas and used to power motor vehicles. In the United Kingdom, for example, biogas is estimated to have the potential to replace around 17% of vehicle fuel. It qualifies for renewable energy subsidies in some parts of the world. Biogas can be cleaned and upgraded to natural gas standards, when it becomes bio-methane. Biogas is considered to be a renewable resource because its production-and-use cycle is continuous, and it generates no net carbon dioxide. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy.
Production
Biogas is produced by microorganisms, such as methanogens and sulfate-reducing bacteria, performing anaerobic respiration. Biogas can refer to gas produced naturally and industrially.
Natural
In soil, methane is produced in anaerobic environments by methanogens, but is mostly consumed in aerobic zones by methanotrophs. Methane emissions result when the balance favors methanogens. Wetland soils are the main natural source of methane. Other sources include ocea
Document 1:::
Hydrothermal carbonization (HTC) (also referred to as "aqueous carbonization at elevated temperature and pressure") is a chemical process for the conversion of organic compounds to structured carbons. It can be used to make a wide variety of nanostructured carbons, simple production of brown coal substitute, synthesis gas, liquid petroleum precursors and humus from biomass with release of energy. Technically the process imitates, within a few hours, the brown coal formation process (German "Inkohlung" literally "coalification") which takes place in nature over enormously longer geological time periods of 50,000 to 50 million years. It was investigated by Friedrich Bergius and first described in 1913.
Motivation
The carbon efficiency of most processes to convert organic matter to fuel is relatively low. I.e. the proportion of carbon contained in the biomass, which is later contained in the usable end product is relatively low:
In poorly designed systems, the unused carbon escapes into the atmosphere as carbon dioxide, or, when fermented, as methane. Both gases are greenhouse gases with methane even more climate-active on a per molecule basis than . In addition, the heat which is released in these processes is not generally used. Advanced modern systems capture nearly all the gases and use the heat as part of the process or for district heating.
The problem with the production of biodiesel from oil plants is the fact that only the energy contained in the fruit can be used. If the entire plant could be used for fuel production, the energy yield could be increased by a factor of three to five with the same cultivation area when growing fast-growing plants such as willow, poplar, miscanthus, hemp, reeds or forestry, while simultaneously reducing energy, fertilizer and herbicide use, with the possibility of using - for current energy plant cultivation - poor soil. Hydrothermal carbonization makes it possible - similar to the biomass-to-liquid process - to use almos
Document 2:::
The Fischer–Tropsch process (FT) is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen, known as syngas, into liquid hydrocarbons. These reactions occur in the presence of metal catalysts, typically at temperatures of and pressures of one to several tens of atmospheres. The Fischer–Tropsch process is an important reaction in both coal liquefaction and gas to liquids technology for producing liquid hydrocarbons.
In the usual implementation, carbon monoxide and hydrogen, the feedstocks for FT, are produced from coal, natural gas, or biomass in a process known as gasification. The process then converts these gases into synthetic lubrication oil and synthetic fuel. This process has received intermittent attention as a source of low-sulfur diesel fuel and to address the supply or cost of petroleum-derived hydrocarbons. Fischer-Tropsch process is discussed as a step of producing carbon-neutral liquid hydrocarbon fuels from CO2 and hydrogen.
The process was first developed by Franz Fischer and Hans Tropsch at the Kaiser Wilhelm Institute for Coal Research in Mülheim an der Ruhr, Germany, in 1925.
Reaction mechanism
The Fischer–Tropsch process involves a series of chemical reactions that produce a variety of hydrocarbons, ideally having the formula (CnH2n+2). The more useful reactions produce alkanes as follows:
(2n + 1) H2 + n CO → CnH2n+2 + n H2O
where n is typically 10–20. The formation of methane (n = 1) is unwanted. Most of the alkanes produced tend to be straight-chain, suitable as diesel fuel. In addition to alkane formation, competing reactions give small amounts of alkenes, as well as alcohols and other oxygenated hydrocarbons.
The reaction is a highly exothermic reaction due to a standard reaction enthalpy (ΔH) of −165 kJ/mol CO combined.
Fischer–Tropsch intermediates and elemental reactions
Converting a mixture of H2 and CO into aliphatic products is a multi-step reaction with several intermediate compounds. The
Document 3:::
The molecules that an organism uses as its carbon source for generating biomass are referred to as "carbon sources" in biology. It is possible for organic or inorganic sources of carbon. Heterotrophs must use organic molecules as both are a source of carbon and energy, in contrast to autotrophs, which can use inorganic materials as both a source of carbon and an abiotic source of energy, such as, for instance, inorganic chemical energy or light (photoautotrophs) (chemolithotrophs).
The carbon cycle, which begins with a carbon source that is inorganic, such as carbon dioxide and progresses through the carbon fixation process, includes the biological use of carbon as one of its components.[1]
Types of organism by carbon source
Heterotrophs
Autotrophs
Document 4:::
Butane () or n-butane is an alkane with the formula C4H10. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature and pressure. The name butane comes from the root but- (from butyric acid, named after the Greek word for butter) and the suffix -ane. It was discovered in crude petroleum in 1864 by Edmund Ronalds, who was the first to describe its properties, and commercialized by Walter O. Snelling in early 1910s.
Butane is one of a group of liquefied petroleum gases (LP gases). The others include propane, propylene, butadiene, butylene, isobutylene, and mixtures thereof. Butane burns more cleanly than both gasoline and coal.
History
The first synthesis of butane was accidentally achieved by British chemist Edward Frankland in 1849 from ethyl iodide and zinc, but he had not realized that the ethyl radical dimerized and misidentified the substance.
The proper discoverer of the butane called it "hydride of butyl", but already in the 1860s more names were used: "butyl hydride", "hydride of tetryl" and "tetryl hydride", "diethyl" or "ethyl ethylide" and others. August Wilhelm von Hofmann in his 1866 systemic nomenclature proposed the name "quartane", and the modern name was introduced to English from German around 1874.
Butane did not have much practical use until the 1910s, when W. Snelling identified butane and propane as components in gasoline and found that, if they were cooled, they could be stored in a volume-reduced liquified state in pressurized containers.
Density
The density of butane is highly dependent on temperature and pressure in the reservoir. For example, the density of liquid propane is 571.8±1 kg/m3 (for pressures up to 2MPa and temperature 27±0.2 °C), while the density of liquid butane is 625.5±0.7 kg/m3 (for pressures up to 2MPa and temperature -13±0.2 °C).
Isomers
Rotation about the central C−C bond produces two different conformations (trans and gauche) for n-butane.
Reactions
When oxyg
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When methane burns, what is produced along with carbon dioxide?
A. hydrogen
B. oxygen
C. nitrogen
D. water
Answer:
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sciq-3812
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multiple_choice
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What is the ratio of solutes in a solution to a volume of solvent in a solution known as?
|
[
"molarity",
"equilibrium",
"molality",
"osmolality"
] |
D
|
Relavent Documents:
Document 0:::
Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L (pronounced "osmolar"), in the same way that the molarity of a solution is expressed as "M" (pronounced "molar"). Whereas molarity measures the number of moles of solute per unit volume of solution, osmolarity measures the number of osmoles of solute particles per unit volume of solution. This value allows the measurement of the osmotic pressure of a solution and the determination of how the solvent will diffuse across a semipermeable membrane (osmosis) separating two solutions of different osmotic concentration.
Unit
The unit of osmotic concentration is the osmole. This is a non-SI unit of measurement that defines the number of moles of solute that contribute to the osmotic pressure of a solution. A milliosmole (mOsm) is 1/1,000 of an osmole. A microosmole (μOsm) (also spelled micro-osmole) is 1/1,000,000 of an osmole.
Types of solutes
Osmolarity is distinct from molarity because it measures osmoles of solute particles rather than moles of solute. The distinction arises because some compounds can dissociate in solution, whereas others cannot.
Ionic compounds, such as salts, can dissociate in solution into their constituent ions, so there is not a one-to-one relationship between the molarity and the osmolarity of a solution. For example, sodium chloride (NaCl) dissociates into Na+ and Cl− ions. Thus, for every 1 mole of NaCl in solution, there are 2 osmoles of solute particles (i.e., a 1 mol/L NaCl solution is a 2 osmol/L NaCl solution). Both sodium and chloride ions affect the osmotic pressure of the solution.
Document 1:::
Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular, of a solute in a solution, in terms of amount of substance per unit volume of solution. In chemistry, the most commonly used unit for molarity is the number of moles per liter, having the unit symbol mol/L or mol/dm3 in SI units. A solution with a concentration of 1 mol/L is said to be 1 molar, commonly designated as 1 M or 1 M. Molarity is often depicted with square brackets around the substance of interest; for example, the molarity of the hydrogen ion is depicted as [H+].
Definition
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase :
Here, is the amount of the solute in moles, is the number of constituent particles present in volume (in litres) of the solution, and is the Avogadro constant, since 2019 defined as exactly . The ratio is the number density .
In thermodynamics the use of molar concentration is often not convenient because the volume of most solutions slightly depends on temperature due to thermal expansion. This problem is usually resolved by introducing temperature correction factors, or by using a temperature-independent measure of concentration such as molality.
The reciprocal quantity represents the dilution (volume) which can appear in Ostwald's law of dilution.
