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sciq-3831
|
multiple_choice
|
What hydrocarbons contain only single bonds between carbon atoms?
|
[
"caloric hydrocarbons",
"saturated hydrocarbons",
"simple carbohydrates",
"unsaturated hydrocarbons"
] |
B
|
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, 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 2:::
Bisnorhopanes (BNH) are a group of demethylated hopanes found in oil shales across the globe and can be used for understanding depositional conditions of the source rock. The most common member, 28,30-bisnorhopane, can be found in high concentrations in petroleum source rocks, most notably the Monterey Shale, as well as in oil and tar samples. 28,30-Bisnorhopane was first identified in samples from the Monterey Shale Formation in 1985. It occurs in abundance throughout the formation and appears in stratigraphically analogous locations along the California coast. Since its identification and analysis, 28,30-bisnorhopane has been discovered in oil shales around the globe, including lacustrine and offshore deposits of Brazil, silicified shales of the Eocene in Gabon, the Kimmeridge Clay Formation in the North Sea, and in Western Australian oil shales.
Chemistry
28,30-bisnorhopane exists in three epimers: 17α,18α21β(H), 17β,18α,21α(H), and 17β,18α,21β(H). During GC-MS, the three epimers coelute at the same time and are nearly indistinguishable. However, mass spectral fragmentation of the 28,30-bisnorhopane is predominantly characterized by m/z 191, 177, and 163. The ratios of 163/191 fragments can be used to distinguish the epimers, where the βαβ orientation has the highest, m/z 163/191 ratio. Further, the D/E ring ratios can be used to create a hierarchy of epimer maturity. From this, it is believed that the ααβ epimer is the first-formed, diagenetically, supported also by its percent dominance in younger shales. 28,30-bisnorhopane is created independently from kerogen, instead derived from bitumen, unbound as free oil-hydrocarbons. As such, as oil generation increases with source maturation, the concentration of 28,30-bisnorhopane decreases. Bisnorhopane may not be a reliable diagnostic for oil maturity due to microbial biodegradation.
Nomenclature
Norhopanes are a family of demethylated hopanes, identical to the methylated hopane structure, minus indicated desmet
Document 3:::
Phyllocladane is a tricyclic diterpane which is generally found in gymnosperm resins. It has a formula of C20H34 and a molecular weight of 274.4840. As a biomarker, it can be used to learn about the gymnosperm input into a hydrocarbon deposit, and about the age of the deposit in general. It indicates a terrogenous origin of the source rock. Diterpanes, such as Phyllocladane are found in source rocks as early as the middle and late Devonian periods, which indicates any rock containing them must be no more than approximately 360 Ma. Phyllocladane is commonly found in lignite, and like other resinites derived from gymnosperms, is naturally enriched in 13C. This enrichment is a result of the enzymatic pathways used to synthesize the compound.
The compound can be identified by GC-MS. A peak of m/z 123 is indicative of tricyclic diterpenoids in general, and phyllocladane in particular is further characterized by strong peaks at m/z 231 and m/z 189. Presence of phyllocladane and its relative abundance to other tricyclic diterpanes can be used to differentiate between various oil fields.
Document 4:::
In chemistry, an open-chain compound (also spelled as open chain compound) or acyclic compound (Greek prefix "α", without and "κύκλος", cycle) is a compound with a linear structure, rather than a cyclic one.
An open-chain compound having no side groups is called a straight-chain compound (also spelled as straight chain compound). Many of the simple molecules of organic chemistry, such as the alkanes and alkenes, have both linear and ring isomers, that is, both acyclic and cyclic. For those with 4 or more carbons, the linear forms can have straight-chain or branched-chain isomers. The lowercase prefix n- denotes the straight-chain isomer; for example, n-butane is straight-chain butane, whereas i-butane is isobutane. Cycloalkanes are isomers of alkenes, not of alkanes, because the ring's closure involves a C-C bond. Having no rings (aromatic or otherwise), all open-chain compounds are aliphatic.
Typically in biochemistry, some isomers are more prevalent than others. For example, in living organisms, the open-chain isomer of glucose usually exists only transiently, in small amounts; D-glucose is the usual isomer; and L-glucose is rare.
Straight-chain molecules are often not literally straight, in the sense that their bond angles are often not 180°, but the name reflects that they are schematically straight. For example, the straight-chain alkanes are wavy or "puckered", as the models below show.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What hydrocarbons contain only single bonds between carbon atoms?
A. caloric hydrocarbons
B. saturated hydrocarbons
C. simple carbohydrates
D. unsaturated hydrocarbons
Answer:
|
|
sciq-9989
|
multiple_choice
|
What adds phosphate groups to receptor proteins at the surface of the cell?
|
[
"brain kinases",
"nitrogen kinases",
"protein kinases",
"receptor kinases"
] |
D
|
Relavent Documents:
Document 0:::
Autophosphorylation is a type of post-translational modification of proteins. It is generally defined as the phosphorylation of the kinase by itself. In eukaryotes, this process occurs by the addition of a phosphate group to serine, threonine or tyrosine residues within protein kinases, normally to regulate the catalytic activity.
Autophosphorylation may occur when a kinases' own active site catalyzes the phosphorylation reaction (cis autophosphorylation), or when another kinase of the same type provides the active site that carries out the chemistry (trans autophosphorylation). The latter often occurs when kinase molecules dimerize. In general, the phosphate groups introduced are gamma phosphates from nucleoside triphosphates, most commonly ATP.
Function
Protein kinases, many of which are regulated by autophosphorylation, are vital in controlling the cellular proliferation, differentiation, metabolism, migration and survival. Mutations in the genes encoding them or their potential activators or repressors can affect any number of functions within an organism.
Phosphorylation is easily reversed by phosphatases. Therefore, it is an effective method of turning 'on' and 'off' kinase activity. Because of this it is recognized as an essential process in cell signaling.
Addition of a negatively charged phosphate group brings about a change in the microenvironment that may lead to attraction or repulsion of other residues or molecules. The result may be a conformational change to expose or hide catalytic or allosteric seats from the surface.
If the phosphorylated residue resides within the catalytic seat itself, it may facilitate or prevent substrate binding by means of charge-interaction, or by providing or preventing complementary shapes necessary for molecular recognition. In addition, the phosphate group yields several potential areas for hydrogen-bonding or establishment of salt-bridges, of which the latter generally involves an arginine residue.
Binding of e
Document 1:::
Class I PI 3-kinases are a subgroup of the enzyme family, phosphoinositide 3-kinase that possess a common protein domain structure, substrate specificity, and method of activation. Class I PI 3-kinases are further divided into two subclasses, class IA PI 3-kinases and class IB PI 3-kinases.
Class IA PI 3-kinases
Class IA PI 3-kinases are activated by receptor tyrosine kinases (RTKs).
There are three catalytic subunits that are classified as class IA PI 3-kinases:
p110α
p110β
p110δ
There are currently five regulatory subunits that are known to associate with class IA PI 3-kinases catalytic subunits:
p85α and p85β
p55α and p55γ
p50α
Class IB PI 3-kinases
Class IB PI 3-kinases are activated by G-protein-coupled receptors (GPCRs).
The only known class IB PI 3-kinase catalytic subunit is p110γ.
There are two known regulatory subunits for p110γ:
p101
p84/ p87PIKAP.
See also
Phosphoinositide 3-kinase#Class I
Phosphoinositide 3-kinase inhibitor
Document 2:::
In molecular biology, the GHMP kinase family is a family of kinase enzymes. Members of this family include homoserine kinases , galactokinases , and mevalonate kinases. These kinases make up the GHMP kinase superfamily of ATP-dependent enzymes. These enzymes are involved in the biosynthesis of isoprenes and amino acids as well as in carbohydrate metabolism. These enzymes contain, in their N-terminal section, a conserved Gly/Ser-rich region which is probably involved in the binding of ATP. The C-terminal domain of homoserine kinase has a central alpha-beta plait fold and an insertion of four helices, which, together with the N-terminal fold, creates a novel nucleotide binding fold.
Document 3:::
In cell biology, protein kinase A (PKA) is a family of serine-threonine kinase whose activity is dependent on cellular levels of cyclic AMP (cAMP). PKA is also known as cAMP-dependent protein kinase (). PKA has several functions in the cell, including regulation of glycogen, sugar, and lipid metabolism. It should not be confused with 5'-AMP-activated protein kinase (AMP-activated protein kinase).
History
Protein kinase A, more precisely known as adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase, abbreviated to PKA, was discovered by chemists Edmond H. Fischer and Edwin G. Krebs in 1968. They won the Nobel Prize in Physiology or Medicine in 1992 for their work on phosphorylation and dephosphorylation and how it relates to PKA activity.
PKA is one of the most widely researched protein kinases, in part because of its uniqueness; out of 540 different protein kinase genes that make up the human kinome, only one other protein kinase, casein kinase 2, is known to exist in a physiological tetrameric complex, meaning it consists of four subunits.
The diversity of mammalian PKA subunits was realized after Dr. Stan McKnight and others identified four possible catalytic subunit genes and four regulatory subunit genes. In 1991, Susan Taylor and colleagues crystallized the PKA Cα subunit, which revealed the bi-lobe structure of the protein kinase core for the very first time, providing a blueprint for all the other protein kinases in a genome (the kinome).
Structure
When inactive, the PKA holoenzyme exists as a tetramer which consists of two regulatory subunits and two catalytic subunits. The catalytic subunit contains the active site, a series of canonical residues found in protein kinases that bind and hydrolyse ATP, and a domain to bind the regulatory subunit. The regulatory subunit has domains to bind to cyclic AMP, a domain that interacts with catalytic subunit, and an auto inhibitory domain. There are two major forms of regulatory subunit; RI and RII
Document 4:::
The lysophosphatidic acid receptors (LPARs) are a group of G protein-coupled receptors for lysophosphatidic acid (LPA) that include:
Lysophosphatidic acid receptor 1 (LPAR1; formerly known as EDG2, GPR26)
Lysophosphatidic acid receptor 2 (LPAR2; formerly known as EDG4)
Lysophosphatidic acid receptor 3 (LPAR3; formerly known as EDG7)
Lysophosphatidic acid receptor 4 (LPAR4; formerly known as GPR23, P2RY9)
Lysophosphatidic acid receptor 5 (LPAR5; formerly known as GPR92)
Lysophosphatidic acid receptor 6 (LPAR6; formerly known as GPR87, P2RY5)
See also
Lysophospholipid receptor
Sphingosine-1-phosphate receptor
P2Y receptor
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What adds phosphate groups to receptor proteins at the surface of the cell?
A. brain kinases
B. nitrogen kinases
C. protein kinases
D. receptor kinases
Answer:
|
|
sciq-4784
|
multiple_choice
|
What is the fluid that carries sperm through the urethra and out of the body, and provides it with nutrients?
|
[
"semen",
"yeast",
"blood",
"bacteria"
] |
A
|
Relavent Documents:
Document 0:::
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 1:::
Sperm chemotaxis is a form of sperm guidance, in which sperm cells (spermatozoa) follow a concentration gradient of a chemoattractant secreted from the oocyte and thereby reach the oocyte.
Background
Since the discovery of sperm attraction to the female gametes in ferns over a century ago, sperm guidance in the form of sperm chemotaxis has been established in a large variety of species Although sperm chemotaxis is prevalent throughout the Metazoa kingdom, from marine species with external fertilization such as sea urchins and corals, to humans, much of the current information on sperm chemotaxis is derived from studies of marine invertebrates, primarily sea urchin and starfish. As a matter of fact, until not too long ago, the dogma was that, in mammals, guidance of spermatozoa to the oocyte was unnecessary. This was due to the common belief that, following ejaculation into the female genital tract, large numbers of spermatozoa 'race' towards the oocyte and compete to fertilize it.
Research during the 1980s caused this belief to be taken apart when it became clear that only few of the ejaculated spermatozoa — in humans, only ~1 of every million spermatozoa — succeed in entering the oviducts (Fallopian tubes) and when more recent studies showed that mammalian spermatozoa do respond chemotactically.
Sperm chemotaxis in non-mammalian species
In sperm chemotaxis, the oocyte secretes a chemoattractant, which, as it diffuses away, forms a concentration gradient: a high concentration close to the egg, and a gradually lower concentration as the distance from the oocyte increases. Spermatozoa can sense this chemoattractant and orient their swimming direction up the concentration gradient towards the oocyte. Sperm chemotaxis was demonstrated in a large number of non-mammalian species, from marine invertebrates to frogs.
Chemoattractants
The sperm chemoattractants in non-mammalian species vary to a large extent. Some examples are shown in Table 1. So far, most sperm c
Document 2:::
Spermarche, also known as semenarche, is the time at which a male experiences his first ejaculation. It is considered to be the counterpart of menarche in girls. Depending on upbringing, cultural differences, and prior sexual knowledge, males may have different reactions to spermarche, ranging from fear to excitement. Spermarche is one of the first events in the life of a male leading to sexual maturity. It occurs at the time when the secondary sex characteristics are just beginning to develop. Researchers have had difficulty determining the onset of spermarche because it is reliant on self-reporting. Other methods to determine it have included the examination of urine samples to determine the presence of spermatozoa. The presence of sperm in urine is referred to as spermaturia.
Age of occurrence
Research on the subject has varied for the reasons stated above, as well as changes in the average age of pubescence, which has been decreasing at an average rate of three months a decade. Research from 2010 indicated that the average age for spermarche in the U.S. was 12–16. In 2015, researchers in China determined that the average age for spermarche in China was 14. Historical data from countries including Nigeria and the United States also suggest 14 as an average age.