Formality or analytical concentration
If a molecular entity dissociates in solution, the concentration refers to the original chemical formula in solution, the molar concentration is sometimes called formal concentration or formality (FA) or analytical concentration (cA). For example, if a sodium carbonate solution () has a formal concentration of c() = 1 mol/L, the molar concentra
Document 2:::
In chemistry and biology, the dilution ratio and dilution factor are two related (but slightly different) expressions of the change in concentration of a liquid substance when mixing it with another liquid substance. They are often used for simple dilutions, one in which a unit volume of a liquid material of interest is combined with an appropriate volume of a solvent liquid to achieve the desired concentration. The diluted material must be thoroughly mixed to achieve the true dilution.
For example, in a solution with a 1:5 dilution ratio, entails combining 1 unit volume of solute (the material to be diluted) with 5 unit volumes of the solvent to give 6 total units of total volume.
In photographic development, dilutions are normally given in a '1+x' format. For example '1+49' would typically mean 1 part concentrate and 49 parts water, meaning a 500ml solution would require 10ml concentrate and 490ml water.
Dilution factor
The "dilution factor" is an expression which describes the ratio of the aliquot volume to the final volume. Dilution factor is a notation often used in commercial assays. For example, in solution with a 1/5 dilution factor (which may be abbreviated as x5 dilution), entails combining 1 unit volume of solute (the material to be diluted) with (approximately) 4 unit volumes of the solvent to give 5 units of total volume. The following formulas can be used to calculate the volumes of solute () and solvent () to be used:
where is the desired total volume, and is the desired dilution factor number (the number in the position of if expressed as " dilution factor" or " dilution").
However, some solutions and mixtures take up slightly less volume than their components.
In other areas of science such as pharmacy, and in non-scientific usage, a dilution is normally given as a plain ratio of solvent to solute. For large factors, this confusion makes only a minor difference, but in precise work it can be important to make clear whether dilution ratio or
Document 3:::
In chemistry, molality is a measure of the amount of solute in a solution relative to a given mass of solvent. This contrasts with the definition of molarity which is based on a given volume of solution.
A commonly used unit for molality is the moles per kilogram (mol/kg). A solution of concentration 1 mol/kg is also sometimes denoted as 1 molal. The unit mol/kg requires that molar mass be expressed in kg/mol, instead of the usual g/mol or kg/kmol.
Definition
The molality (b), of a solution is defined as the amount of substance (in moles) of solute, nsolute, divided by the mass (in kg) of the solvent, msolvent:
In the case of solutions with more than one solvent, molality can be defined for the mixed solvent considered as a pure pseudo-solvent. Instead of mole solute per kilogram solvent as in the binary case, units are defined as mole solute per kilogram mixed solvent.
Origin
The term molality is formed in analogy to molarity which is the molar concentration of a solution. The earliest known use of the intensive property molality and of its adjectival unit, the now-deprecated molal, appears to have been published by G. N. Lewis and M. Randall in the 1923 publication of Thermodynamics and the Free Energies of Chemical Substances. Though the two terms are subject to being confused with one another, the molality and molarity of a dilute aqueous solution are nearly the same, as one kilogram of water (solvent) occupies the volume of 1 liter at room temperature and a small amount of solute has little effect on the volume.
Unit
The SI unit for molality is moles per kilogram of solvent.
A solution with a molality of 3 mol/kg is often described as "3 molal", "3 m" or "3 m". However, following the SI system of units, the National Institute of Standards and Technology, the United States authority on measurement, considers the term "molal" and the unit symbol "m" to be obsolete, and suggests mol/kg or a related unit of the SI.
Usage considerations
Advantages
The pri
Document 4:::
In chemistry and fluid mechanics, the volume fraction φi is defined as the volume of a constituent Vi divided by the volume of all constituents of the mixture V prior to mixing:
Being dimensionless, its unit is 1; it is expressed as a number, e.g., 0.18. It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e.g., 18%.
The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients).
The sum of all volume fractions of a mixture is equal to 1:
The volume fraction (percentage by volume, vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
Volume concentration and volume percent
Volume percent is the concentration of a certain solute, measured by volume, in a solution. It has as a denominator the volume of the mixture itself, as usual for expressions of concentration, rather than the total of all the individual components’ volumes prior to mixing:
Volume percent is usually used when the solution is made by mixing two fluids, such as liquids or gases. However, percentages are only additive for ideal gases.
The percentage by volume (vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
In the case of a mixture of ethanol and water, which are miscible in all proportions, the designation of solvent and solute is arbitrary. The volume of such a mixture is slightly less than the sum of the volumes of the components. Thus, by the above definition, the term "40% alcohol by volume" refers to a mixture of 40 volume units of ethanol with enough water to make a final volume of 100 units, rather than a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the ratio of solutes in a solution to a volume of solvent in a solution known as?
A. molarity
B. equilibrium
C. molality
D. osmolality
Answer:
|
|
ai2_arc-502
|
multiple_choice
|
A student mixed salt and sugar. Which statement describes the physical properties of salt and sugar after they were mixed?
|
[
"The sugar dissolved the salt.",
"The salt and sugar changed color.",
"The sugar and the salt were unchanged.",
"The salt and sugar formed a new material."
] |
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:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 2:::
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:::
In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid, but it can also be applied to liquids and gases dissolved in a liquid. A supersaturated solution is in a metastable state; it may return to equilibrium by separation of the excess of solute from the solution, by dilution of the solution by adding solvent, or by increasing the solubility of the solute in the solvent.
History
Early studies of the phenomenon were conducted with sodium sulfate, also known as Glauber's Salt because, unusually, the solubility of this salt in water may decrease with increasing temperature. Early studies have been summarised by Tomlinson. It was shown that the crystallization of a supersaturated solution does not simply come from its agitation, (the previous belief) but from solid matter entering and acting as a "starting" site for crystals to form, now called "seeds". Expanding upon this, Gay-Lussac brought attention to the kinematics of salt ions and the characteristics of the container having an impact on the supersaturation state. He was also able to expand upon the number of salts with which a supersaturated solution can be obtained. Later Henri Löwel came to the conclusion that both nuclei of the solution and the walls of the container have a catalyzing effect on the solution that cause crystallization. Explaining and providing a model for this phenomenon has been a task taken on by more recent research. Désiré Gernez contributed to this research by discovering that nuclei must be of the same salt that is being crystallized in order to promote crystallization.
Occurrence and examples
Solid precipitate, liquid solvent
A solution of a chemical compound in a liquid will become supersaturated when the temperature of the saturated solution is changed. In most cases solubility decreases wit
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.
A student mixed salt and sugar. Which statement describes the physical properties of salt and sugar after they were mixed?
A. The sugar dissolved the salt.
B. The salt and sugar changed color.
C. The sugar and the salt were unchanged.
D. The salt and sugar formed a new material.
Answer:
|
|
sciq-10503
|
multiple_choice
|
What kind of fats have been implicated in the presence of heart disease?
|
[
"animal fats",
"key fats",
"trans fats",
"plant fats"
] |
C
|
Relavent Documents:
Document 0:::
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond.
A saturated fat has no carbon to carbon double bonds, so the maximum possible number of hydrogens bonded to the carbons, and is "saturated" with hydrogen atoms. To form carbon to carbon double bonds, hydrogen atoms are removed from the carbon chain. In cellular metabolism, unsaturated fat molecules contain less energy (i.e., fewer calories) than an equivalent amount of saturated fat. The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds in the fatty acid) the more vulnerable it is to lipid peroxidation (rancidity). Antioxidants can protect unsaturated fat from lipid peroxidation.
Composition of common fats
In chemical analysis, fats are broken down to their constituent fatty acids, which can be analyzed in various ways. In one approach, fats undergo transesterification to give fatty acid methyl esters (FAMEs), which are amenable to separation and quantitation using by gas chromatography. Classically, unsaturated isomers were separated and identified by argentation thin-layer chromatography.
The saturated fatty acid components are almost exclusively stearic (C18) and palmitic acids (C16). Monounsaturated fats are almost exclusively oleic acid. Linolenic acid comprises most of the triunsaturated fatty acid component.
Chemistry and nutrition
Although polyunsaturated fats are protective against cardiac arrhythmias, a study of post-menopausal women with a relatively low fat intake showed that polyunsaturated fat is positively associated with progression of coronary atherosclerosis, whereas monounsaturated fat is not. This probably is an indication of the greater vulnerability of polyunsaturated fats to lipid peroxidation, against which vitamin E has been shown to be protective.
Examples
Document 1:::
In biochemistry and nutrition, a monounsaturated fat is a fat that contains a monounsaturated fatty acid (MUFA), a subclass of fatty acid characterized by having a double bond in the fatty acid chain with all of the remaining carbon atoms being single-bonded. By contrast, polyunsaturated fatty acids (PUFAs) have more than one double bond.
Molecular description
Monounsaturated fats are triglycerides containing one unsaturated fatty acid. Almost invariably that fatty acid is oleic acid (18:1 n−9). Palmitoleic acid (16:1 n−7) and cis-vaccenic acid (18:1 n−7) occur in small amounts in fats.
Health
Studies have shown that substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure. More physical activity was associated with a higher-oleic acid diet than one of a palmitic acid diet. From the study, it is shown that more monounsaturated fats lead to less anger and irritability.
Foods containing monounsaturated fats may affect low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol.
Levels of oleic acid along with other monounsaturated fatty acids in red blood cell membranes were positively associated with breast cancer risk. The saturation index (SI) of the same membranes was inversely associated with breast cancer risk. Monounsaturated fats and low SI in erythrocyte membranes are predictors of postmenopausal breast cancer. Both of these variables depend on the activity of the enzyme delta-9 desaturase (Δ9-d).
In children, consumption of monounsaturated oils is associated with healthier serum lipid profiles.
The Mediterranean diet is one heavily influenced by monounsaturated fats. People in Mediterranean countries consume more total fat than Northern European countries, but most of the fat is in the form of monounsaturated fatty acids from olive oil and omega-3 fatty acids from fish, vegetables, and certain meats like lamb, while consumption of satur
Document 2:::
A saponifiable lipid is part of the ester functional group. They are made up of long chain carboxylic (of fatty) acids connected to an alcoholic functional group through the ester linkage which can undergo a saponification reaction. The fatty acids are released upon base-catalyzed ester hydrolysis to form ionized salts. The primary saponifiable lipids are free fatty acids, neutral glycerolipids, glycerophospholipids, sphingolipids, and glycolipids.
By comparison, the non-saponifiable class of lipids is made up of terpenes, including fat-soluble A and E vitamins, and certain steroids, such as cholesterol.
Applications
Saponifiable lipids have relevant applications as a source of biofuel and can be extracted from various forms of biomass to produce biodiesel.
See also
Lipids
Simple lipid
Document 3:::
Vitamin D and Omega-3 Trial (VITAL) was a clinical trial designed to investigate the use of daily dietary supplements of vitamin D and fish oil.
The sponsor of the study was Brigham and Women's Hospital, collaborating with The National Cancer Institute, National Heart, Lung, and Blood Institute, Office of Dietary Supplements, National Institute of Neurological Disorders and Stroke, National Center for Complementary and Integrative Health, Pharmavite LLC, Pronova BioPharma and BASF.
The studied aimed to enroll 20,000 participants (women 55 or over, men 50 or over) who were randomized into one of four groups:
daily vitamin D (2000 IU) and fish oil (1 g);
daily vitamin D and fish-oil placebo;
daily vitamin-D placebo and fish oil;
daily vitamin-D placebo and fish-oil placebo.
Participants answered annual questionnaires to determine effects the risks of developing cancer, heart disease, stroke, osteoporosis, diabetes, memory loss and depression.
The outcome of this study was:
"The results of this trial indicate that supplementation with either n–3 fatty acid at a dose of 1 g/day or vitamin D3 at a dose of 2000 IU/day was not effective for primary prevention of CV or cancer events among healthy middle-aged men and women over 5 years of follow-up. There was also no difference in progression/development of CKD among patients with type 2 diabetes. This is one of the largest trials on this topic. The finding of a lower MI risk with n–3 fatty acid is hypothesis generating and deserves further study. The authors also noted some interaction with baseline fish consumption, with greater CV benefit observed among participants who had low fish intake at baseline."
Document 4:::
Lipidology is the scientific study of lipids. Lipids are a group of biological macromolecules that have a multitude of functions in the body. Clinical studies on lipid metabolism in the body have led to developments in therapeutic lipidology for disorders such as cardiovascular disease.
History
Compared to other biomedical fields, lipidology was long-neglected as the handling of oils, smears, and greases was unappealing to scientists and lipid separation was difficult. It was not until 2002 that lipidomics, the study of lipid networks and their interaction with other molecules, appeared in the scientific literature. Attention to the field was bolstered by the introduction of chromatography, spectrometry, and various forms of spectroscopy to the field, allowing lipids to be isolated and analyzed. The field was further popularized following the cytologic application of the electron microscope, which led scientists to find that many metabolic pathways take place within, along, and through the cell membrane - the properties of which are strongly influenced by lipid composition.
Clinical lipidology
The Framingham Heart Study and other epidemiological studies have found a correlation between lipoproteins and cardiovascular disease (CVD). Lipoproteins are generally a major target of study in lipidology since lipids are transported throughout the body in the form of lipoproteins.
A class of lipids known as phospholipids help make up what is known as lipoproteins, and a type of lipoprotein is called high density lipoprotein (HDL). A high concentration of high density lipoproteins-cholesterols (HDL-C) have what is known as a vasoprotective effect on the body, a finding that correlates with an enhanced cardiovascular effect. There is also a correlation between those with diseases such as chronic kidney disease, coronary artery disease, or diabetes mellitus and the possibility of low vasoprotective effect from HDL.
Another factor of CVD that is often overlooked involves the
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of fats have been implicated in the presence of heart disease?
A. animal fats
B. key fats
C. trans fats
D. plant fats
Answer:
|
|
sciq-3370
|
multiple_choice
|
Eukaryotic cells undergo what kinds of divisions that more primitive cells do not?
|
[
"meiosis",
"budding",
"homologous",
"mitosis"
] |
D
|
Relavent Documents:
Document 0:::
A cell type is a classification used to identify cells that share morphological or phenotypical features. A multicellular organism may contain cells of a number of widely differing and specialized cell types, such as muscle cells and skin cells, that differ both in appearance and function yet have identical genomic sequences. Cells may have the same genotype, but belong to different cell types due to the differential regulation of the genes they contain. Classification of a specific cell type is often done through the use of microscopy (such as those from the cluster of differentiation family that are commonly used for this purpose in immunology). Recent developments in single cell RNA sequencing facilitated classification of cell types based on shared gene expression patterns. This has led to the discovery of many new cell types in e.g. mouse cortex, hippocampus, dorsal root ganglion and spinal cord.
Animals have evolved a greater diversity of cell types in a multicellular body (100–150 different cell types), compared
with 10–20 in plants, fungi, and protists. The exact number of cell types is, however, undefined, and the Cell Ontology, as of 2021, lists over 2,300 different cell types.
Multicellular organisms
All higher multicellular organisms contain cells specialised for different functions. Most distinct cell types arise from a single totipotent cell that differentiates into hundreds of different cell types during the course of development. Differentiation of cells is driven by different environmental cues (such as cell–cell interaction) and intrinsic differences (such as those caused by the uneven distribution of molecules during division). Multicellular organisms are composed of cells that fall into two fundamental types: germ cells and somatic cells. During development, somatic cells will become more specialized and form the three primary germ layers: ectoderm, mesoderm, and endoderm. After formation of the three germ layers, cells will continue to special
Document 1:::
Cell potency is a cell's ability to differentiate into other cell types.
The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation potential, pluripotency, multipotency, oligopotency, and finally unipotency.
Totipotency
Totipotency (Lat. totipotentia, "ability for all [things]") is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells.
In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential, being able to differentiate into any embryonic cell, as well as any extraembryonic cell. In contrast, pluripotent cells can only differentiate into embryonic cells.
A fully differentiated cell can return to a state of totipotency. The conversion to totipotency is complex and not fully understood. In 2011, research revealed that cells may differentiate not into a fully totipotent cell, but instead into a "complex cellular variation" of totipotency. Stem cells resembling totipotent blastomeres from 2-cell stage embryos can arise spontaneously in mouse embryonic stem cell cultures and also can be induced to arise more frequently in vitro through down-regulation of the chromatin assembly activity of CAF-1.
The human development model can be used to describe how totipotent cells arise. Human development begins when a sperm fertilizes an egg and the resulting fertilized egg creates a single totipotent cell, a zygote. In the first hours after fertilization, this zygote divides into identical totipotent cells, which can later develop into any of the three germ layers of a human (endoderm, mesoderm, or ectoderm), or into cells of the placenta (cytotrophoblast or syncytiotrophoblast). After reaching a 16-cell stage, the totipotent cells of the morula 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:::
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:::
Embryomics is the identification, characterization and study of the diverse cell types which arise during embryogenesis, especially as this relates to the location and developmental history of cells in the embryo. Cell type may be determined according to several criteria: location in the developing embryo, gene expression as indicated by protein and nucleic acid markers and surface antigens, and also position on the embryogenic tree.
Embryome
There are many cell markers useful in distinguishing, classifying, separating and purifying the numerous cell types present at any given time in a developing organism. These cell markers consist of select RNAs and proteins present inside, and surface antigens present on the surface of, the cells making up the embryo. For any given cell type, these RNA and protein markers reflect the genes characteristically active in that cell type. The catalog of all these cell types and their characteristic markers is known as the organism's embryome. The word is a portmanteau of embryo and genome. “Embryome” may also refer to the totality of the physical cell markers themselves.
Embryogenesis
As an embryo develops from a fertilized egg, the single egg cell splits into many cells, which grow in number and migrate to the appropriate locations inside the embryo at appropriate times during development. As the embryo's cells grow in number and migrate, they also differentiate into an increasing number of different cell types, ultimately turning into the stable, specialized cell types characteristic of the adult organism. Each of the cells in an embryo contains the same genome, characteristic of the species, but the level of activity of each of the many thousands of genes that make up the complete genome varies with, and determines, a particular cell's type (e.g. neuron, bone cell, skin cell, muscle cell, etc.).