Context
Various studies have examined the circumstances in which first ejaculation occurred. Most commonly this occurred via a nocturnal emission, with a significant number experiencing semenarche via masturbation, which is very common at that stage. Less commonly, the first ejaculation occurred during sexual intercourse with a partner.
See also
Adrenarche
Document 3:::
The blood–testis barrier is a physical barrier between the blood vessels and the seminiferous tubules of the animal testes. The name "blood-testis barrier" is misleading as it is not a blood-organ barrier in a strict sense, but is formed between Sertoli cells of the seminiferous tubule and isolates the further developed stages of germ cells from the blood. A more correct term is the Sertoli cell barrier (SCB).
Structure
The walls of seminiferous tubules are lined with primitive germ layer cells and by Sertoli cells. The barrier is formed by tight junctions, adherens junctions and gap junctions between the Sertoli cells, which are sustentacular cells (supporting cells) of the seminiferous tubules, and divides the seminiferous tubule into a basal compartment (outer side of the tubule, in contact with blood and lymph) and an endoluminal compartment (inner side of the tubule, isolated from blood and lymph). The tight junctions are formed by intercellular adhesion molecules in between cells that are anchored to actin fibers within the cells. For the visualization of the actin fibers within the seminiferous tubules see Sharma et al.'s immunofluorescence studies.
Function
The presence of the SCB allows Sertoli cells to control the adluminal environment in which germ cells (spermatocytes, spermatids and sperm) develop by influencing the chemical composition of the luminal fluid.
The barrier also prevents passage of cytotoxic agents (bodies or substances that are toxic to cells) into the seminiferous tubules.
The fluid in the lumen of seminiferous tubules is quite different from plasma; it contains very little protein and glucose but is rich in androgens, estrogens, potassium, inositol and glutamic and aspartic acid. This composition is maintained by blood–testis barrier.
The barrier also protects the germ cells from blood-borne noxious agents,
prevents antigenic products of germ cell maturation from entering the circulation and generating an autoimmune response, and ma
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the fluid that carries sperm through the urethra and out of the body, and provides it with nutrients?
A. semen
B. yeast
C. blood
D. bacteria
Answer:
|
|
sciq-567
|
multiple_choice
|
How many cycles do cells have?
|
[
"six",
"four",
"two",
"seven"
] |
B
|
Relavent Documents:
Document 0:::
This lecture, named in memory of Keith R. Porter, is presented to an eminent cell biologist each year at the ASCB Annual Meeting. The ASCB Program Committee and the ASCB President recommend the Porter Lecturer to the Porter Endowment each year.
Lecturers
Source: ASCB
See also
List of biology awards
Document 1:::
Induced cell cycle arrest is the use of a chemical or genetic manipulation to artificially halt progression through the cell cycle. Cellular processes like genome duplication and cell division stop. It can be temporary or permanent. It is an artificial activation of naturally occurring cell cycle checkpoints, induced by exogenous stimuli controlled by an experimenter.
Model organisms
In an academic research context, cell cycle arrest is typically performed in model organisms and cell extracts, such as Saccharomyces cervisiae (yeast) or Xenopus oocytes (frog eggs). Frog egg cell extracts have been used extensively in cell cycle research because they are relatively large, reaching a diameter of 1mm, and so contain large amounts of protein, making protein levels more easily measurable.
Purposes
There are a variety of reasons a researcher may want to temporarily or permanently prevent progress through the cell cycle.
Cell cycle synchronization
In some experiments, a researcher may want to control and synchronize the time when a group of cells progress to the next phase of the cell cycle. The cells can be induced to arrest as they arrive (at different time points) at a certain phase, so that when the arrest is lifted (for instance, rescuing cell cycle progression by introducing another chemical) all the cells resume cell cycle progression at the same time. In addition to this method acting as a scientific control for when the cells resume the cell cycle, this can be used to investigate necessity and sufficiency.
Another reason synchrony is important is the control for amount of DNA content, which varies at different parts of the cell cycle based on whether DNA replication has occurred since the last round of completed mitosis and cytokinesis.
Furthermore, synchronization of large numbers of cells into the same phase allows for the collection of large enough groups of cells in the same cycle for the use in other assays, such as western blot and RNA sequencing.
D
Document 2:::
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 3:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How many cycles do cells have?
A. six
B. four
C. two
D. seven
Answer:
|
|
sciq-5383
|
multiple_choice
|
What term refers to any method of removing carbon dioxide from the atmosphere and storing it in another form?
|
[
"carbon footprint",
"carbon sequestration",
"carbon transfer",
"carbon metamorphosis"
] |
B
|
Relavent Documents:
Document 0:::
Carbon sequestration (or carbon storage) is the process of storing carbon in a carbon pool. Carbon sequestration is a naturally occurring process but it can also be enhanced or achieved with technology, for example within carbon capture and storage projects. There are two main types of carbon sequestration: geologic and biologic (also called biosequestration).
Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land use and agricultural practices, such as converting crop land into land for non-crop fast growing plants. Artificial processes have been devised to produce similar effects, including large-scale, artificial capture and sequestration of industrially produced using subsurface saline aquifers or aging oil fields. Other technologies that work with carbon sequestration include bio-energy with carbon capture and storage, biochar, enhanced weathering, direct air carbon capture and sequestration (DACCS).
Forests, kelp beds, and other forms of plant life absorb carbon dioxide from the air as they grow, and bind it into biomass. However, these biological stores are considered volatile carbon sinks as the long-term sequestration cannot be guaranteed. For example, natural events, such as wildfires or disease, economic pressures and changing political priorities can result in the sequestered carbon being released back into the atmosphere. Carbon dioxide that has been removed from the atmosphere can also be stored in the Earth's crust by injecting it into the subsurface, or in the form of insoluble carbonate salts (mineral sequestration). These methods are considered non-volatile because they remove carbon from the atmosphere and sequester it indefinitely and presumably for a considerable duration (thousands to millions of years).
To enhance carbon sequestration processes in oceans the following technologies have been proposed but none have achieved lar
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The carbon cycle is that part of the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycle. Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone. The carbon cycle comprises a sequence of events that are key to making Earth capable of sustaining life. It describes the movement of carbon as it is recycled and reused throughout the biosphere, as well as long-term processes of carbon sequestration (storage) to and release from carbon sinks.
To describe the dynamics of the carbon cycle, a distinction can be made between the fast and slow carbon cycle. The fast carbon cycle is also referred to as the biological carbon cycle. Fast carbon cycles can complete within years, moving substances from atmosphere to biosphere, then back to the atmosphere. Slow or geological cycles (also called deep carbon cycle) can take millions of years to complete, moving substances through the Earth's crust between rocks, soil, ocean and atmosphere.
Human activities have disturbed the fast carbon cycle for many centuries by modifying land use, and moreover with the recent industrial-scale mining of fossil carbon (coal, petroleum, and gas extraction, and cement manufacture) from the geosphere. Carbon dioxide in the atmosphere had increased nearly 52% over pre-industrial levels by 2020, forcing greater atmospheric and Earth surface heating by the Sun. The increased carbon dioxide has also caused a reduction in the ocean's pH value and is fundamentally altering marine chemistry. The majority of fossil carbon has been extracted over just the past half century, and rates continue to rise rapidly, contributing to human-caused climate change.
Main compartments
The carbon cycle was first described by Antoine Lavoisier and Joseph Priestley, and popularised by Humphry Davy. The g
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Climate change mitigation is action to limit climate change by reducing emissions of greenhouse gases or removing those gases from the atmosphere. The recent rise in global average temperature is mostly due to emissions from unabated burning of fossil fuels such as coal, oil, and natural gas. Mitigation can reduce emissions by transitioning to sustainable energy sources, conserving energy, and increasing efficiency. It is possible to remove carbon dioxide () from the atmosphere by enlarging forests, restoring wetlands and using other natural and technical processes. Experts call these processes carbon sequestration. Governments and companies have pledged to reduce emissions to prevent dangerous climate change in line with international negotiations to limit warming by reducing emissions.
Solar energy and wind power have the greatest potential for mitigation at the lowest cost compared to a range of other options. The availability of sunshine and wind is variable. But it is possible to deal with this through energy storage and improved electrical grids. These include long-distance electricity transmission, demand management and diversification of renewables. It is possible to reduce emissions from infrastructure that directly burns fossil fuels, such as vehicles and heating appliances, by electrifying the infrastructure. If the electricity comes from renewable sources instead of fossil fuels this will reduce emissions. Using heat pumps and electric vehicles can improve energy efficiency. If industrial processes must create carbon dioxide, carbon capture and storage can reduce net emissions.
Greenhouse gas emissions from agriculture include methane as well as nitrous oxide. It is possible to cut emissions from agriculture by reducing food waste, switching to a more plant-based diet, by protecting ecosystems and by improving farming processes. Changing energy sources, industrial processes and farming methods can reduce emissions. So can changes in demand, for instanc
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Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (), which causes ocean acidification as atmospheric levels increase.
It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.025%. Burning fossil fuels is the primary cause of these increased concentrations and also the primary cause of climate change.
Its concentration in Earth's pre-industrial atmosphere since late in the Precambrian was regulated by organisms and geological phenomena. Plants, algae and cyanobacteria use energy from sunlight to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis, which produces oxygen as a waste product. In turn, oxygen is consumed and is released as waste by all aerobic organisms when they metabolize organic compounds to produce energy by respiration. is released from organic materials when they decay or combust, such as in forest fires. Since plants require for photosynthesis, and humans and animals depend on plants for food, is necessary for the survival of life on earth.
Carbon dioxide is 53% more dense than dry air, but is long lived and thoroughly mixes in the atmosphere. About half of excess emissions to the atmosphere are absorbed by land and ocean carbon sinks. These sinks can become saturated and are volatile, as decay and wildfires result i
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Bio-geoengineering is a form of climate engineering which seeks to use or modify plants or other living things to modify the Earth's climate.
Bio-energy with carbon storage, afforestation projects, and ocean nourishment (including iron fertilization) could be considered examples of bio-geoengineering.
Biogenic aerosols can be grown to replace those beneficial aerosols lost as the result of the death of 50% of Earth's boreal forests. Agricultural production of atmospheric aerosols called "monoterpenes" is possible if crops that are rich in monoterpenes are grown.
Introduction
Geoengineering is conventionally split into two broad categories. Carbon geoengineering tries to expel carbon dioxide from the environment, which would address the underlying driver of environmental change — the collection of carbon dioxide in the climate. In the chain from outflows to focuses to temperatures to impacts, it breaks the connection from discharges to fixations. Sun powered geoengineering tries to mirror a little part of daylight once more into space or increment the measure of sun oriented radiation that escapes once again into space to cool the planet. Rather than carbon geoengineering, sun based geoengineering does not address the underlying driver of environmental change. It rather expects to break the connection from fixations to temperatures, along these lines diminishing some atmosphere harms.
The quick increment in the centralization of air CO2 proceeded with anthropogenic emanations of this gas is the fundamental factor driving worldwide environmental change. Due to many different causes global temperatures are to increase by 3-5 degrees celsius or 5.4 - 9 degrees fahrenheit within this century.
Bio-geoengineering solutions to climate change
Carbon capture and storage.
The CO2 is ordinarily caught before the emissions leave the smokestack, for the most part with a sorbent concoction. The liquified CO2 is then siphoned into underground aquifers for long haul storage.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term refers to any method of removing carbon dioxide from the atmosphere and storing it in another form?
A. carbon footprint
B. carbon sequestration
C. carbon transfer
D. carbon metamorphosis
Answer:
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sciq-2897
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multiple_choice
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Although lots of symbiotic relationships help both organisms, sometimes one of the organisms is harmed. when that happens, the organism that benefits, and is not harmed, is called a what?
|
[
"viruses",
"infection",
"child",
"parasite"
] |
D
|
Relavent Documents:
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In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist guest (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cells harbouring pathogenic (disease-causing) viruses, or a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner.
Symbiosis
Symbiosis spans a wide variety of possible relationships between organisms, differing in their permanence and their effects on the two parties. If one of the partners in an association is much larger than the other, it is generally known as the host. In parasitism, the parasite benefits at the host's expense. In commensalism, the two live together without harming each other, while in mutualism, both parties benefit.
Most parasites are only parasitic for part of their life cycle. By comparing parasites with their closest free-living relatives, parasitism has been shown to have evolved on at least 233 separate occasions. Some organisms live in close association with a host and only become parasitic when environmental conditions deteriorate.
A parasite may have a long-term relationship with its host, as is the case with all endoparasites. The guest seeks out the host and obtains food or another service from it, but does not usually kill it. In contrast, a parasitoid spends a large part of its life within or on a single host, ultimately causing the host's death, with some of the strategies involved verging on predation. Generally, the host is kept alive until the parasitoid is fully grown and ready to pass on to its next life stage. A guest's relationship with its host may be intermitten
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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
Document 2:::
Symbiotic bacteria are bacteria living in symbiosis with another organism or each other. For example, rhizobia living in root nodules of legumes provide nitrogen fixing activity for these plants.
Types of symbiosis
Types of symbiotic relationships are mutualism, commensalism, parasitism, and amensalism.
Endosymbiosis
Endosymbionts live inside other organisms whether that be in their bodies or cells. The theory of endosymbiosis, as known as symbiogenesis, provides an explanation for the evolution of eukaryotic organisms. According to the theory of endosymbiosis for the origin of eukaryotic cells, scientists believe that eukaryotes originated from the relationship between two or more prokaryotic cells approximately 2.7 billion years ago. It is suggested that specifically ancestors of mitochondria and chloroplasts entered into an endosymbiotic relationship with another prokaryotic cell, eventually evolving into the eukaryotic cells that people are familiar with today.
Ectosymbiosis
Ectosymbiosis is defined as a symbiotic relationship in which one organism lives on the outside surface of a different organism. For instance, barnacles on whales is an example of an ectosymbiotic relationship where the whale provides the barnacle with a home, a ride, and access to food. The whale is not harmed, but it also does not receive any benefits so this is also an example of commensalism. An example of ectosymbiotic bacteria is cutibacterium acnes. These bacteria are involved in a symbiotic relationship with humans on whose skin they live. Cutibacterium acnes can cause acne when the skin becomes too oily, but they also reduce the skin's susceptibility to skin diseases caused by oxidative stress.
Symbiotic relationships
Certain plants establish a symbiotic relationship with bacteria, enabling them to produce nodules that facilitate the conversion of atmospheric nitrogen to ammonia. In this connection, cytokinins have been found to play a role in the development of root fixing n
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A mycetome is a specialized organ in a variety of animal species which houses that animal's symbionts, isolating them from the animal's natural cellular defense mechanisms and allowing sustained controlled symbiotic growth. In several species, such as bed bugs and certain families of leech, these symbionts are attached to the gut and aid in the production of vitamin B from ingested meals of blood. In insects, the organisms that inhabit these structures are either bacteria or yeasts.
In bed bugs, it has been found that heat stress can cause damage to the mycetome, preventing the symbionts from being successfully passed from the adult female to her eggs at the time of oogenesis, causing the resulting nymphs to develop abnormally or to die prematurely.
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Horizontal transmission is the transmission of organisms between biotic and/or abiotic members of an ecosystem that are not in a parent-progeny relationship. This concept has been generalized to include transmissions of infectious agents, symbionts, and cultural traits between humans.
Because the evolutionary fate of the agent is not tied to reproductive success of the host, horizontal transmission tends to evolve virulence. It is therefore a critical concept for evolutionary medicine.
Biological
Pathogen transmission
In biological, but not cultural, transmissions the carriers (also known as vectors) may include other species. The two main biological modes of transmission are anterior station and posterior station. In anterior station, transmission occurs via the bite of an infected organism (the vector), like in malaria, dengue fever, and bubonic plague. Posterior station is transmission via contact with infected feces. Examples are rickettsiae driven diseases (like typhus), which are contracted by a body louse's fecal material being scratched into the bloodstream. The vector is not necessarily another species, however. For example, a dog infected with Rabies may infect another dog via anterior station transmission. Moreover, there are other modes of biological transmission, such as generalized bleeding in ebola.
Symbiont transmission
Symbiosis describes a relationship in which at least two organisms are in an intimately integrated state, such that one organism acts a host and the other as the symbiont. There are obligate, those that require the host for survival, and facultative symbionts, those that can survive independently of the host. Symbionts can follow vertical, horizontal, or a mixed mode of transmission to their host. Horizontal, or lateral, transmission describes the acquisition of a facultative symbiont from the environment or from a nearby host.
The life cycle of the host includes both symbiotic and aposymbiotic phases. The aposymbiotic p
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Although lots of symbiotic relationships help both organisms, sometimes one of the organisms is harmed. when that happens, the organism that benefits, and is not harmed, is called a what?
A. viruses
B. infection
C. child
D. parasite
Answer:
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|
sciq-11557
|
multiple_choice
|
The number of electron pairs that hold two atoms together is called?
|
[
"bond order",
"nuclear order",
"proton order",
"electron order"
] |
A
|
Relavent Documents:
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Atomic spacing refers to the distance between the nuclei of atoms in a material. This space is extremely large compared to the size of the atomic nucleus, and is related to the chemical bonds which bind atoms together. In solid materials, the atomic spacing is described by the bond lengths of its atoms. In ordered solids, the atomic spacing between two bonded atoms is generally around a few ångströms (Å), which is on the order of 10−10 meters. However, in very low density gases (for example, in outer space) the average distance between atoms can be as large as a meter. In this case, the atomic spacing isn't referring to bond length.
The atomic spacing of crystalline structures is usually determined by passing an electromagnetic wave of known frequency through the material, and using the laws of diffraction to determine its atomic spacing. The atomic spacing of amorphous materials (such as glass) varies substantially between different pairs of atoms, therefore diffraction cannot be used to accurately determine atomic spacing. In this case, the average bond length is a common way of expressing the distance between its atoms.
Example
Bond length can be determined between different elements in molecules by using the atomic radii of the atoms. Carbon bonds with itself to form two covalent network solids. Diamond's C-C bond has a distance of Sqrt[3]a/4 ≈ 0.154 nm away from each carbon since adiamond ≈ 0.357 nm, while graphite's C-C bond has a distance of a/Sqrt[3] ≈ 0.142 nm away from each carbon since agraphite ≈ 0.246 nm. Although both bonds are between the same pair of elements they can have different bond lengths.
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In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 3:::
Atomicity is the total number of atoms present in a molecule. For example, each molecule of oxygen (O2) is composed of two oxygen atoms. Therefore, the atomicity of oxygen is 2.
In older contexts, atomicity is sometimes equivalent to valency. Some authors also use the term to refer to the maximum number of valencies observed for an element.
Classifications
Based on atomicity, molecules can be classified as:
Monoatomic (composed of one atom). Examples include He (helium), Ne (neon), Ar (argon), and Kr (krypton). All noble gases are monoatomic.
Diatomic (composed of two atoms). Examples include H2 (hydrogen), N2 (nitrogen), O2 (oxygen), F2 (fluorine), and Cl2 (chlorine). Halogens are usually diatomic.
Triatomic (composed of three atoms). Examples include O3 (ozone).
Polyatomic (composed of three or more atoms). Examples include S8.
Atomicity may vary in different allotropes of the same element.
The exact atomicity of metals, as well as some other elements such as carbon, cannot be determined because they consist of a large and indefinite number of atoms bonded together. They are typically designated as having an atomicity of 1.
The atomicity of homonuclear molecule can be derived by dividing the molecular weight by the atomic weight. For example, the molecular weight of oxygen is 31.999, while its atomic weight is 15.879; therefore, its atomicity is approximately 2 (31.999/15.879 ≈ 2).
Examples
The most common values of atomicity for the first 30 elements in the periodic table are as follows:
Document 4:::
The octet rule is a chemical rule of thumb that reflects the theory that main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens; although more generally the rule is applicable for the s-block and p-block of the periodic table. Other rules exist for other elements, such as the duplet rule for hydrogen and helium, or the 18-electron rule for transition metals.
The valence electrons can be counted using a Lewis electron dot diagram as shown at the right for carbon dioxide. The electrons shared by the two atoms in a covalent bond are counted twice, once for each atom. In carbon dioxide each oxygen shares four electrons with the central carbon, two (shown in red) from the oxygen itself and two (shown in black) from the carbon. All four of these electrons are counted in both the carbon octet and the oxygen octet, so that both atoms are considered to obey the octet rule.
Example: sodium chloride (NaCl)
Ionic bonding is common between pairs of atoms, where one of the pair is a metal of low electronegativity (such as sodium) and the second a nonmetal of high electronegativity (such as chlorine).
A chlorine atom has seven electrons in its third and outer electron shell, the first and second shells being filled with two and eight electrons respectively. The first electron affinity of chlorine (the energy release when chlorine gains an electron to form Cl−) is 349 kJ per mole of chlorine atoms. Adding a second electron to form a hypothetical Cl2- would require energy, energy that cannot be recovered by the formation of a chemical bond. The result is that chlorine will very often form a compound in which it has eight electrons in its outer shell (a complete octet), as in Cl−.
A sodium atom has a single electron in its outermost electron shell, the first and second shells again being full
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The number of electron pairs that hold two atoms together is called?
A. bond order
B. nuclear order
C. proton order
D. electron order
Answer:
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|
sciq-5051
|
multiple_choice
|
Many species use their body shape and coloration to avoid what?
|
[
"human contact",
"sunlight",
"detection by predators",
"exposure"
] |
C
|
Relavent Documents:
Document 0:::
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm.
The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, where species with strong defences evolve to resemble one another. By mimicking similarly coloured species, the warning signal to predators is shared, causing them to learn more quickly at less of a cost.
A genuine aposematic signal that a species actually possesses chemical or physical defences is not the only way to deter predators. In Batesian mimicry, a mimicking species resembles an aposematic model closely enough to share the protection, while many species have bluffing deimatic displays which may startle a predator long enough to enable an otherwise undefended prey to escape.
There is good evidence for aposematism in terrestrial animals; its existence in marine animals is possible but disputed.
Etymology
The term aposematism was coined by the English zoologist Edward Bagnall Poulton in his 1890 book The Colours of Animals. He based the term on the Ancient Greek words ἀπό apo 'away' and σῆμα sēma 'sign', referring to signs that warn other animals away.
Defense mechanism
The function of aposematism is to prevent attack, by warning potential predators that the prey animal has defenses such as being unpalatable or poisonous. The easily detected warning is a primary defense mechanism, and the non-visible defenses are secondary. Aposematic signals are primarily visual, using bright colors and high-con
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In ecology, crypsis is the ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle and mimicry. Crypsis can involve visual, olfactory (with pheromones) or auditory concealment. When it is visual, the term cryptic coloration, effectively a synonym for animal camouflage, is sometimes used, but many different methods of camouflage are employed by animals or plants.
Overview
There is a strong evolutionary pressure for animals to blend into their environment or conceal their shape, for prey animals to avoid predators and for predators to be able to avoid detection by prey. Exceptions include large herbivores without natural enemies, brilliantly colored birds that rely on flight to escape predators, and venomous or otherwise powerfully armed animals with warning coloration. Cryptic animals include the tawny frogmouth (feather patterning resembles bark), the tuatara (hides in burrows all day; nocturnal), some jellyfish (transparent), the leafy sea dragon, and the flounder (covers itself in sediment).
Methods
Methods of crypsis include (visual) camouflage, nocturnality, and subterranean lifestyle. Camouflage can be achieved by a wide variety of methods, from disruptive coloration to transparency and some forms of mimicry, even in habitats like the open sea where there is no background.
As a strategy, crypsis is used by predators against prey and by prey against predators.
Crypsis also applies to eggs and pheromone production. Crypsis can in principle involve visual, olfactory, or auditory camouflage.
Visual
Many animals have evolved so that they visually resemble their surroundings by using any of the many methods of natural camouflage that may match the color and texture of the surroundings (cryptic coloration) and/or break up the visual outline of the animal itself (disruptive coloration). Such animals, like the
Document 2:::
Ecomorphology or ecological morphology is the study of the relationship between the ecological role of an individual and its morphological adaptations. The term "morphological" here is in the anatomical context. Both the morphology and ecology exhibited by an organism are directly or indirectly influenced by their environment, and ecomorphology aims to identify the differences. Current research places emphasis on linking morphology and ecological niche by measuring the performance of traits (i.e. sprint speed, bite force, etc.) associated behaviours, and fitness outcomes of the relationships.
Current ecomorphological research focuses on a functional approach and application to the science. A broadening of this field welcomes further research in the debate regarding differences between both the ecological and morphological makeup of an organism.
Development of ecomorphology
The roots of ecomorphology date back to the late 19th century. Then, description and comparison of morphological form, primarily for use in avian classification, was focal point of morphological research. However, during the 1930s and 40s morphology as a field shrank. This was likely due to the emergence of new areas of biological inquiry enabled by new techniques. The 1950s brought about not only a change in the approach of morphological studies, resulting in the development of evolutionary morphology in the form of theoretical questions, and a resurgence of interest in the field. High-speed cinematography and x-ray cinematography began to allow for observations of movements of parts while electromyography allowed for observation of the integration of muscle activities. Together, these methodologies allowed morphologists to better delve into the intricacies of their study. It was then, in the 1950s and 60s, that ecologists began to use morphological measures to study evolutionary and ecological questions. This culminated in Karr and James coining the term "ecomorphology" in 1975. The follo
Document 3:::
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 4:::
Escape response, escape reaction, or escape behavior is a mechanism by which animals avoid potential predation. It consists of a rapid sequence of movements, or lack of movement, that position the animal in such a way that allows it to hide, freeze, or flee from the supposed predator. Often, an animal's escape response is representative of an instinctual defensive mechanism, though there is evidence that these escape responses may be learned or influenced by experience.
The classical escape response follows this generalized, conceptual timeline: threat detection, escape initiation, escape execution, and escape termination or conclusion. Threat detection notifies an animal to a potential predator or otherwise dangerous stimulus, which provokes escape initiation, through neural reflexes or more coordinated cognitive processes. Escape execution refers to the movement or series of movements that will hide the animal from the threat or will allow for the animal to flee. Once the animal has effectively avoided the predator or threat, the escape response is terminated. Upon completion of the escape behavior or response, the animal may integrate the experience with its memory, allowing it to learn and adapt its escape response.
Escape responses are anti-predator behaviour that can vary from species to species. The behaviors themselves differ depending upon the species, but may include camouflaging techniques, freezing, or some form of fleeing (jumping, flying, withdrawal, etc.). In fact, variation between individuals is linked to increased survival. In addition, it is not merely increased speed that contributes to the success of the escape response; other factors, including reaction time and the individual's context can play a role. The individual escape response of a particular animal can vary based on an animal's previous experiences and its current state.
Evolutionary importance
The ability to perform an effective escape maneuver directly affects the fitness of the
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Many species use their body shape and coloration to avoid what?