During embryo development (embryogenesis), many cell types are present which are not present in the adult organism. These temporary c
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Eukaryotic cells undergo what kinds of divisions that more primitive cells do not?
A. meiosis
B. budding
C. homologous
D. mitosis
Answer:
|
|
sciq-6649
|
multiple_choice
|
What is the amount of energy required to begin a chemical reaction known as?
|
[
"reaction energy",
"positive energy",
"decomposition energy",
"activation energy"
] |
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
Document 1:::
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 2:::
Activation, in chemistry and biology, is the process whereby something is prepared or excited for a subsequent reaction.
Chemistry
In chemistry, "activation" refers to the reversible transition of a molecule into a nearly identical chemical or physical state, with the defining characteristic being that this resultant state exhibits an increased propensity to undergo a specified chemical reaction. Thus, activation is conceptually the opposite of protection, in which the resulting state exhibits a decreased propensity to undergo a certain reaction.
The energy of activation specifies the amount of free energy the reactants must possess (in addition to their rest energy) in order to initiate their conversion into corresponding products—that is, in order to reach the transition state for the reaction. The energy needed for activation can be quite small, and often it is provided by the natural random thermal fluctuations of the molecules themselves (i.e. without any external sources of energy).
The branch of chemistry that deals with this topic is called chemical kinetics.
Biology
Biochemistry
In biochemistry, activation, specifically called bioactivation, is where enzymes or other biologically active molecules acquire the ability to perform their biological function, such as inactive proenzymes being converted into active enzymes that are able to catalyze their substrates' reactions into products. Bioactivation may also refer to the process where inactive prodrugs are converted into their active metabolites, or the toxication of protoxins into actual toxins.
An enzyme may be reversibly or irreversibly bioactivated. A major mechanism of irreversible bioactivation is where a piece of a protein is cut off by cleavage, producing an enzyme that will then stay active. A major mechanism of reversible bioactivation is substrate presentation where an enzyme translocates near its substrate. Another reversible reaction is where a cofactor binds to an enzyme, which then rem
Document 3:::
Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering. They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S — selectivity).
There are conflicting definitions in the literature for selectivity and yield, so each author's intended definition should be verified.
Conversion can be defined for (semi-)batch and continuous reactors and as instantaneous and overall conversion.
Assumptions
The following assumptions are made:
The following chemical reaction takes place:
,
where and are the stoichiometric coefficients. For multiple parallel reactions, the definitions can also be applied, either per reaction or using the limiting reaction.
Batch reaction assumes all reactants are added at the beginning.
Semi-Batch reaction assumes some reactants are added at the beginning and the rest fed during the batch.
Continuous reaction assumes reactants are fed and products leave the reactor continuously and in steady state.
Conversion
Conversion can be separated into instantaneous conversion and overall conversion. For continuous processes the two are the same, for batch and semi-batch there are important differences. Furthermore, for multiple reactants, conversion can be defined overall or per reactant.
Instantaneous conversion
Semi-batch
In this setting there are different definitions. One definition regards the instantaneous conversion as the ratio of the instantaneously converted amount to
the amount fed at any point in time:
.
with as the change of moles with time of species i.
This ratio can become larger than 1. It can be used to indicate whether reservoirs are built
up and it is ideally close to 1. When the feed stops, its value is not defined.
In semi-batch polymerisation,
Document 4:::
In chemistry, a reaction coordinate is an abstract one-dimensional coordinate chosen to represent progress along a reaction pathway. Where possible it is usually a geometric parameter that changes during the conversion of one or more molecular entities, such as bond length or bond angle. For example, in the homolytic dissociation of molecular hydrogen, an apt choice would be the coordinate corresponding to the bond length. Non-geometric parameters such as bond order are also used, but such direct representation of the reaction process can be difficult, especially for more complex reactions.
In molecular dynamics simulations, a reaction coordinate is called a collective variable.
A reaction coordinate parametrises reaction process at the level of the molecular entities involved. It differs from extent of reaction, which measures reaction progress in terms of the composition of the reaction system.
(Free) energy is often plotted against reaction coordinate(s) to demonstrate in schematic form the potential energy profile (an intersection of a potential energy surface) associated with the reaction.
In the formalism of transition-state theory the reaction coordinate for each reaction step is one of a set of curvilinear coordinates obtained from the conventional coordinates for the reactants, and leads smoothly among configurations, from reactants to products via the transition state. It is typically chosen to follow the path defined by potential energy gradient – shallowest ascent/steepest descent – from reactants to products.
Notes and references
Physical chemistry
Quantum chemistry
Theoretical chemistry
Computational chemistry
Molecular physics
Chemical kinetics
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the amount of energy required to begin a chemical reaction known as?
A. reaction energy
B. positive energy
C. decomposition energy
D. activation energy
Answer:
|
|
sciq-9010
|
multiple_choice
|
When the volume of a gas is decreased, what happens to its pressure?
|
[
"STAYS THE SAME",
"increases",
"LOWERS",
"drops"
] |
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:::
Gas networks simulation or gas pipeline simulation is a process of defining the mathematical model of gas transmission and gas distribution systems, which are usually composed of highly integrated pipe networks operating over a wide range of pressures. Simulation allows to predict the behaviour of gas network systems under different conditions. Such predictions can be effectively used to guide decisions regarding the design and operation of the real system.
Simulation types
Depending on the gas flow characteristics in the system there are two states that can be matter of simulation:
Steady state – the simulation does not take into account the gas flow characteristics' variations over time and described by the system of algebraic equations, in general nonlinear ones.
Unsteady state (transient flow analysis) – described either by a partial differential equation or a system of such equations. Gas flow characteristics are mainly functions of time.
Network topology
In the gas networks simulation and analysis, matrices turned out to be the natural way of expressing the problem. Any network can be described by set of matrices based on the network topology.
The network consists of one source node (reference node) L1, four load nodes (2, 3, 4 and 5) and seven pipes or branches. For network analysis it is necessary to select at least one reference node. Mathematically, the reference node is referred to as the independent node and all nodal and branch quantities are dependent on it. The pressure at source node is usually known, and this node is often used as the reference node. However, any node in the network may have its pressure defined and can be used as the reference node. A network may contain several sources or other pressure-defined nodes and these form a set of reference nodes for the network.The load nodes are points in the network where load values are known. These loads may be positive, negative or zero. A negative load represents a demand for gas from the
Document 2:::
Pressure experiments are experiments performed at pressures lower or higher than atmospheric pressure, called low-pressure experiments and high-pressure experiments, respectively. Pressure experiment are necessary because substances behave differently at different pressures. For example, water boils at a lower temperature at lower pressures. The equipment used for pressure experiments depends on whether the pressure is to be increased or decreased and by how much. A vacuum pump is used to remove the air out of a vacuum vessel for low-pressure experiments. High-pressures can be created with a piston-cylinder apparatus, up to () and . The piston is shifted with hydraulics, decreasing the volume inside the confining cylinder and increasing the pressure. For higher pressures, up to , a multi-anvil cell is used and for even higher pressures the diamond anvil cell. The diamond anvil cell is used to create extremely high pressures, as much as a million atmospheres (), though only over a small area. The current record is , but the sample size is confined to the order of tens of micrometres ().
Document 3:::
A pressure–volume diagram (or PV diagram, or volume–pressure loop) is used to describe corresponding changes in volume and pressure in a system. They are commonly used in thermodynamics, cardiovascular physiology, and respiratory physiology.
PV diagrams, originally called indicator diagrams, were developed in the 18th century as tools for understanding the efficiency of steam engines.
Description
A PV diagram plots the change in pressure P with respect to volume V for some process or processes. Typically in thermodynamics, the set of processes forms a cycle, so that upon completion of the cycle there has been no net change in state of the system; i.e. the device returns to the starting pressure and volume.
The figure shows the features of an idealized PV diagram. It shows a series of numbered states (1 through 4). The path between each state consists of some process (A through D) which alters the pressure or volume of the system (or both).
A key feature of the diagram is that the amount of energy expended or received by the system as work can be measured because the net work is represented by the area enclosed by the four lines.
In the figure, the processes 1-2-3 produce a work output, but processes from 3-4-1 require a smaller energy input to return to the starting position / state; so the net work is the difference between the two.
This figure is highly idealized, in so far as all the lines are straight and the corners are right angles. A diagram showing the changes in pressure and volume in a real device will show a more complex shape enclosing the work cycle. ().
History
The PV diagram, then called an indicator diagram, was developed in 1796 by James Watt and his employee John Southern. Volume was traced by a plate moving with the piston, while pressure was traced by a pressure gauge whose indicator moved at right angles to the piston. A pencil was used to draw the diagram. Watt used the diagram to make radical improvements to steam engine performance.
Document 4:::
The Timeline of the oil and gas industry in the United Kingdom is a selection of significant events in the history of the oil and gas sector in the United Kingdom.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When the volume of a gas is decreased, what happens to its pressure?
A. STAYS THE SAME
B. increases
C. LOWERS
D. drops
Answer:
|
|
sciq-4499
|
multiple_choice
|
If water from a spring can't flow downwards, it can spread out to form one of 2 things. what are they?
|
[
"ocean or sea",
"lake or ocean",
"ocean or river",
"pond or lake"
] |
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:::
Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matrix effects such as capillary action (which is caused by surface tension). The concept of water potential has proved useful in understanding and computing water movement within plants, animals, and soil. Water potential is typically expressed in potential energy per unit volume and very often is represented by the Greek letter ψ.