A. human contact
B. sunlight
C. detection by predators
D. exposure
Answer:
|
|
sciq-10744
|
multiple_choice
|
What do the planets orbit around in the solar system?
|
[
"the Milky Way",
"the Earth",
"the moon",
"the sun"
] |
D
|
Relavent Documents:
Document 0:::
This is a list of most likely gravitationally rounded objects of the Solar System, which are objects that have a rounded, ellipsoidal shape due to their own gravity (but are not necessarily in hydrostatic equilibrium). Apart from the Sun itself, these objects qualify as planets according to common geophysical definitions of that term. The sizes of these objects range over three orders of magnitude in radius, from planetary-mass objects like dwarf planets and some moons to the planets and the Sun. This list does not include small Solar System bodies, but it does include a sample of possible planetary-mass objects whose shapes have yet to be determined. The Sun's orbital characteristics are listed in relation to the Galactic Center, while all other objects are listed in order of their distance from the Sun.
Star
The Sun is a G-type main-sequence star. It contains almost 99.9% of all the mass in the Solar System.
Planets
In 2006, the International Astronomical Union (IAU) defined a planet as a body in orbit around the Sun that was large enough to have achieved hydrostatic equilibrium and to have "cleared the neighbourhood around its orbit". The practical meaning of "cleared the neighborhood" is that a planet is comparatively massive enough for its gravitation to control the orbits of all objects in its vicinity. In practice, the term "hydrostatic equilibrium" is interpreted loosely. Mercury is round but not actually in hydrostatic equilibrium, but it is universally regarded as a planet nonetheless.
According to the IAU's explicit count, there are eight planets in the Solar System; four terrestrial planets (Mercury, Venus, Earth, and Mars) and four giant planets, which can be divided further into two gas giants (Jupiter and Saturn) and two ice giants (Uranus and Neptune). When excluding the Sun, the four giant planets account for more than 99% of the mass of the Solar System.
Dwarf planets
Dwarf planets are bodies orbiting the Sun that are massive and warm eno
Document 1:::
This article is a list of notable unsolved problems in astronomy. Some of these problems are theoretical, meaning that existing theories may be incapable of explaining certain observed phenomena or experimental results. Others are experimental, meaning that experiments necessary to test proposed theory or investigate a phenomenon in greater detail have not yet been performed. Some pertain to unique events or occurrences that have not repeated themselves and whose causes remain unclear.
Planetary astronomy
Our solar system
Orbiting bodies and rotation:
Are there any non-dwarf planets beyond Neptune?
Why do extreme trans-Neptunian objects have elongated orbits?
Rotation rate of Saturn:
Why does the magnetosphere of Saturn rotate at a rate close to that at which the planet's clouds rotate?
What is the rotation rate of Saturn's deep interior?
Satellite geomorphology:
What is the origin of the chain of high mountains that closely follows the equator of Saturn's moon, Iapetus?
Are the mountains the remnant of hot and fast-rotating young Iapetus?
Are the mountains the result of material (either from the rings of Saturn or its own ring) that over time collected upon the surface?
Extra-solar
How common are Solar System-like planetary systems? Some observed planetary systems contain Super-Earths and Hot Jupiters that orbit very close to their stars. Systems with Jupiter-like planets in Jupiter-like orbits appear to be rare. There are several possibilities why Jupiter-like orbits are rare, including that data is lacking or the grand tack hypothesis.
Stellar astronomy and astrophysics
Solar cycle:
How does the Sun generate its periodically reversing large-scale magnetic field?
How do other Sol-like stars generate their magnetic fields, and what are the similarities and differences between stellar activity cycles and that of the Sun?
What caused the Maunder Minimum and other grand minima, and how does the solar cycle recover from a minimum state?
Coronal heat
Document 2:::
The Somerset Space Walk is a sculpture trail model of the Solar System, located in Somerset, England. The model uses the towpath of the Bridgwater and Taunton Canal to display a model of the Sun and its planets in their proportionally correct sizes and distances apart. Unusually for a Solar System model, there are two sets of planets, so that the diameter of the orbits is represented.
Aware of the inadequacies of printed pictures of the Solar System, the inventor Pip Youngman designed the Space Walk as a way of challenging people's perceptions of space and experiencing the vastness of the Solar System.
The model is built to a scale of 1:530,000,000, meaning that one millimetre on the model equates to 530 kilometres. The Sun is sited at Higher Maunsel Lock, and one set of planets is installed in each direction along the canal towards Taunton and Bridgwater; the distance between the Sun and each model of Pluto being . For less hardy walkers, the inner planets are within of the Sun, and near to the Maunsel Canal Centre (and tea shop) at Lower Maunsel Lock, where a more detailed leaflet about the model is available.
The Space Walk was opened on 9 August 1997 by British astronomer Heather Couper. In 2007, a project team from Somerset County Council refurbished some of the models.
Background
The Walk is a joint venture between the Taunton Solar Model Group and British Waterways, with support from Somerset County Council, Taunton Deane Borough Council and the Somerset Waterways Development Trust. The Taunton Solar Model Group comprised Pip Youngman, Trevor Hill – a local physics teacher who had been awarded the title of "Institute of Physics (IOP) Physics Teacher of the Year" – and David Applegate who, during his time as Mayor of Taunton, had expressed a wish to see some kind of science initiative in the area. Youngman came up with the idea for the Space Walk, and Hill assisted by calculating the respective positions and sizes of the planets.
Funding for the projec
Document 3:::
The Sweden Solar System is the world's largest permanent scale model of the Solar System. The Sun is represented by the Avicii Arena in Stockholm, the second-largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea. The system was started by Nils Brenning, professor at the Royal Institute of Technology in Stockholm, and Gösta Gahm, professor at the Stockholm University. The model represents the Solar System on the scale of 1:20 million.
The system
The bodies represented in this model include the Sun, the planets (and some of their moons), dwarf planets and many types of small bodies (comets, asteroids, trans-Neptunians, etc.), as well as some abstract concepts (like the Termination Shock zone). Because of the existence of many small bodies in the real Solar System, the model can always be further increased.
The Sun is represented by the Avicii Arena (Globen), Stockholm, which is the second-largest hemispherical building in the world, in diameter. To respect the scale, the globe represents the Sun including its corona.
Inner planets
Mercury ( in diameter) is placed at Stockholm City Museum, from the Globe. The small metallic sphere was built by the artist Peter Varhelyi.
Venus ( in diameter) is placed at Vetenskapens Hus at KTH (Royal Institute of Technology), from the Globe. The previous model, made by the United States artist Daniel Oberti, was inaugurated on 8 June 2004, during a Venus transit and placed at KTH. It fell and shattered around 11 June 2011. Due to construction work at the location of the previous model of Venus it was removed and as of October 2012 cannot be seen. The current model now at Vetenskapens Hus was previously located at the Observatory Museum in Stockholm (now closed).
Earth ( in diameter) is located at the Swedish Museum of Natural History (Cosmonova), from the Globe. Satellite images of the Earth are exhibited
Document 4:::
A planetary system is a set of gravitationally bound non-stellar objects in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with the planetary system revolving around it, including Earth, forms the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
Debris disks are also known to be common, though other objects are more difficult to observe.
Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water, and thus the capacity to support Earth-like life.
History
Heliocentrism
Historically, heliocentrism (the doctrine that the Sun is at the centre of the universe) was opposed to geocentrism (placing Earth at the centre of the universe).
The notion of a heliocentric Solar System with the Sun at its centre is possibly first suggested in the Vedic literature of ancient India, which often refer to the Sun as the "centre of spheres". Some interpret Aryabhatta's writings in Āryabhaṭīya as implicitly heliocentric.
The idea was first proposed in Western philosophy and Greek astronomy as early as the 3rd century BC by Aristarchus of Samos, but received no support from most other ancient astronomers.
Discovery of the Solar System
De revolutionibus orbium coelestium by Nicolaus Copernicus, published in 1543, presented the first mathematically predictive heliocentric model of a planetary system. 17th-century successors Galileo Galilei, Johannes Kepler, and Sir Isaac Newton developed an understanding of physics which led to the gradual acceptance of the idea that the Earth moves around the Sun and that the planets are governed by the same physical laws that governed Earth.
Speculation on extrasolar pla
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do the planets orbit around in the solar system?
A. the Milky Way
B. the Earth
C. the moon
D. the sun
Answer:
|
|
scienceQA-1351
|
multiple_choice
|
Select the invertebrate.
|
[
"birdwing butterfly",
"dwarf crocodile",
"rainbow trout",
"yak"
] |
A
|
A yak is a mammal. Like other mammals, a yak is a vertebrate. It has a backbone.
A birdwing butterfly is an insect. Like other insects, a birdwing butterfly is an invertebrate. It does not have a backbone. It has an exoskeleton.
A rainbow trout is a fish. Like other fish, a rainbow trout is a vertebrate. It has a backbone.
A dwarf crocodile is a reptile. Like other reptiles, a dwarf crocodile is a vertebrate. It has a backbone.
|
Relavent Documents:
Document 0:::
International Society for Invertebrate Morphology (ISIM) was founded during the 1st International Congress on Invertebrate Morphology, in Copenhagen, August 2008. The objectives of the society are to promote international collaboration and provide educational opportunities and training on invertebrate morphology, and to organize and promote the international congresses of invertebrate morphology, international meetings and other forms of scientific exchange.
The ISIM has its own Constitution
ISIM board 2014-2017
Gerhard Scholtz (President) Institute of Biology, Humboldt-Universität zu Berlin, Germany. https://www.biologie.hu-berlin.de/de/gruppenseiten/compzool/people/gerhard_scholtz_page
Natalia Biserova (President-Elect) Moscow State University, Moscow, Russia.
Gonzalo Giribet (Past-President) Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA.
Julia Sigwart (Secretary)
Katrina Worsaae (Treasurer)
Greg Edgecombe (2nd term)
Andreas Hejnol (2nd term)
Sally Leys (2nd term)
Fernando Pardos (2nd term)
Katharina Jörger (1st term)
Marymegan Daly (1st term)
Georg Mayer (1st term)
ISIM board 2017-2020
Natalia Biserova (President), Lomonosov Moscow State University, Moscow, Russian Federation http://invert.bio.msu.ru/en/staff-en/33-biserova-en .
Andreas Wanninger (President-elect), Department of Integrative Zoology, University of Vienna, Vienna, Austria.
Gerhard Scholtz (Past-president), Department of Biology, Humboldt-Universität zu Berlin, Germany.
Julia Sigwart (Secretary), School of Biological Sciences, Queen's University Belfast, UK.
Katrine Worsaae (Treasurer), Department of Biology, University of Copenhagen, Copenhagen, Denmark.
Advisory Council:
Ariel Chipman (Israel)
D. Bruce Conn (USA)
Conrad Helm (Germany)
Xiaoya Ma (UK)
Pedro Martinez (Spain)
Ana Riesgo (Spain)
Nadezhda Rimskaya-Korsakova (Russia)
Elected 23-08-2017, Moscow
Former meetings
ICIM 1 (2008) University of Copenhagen, Denmark
ICIM 2 (2011) H
Document 1:::
Invertebrate zoology is the subdiscipline of zoology that consists of the study of invertebrates, animals without a backbone (a structure which is found only in fish, amphibians, reptiles, birds and mammals).
Invertebrates are a vast and very diverse group of animals that includes sponges, echinoderms, tunicates, numerous different phyla of worms, molluscs, arthropods and many additional phyla. Single-celled organisms or protists are usually not included within the same group as invertebrates.
Subdivisions
Invertebrates represent 97% of all named animal species, and because of that fact, this subdivision of zoology has many further
subdivisions, including but not limited to:
Arthropodology - the study of arthropods, which includes
Arachnology - the study of spiders and other arachnids
Entomology - the study of insects
Carcinology - the study of crustaceans
Myriapodology - the study of centipedes, millipedes, and other myriapods
Cnidariology - the study of Cnidaria
Helminthology - the study of parasitic worms.
Malacology - the study of mollusks, which includes
Conchology - the study of Mollusk shells.
Limacology - the study of slugs.
Teuthology - the study of cephalopods.
Invertebrate paleontology - the study of fossil invertebrates
These divisions are sometimes further divided into more specific specialties. For example, within arachnology, acarology is the study of mites and ticks; within entomology, lepidoptery is the study of butterflies and moths, myrmecology is the study of ants and so on. Marine invertebrates are all those invertebrates that exist in marine habitats.
History
Early Modern Era
In the early modern period starting in the late 16th century, invertebrate zoology saw growth in the number of publications made and improvement in the experimental practices associated with the field. (Insects are one of the most diverse groups of organisms on Earth. They play important roles in ecosystems, including pollination, natural enemies, saprophytes, and
Document 2:::
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. As of 2022, 2.16 million living animal species have been described—of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are around 7.77 million animal species. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and the chordates, the latter including the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on ad
Document 3:::
This is a list of scientific journals which cover the field of zoology.
A
Acta Entomologica Musei Nationalis Pragae
Acta Zoologica Academiae Scientiarum Hungaricae
Acta Zoologica Bulgarica
Acta Zoológica Mexicana
Acta Zoologica: Morphology and Evolution
African Entomology
African Invertebrates
African Journal of Herpetology
African Zoology
Alces
American Journal of Primatology
Animal Biology, formerly Netherlands Journal of Zoology
Animal Cognition
Arctic
Australian Journal of Zoology
Australian Mammalogy
B
Bulgarian Journal of Agricultural Science
Bulletin of the American Museum of Natural History
C
Canadian Journal of Zoology
Caribbean Herpetology
Central European Journal of Biology
Contributions to Zoology
Copeia
Crustaceana
E
Environmental Biology of Fishes
F
Frontiers in Zoology
H
Herpetological Monographs
I
Integrative and Comparative Biology, formerly American Zoologist
International Journal of Acarology
International Journal of Primatology
J
M
Malacologia
N
North-Western Journal of Zoology
P
Physiological and Biochemical Zoology
R
Raffles Bulletin of Zoology
Rangifer
Russian Journal of Nematology
V
The Veliger
W
Worm Runner's Digest
Z
See also
List of biology journals
List of ornithology journals
List of entomology journals
Lists of academic journals
Zoology-related lists
Document 4:::
Roshd Biological Education is a quarterly science educational magazine covering recent developments in biology and biology education for a biology teacher Persian -speaking audience. Founded in 1985, it is published by The Teaching Aids Publication Bureau, Organization for Educational Planning and Research, Ministry of Education, Iran. Roshd Biological Education has an editorial board composed of Iranian biologists, experts in biology education, science journalists and biology teachers.
It is read by both biology teachers and students, as a way of launching innovations and new trends in biology education, and helping biology teachers to teach biology in better and more effective ways.
Magazine layout
As of Autumn 2012, the magazine is laid out as follows:
Editorial—often offering a view of point from editor in chief on an educational and/or biological topics.
Explore— New research methods and results on biology and/or education.
World— Reports and explores on biological education worldwide.
In Brief—Summaries of research news and discoveries.
Trends—showing how new technology is altering the way we live our lives.
Point of View—Offering personal commentaries on contemporary topics.
Essay or Interview—often with a pioneer of a biological and/or educational researcher or an influential scientific educational leader.
Muslim Biologists—Short histories of Muslim Biologists.
Environment—An article on Iranian environment and its problems.
News and Reports—Offering short news and reports events on biology education.
In Brief—Short articles explaining interesting facts.
Questions and Answers—Questions about biology concepts and their answers.
Book and periodical Reviews—About new publication on biology and/or education.
Reactions—Letter to the editors.
Editorial staff
Mohammad Karamudini, editor in chief
History
Roshd Biological Education started in 1985 together with many other magazines in other science and art. The first editor was Dr. Nouri-Dalooi, th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the invertebrate.
A. birdwing butterfly
B. dwarf crocodile
C. rainbow trout
D. yak
Answer:
|
sciq-10108
|
multiple_choice
|
What is the molecule, dipeptide formed together by?
|
[
"polymer acids",
"amino acids",
"acetic acids",
"rna acids"
] |
B
|
Relavent Documents:
Document 0:::
Biomolecular structure is the intricate folded, three-dimensional shape that is formed by a molecule of protein, DNA, or RNA, and that is important to its function. The structure of these molecules may be considered at any of several length scales ranging from the level of individual atoms to the relationships among entire protein subunits. This useful distinction among scales is often expressed as a decomposition of molecular structure into four levels: primary, secondary, tertiary, and quaternary. The scaffold for this multiscale organization of the molecule arises at the secondary level, where the fundamental structural elements are the molecule's various hydrogen bonds. This leads to several recognizable domains of protein structure and nucleic acid structure, including such secondary-structure features as alpha helixes and beta sheets for proteins, and hairpin loops, bulges, and internal loops for nucleic acids.
The terms primary, secondary, tertiary, and quaternary structure were introduced by Kaj Ulrik Linderstrøm-Lang in his 1951 Lane Medical Lectures at Stanford University.
Primary structure
The primary structure of a biopolymer is the exact specification of its atomic composition and the chemical bonds connecting those atoms (including stereochemistry). For a typical unbranched, un-crosslinked biopolymer (such as a molecule of a typical intracellular protein, or of DNA or RNA), the primary structure is equivalent to specifying the sequence of its monomeric subunits, such as amino acids or nucleotides.
The primary structure of a protein is reported starting from the amino N-terminus to the carboxyl C-terminus, while the primary structure of DNA or RNA molecule is known as the nucleic acid sequence reported from the 5' end to the 3' end.
The nucleic acid sequence refers to the exact sequence of nucleotides that comprise the whole molecule. Often, the primary structure encodes sequence motifs that are of functional importance. Some examples of such motif
Document 1:::
This is a list of topics in molecular biology. See also index of biochemistry articles.
Document 2:::
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 3:::
A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nucleotides. By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, with its double helix, there are two possible directions for the notated sequence; of these two, the sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure.
The sequence represents biological information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism.
Nucleic acids also have a secondary structure and tertiary structure. Primary structure is sometimes mistakenly referred to as "primary sequence". However there is no parallel concept of secondary or tertiary sequence.
Nucleotides
Nucleic acids consist of a chain of linked units called nucleotides. Each nucleotide consists of three subunits: a phosphate group and a sugar (ribose in the case of RNA, deoxyribose in DNA) make up the backbone of the nucleic acid strand, and attached to the sugar is one of a set of nucleobases. The nucleobases are important in base pairing of strands to form higher-level secondary and tertiary structures such as the famed double helix.
The possible letters are A, C, G, and T, representing the four nucleotide bases of a DNA strand – adenine, cytosine, guanine, thymine – covalently linked to a phosphodiester backbone. In the typical case, the sequences are printed abutting one another without gaps, as in the sequence AAAGTCTGAC, read left to right in the 5' to 3' direction. With regards to transcription, a sequence is on the coding strand if it has the same order as the transcribed RNA.
Document 4:::
The central dogma of molecular biology is an explanation of the flow of genetic information within a biological system. It is often stated as "DNA makes RNA, and RNA makes protein", although this is not its original meaning. It was first stated by Francis Crick in 1957, then published in 1958:
He re-stated it in a Nature paper published in 1970: "The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid."
A second version of the central dogma is popular but incorrect. This is the simplistic DNA → RNA → protein pathway published by James Watson in the first edition of The Molecular Biology of the Gene (1965). Watson's version differs from Crick's because Watson describes a two-step (DNA → RNA and RNA → protein) process as the central dogma. While the dogma as originally stated by Crick remains valid today, Watson's version does not.
The dogma is a framework for understanding the transfer of sequence information between information-carrying biopolymers, in the most common or general case, in living organisms. There are 3 major classes of such biopolymers: DNA and RNA (both nucleic acids), and protein. There are conceivable direct transfers of information that can occur between these. The dogma classes these into 3 groups of 3: three general transfers (believed to occur normally in most cells), two special transfers (known to occur, but only under specific conditions in case of some viruses or in a laboratory), and four unknown transfers (believed never to occur). The general transfers describe the normal flow of biological information: DNA can be copied to DNA (DNA replication), DNA information can be copied into mRNA (transcription), and proteins can be synthesized using the information in mRNA as a template (translation). The special transfers describe: RNA being copied from RNA (RNA replication), D
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the molecule, dipeptide formed together by?
A. polymer acids
B. amino acids
C. acetic acids
D. rna acids
Answer:
|
|
sciq-11087
|
multiple_choice
|
A fact or question is only considered science if it has what property?
|
[
"it is testable",
"it is mineral",
"it is believable",
"it is interesting"
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 2:::
The 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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The mathematical sciences are a group of areas of study that includes, in addition to mathematics, those academic disciplines that are primarily mathematical in nature but may not be universally considered subfields of mathematics proper.
Statistics, for example, is mathematical in its methods but grew out of bureaucratic and scientific observations, which merged with inverse probability and then grew through applications in some areas of physics, biometrics, and the social sciences to become its own separate, though closely allied, field. Theoretical astronomy, theoretical physics, theoretical and applied mechanics, continuum mechanics, mathematical chemistry, actuarial science, computer science, computational science, data science, operations research, quantitative biology, control theory, econometrics, geophysics and mathematical geosciences are likewise other fields often considered part of the mathematical sciences.
Some institutions offer degrees in mathematical sciences (e.g. the United States Military Academy, Stanford University, and University of Khartoum) or applied mathematical sciences (for example, the University of Rhode Island).
See also
Document 4:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A fact or question is only considered science if it has what property?
A. it is testable
B. it is mineral
C. it is believable
D. it is interesting
Answer:
|
|
sciq-29
|
multiple_choice
|
What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty?
|
[
"steroids",
"epinephrine",
"estrogen",
"testosterone"
] |
D
|
Relavent Documents:
Document 0:::
The following is a list of hormones found in Homo sapiens. Spelling is not uniform for many hormones. For example, current North American and international usage uses estrogen and gonadotropin, while British usage retains the Greek digraph in oestrogen and favours the earlier spelling gonadotrophin.
Hormone listing
Steroid
Document 1:::
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 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
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Testosterone glucuronide is an endogenous, naturally occurring steroid and minor urinary metabolite of testosterone.
See also
Androstanediol glucuronide
Androsterone glucuronide
Etiocholanolone glucuronide
Testosterone sulfate
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty?
A. steroids
B. epinephrine
C. estrogen
D. testosterone
Answer:
|
|
sciq-469
|
multiple_choice
|
An action potential that starts at the axon hillock moves along the axon only toward what?
|
[
"polar synapses",
"nerve endings",
"ionic pathways",
"the synaptic terminals"
] |
D
|
Relavent Documents:
Document 0:::
Neural backpropagation is the phenomenon in which, after the action potential of a neuron creates a voltage spike down the axon (normal propagation), another impulse is generated from the soma and propagates towards the apical portions of the dendritic arbor or dendrites (from which much of the original input current originated). In addition to active backpropagation of the action potential, there is also passive electrotonic spread. While there is ample evidence to prove the existence of backpropagating action potentials, the function of such action potentials and the extent to which they invade the most distal dendrites remain highly controversial.
Mechanism
When the graded excitatory postsynaptic potentials (EPSPs) depolarize the soma to spike threshold at the axon hillock, first, the axon experiences a propagating impulse through the electrical properties of its voltage-gated sodium and voltage-gated potassium channels. An action potential occurs in the axon first as research illustrates that sodium channels at the dendrites exhibit a higher threshold than those on the membrane of the axon (Rapp et al., 1996). Moreover, the voltage-gated sodium channels on the dendritic membranes having a higher threshold helps prevent them triggering an action potential from synaptic input. Instead, only when the soma depolarizes enough from accumulating graded potentials and firing an axonal action potential will these channels be activated to propagate a signal traveling backwards (Rapp et al. 1996). Generally, EPSPs from synaptic activation are not large enough to activate the dendritic voltage-gated calcium channels (usually on the order of a couple milliamperes each) so backpropagation is typically believed to happen only when the cell is activated to fire an action potential. These sodium channels on the dendrites are abundant in certain types of neurons, especially mitral and pyramidal cells, and quickly inactivate. Initially, it was thought that an action poten
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Spike directivity is a vector that quantifies changes in transient charge density during action potential propagation.
The digital-like uniformity of action potentials is contradicted by experimental data. Electrophysiologists have observed that the shape of recorded action potentials changes in time. Recent experimental evidence has shown that action potentials in neurons are subject to waveform modulation while they travel down axons or dendrites. The action potential waveform can be modulated by neuron geometry, local alterations in the ion conductance, and other biophysical properties including neurotransmitter release.
See also
Cellular neuroscience
Neuron
NeuroElectroDynamics
Document 2:::
Non-spiking neurons are neurons that are located in the central and peripheral nervous systems and function as intermediary relays for sensory-motor neurons. They do not exhibit the characteristic spiking behavior of action potential generating neurons.
Non-spiking neural networks are integrated with spiking neural networks to have a synergistic effect in being able to stimulate some sensory or motor response while also being able to modulate the response.
Discovery
Animal models
There are an abundance of neurons that propagate signals via action potentials and the mechanics of this particular kind of transmission is well understood. Spiking neurons exhibit action potentials as a result of a neuron characteristic known as membrane potential. Through studying these complex spiking networks in animals, a neuron that did not exhibit characteristic spiking behavior was discovered. These neurons use a graded potential to transmit data as they lack the membrane potential that spiking neurons possess. This method of transmission has a huge effect on the fidelity, strength, and lifetime of the signal. Non-spiking neurons were identified as a special kind of interneuron and function as an intermediary point of process for sensory-motor systems. Animals have become substantial models for understanding more about non-spiking neural networks and the role they play in an animal’s ability to process information and its overall function. Animal models indicate that the interneurons modulate directional and posture coordinating behaviors.
Crustaceans and arthropods such as the crawfish have created many opportunities to learn about the modulatory role that these neurons have in addition to their potential to be modulated regardless of their lack of exhibiting spiking behavior. Most of the known information about nonspiking neurons is derived from animal models. Studies focus on neuromuscular junctions and modulation of abdominal motor cells. Modulatory interneurons are neurons
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An action potential occurs when the membrane potential of a specific cell rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells.
In neurons, action potentials play a central role in cell–cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events leading to contraction. In beta cells of the pancreas, they provoke release of insulin. Action potentials in neurons are also known as "nerve impulses" or "spikes", and the temporal sequence of action potentials generated by a neuron is called its "spike train". A neuron that emits an action potential, or nerve impulse, is often said to "fire".
Action potentials are generated by special types of voltage-gated ion channels embedded in a cell's plasma membrane. These channels are shut when the membrane potential is near the (negative) resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined threshold voltage, depolarising the transmembrane potential. When the channels open, they allow an inward flow of sodium ions, which changes the electrochemical gradient, which in turn produces a further rise in the membrane potential towards zero. This then causes more channels to open, producing a greater electric current across the cell membrane and so on. The pr
Document 4:::
Classical cable theory uses mathematical models to calculate the electric current (and accompanying voltage) along passive neurites, particularly the dendrites that receive synaptic inputs at different sites and times. Estimates are made by modeling dendrites and axons as cylinders composed of segments with capacitances and resistances combined in parallel (see Fig. 1). The capacitance of a neuronal fiber comes about because electrostatic forces are acting through the very thin lipid bilayer (see Figure 2). The resistance in series along the fiber is due to the axoplasm's significant resistance to movement of electric charge.