Water potential integrates a variety of different potential drivers of water movement, which may operate in the same or different directions. Within complex biological systems, many potential factors may be operating simultaneously. For example, the addition of solutes lowers the potential (negative vector), while an increase in pressure increases the potential (positive vector). If the flow is not restricted, water will move from an area of higher water potential to an area that is lower potential. A common example is water with dissolved salts, such as seawater or the fluid in a living cell. These solutions have negative water potential, relative to the pure water reference. With no restriction on flow, water will move from the locus of greater potential (pure water) to the locus of lesser (the solution); flow proceeds until the difference in potential is equalized or balanced by another water potential factor, such as pressure or elevation.
Components of water potential
Many different factors may affect the total water potential, and the sum of these potentials determines the overall water potential and the direction of water flow:
where:
is the reference correction,
is the solute or osmotic potential,
is the pressure component,
is the gravimetric component,
is the potential due to humidity, and
is the potential due to matrix effects (e.g., fluid cohesion and surface tension.)
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:::
In mathematics, the are three disjoint connected open sets of the plane or open unit square with the counterintuitive property that they all have the same boundary. In other words, for any point selected on the boundary of one of the lakes, the other two lakes' boundaries also contain that point.
More than two sets with the same boundary are said to have the Wada property; examples include Wada basins in dynamical systems. This property is rare in real-world systems.
The lakes of Wada were introduced by , who credited the discovery to Takeo Wada. His construction is similar to the construction by of an indecomposable continuum, and in fact it is possible for the common boundary of the three sets to be an indecomposable continuum.
Construction of the lakes of Wada
The Lakes of Wada are formed by starting with a closed unit square of dry land, and then digging 3 lakes according to the following rule:
On day n = 1, 2, 3,... extend lake n mod 3 (= 0, 1, 2) so that it is open and connected and passes within a distance 1/n of all remaining dry land. This should be done so that the remaining dry land remains homeomorphic to a closed unit square.
After an infinite number of days, the three lakes are still disjoint connected open sets, and the remaining dry land is the boundary of each of the 3 lakes.
For example, the first five days might be (see the image on the right):
Dig a blue lake of width 1/3 passing within /3 of all dry land.
Dig a red lake of width 1/32 passing within /32 of all dry land.
Dig a green lake of width 1/33 passing within /33 of all dry land.
Extend the blue lake by a channel of width 1/34 passing within /34 of all dry land. (The small channel connects the thin blue lake to the thick one, near the middle of the image.)
Extend the red lake by a channel of width 1/35 passing within /35 of all dry land. (The tiny channel connects the thin red lake to the thick one, near the top left of the image.)
A variation of this construction can produce
Document 4:::
A marine outfall (or ocean outfall) is a pipeline or tunnel that discharges municipal or industrial wastewater, stormwater, combined sewer overflows (CSOs), cooling water, or brine effluents from water desalination plants to the sea. Usually they discharge under the sea's surface (submarine outfall). In the case of municipal wastewater, effluent is often being discharged after having undergone no or only primary treatment, with the intention of using the assimilative capacity of the sea for further treatment. Submarine outfalls are common throughout the world and probably number in the thousands. The light intensity and salinity in natural sea water disinfects the wastewater to ocean outfall system significantly. More than 200 outfalls alone have been listed in a single international database maintained by the Institute for Hydromechanics at Karlsruhe University for the International Association of Hydraulic Engineering and Research (IAHR) / International Water Association (IWA) Committee on Marine Outfall Systems.
The world's first marine outfall was built in Santa Monica, United States, in 1910. In Latin America and the Caribbean there were 134 outfalls with more than 500 m length in 2006 for wastewater disposal alone, according to a survey by the Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS) of PAHO. According to the survey, the largest number of municipal wastewater outfalls in the region exist in Venezuela (39), Chile (39) and Brazil (22). The world's largest marine outfall stems from the Deer Island Waste Water Treatment Plant located in Boston, United States. Currently, Boston has approximately 235 miles of combined sewers and 37 active CSO outfalls. Many outfalls are simply known by a public used name, e.g. Boston Outfall.
Advantages
The main advantages of marine outfalls for the discharge of wastewater are:
the natural dilution and dispersion of organic matter, pathogens and other pollutants
the ability to keep the sewa
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
If water from a spring can't flow downwards, it can spread out to form one of 2 things. what are they?
A. ocean or sea
B. lake or ocean
C. ocean or river
D. pond or lake
Answer:
|
|
ai2_arc-886
|
multiple_choice
|
A beaker containing 50 milliliters of ice is placed on a windowsill. After several hours, the ice melts. What property of the ice did not change when it melted?
|
[
"the mass",
"the volume",
"the temperature",
"the state of matter"
] |
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:::
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 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:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 4:::
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.
A beaker containing 50 milliliters of ice is placed on a windowsill. After several hours, the ice melts. What property of the ice did not change when it melted?
A. the mass
B. the volume
C. the temperature
D. the state of matter
Answer:
|
|
sciq-10364
|
multiple_choice
|
What is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane?
|
[
"ectocytosis",
"endocytosis",
"autolysis",
"metastasis"
] |
B
|
Relavent Documents:
Document 0:::
Trans-endocytosis is the biological process where material created in one cell undergoes endocytosis (enters) into another cell. If the material is large enough, this can be observed using an electron microscope. Trans-endocytosis from neurons to glia has been observed using time-lapse microscopy.
Trans-endocytosis also applies to molecules. For example, this process is involved when a part of the protein Notch is cleaved off and undergoes endocytosis into its neighboring cell. Without Notch trans-endocytosis, there would be too many neurons in a developing embryo. Trans-endocytosis is also involved in cell movement when the protein ephrin is bound by its receptor from a neighboring cell.
Document 1:::
-Cytosis is a suffix that either refers to certain aspects of cells ie cellular process or phenomenon or sometimes refers to predominance of certain type of cells. It essentially means "of the cell". Sometimes it may be shortened to -osis (necrosis, apoptosis) and may be related to some of the processes ending with -esis (eg diapedesis, or emperipolesis, cytokinesis) or similar suffixes.
There are three main types of cytosis: endocytosis (into the cell), exocytosis (out of the cell), and transcytosis (through the cell, in and out).
Etymology and pronunciation
The word cytosis () uses combining forms of cyto- and -osis, reflecting a cellular process. The term was coined by Novikoff in 1961.
Processes related to subcellular entry or exit
Endocytosis
Endocytosis is when a cell absorbs a molecule, such as a protein, from outside the cell by engulfing it with the cell membrane. It is used by most cells, because many critical substances are large polar molecules that cannot pass through the cell membrane. The two major types of endocytosis are pinocytosis and phagocytosis.
Pinocytosis
Pinocytosis, also known as cell drinking, is the absorption of small aqueous particles along with the membrane receptors that recognize them. It is an example of fluid phase endocytosis and is usually a continuous process within the cell. The particles are absorbed through the use of clathrin-coated pits. These clathrin-coated pits are short lived and serve only to form a vesicle for transfer of particles to the lysosome. The clathrin-coated pit invaginates into the cytosol and forms a clathrin-coated vesicle. The clathrin proteins will then dissociate. What is left is known as an early endosome. The early endosome merges with a late endosome. This is the vesicle that allows the particles that were endocytosed to be transported into the lysosome. Here there are hydrolytic enzymes that will degrade the contents of the late endosome. Sometimes, rather than being degraded, the receptors t
Document 2:::
Extracellular space refers to the part of a multicellular organism outside the cells, usually taken to be outside the plasma membranes, and occupied by fluid. This is distinguished from intracellular space, which is inside the cells.
The composition of the extracellular space includes metabolites, ions, proteins, and many other substances that might affect cellular function. For example, neurotransmitters "jump" from cell to cell to facilitate the transmission of an electric current in the nervous system. Hormones also act by travelling the extracellular space towards cell receptors.
In cell biology, molecular biology and related fields, the word extracellular (or sometimes extracellular space) means "outside the cell". This space is usually taken to be outside the plasma membranes, and occupied by fluid (see extracellular matrix). The term is used in contrast to intracellular (inside the cell).
According to the Gene Ontology, the extracellular space is a cellular component defined as: "That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid. For multicellular organisms, the extracellular space refers to everything outside a cell, but still within the organism (excluding the extracellular matrix). Gene products from a multi-cellular organism that are secreted from a cell into the interstitial fluid or blood can therefore be annotated to this term".
The composition of the extracellular space includes metabolites, ions, various proteins and non-protein substances (e.g. DNA, RNA, lipids, microbial products etc.), and particles such as extracellular vesicles that might affect cellular function. For example, hormones, growth factors, cytokines and chemokines act by travelling the extracellular space towards biochemical receptors on cells. Other proteins that are active outside the cell are various enzymes, including digestive enzymes (Trypsin, Pepsin), extracellular proteinases (Matrix me
Document 3:::
Microtentacles are microtubule-based membrane protrusions that occur in detached cells. They were discovered by scientists studying metastatic breast cancer cells at the University of Maryland, Baltimore.
These novel structures are distinct from classical actin based extensions of adherent cells, persist for days in breast tumor lines that are resistant to apoptosis, and aid in the reattachment to matrix or cell monolayers.
The formation of microtentacles (McTNs) in detached or circulating tumor cells may promote seeding of bloodborne metastatic disease.
Document 4:::
In cellular biology, pinocytosis, otherwise known as fluid endocytosis and bulk-phase pinocytosis, is a mode of endocytosis in which small molecules dissolved in extracellular fluid are brought into the cell through an invagination of the cell membrane, resulting in their containment within a small vesicle inside the cell. These pinocytotic vesicles then typically fuse with early endosomes to hydrolyze (break down) the particles.
Pinocytosis is variably subdivided into categories depending on the molecular mechanism and the fate of the internalized molecules.
Function
In humans, this process occurs primarily for absorption of fat droplets. In endocytosis the cell plasma membrane extends and folds around desired extracellular material, forming a pouch that pinches off creating an internalized vesicle. The invaginated pinocytosis vesicles are much smaller than those generated by phagocytosis. The vesicles eventually fuse with the lysosome, whereupon the vesicle contents are digested. Pinocytosis involves a considerable investment of cellular energy in the form of ATP.
Pinocytosis and ATP
Pinocytosis is used primarily for clearing extracellular fluids (ECF) and as part of immune surveillance. In contrast to phagocytosis, it generates very small amounts of ATP from the wastes of alternative substances such as lipids (fat). Unlike receptor-mediated endocytosis, pinocytosis is nonspecific in the substances that it transport: the cell takes in surrounding fluids, including all solutes present.
Etymology and pronunciation
The word pinocytosis () uses combining forms of pino- + cyto- + -osis, all Neo-Latin from Greek, reflecting píno, to drink, and cytosis. The term was proposed by W. H. Lewis in 1931.
Non-specific, adsorptive pinocytosis
Non-specific, adsorptive pinocytosis is a form of endocytosis, a process in which small particles are taken in by a cell by splitting off small vesicles from the cell membrane. Cationic proteins bind to the negative cell surface and
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane?
A. ectocytosis
B. endocytosis
C. autolysis
D. metastasis
Answer:
|
|
scienceQA-2176
|
multiple_choice
|
What do these two changes have in common?
boiling sugar to make caramel
water boiling on a stove
|
[
"Both are only physical changes.",
"Both are caused by heating.",
"Both are caused by cooling.",
"Both are chemical changes."
] |
B
|
Step 1: Think about each change.
Boiling sugar to make caramel is a chemical change. The heat causes the sugar to change into a different type of matter. Unlike sugar, the new matter is brown and sticky.
Water boiling on the stove is a change of state. So, it is a physical change. The liquid changes into a gas, but a different type of matter is not formed.
Step 2: Look at each answer choice.
Both are only physical changes.
Water boiling is a physical change. But boiling sugar to make caramel is not.
Both are chemical changes.
Boiling sugar to make caramel is a chemical change. But water boiling is not.
Both are caused by heating.
Both changes are caused by heating.
Both are caused by cooling.
Neither change is caused by cooling.
|
Relavent Documents:
Document 0:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
Thermofluids is a branch of science and engineering encompassing four intersecting fields:
Heat transfer
Thermodynamics
Fluid mechanics
Combustion
The term is a combination of "thermo", referring to heat, and "fluids", which refers to liquids, gases and vapors. Temperature, pressure, equations of state, and transport laws all play an important role in thermofluid problems. Phase transition and chemical reactions may also be important in a thermofluid context. The subject is sometimes also referred to as "thermal fluids".
Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the transfer of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer. Engineers also consider the transfer of mass of differing chemical species, either cold or hot, to achieve heat transfer.
Sections include :
Energy transfer by heat, work and mass
Laws of thermodynamics
Entropy
Refrigeration Techniques
Properties and nature of pure substances
Applications
Engineering : Predicting and analysing the performance of machines
Thermodynamics
Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.
Fluid mechanics
Fluid Mechanics the study of the physical forces at work during fluid flow. Fluid mechanics can be divided into fluid kinematics, the study of fluid motion, and fluid kinetics, the study of the effect of forces on fluid motion. Fluid mechanics can further be divided into fluid statics, the study of fluids at rest, and fluid dynamics, the study of fluids in motion. Some of its more interesting concepts include momentum and reactive forces in fluid flow and fluid machinery theory and performance.
Sections include:
Flu
Document 3:::
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:::
Boiling is the rapid phase transition from liquid to gas or vapor; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. Boiling and evaporation are the two main forms of liquid vapourization.
There are two main types of boiling: nucleate boiling where small bubbles of vapour form at discrete points, and critical heat flux boiling where the boiling surface is heated above a certain critical temperature and a film of vapour forms on the surface. Transition boiling is an intermediate, unstable form of boiling with elements of both types. The boiling point of water is 100 °C or 212 °F but is lower with the decreased atmospheric pressure found at higher altitudes.
Boiling water is used as a method of making it potable by killing microbes and viruses that may be present. The sensitivity of different micro-organisms to heat varies, but if water is held at for one minute, most micro-organisms and viruses are inactivated. Ten minutes at a temperature of 70 °C (158 °F) is also sufficient to inactivate most bacteria.
Boiling water is also used in several cooking methods including boiling, steaming, and poaching.
Types
Free convection
The lowest heat flux seen in boiling is only sufficient to cause [natural convection], where the warmer fluid rises due to its slightly lower density. This condition occurs only when the superheat is very low, meaning that the hot surface near the fluid is nearly the same temperature as the boiling point.
Nucleate
Nucleate boiling is characterised by the growth of bubbles or pops on a heated surface (heterogeneous nucleation), which rises from discrete points on a surface, whose temperature is only slightly above the temperature of the liquid. In general, the number of nucleation sites is increased by an increasing surface temperature.
An irregular surface of the boiling
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?
boiling sugar to make caramel
water boiling on a stove
A. Both are only physical changes.
B. Both are caused by heating.
C. Both are caused by cooling.
D. Both are chemical changes.
Answer:
|
sciq-3780
|
multiple_choice
|
What are a class of tetrapod vertebrates that produce amniotic eggs called?
|
[
"amphibians",
"insects",
"reptiles",
"mammals"
] |
C
|
Relavent Documents:
Document 0:::
Amniotes are animals belonging to the clade Amniota, a large group of tetrapod vertebrates that comprises the vast majority of living terrestrial vertebrates. Amniotes evolved from amphibian ancestors during the Carboniferous period and further diverged into two groups, namely the sauropsids (including all reptiles and birds) and synapsids (including mammals and extinct ancestors like "pelycosaurs" and therapsids). They are distinguished from the other living tetrapod clade — the lissamphibians (frogs/toads, salamanders, newts and caecilians) — by the development of three extraembryonic membranes (amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage), thicker and keratinized skin, and costal respiration (breathing by expanding/constricting the rib cage).
All three main amniote features listed above, namely the presence of an amniotic buffer, water-impermeable cutes and a robust air-breathing respiratory system, are very important for living on land as true terrestrial animals — the ability to survive and procreate in locations away from water bodies, better homeostasis in drier environments, and more efficient non-aquatic gas exchange to power terrestrial locomotions, although they might still require regular access to drinking water for rehydration like the semiaquatic amphibians do. Because the amnion and the fluid it secretes shields the embryo from environmental fluctuations, amniotes can reproduce on dry land by either laying shelled eggs (reptiles, birds and monotremes) or nurturing fertilized eggs within the mother (marsupial and placental mammals), unlike anamniotes (fish and amphibians) that have to spawn in or closely adjacent to aquatic environments. Additional unique features are the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys, which are more complex, the presence of an astragalus for better extremity range of motion, and the complete loss o
Document 1:::
The "Standard Event System" (SES) to Study Vertebrate Embryos was developed in 2009 to establish a common language in comparative embryology. Homologous developmental characters are defined therein and should be recognisable in all vertebrate embryos. The SES includes a protocol on how to describe and depict vertebrate embryonic characters. The SES was initially developed for external developmental characters of organogenesis, particularly for turtle embryos. However, it is expandable both taxonomically and in regard to anatomical or molecular characters. This article should act as an overview on the species staged with SES and document the expansions of this system. New entries need to be validated based on the citation of scientific publications. The guideline on how to establish new SES-characters and to describe species can be found in the original paper of Werneburg (2009).
SES-characters are used to reconstruct ancestral developmental sequences in evolution such as that of the last common ancestor of placental mammals. Also the plasticity of developmental characters can be documented and analysed.
SES-staged species
Overview on the vertebrate species staged with SES.
SES-characters
New SES-characters are continuously described in new publications. Currently, characters of organogenesis are described for Vertebrata (V), Gnathostomata (G), Tetrapoda (T), Amniota (A), Sauropsida (S), Squamata (SQ), Mammalia (M), and Monotremata (MO). In total, 166 SES-characters are currently defined.
Document 2:::
The anamniotes are an informal group of craniates comprising all fishes and amphibians, which lay their eggs in aquatic environments. They are distinguished from the amniotes (reptiles, birds and mammals), which can reproduce on dry land either by laying shelled eggs or by carrying fertilized eggs within the female. Older sources, particularly before the 20th century, may refer to anamniotes as "lower vertebrates" and amniotes as "higher vertebrates", based on the antiquated idea of the evolutionary great chain of being.