History
Cable theory in computational neuroscience has roots leading back to the 1850s, when Professor William Thomson (later known as Lord Kelvin) began developing mathematical models of signal decay in submarine (underwater) telegraphic cables. The models resembled the partial differential equations used by Fourier to describe heat conduction in a wire.
The 1870s saw the first attempts by Hermann to model neuronal electrotonic potentials also by focusing on analogies with heat conduction. However, it was Hoorweg who first discovered the analogies with Kelvin's undersea cables in 1898 and then Hermann and Cremer who independently developed the cable theory for neuronal fibers in the early 20th century. Further mathematical theories of nerve fiber conduction based on cable theory were developed by Cole and Hodgkin (1920s–1930s), Offner et al. (1940), and Rushton (1951).
Experimental evidence for the importance of cable theory in modelling the behavior of axons began surfacing in the 1930s from work done by Cole, Curtis, Hodgkin, Sir Bernard Katz, Rushton, Tasaki and others. Two key papers from this era are those of Davis and Lorente de Nó (1947) and Hodgkin and Rushton (1946).
The 1950s saw improvements in techniques for measuring the electric activity of individual neurons. Thus cable theory became important for analyzing data collect
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
An action potential that starts at the axon hillock moves along the axon only toward what?
A. polar synapses
B. nerve endings
C. ionic pathways
D. the synaptic terminals
Answer:
|
|
ai2_arc-100
|
multiple_choice
|
Many states require vehicles to be examined and to meet safety and pollution standards. What impact might vehicle inspections have on the environment?
|
[
"The environment will not be polluted.",
"The environment will become more polluted.",
"Fewer pollutants will be released by vehicles.",
"Fewer pollutants will be produced by older vehicles."
] |
C
|
Relavent Documents:
Document 0:::
The Certification for Sustainable Transportation is a national program housed at the University of Vermont Extension that seeks to promote the practice of using energy efficient modes of transportation. The CST work centers on its eRating vehicle certification program, which is an eco-label for passenger transportation vehicles. The eRating uses a sustainability index which includes factors such as green house gas emissions per passenger mile, emission levels of criteria pollutants, and in certain circumstances factors such as training for drivers and use of endorsed carbon offsets. Once a certain threshold is met, vehicles may qualify for e1, e2, e3, or e4 levels in the certification program.
Other key components of the CST's work are online and in person training programs. The CST offers training programs geared to help drivers and organizations eliminate all unnecessary idling and on eco-driving. These training programs are focused on helping reduce environmental impacts, save fuel, and save money.
The CST is now actively working with companies in 48 states and three Canadian provinces to prevent unnecessary emissions, reduce environmental impact, and decrease consumption of fossil fuels.
This program is not to be confused with the "E-Mark" vehicle equipment safety certification promulgated by the European Union since 2002 under EU Directive 72/245/EEC and amendments to the requirements of Directive 95/54/EC.
History
In 2007, the University of Vermont began the Green Coach Certification research project, which sought to investigate what efficiency standards would be best applied to motor coaches to promote greater energy sustainability. Research was conducted on actual motor coach companies. It also researched whether a certification program could help reduce environmental impacts from the motor coach industry by educating operators and executives about the benefits, both financial and environmental, of adopting fuel saving strategies and switching to alterna
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The worst-case analysis regulation was promulgated in 1979 by the US Council on Environmental Quality (CEQ). The regulation is one of many implementing the National Environmental Policy Act of 1969 and it sets out the formal procedure a US government agency must follow when confronted with gaps in relevant information or scientific uncertainty about significant adverse effects on the environment from a major federal action.
Synopsis
The regulation requires an agency to make known when it is confronted with gaps in relevant information or scientific uncertainty. The agency then must determine if the missing information is essential to a reasoned choice among the alternatives. When the missing information is material to the decision an agency ordinarily must obtain the information and include it in an environmental impact statement (EIS). If the means for obtaining the missing information are beyond the state of the art or alternatively if the costs of obtaining it are exorbitant the agency must then prepare a worst-case analysis. In this analysis the agency must weigh the need for the action against the risks and in the face of uncertainty. The agency also is to indicate the probability or improbability of the worst case's occurrence.
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The National Air Pollution Monitoring Network (NABEL) is a joint project of the Swiss Federal Office for the Environment (BAFU) and the Swiss Federal Laboratories for Materials Science and Technology (EMPA), based in Dübendorf, in the canton of Zurich.
Establishment of the National Monitoring Network
As part of an international collaboration of 11 countries, EMPA has been continuously measuring air pollutants since 1968, initially with four stations. From 1972 to 1977, the measurements were continued in the OECD Base Program, and the project was expanded to eight stations in 1978. The international measurements of the European Monitoring and Evaluation Programme (EMEP) were integrated following the signing of the United Nations Economic Commission for Europe (UN/ECE) Convention on Long Range Transboundary Air Pollution the following year. Within the framework of the research program "Forest Damage and Air Pollution in Switzerland" (NFP14), measurements were taken at three forest sites. The measurement network was expanded to its current level of 16 stations in 1990/91.
Activities and Monitoring Stations
NABEL monitors the current air pollutant levels and tracks the long-term development of air quality in Switzerland. The monitoring network consists of 16 stations distributed throughout Switzerland: Basel Sternwarte St. Margarethen, Bern, Beromünster (replacing the former Lägern station since summer 2016), Chaumont, Davos, Dübendorf (replaced in 2020), Härkingen, Jungfraujoch, Lausanne, Lugano, Magadino, Payerne, Rigi, Sion, Tänikon, and Zurich. These locations reflect the most common air pollution situations in Switzerland, ranging from low to high levels of pollution. Despite the relatively small number of measurement points, a detailed picture of air quality in Switzerland can be obtained.
Some of the stations are part of international measurement programs, namely the European Monitoring and Evaluation Programme (EMEP) and the Global Atmosphere Watch (GAW).
Document 3:::
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 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.
Many states require vehicles to be examined and to meet safety and pollution standards. What impact might vehicle inspections have on the environment?
A. The environment will not be polluted.
B. The environment will become more polluted.
C. Fewer pollutants will be released by vehicles.
D. Fewer pollutants will be produced by older vehicles.
Answer:
|
|
sciq-1963
|
multiple_choice
|
What are small, icy objects that have very elliptical orbits around the sun?
|
[
"meteors",
"asteroids",
"comets",
"craters"
] |
C
|
Relavent Documents:
Document 0:::
This article is a list of notable unsolved problems in astronomy. Some of these problems are theoretical, meaning that existing theories may be incapable of explaining certain observed phenomena or experimental results. Others are experimental, meaning that experiments necessary to test proposed theory or investigate a phenomenon in greater detail have not yet been performed. Some pertain to unique events or occurrences that have not repeated themselves and whose causes remain unclear.
Planetary astronomy
Our solar system
Orbiting bodies and rotation:
Are there any non-dwarf planets beyond Neptune?
Why do extreme trans-Neptunian objects have elongated orbits?
Rotation rate of Saturn:
Why does the magnetosphere of Saturn rotate at a rate close to that at which the planet's clouds rotate?
What is the rotation rate of Saturn's deep interior?
Satellite geomorphology:
What is the origin of the chain of high mountains that closely follows the equator of Saturn's moon, Iapetus?
Are the mountains the remnant of hot and fast-rotating young Iapetus?
Are the mountains the result of material (either from the rings of Saturn or its own ring) that over time collected upon the surface?
Extra-solar
How common are Solar System-like planetary systems? Some observed planetary systems contain Super-Earths and Hot Jupiters that orbit very close to their stars. Systems with Jupiter-like planets in Jupiter-like orbits appear to be rare. There are several possibilities why Jupiter-like orbits are rare, including that data is lacking or the grand tack hypothesis.
Stellar astronomy and astrophysics
Solar cycle:
How does the Sun generate its periodically reversing large-scale magnetic field?
How do other Sol-like stars generate their magnetic fields, and what are the similarities and differences between stellar activity cycles and that of the Sun?
What caused the Maunder Minimum and other grand minima, and how does the solar cycle recover from a minimum state?
Coronal heat
Document 1:::
This article includes a list of the most massive known objects of the Solar System and partial lists of smaller objects by observed mean radius. These lists can be sorted according to an object's radius and mass and, for the most massive objects, volume, density, and surface gravity, if these values are available.
These lists contain the Sun, the planets, dwarf planets, many of the larger small Solar System bodies (which includes the asteroids), all named natural satellites, and a number of smaller objects of historical or scientific interest, such as comets and near-Earth objects.
Many trans-Neptunian objects (TNOs) have been discovered; in many cases their positions in this list are approximate, as there is frequently a large uncertainty in their estimated diameters due to their distance from Earth.
Solar System objects more massive than 1021 kilograms are known or expected to be approximately spherical. Astronomical bodies relax into rounded shapes (spheroids), achieving hydrostatic equilibrium, when their own gravity is sufficient to overcome the structural strength of their material. It was believed that the cutoff for round objects is somewhere between 100 km and 200 km in radius if they have a large amount of ice in their makeup; however, later studies revealed that icy satellites as large as Iapetus (1,470 kilometers in diameter) are not in hydrostatic equilibrium at this time, and a 2019 assessment suggests that many TNOs in the size range of 400–1,000 kilometers may not even be fully solid bodies, much less gravitationally rounded. Objects that are ellipsoids due to their own gravity are here generally referred to as being "round", whether or not they are actually in equilibrium today, while objects that are clearly not ellipsoidal are referred to as being "irregular."
Spheroidal bodies typically have some polar flattening due to the centrifugal force from their rotation, and can sometimes even have quite different equatorial diameters (scalene ellipso
Document 2:::
The following list of instrument-resolved minor planets consists of minor planets whose disks have been resolved, whether by telescope, a visit by an uncrewed spacecraft, or by observing the occultation of a background star from multiple sites. Disk resolution allows the density of an body to be computed, providing useful information about the internal composition. It can also be used to determine the shape of the object, to search for albedo features, and to look for companions.
Techniques
Because of their distance from Earth and their small dimension, minor planets such as asteroids represent a challenge for astronomical instruments to resolve. Even two of the largest objects in the asteroid belt, 2 Pallas and 4 Vesta, have maximum angular diameters of less than an arcsecond. With a ground-based optical telescope, resolution of these objects through the Earth's thick atmosphere can require techniques such as speckle interferometry or adaptive optics.
Radio telescopes such as Arecibo or Goldstone have been used to observe asteroids. This technique can be used to measure the Doppler shifts and radar cross-sections of the bodies, while more detailed studies allow three-dimensional shape models to be built. The first radar detection of a minor planet was 1566 Icarus by JPL astronomer Richard M. Goldstein in June 1968. This was followed by 1685 Toro in 1972. A regular program of radar observation of the asteroid belt asteroids was begun in 1980 at Arecibo. Goldstone joined the effort in 1990. Together, they observed 37 main-belt asteroids between 1980–1997.
A more direct approach to asteroid study, allowing the object to be examined greater detail, is to send a spacecraft to either make a fly-by or go into orbit. The first such asteroid to be imaged in this manner was 951 Gaspra in 1991 by the Galileo spacecraft. In 2000, the NEAR Shoemaker spacecraft went into orbit around 433 Eros after making a fly-by of 253 Mathilde in 1997.
Objects
The tables below list selec
Document 3:::
This is a list of periodic comets that were numbered by the Minor Planet Center after having been observed on at least two occasions. Their orbital periods vary from 3.2 to 366 years. there are 471 numbered comets (1P–471P). There are 405 Jupiter-family comets (JFCs), 38 Encke-type comets (ETCs), 14 Halley-type comets (HTCs), five Chiron-type comets (CTCs), and one long-period comet (153P). 75 bodies are also near-Earth comets (NECs). In addition, eight numbered comets are principally classified as minor planets – five main-belt comets, two centaurs (CEN), and one Apollo asteroid – and display characteristics of both an asteroid and a comet.
Occasionally, comets will break up into multiple chunks, as volatiles coming off the comet and rotational forces may cause it to break into two or more pieces. An extreme example of this is 73P/Schwassmann–Wachmann, which broke into over 50 pieces during its 1995 perihelion.
For a larger list of periodic Jupiter-family and Halley-type comets including unnumbered bodies, see list of periodic comets.
List
Multiples
51P/Harrington
back to main list
This is a list of (3 entries) with all its cometary fragments listed at JPL's SBDB (see ).
57P/du Toit–Neujmin–Delporte
back to main list
This is a list of (2 entries) with all its cometary fragments listed at JPL's SBDB (see ).
73P/Schwassmann–Wachmann
back to main list
In 1995, comet 73P/Schwassmann–Wachmann, broke up into several pieces and as of its last perihelion date, the pieces numbered at least 67 with 73P/Schwassmann–Wachmann C as the presumed original nucleus. Because of the enormous number, the pieces of it have been compiled into a separate list.
This is a list of (68 entries) with all its cometary fragments listed at JPL's SBDB (see ).
101P/Chernykh
back to main list
This is a list of (2 entries) with all its cometary fragments listed at JPL's SBDB (see ).
128P/Shoemaker–Holt
back to main list
Document 4:::
The following is a list of Solar System objects by orbit, ordered by increasing distance from the Sun. Most named objects in this list have a diameter of 500 km or more.