The name "anamniote" is a back-formation word created by adding the prefix an- to the word amniote, which in turn refers to the amnion, an extraembryonic membrane present during the amniotes' embryonic development which serves as a biochemical barrier that shields the embryo from environmental fluctuations by regulating the oxygen, carbon dioxide and metabolic waste exchanges and secreting a cushioning fluid. As the name suggests, anamniote embryos lack an amnion during embryonic development, and therefore rely on the presence of external water to provide oxygen and help dilute and excrete waste products (particularly ammonia) via diffusion in order for the embryo to complete development without being intoxicated by their own metabolites. This means anamniotes are almost always dependent on an aqueous (or at least very moist) environment for reproduction and are thus restricted to spawning in or near water bodies. They are also highly sensitive to chemical and temperature variation in the surrounding water, and are also more vulnerable to egg predation and parasitism.
During their life cycle, all anamniote classes pass through a completely aquatic egg stage, as well as an aquatic larval stage during which all hatchlings are gill-dependent and morphologically resemble tiny finless fish (known as a fry or a tadpole for fish and amphibians, respectively), before metamorphosizing into juvenile and adult forms (which might be aquatic, semiaquatic or e
Document 3:::
Early stages of embryogenesis of tailless amphibians
Embryogenesis in living creatures occurs in different ways depending on class and species. One of the most basic criteria of such development is independence from a water habitat.
Amphibians were the earliest animals to adapt themselves to a mixed environment containing both water and dry land.
The embryonic development of tailless amphibians is presented below using the African clawed frog (Xenopus laevis) and the northern leopard frog (Rana pipiens) as examples.
The oocyte in these frog species is a polarized cell - it has specified axes and poles. The animal pole of the cell contains pigment cells, whereas the vegetal pole (the yolk) contains most of the nutritive material. The pigment is composed of light-absorbing melanin.
The sperm cell enters the oocyte in the region of the animal pole. Two blocks - defensive mechanisms meant to prevent polyspermy - occur: the fast block and the slow block. A relatively short time after fertilization, the cortical cytoplasm (located just beneath the cell membrane) rotates by 30 degrees. This results in the creation of the gray crescent. Its establishment determines the location of the dorsal and ventral (up-down) axis, as well as of the anterior and posterior (front-back) axis and the dextro-sinistral (left-right) axis of the embryo.
Embryo cleavage
The cleavage (cell division) of a frog’s embryo is complete and uneven, because most of the yolk is gathered in the vegetal region. The first cleavage runs across the animal-vegetal axis, dividing the gray crescent into two parts. The second cleavage also cuts through the gray crescent, although always running perpendicularly to the first one. This results in the creation of four identical blastomeres - separate cells now forming the embryo. The third cleavage runs equatorially and closer to the animal pole, thus creating blastomeres of unequal size (micromeres in the animal region and macromeres in the vegetal region).
Document 4:::
Vegetal rotation is a morphogenetic movement that drives mesoderm internalization during gastrulation in amphibian embryos. The internalization of vegetal cells prior to gastrulation was first observed in the 1930s by Abraham Mandel Schechtman through the use of vital dye labeling experiments in Triturus torosus embryos. More recently, Winklbauer and Schürfeld (1999) described the internal movements in more detail using pregastrular explants of Xenopus laevis.
Gastrulation in amphibians is initiated by formation of bottle cells at the dorsal marginal zone, followed by involution of prospective mesodermal cells. The mesoderm and endoderm then migrate animally along the blastocoel roof, driven in part by movement of the vegetal endoderm cells. In Xenopus embryos in which the blastocoel roof is removed prior to gastrulation, the movement of vegetal cells toward the blastocoel and their intercalation into the blastocoel floor causes the floor to spread, pushing the dorsal edge downward. In the context of the embryo, active vegetal rotation, together with epiboly of the animal cap ectodermal cells, appears to bring the vegetal mesendoderm into contact with the blastocoel roof. This movement results in formation of Brachet's cleft. As gastrulation continues, further spreading of the blastocoel floor by upward movement of vegetal cells contributes to the advancement of the mesendoderm along the blastocoel roof. This process is aided by crawling mesodermal cells at the leading edge of the mesendoderm. Much like bottle cell formation at the blastopore lip, vegetal rotation begins at the dorsal side of the embryo, and spreads laterally to the ventral side. These processes, however, occur independently. While vegetal rotation appears to be important prior to and in the early stages of gastrulation, by stages 10.5–11, vegetal rotation ceases and further involution appears to be driven primarily by cell rearrangements.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are a class of tetrapod vertebrates that produce amniotic eggs called?
A. amphibians
B. insects
C. reptiles
D. mammals
Answer:
|
|
sciq-9586
|
multiple_choice
|
When cardiac muscle contracts, the heart does what?
|
[
"cardiac arrest",
"irregular heartbeat",
"pumps blood",
"heart murmur"
] |
C
|
Relavent Documents:
Document 0:::
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix.
Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's myofilaments to slide past each other in a process called excitation-contraction coupling.
Diseases of the heart muscle known as cardiomyopathies are of major importance. These include ischemic conditions caused by a restricted blood supply to the muscle such as angina, and myocardial infarction.
Structure
Gross anatomy
Cardiac muscle tissue or myocardium forms the bulk of the heart. The heart wall is a three-layered structure with a thick layer of myocardium sandwiched between the inner endocardium and the outer epicardium (also known as the visceral pericardium). The inner endocardium lines the cardiac chambers, covers the cardiac valves, and joins with the endothelium that lines the blood vessels that connect to the heart. On the outer aspect of the myocardium is the epicardium which forms part of the pericardial sac that surrounds, protects, and lubricates the heart.
Within the myocardium, there are several sheets of cardiac muscle cells or cardiomyocytes. The sheets of muscle that wrap around the left ventricle clos
Document 1:::
Cardiophysics is an interdisciplinary science that stands at the junction of cardiology and medical physics, with researchers using the methods of, and theories from, physics to study cardiovascular system at different levels of its organisation, from the molecular scale to whole organisms. Being formed historically as part of systems biology, cardiophysics designed to reveal connections between the physical mechanisms, underlying the organization of the cardiovascular system, and biological features of its functioning.
Zbigniew R. Struzik seems to be a first author who used the term in a scientific publication in 2004.
One can use interchangeably also the terms cardiovascular physics.
See also
Medical physics
Important publications in medical physics
Biomedicine
Biomedical engineering
Physiome
Nanomedicine
Document 2:::
The Frank–Starling law of the heart (also known as Starling's law and the Frank–Starling mechanism) represents the relationship between stroke volume and end diastolic volume. The law states that the stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles, before contraction (the end diastolic volume), when all other factors remain constant. As a larger volume of blood flows into the ventricle, the blood stretches cardiac muscle, leading to an increase in the force of contraction. The Frank-Starling mechanism allows the cardiac output to be synchronized with the venous return, arterial blood supply and humoral length, without depending upon external regulation to make alterations. The physiological importance of the mechanism lies mainly in maintaining left and right ventricular output equality.
Physiology
The Frank-Starling mechanism occurs as the result of the length-tension relationship observed in striated muscle, including for example skeletal muscles, arthropod muscle and cardiac (heart) muscle. As striated muscle is stretched, active tension is created by altering the overlap of thick and thin filaments. The greatest isometric active tension is developed when a muscle is at its optimal length. In most relaxed skeletal muscle fibers, passive elastic properties maintain the muscle fibers length near optimal, as determined usually by the fixed distance between the attachment points of tendons to the bones (or the exoskeleton of arthropods) at either end of the muscle. In contrast, the relaxed sarcomere length of cardiac muscle cells, in a resting ventricle, is lower than the optimal length for contraction. There is no bone to fix sarcomere length in the heart (of any animal) so sarcomere length is very variable and depends directly upon blood filling and thereby expanding the heart chambers. In the human heart, maximal force is generated with an initial sarcomere length of 2.2 micrometers, a length which is rare
Document 3:::
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. After emptying, the heart relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again contracting to pump blood to the lungs and those systems. A normally performing heart must be fully expanded before it can efficiently pump again. Assuming a healthy heart and a typical rate of 70 to 75 beats per minute, each cardiac cycle, or heartbeat, takes about 0.8 second to complete the cycle.
There are two atrial and two ventricle chambers of the heart; they are paired as the left heart and the right heart—that is, the left atrium with the left ventricle, the right atrium with the right ventricle—and they work in concert to repeat the cardiac cycle continuously (see cycle diagram at right margin). At the start of the cycle, during ventricular diastole–early, the heart relaxes and expands while receiving blood into both ventricles through both atria; then, near the end of ventricular diastole–late, the two atria begin to contract (atrial systole), and each atrium pumps blood into the ventricle below it. During ventricular systole the ventricles are contracting and vigorously pulsing (or ejecting) two separated blood supplies from the heart—one to the lungs and one to all other body organs and systems—while the two atria are relaxed (atrial diastole). This precise coordination ensures that blood is efficiently collected and circulated throughout the body.
The mitral and tricuspid valves, also known as the atrioventricular, or AV valves, open during ventricular diastole to permit filling. Late in the filling period the atria begin to contract (atrial systole) forcing a final crop of blood into the ventric
Document 4:::
The Cardiac Electrophysiology Society (CES) is an international society of basic and clinical scientists and physicians interested in cardiac electrophysiology and arrhythmias. The Cardiac Electrophysiology Society's founder was George Burch in 1949 and its current president is Jonathan C. Makielski, M.D.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When cardiac muscle contracts, the heart does what?
A. cardiac arrest
B. irregular heartbeat
C. pumps blood
D. heart murmur
Answer:
|
|
sciq-7977
|
multiple_choice
|
Karyotyping shows whether what structures, which contain genetic information, are normal in number and appearance?
|
[
"chromosomes",
"ribosomes",
"nucleoids",
"neutrons"
] |
A
|
Relavent Documents:
Document 0:::
A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities.
A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are generally organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography in the metaphase of the cell cycle, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well unless the resolution is high enough to distinguish them. The study of whole sets of chromosomes is sometimes known as karyology.
Karyotypes describe the chromosome count of an organism and what these chromosomes look like under a light microscope. Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics. The preparation and study of karyotypes is part of cytogenetics.
The basic number of chromosomes in the somatic cells of an individual or a species is called the somatic number and is designated 2n. In the germ-line (the sex cells) the chromosome number is n (humans: n = 23).p28 Thus, in humans 2n = 46.
So, in normal diploid organisms, autosomal chromosomes are present in two copies. There may, or may not, be sex chromosomes. Polyploid cells have multiple copies of chromosomes and haploid cells have single copies.
Karyotypes can be used for
Document 1:::
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms. This number, along with the visual appearance of the chromosome, is known as the karyotype, and can be found by looking at the chromosomes through a microscope. Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics. The preparation and study of karyotypes is part of cytogenetics.
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:::
This list of life sciences comprises the branches of science that involve the scientific study of life – such as microorganisms, plants, and animals including human beings. This science is one of the two major branches of natural science, the other being physical science, which is concerned with non-living matter. Biology is the overall natural science that studies life, with the other life sciences as its sub-disciplines.
Some life sciences focus on a specific type of organism. For example, zoology is the study of animals, while botany is the study of plants. Other life sciences focus on aspects common to all or many life forms, such as anatomy and genetics. Some focus on the micro-scale (e.g. molecular biology, biochemistry) other on larger scales (e.g. cytology, immunology, ethology, pharmacy, ecology). Another major branch of life sciences involves understanding the mindneuroscience. Life sciences discoveries are helpful in improving the quality and standard of life and have applications in health, agriculture, medicine, and the pharmaceutical and food science industries. For example, it has provided information on certain diseases which has overall aided in the understanding of human health.
Basic life science branches
Biology – scientific study of life
Anatomy – study of form and function, in plants, animals, and other organisms, or specifically in humans
Astrobiology – the study of the formation and presence of life in the universe
Bacteriology – study of bacteria
Biotechnology – study of combination of both the living organism and technology
Biochemistry – study of the chemical reactions required for life to exist and function, usually a focus on the cellular level
Bioinformatics – developing of methods or software tools for storing, retrieving, organizing and analyzing biological data to generate useful biological knowledge
Biolinguistics – the study of the biology and evolution of language.
Biological anthropology – the study of humans, non-hum
Document 4:::
Genetics (from Ancient Greek , “genite” and that from , “origin”), a discipline of biology, is the science of heredity and variation in living organisms.
Articles (arranged alphabetically) related to genetics include:
#
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Karyotyping shows whether what structures, which contain genetic information, are normal in number and appearance?
A. chromosomes
B. ribosomes
C. nucleoids
D. neutrons
Answer:
|
|
ai2_arc-89
|
multiple_choice
|
Which factor can increase the amount of sulfur dioxide in the air?
|
[
"applying too much fertilizer to agricultural fields",
"operation of coal-fired electric generating plants",
"a hot summer day",
"too much rain"
] |
B
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 2:::
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:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which factor can increase the amount of sulfur dioxide in the air?
A. applying too much fertilizer to agricultural fields
B. operation of coal-fired electric generating plants
C. a hot summer day
D. too much rain
Answer:
|
|
sciq-808
|
multiple_choice
|
How are classic sedimentary rocks group?
|
[
"density",
"size of sediment",
"particle depth",
"color"
] |
B
|
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:::
The Index to Marine & Lacustrine Geological Samples is a collaboration between multiple institutions and agencies that operate geological sample repositories. The purpose of the database is to help researchers locate sea floor and lakebed cores, grabs, dredges, and drill samples in their collections.
Sample material is available from participating institutions unless noted as unavailable.
Data include basic collection and storage information. Lithology, texture, age, principal investigator, province, weathering/metamorphism, glass remarks, and descriptive comments are included for some samples. Links are provided to related data and information at the institutions and at NCEI.
Data are coded by individual institutions, several of which receive funding from the US National Science Foundation. For more information see the NSF Division of Ocean Sciences Data and Sample Policy.
The Index is endorsed by the Intergovernmental Oceanographic Commission, Committee on International Oceanographic Data and Information Exchange (IODE-XIV.2).
The index is maintained by the National Centers for Environmental Information (NCEI), formerly the National Geophysical Data Center (NGDC), and collocated World Data Center for Geophysics, Boulder, Colorado. NCEI is part of the National Environmental Satellite, Data and Information Service of the National Oceanic & Atmospheric Administration, U. S. Department of Commerce.
Searches and data downloads are available via a JSP and an ArcIMS interface. Data selections can be downloaded in tab-delimited or shapefile form, depending on the interface used. Both WMS and WFS interfaces are also available.
The Index was created in 1977 in response to a meeting of Curators of Marine Geological Samples, sponsored by the U.S. National Science Foundation. The Curators' group continues to meet every 2–3 years.
Dataset Digital Object Identifier
DOI:10.7289/V5H41PB8
Web site
The Index to Marine and Lacustrine Geological Samples
Participating Ins
Document 3:::
In 2017 the department was merged with the Department of Geology and Mineral Resources Engineering, forming the new
Department of Geoscience and Petroleum.
The Norwegian University of Science and Technology (NTNU) is the key university of science and technology in Norway. The Department of Petroleum Engineering and Applied Geophysics (IPT) was established in 1973, shortly after the start of production (Ekofisk field) from the Norwegian continental shelf. The department came to include Petroleum Engineering as well as Geophysics, which is seen as a major strength of the petroleum education at NTNU. The department has elected chairman and vice chairman, and 4 informal groups of professors; geophysics, drilling, production and reservoir engineering. The stated primary purpose of maintaining the informal groups is to take care of the teaching in their respective disciplines. Each group is responsible for offering a sufficient number of courses, semester projects and thesis projects at MSc and PhD levels in their discipline, and to make annual revisions of these in accordance with the needs of society and industry. The total number of professors, associate professors, assistant professors and adjunct professors is 32. The administrative staff is led by a department administrator, and consists of a total of 6 secretaries. The technical support staff reports to the department head, and consists of 8 engineers and technicians. Until 2000, the department was part of the Applied Earth Sciences faculty, together with the Geology-department. After that, the department is part of the Faculty of Engineering Science and Technology (one of a total of 10 departments).
Brief historical statistics of the department:
Established in 1973
More than 2000 graduated M.Sc.´s
More than 150 graduated Ph.D.´s
Around 120 M.Sc.´s graduate every year
Around 10 Ph.D.´s graduate every year
Currently around 120 full-time teachers, researchers and staff
Around 450 students enrolled at B.Sc.
Document 4:::
The Bachelor of Fisheries Science (B.F.Sc) is a bachelor's degree for studies in fisheries science in India. "Fisheries science" is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of aquaculture including breeding, genetics, biotechnology, nutrition, farming, diagnosis of diseases in fishes, other aquatic resources, medical treatment of aquatic animals; fish processing including curing, canning, freezing, value addition, byproducts and waste utilization, quality assurance and certification, fisheries microbiology, fisheries biochemistry; fisheries resource management including biology, anatomy, taxonomy, physiology, population dynamics; fisheries environment including oceanography, limnology, ecology, biodiversity, aquatic pollution; fishing technology including gear and craft engineering, navigation and seamanship, marine engines; fisheries economics and management and fisheries extension. Fisheries science is generally a 4-year course typically taught in a university setting, and can be the focus of an undergraduate, postgraduate or Ph.D. program. Bachelor level fisheries courses (B.F.Sc) were started by the state agricultural universities to make available the much needed technically competent personnel for teaching, research and development and transfer of technology in the field of fisheries science.
History
Fisheries education in India, started with the establishment of the Central Institute of Fisheries Education, Mumbai in 1961 for in service training and later the establishment of the first Fisheries College at Mangalore under the State Agricultural University (SAU) system in 1969, has grown manifold and evolved in the last four decades as a professional discipline consisting of Bachelors, Masters and Doctoral programmes in various branches of Fisheries Science. At present, 25 Fisheries Colleges offer four-year degree programme in Bachelor of Fisheries Science (B.F.Sc), whi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How are classic sedimentary rocks group?
A. density
B. size of sediment
C. particle depth
D. color
Answer:
|
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