The Sun, a spectral class G2V main-sequence star
The inner Solar System and the terrestrial planets
Mercury
Mercury-crossing minor planets
Venus
Venus-crossing minor planets
, Venus's quasi-satellite
Earth
Moon
Near-Earth asteroids (including 99942 Apophis)
Earth trojan ()
Earth-crosser asteroids
Earth's quasi-satellites
Mars
Deimos
Phobos
Mars trojans
Mars-crossing minor planets
Asteroids in the asteroid belt, between the orbits of Mars and Jupiter
Ceres, a dwarf planet
Pallas
Vesta
Hygiea
Asteroids number in the hundreds of thousands. For longer lists, see list of exceptional asteroids, list of asteroids, or list of Solar System objects by size.
Asteroid moons
A number of smaller groups distinct from the asteroid belt
The outer Solar System with the giant planets, their satellites, trojan asteroids and some minor planets
Jupiter
Rings of Jupiter
Complete list of Jupiter's natural satellites
Io
Europa
Ganymede
Callisto
Jupiter trojans
Jupiter-crossing minor planets
Saturn
Rings of Saturn
Complete list of Saturn's natural satellites
Mimas
Enceladus
Tethys (trojans: Telesto and Calypso)
Dione (trojans: Helene and Polydeuces)
Rhea
Rings of Rhea
Titan
Hyperion
Iapetus
Phoebe
Shepherd moons
Saturn-crossing minor planets
Uranus
Rings of Uranus
Complete list of Uranus's natural satellites
Miranda
Ariel
Umbriel
Titania
Oberon
Uranus trojan ()
Uranus-crossing minor planets
Neptune
Rings of Neptune
Complete list of Neptune's natural satellites
Proteus
Triton
Nereid
Neptune trojans
Neptune-crossing minor planets
Non-trojan minor planets
Centaurs
Damocloids
Trans-Neptunian objects (beyond the orbit of Neptune)
Kuiper-belt objects (KBOs)
Plutinos
Pluto, a dwarf planet
Complete list of Pluto's natural satellites
Charon
90482 Orcus
Vanth
Twotinos
Cubewanos (classical objects)
, a dwarf planet
Namaka
Hiʻiaka
, a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are small, icy objects that have very elliptical orbits around the sun?
A. meteors
B. asteroids
C. comets
D. craters
Answer:
|
|
scienceQA-1044
|
multiple_choice
|
Which of the following organisms is the producer in this food web?
|
[
"orca",
"bat star",
"zooplankton",
"kelp"
] |
D
|
Producers do not eat other organisms. So, in a food web, producers do not have arrows pointing to them from other organisms.
The phytoplankton does not have any arrows pointing to it. So, the phytoplankton is a producer.
The bat star has an arrow pointing to it, so it is not a producer.
The orca has an arrow pointing to it, so it is not a producer.
The zooplankton has an arrow pointing to it, so it is not a producer.
The kelp does not have any arrows pointing to it. So, the kelp is a producer.
|
Relavent Documents:
Document 0:::
The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a food "web". Ecological communities with higher biodiversity form more complex trophic paths.
The word trophic derives from the Greek τροφή (trophē) referring to food or nourishment.
History
The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers", and "reducers" (modified to "decomposers" by Lindeman).
Overview
The three basic ways in which organisms get food are as producers, consumers, and decomposers.
Producers (autotrophs) are typically plants or algae. Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers. In this way, it is energy from the sun that usually powers the base of the food chain. An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight. Here primary producers manufacture food through a process called chemosynthesis.
Consumers (heterotrophs) are species that cannot manufacture their own food and need to consume other organisms. Animals that eat primary producers (like plants) are called herbivores. Animals that eat other animals are called carnivores, and animals that eat both plants and other animals are called omnivores.
Decomposers (detritivores) break down dead plant and animal material and wastes and release it again as energy and nutrients into
Document 1:::
Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator (see predation), host-parasite (see parasitism), plant-herbivore and victim-exploiter systems. These kinds of interactions have been studied and modeled by population ecologists for nearly a century. Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources. Species higher up in the food chain survive by consuming other species and can be classified by what they eat and how they obtain or find their food.
Classification of consumer types
The standard categorization
Various terms have arisen to define consumers by what they eat, such as meat-eating carnivores, fish-eating piscivores, insect-eating insectivores, plant-eating herbivores, seed-eating granivores, and fruit-eating frugivores and omnivores are meat eaters and plant eaters. An extensive classification of consumer categories based on a list of feeding behaviors exists.
The Getz categorization
Another way of categorizing consumers, proposed by South African American ecologist Wayne Getz, is based on a biomass transformation web (BTW) formulation that organizes resources into five components: live and dead animal, live and dead plant, and particulate (i.e. broken down plant and animal) matter. It also distinguishes between consumers that gather their resources by moving across landscapes from those that mine their resources by becoming sessile once they have located a stock of resources large enough for them to feed on during completion of a full life history stage.
In Getz's scheme, words for miners are of Greek etymology and words for gatherers are of Latin etymology. Thus a bestivore, such as a cat, preys on live animal
Document 2:::
The soil food web is the community of organisms living all or part of their lives in the soil. It describes a complex living system in the soil and how it interacts with the environment, plants, and animals.
Food webs describe the transfer of energy between species in an ecosystem. While a food chain examines one, linear, energy pathway through an ecosystem, a food web is more complex and illustrates all of the potential pathways. Much of this transferred energy comes from the sun. Plants use the sun’s energy to convert inorganic compounds into energy-rich, organic compounds, turning carbon dioxide and minerals into plant material by photosynthesis. Plant flowers exude energy-rich nectar above ground and plant roots exude acids, sugars, and ectoenzymes into the rhizosphere, adjusting the pH and feeding the food web underground.
Plants are called autotrophs because they make their own energy; they are also called producers because they produce energy available for other organisms to eat. Heterotrophs are consumers that cannot make their own food. In order to obtain energy they eat plants or other heterotrophs.
Above ground food webs
In above ground food webs, energy moves from producers (plants) to primary consumers (herbivores) and then to secondary consumers (predators). The phrase, trophic level, refers to the different levels or steps in the energy pathway. In other words, the producers, consumers, and decomposers are the main trophic levels. This chain of energy transferring from one species to another can continue several more times, but eventually ends. At the end of the food chain, decomposers such as bacteria and fungi break down dead plant and animal material into simple nutrients.
Methodology
The nature of soil makes direct observation of food webs difficult. Since soil organisms range in size from less than 0.1 mm (nematodes) to greater than 2 mm (earthworms) there are many different ways to extract them. Soil samples are often taken using a metal
Document 3:::
Agroecology and Sustainable Food Systems is a peer-reviewed scientific journal covering sustainable agriculture. It was established in 1990 as the Journal of Sustainable Agriculture, obtaining its current title in 2013. It is published by Taylor & Francis and the editor-in-chief is Stephen R. Gliessman (University of California, Santa Cruz).
Abstracting and indexing
The journal is abstracted and indexed in the Science Citation Index Expanded and Scopus.
Document 4:::
The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is a teaching, research and Extension scientific organization focused on agriculture and natural resources. It is a partnership of federal, state, and county governments that includes an Extension office in each of Florida's 67 counties, 12 off-campus research and education centers, five demonstration units, the University of Florida College of Agricultural and Life Sciences (including the School of Forest, Fisheries and Geomatics Sciences and the School of Natural Resources and Environment), three 4-H camps, portions of the UF College of Veterinary Medicine, the Florida Sea Grant program, the Emerging Pathogens Institute, the UF Water Institute and the UF Genetics Institute.
UF/IFAS research and development covers natural resource industries that have a $101 billion annual impact. The program is ranked #1 in the nation in federally financed higher education R&D expenditures in agricultural sciences and natural resources conservation by the National Science Foundation for FY 2019. Because of this mission and the diversity of Florida's climate and agricultural commodities, IFAS has facilities located throughout Florida. On July 13, 2020, Dr. J. Scott Angle became leader of UF/IFAS and UF's vice president for agriculture and natural resources.
History
Research
The mission of UF/IFAS is to develop knowledge in agricultural, human, and natural resources, and to make that knowledge accessible to sustain and enhance the quality of human life. Faculty members pursue fundamental and applied research that furthers understanding of natural and human systems. Research is supported by state and federally appropriated funds and supplemented by grants and contracts. UF/IFAS received $155.6 million in annual research expenditures in sponsored research for FY 2021.
The Florida Agricultural Experiment Station administers and supports research programs in UF/IFAS. The research program was created in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which of the following organisms is the producer in this food web?
A. orca
B. bat star
C. zooplankton
D. kelp
Answer:
|
sciq-11080
|
multiple_choice
|
What thickens the cortex around the inner edge of a cell?
|
[
"vacuoles",
"mitochondria",
"microfilaments",
"plasma membrane"
] |
C
|
Relavent Documents:
Document 0:::
In the anatomy of the eye, the inner nuclear layer or layer of inner granules, of the retina, is made up of a number of closely packed cells, of which there are three varieties: bipolar cells, horizontal cells, and amacrine cells.
Bipolar cells
The bipolar cells, by far the most numerous, are round or oval in shape, and each is prolonged into an inner and an outer process.
They are divisible into rod bipolars and cone bipolars.
The inner processes of the rod bipolars run through the inner plexiform layer and arborize around the bodies of the cells of the ganglionic layer; their outer processes end in the outer plexiform layer in tufts of fibrils around the button-like ends of the inner processes of the rod granules.
The inner processes of the cone bipolars ramify in the inner plexiform layer in contact with the dendrites of the ganglionic cells.
Connection types
Midget bipolars are linked to one cone while diffuse bipolars take groups of receptors. Diffuse bipolars can take signals from up to 50 rods or can be a flat cone form and take signals from seven cones. The bipolar cells corresponds to the intermediary cells between the touch and heat receptors on the skin and the medulla or spinal cord.
Horizontal cells
The horizontal cells lie in the outer part of the inner nuclear layer and possess somewhat flattened cell bodies.
Their dendrites divide into numerous branches in the outer plexiform layer, while their axons run horizontally for some distance and finally ramify in the same layer.
Amacrine cells
The amacrine cells are placed in the inner part of the inner nuclear layer, and are so named because they have not yet been shown to possess axis-cylinder processes.
Their dendrites undergo extensive ramification in the inner plexiform layer.
Document 1:::
In the anatomy of the eye, the ganglion cell layer (ganglionic layer) is a layer of the retina that consists of retinal ganglion cells and displaced amacrine cells.
The cells are somewhat flask-shaped; the rounded internal surface of each resting on the stratum opticum, and sending off an axon which is prolonged into it.
From the opposite end numerous dendrites extend into the inner plexiform layer, where they branch and form flattened arborizations at different levels.
The ganglion cells vary much in size, and the dendrites of the smaller ones as a rule arborize in the inner plexiform layer as soon as they enter it; while those of the larger cells ramify close to the inner nuclear layer.
Document 2:::
A laminar organization describes the way certain tissues, such as bone membrane, skin, or brain tissues, are arranged in layers.
Types
Embryo
The earliest forms of laminar organization are shown in the diploblastic and triploblastic formation of the germ layers in the embryo. In the first week of human embryogenesis two layers of cells have formed, an external epiblast layer (the primitive ectoderm), and an internal hypoblast layer (primitive endoderm). This gives the early bilaminar disc. In the third week in the stage of gastrulation epiblast cells invaginate to form endoderm, and a third layer of cells known as mesoderm. Cells that remain in the epiblast become ectoderm. This is the trilaminar disc and the epiblast cells have given rise to the three germ layers.
Brain
In the brain a laminar organization is evident in the arrangement of the three meninges, the membranes that cover the brain and spinal cord. These membranes are the dura mater, arachnoid mater, and pia mater. The dura mater has two layers a periosteal layer near to the bone of the skull, and a meningeal layer next to the other meninges.
The cerebral cortex, the outer neural sheet covering the cerebral hemispheres can be described by its laminar organization, due to the arrangement of cortical neurons into six distinct layers.
Eye
The eye in mammals has an extensive laminar organization. There are three main layers – the outer fibrous tunic, the middle uvea, and the inner retina. These layers have sublayers with the retina having ten ranging from the outer choroid to the inner vitreous humor and including the retinal nerve fiber layer.
Skin
The human skin has a dense laminar organization. The outer epidermis has four or five layers.
Document 3:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 4:::
The ovarian cortex is the outer portion of the ovary. The ovarian follicles are located within the ovarian cortex. The ovarian cortex is made up of connective tissue. Ovarian cortex tissue transplant has been performed to treat infertility.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What thickens the cortex around the inner edge of a cell?
A. vacuoles
B. mitochondria
C. microfilaments
D. plasma membrane
Answer:
|
|
sciq-5094
|
multiple_choice
|
Genetic equilibrium occurs when what process doesn't exist within the population?
|
[
"reproduction",
"variation",
"evolution",
"movement"
] |
C
|
Relavent Documents:
Document 0:::
Genetic equilibrium is the condition of an allele or genotype in a gene pool (such as a population) where the frequency does not change from generation to generation. Genetic equilibrium describes a theoretical state that is the basis for determining whether and in what ways populations may deviate from it. Hardy–Weinberg equilibrium is one theoretical framework for studying genetic equilibrium. It is commonly studied using models that take as their assumptions those of Hardy-Weinberg, meaning:
No gene mutations occurring at that locus or the loci associated with the trait
A large population size
Limited-to-no immigration, emigration, or migration (genetic flow)
No natural selection on that locus or trait
Random mating (panmixis)
It can describe other types of equilibrium as well, especially in modeling contexts. In particular, many models use a variation of the Hardy–Weinberg principle as their basis. Instead of all of the Hardy–Weinberg characters being present, these instead assume a balance between the diversifying effects of genetic drift and the homogenizing effects of migration between populations. A population not at equilibrium suggests that one of the assumptions of the model in question has been violated.
Theoretical models of genetic equilibrium
The Hardy–Weinberg principle provides the mathematical framework for genetic equilibrium. Genetic equilibrium itself, whether Hardy-Weinberg or otherwise, provides the groundwork for a number of applications, in including population genetics, conservation and evolutionary biology. With the rapid increase in whole genome sequences available as well as the proliferation of anonymous markers, models have been used to extend the initial theory to all manner of biological contexts. Using data from genetic markers such as ISSRs and RAPDs as well as the predictive potential of statistics, studies have developed models to infer what processes drove the lack of equilibrium. This includes local adaptation, range contr
Document 1:::
A population can be described as being in an evolutionarily stable state when that population's "genetic composition is restored by selection after a disturbance, provided the disturbance is not too large" (Maynard Smith, 1982). This population as a whole can be either monomorphic or polymorphic. This is now referred to as convergent stability.
History & connection to evolutionary stable strategy
While related to the concept of an evolutionarily stable strategy (ESS), evolutionarily stable states are not identical and the two terms cannot be used interchangeably.
An ESS is a strategy that, if adopted by all individuals within a population, cannot be invaded by alternative or mutant strategies. This strategy becomes fixed in the population because alternatives provide no fitness benefit that would be selected for. In comparison, an evolutionarily stable state describes a population that returns as a whole to its previous composition even after being disturbed. In short: the ESS refers to the strategy itself, uninterrupted and supported through natural selection, while the evolutionarily stable state refers more broadly to a population-wide balance of one or more strategies that may be subjected to temporary change.
The term ESS was first used by John Maynard Smith in an essay from the 1972 book On Evolution. Maynard Smith developed the ESS drawing in part from game theory and Hamilton’s work on the evolution of sex ratio. The ESS was later expanded upon in his book Evolution and the Theory of Games in 1982, which also discussed the evolutionarily stable state.
Mixed v. single strategies
There has been variation in how the term is used and exploration of under what conditions an evolutionarily stable state might exist. In 1984, Benhard Thomas compared “discrete” models in which all individuals use only one strategy to “continuous” models in which individuals employ mixed strategies. While Maynard Smith had originally defined an ESS as being a single “uninvadable
Document 2:::
The term population biology has been used with different meanings.
In 1971 Edward O. Wilson et al. used the term in the sense of applying mathematical models to population genetics, community ecology, and population dynamics. Alan Hastings used the term in 1997 as the title of his book on the mathematics used in population dynamics. The name was also used for a course given at UC Davis in the late 2010s, which describes it as an interdisciplinary field combining the areas of ecology and evolutionary biology. The course includes mathematics, statistics, ecology, genetics, and systematics. Numerous types of organisms are studied.
The journal Theoretical Population Biology is published.
See also
Document 3:::
In evolutionary game theory, complete mixing refers to an assumption about the type of interactions that occur between individual organisms. Interactions between individuals in a population attains complete mixing if and only if the probably individual x interacts with individual y is equal for all y.
This assumption is implicit in the replicator equation a system of differential equations that represents one model in evolutionary game theory. This assumption usually does not hold for most organismic populations, since usually interactions occur in some spatial setting where individuals are more likely to interact with those around them. Although the assumption is empirically violated, it represents a certain sort of scientific idealization which may or may not be harmful to the conclusions reached by that model. This question has led individuals to investigate a series of other models where there is not complete mixing (e.g. Cellular automata models).
Game theory
Population genetics
Document 4:::
Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.
Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics. Traditionally a highly mathematical discipline, modern population genetics encompasses theoretical, laboratory, and field work. Population genetic models are used both for statistical inference from DNA sequence data and for proof/disproof of concept.
What sets population genetics apart from newer, more phenotypic approaches to modelling evolution, such as evolutionary game theory and adaptive dynamics, is its emphasis on such genetic phenomena as dominance, epistasis, the degree to which genetic recombination breaks linkage disequilibrium, and the random phenomena of mutation and genetic drift. This makes it appropriate for comparison to population genomics data.
History
Population genetics began as a reconciliation of Mendelian inheritance and biostatistics models. Natural selection will only cause evolution if there is enough genetic variation in a population. Before the discovery of Mendelian genetics, one common hypothesis was blending inheritance. But with blending inheritance, genetic variance would be rapidly lost, making evolution by natural or sexual selection implausible. The Hardy–Weinberg principle provides the solution to how variation is maintained in a population with Mendelian inheritance. According to this principle, the frequencies of alleles (variations in a gene) will remain constant in the absence of selection, mutation, migration and genetic drift.
The next key step was the work of the British biologist and statistician Ronald Fi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Genetic equilibrium occurs when what process doesn't exist within the population?
A. reproduction
B. variation
C. evolution
D. movement
Answer:
|
|
sciq-9373
|
multiple_choice
|
What are bones made up of?
|
[
"tissues",
"platelets",
"muscles",
"molecules"
] |
A
|
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:::
Animal science is described as "studying the biology of animals that are under the control of humankind". It can also be described as the production and management of farm animals. Historically, the degree was called animal husbandry and the animals studied were livestock species, like cattle, sheep, pigs, poultry, and horses. Today, courses available look at a broader area, including companion animals, like dogs and cats, and many exotic species. Degrees in Animal Science are offered at a number of colleges and universities. Animal science degrees are often offered at land-grant universities, which will often have on-campus farms to give students hands-on experience with livestock animals.
Education
Professional education in animal science prepares students for careers in areas such as animal breeding, food and fiber production, nutrition, animal agribusiness, animal behavior, and welfare. Courses in a typical Animal Science program may include genetics, microbiology, animal behavior, nutrition, physiology, and reproduction. Courses in support areas, such as genetics, soils, agricultural economics and marketing, legal aspects, and the environment also are offered.
Bachelor degree
At many universities, a Bachelor of Science (BS) degree in Animal Science allows emphasis in certain areas. Typical areas are species-specific or career-specific. Species-specific areas of emphasis prepare students for a career in dairy management, beef management, swine management, sheep or small ruminant management, poultry production, or the horse industry. Other career-specific areas of study include pre-veterinary medicine studies, livestock business and marketing, animal welfare and behavior, animal nutrition science, animal reproduction science, or genetics. Youth programs are also an important part of animal science programs.
Pre-veterinary emphasis
Many schools that offer a degree option in Animal Science also offer a pre-veterinary emphasis such as Iowa State University, th
Document 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:::
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:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are bones made up of?
A. tissues
B. platelets
C. muscles
D. molecules
Answer:
|
|
sciq-8406
|
multiple_choice
|
What process creates sperm?
|
[
"genesis",
"spermatogensis",
"altostratus",
"hypothalamus"
] |
B
|
Relavent Documents:
Document 0:::
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:::
Sperm (: sperm or sperms) is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, which are known as spermatozoa, while some red algae and fungi produce non-motile sperm cells, known as spermatia. Flowering plants contain non-motile sperm inside pollen, while some more basal plants like ferns and some gymnosperms have motile sperm.
Sperm cells form during the process known as spermatogenesis, which in amniotes (reptiles and mammals) takes place in the seminiferous tubules of the testes. This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which differentiate into spermatocytes. The spermatocytes then undergo meiosis, reducing their chromosome number by half, which produces spermatids. The spermatids then mature and, in animals, construct a tail, or flagellum, which gives rise to the mature, motile sperm cell. This whole process occurs constantly and takes around 3 months from start to finish.
Sperm cells cannot divide and have a limited lifespan, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell with 46 paired chromosomes. In mammals, sperm is stored in the epididymis and is released from the penis during ejaculation in a fluid known as semen.
The word sperm is derived from the Greek word σπέρμα, sperma, meaning "seed".
Evolution
It is generally accepted that isogamy is the ancestor to sperm and eggs. However, there are no fossil records for the evolution of sperm and eggs from isogamy leading there to be a strong emphasis on mathematical models to understand the evolution of sperm.
A widespread hypothesis states that sperm evolve
Document 2:::
The spermatid is the haploid male gametid that results from division of secondary spermatocytes. As a result of meiosis, each spermatid contains only half of the genetic material present in the original primary spermatocyte.
Spermatids are connected by cytoplasmic material and have superfluous cytoplasmic material around their nuclei.
When formed, early round spermatids must undergo further maturational events to develop into spermatozoa, a process termed spermiogenesis (also termed spermeteliosis).
The spermatids begin to grow a living thread, develop a thickened mid-piece where the mitochondria become localised, and form an acrosome. Spermatid DNA also undergoes packaging, becoming highly condensed. The DNA is packaged firstly with specific nuclear basic proteins, which are subsequently replaced with protamines during spermatid elongation. The resultant tightly packed chromatin is transcriptionally inactive.
In 2016 scientists at Nanjing Medical University claimed they had produced cells resembling mouse spermatids artificially from stem cells. They injected these spermatids into mouse eggs and produced pups.
DNA repair
As postmeiotic germ cells develop to mature sperm they progressively lose the ability to repair DNA damage that may then accumulate and be transmitted to the zygote and ultimately the embryo. In particular, the repair of DNA double-strand breaks by the non-homologous end joining pathway, although present in round spermatids, appears to be lost as they develop into elongated spermatids.
Additional images
See also
List of distinct cell types in the adult human body
Document 3:::
Spermarche, also known as semenarche, is the time at which a male experiences his first ejaculation. It is considered to be the counterpart of menarche in girls. Depending on upbringing, cultural differences, and prior sexual knowledge, males may have different reactions to spermarche, ranging from fear to excitement. Spermarche is one of the first events in the life of a male leading to sexual maturity. It occurs at the time when the secondary sex characteristics are just beginning to develop. Researchers have had difficulty determining the onset of spermarche because it is reliant on self-reporting. Other methods to determine it have included the examination of urine samples to determine the presence of spermatozoa. The presence of sperm in urine is referred to as spermaturia.
Age of occurrence
Research on the subject has varied for the reasons stated above, as well as changes in the average age of pubescence, which has been decreasing at an average rate of three months a decade. Research from 2010 indicated that the average age for spermarche in the U.S. was 12–16. In 2015, researchers in China determined that the average age for spermarche in China was 14. Historical data from countries including Nigeria and the United States also suggest 14 as an average age.
Context
Various studies have examined the circumstances in which first ejaculation occurred. Most commonly this occurred via a nocturnal emission, with a significant number experiencing semenarche via masturbation, which is very common at that stage. Less commonly, the first ejaculation occurred during sexual intercourse with a partner.
See also
Adrenarche
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What process creates sperm?
A. genesis
B. spermatogensis
C. altostratus
D. hypothalamus
Answer:
|
|
ai2_arc-1016
|
multiple_choice
|
While collecting wildflowers, a student begins to sneeze and has itchy, watery eyes. What bodily system causes this reaction?
|
[
"immune",
"nervous",
"muscular",
"circulatory"
] |
A
|
Relavent Documents:
Document 0:::
Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in 1910, it has been considered a local hormone (autocoid) because it lacks the classic endocrine glands to secrete it; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino group of the side-chain is protonated.
Properties
Histamine base, obtained as a mineral oil mull, melts at 83–84 °C. Hydrochloride and phosphorus salts form white hygroscopic crystals and are easily dissolved in water or ethanol, but not in ether. In aqueous solution, the imidazole ring of histamine exists in two tautomeric forms, identified by which of the two nitrogen atoms is protonated. The nitrogen farther away from the side chain is the 'tele' nitrogen and is denoted by a lowercase tau sign and the nitrogen closer to the side chain is the 'pros' nitrogen and is denoted by the pi sign. The tele tautomer, Nτ-H-histamine, is preferred in solution as compared to the pros tautomer, Nπ-H-histamine.
Histamine has two basic centres, namely the aliphatic amino group and whichever nitrogen atom of the imidazole ring does not already have a proton. Under physiological conditions, the aliphatic amino group (having a pKa around 9.4) will be protonated, whereas the second nitrogen of the imidazole ring (pKa ≈ 5.8) will no
Document 1:::
An allergic response is a hypersensitive immune reaction to a substance that normally is harmless or would not cause an immune response in everyone. An allergic response may cause harmful symptoms such as itching or inflammation or tissue injury.
Mechanism
Allergies are an abnormal immune reaction. The human immune system is designed to protect the body from potential harm and in people who have allergies the immune system will react to allergens (substances that trigger an immune response).
The immune system will produce immunoglobulin E, IgE, antibodies for each allergen. The antibodies will cause cells in the body to produce histamine. This histamine will act on different areas of the body (eyes, throat, nose, gastrointestinal tract, skin or lungs) to produce symptoms of an allergic reaction.
The allergic response is not limited to a certain amount of exposure. If the body is exposed to the allergen multiple times the immune system will react every time the allergen is present.
The reason why people get allergies is not known. The allergens are not passed down through generations. It is believed if parents have allergies the child is more likely to be allergic to the same allergens.
Some common symptoms include itchiness, swelling, running nose, watery eyes, coughing, wheezing, trouble breathing, hives, rashes, mucus production, or a more severe reaction anaphylaxis. Allergic responses and the severity vary from person to person.
Many substances can trigger an allergic reaction. Common triggers of a reaction include foods, likes nuts, eggs, milk, gluten, fruit and vegetables; insect bites from bees or wasps (often a severe response occurs); environmental factors such as pollen, dust, mold, plants like grass or trees, animal dander; medications or chemicals. Some people experience an allergic response to cold or hot temperatures outside, jewelry or sunlight.
There are daily treatments to reduce the severity of the allergic response. Often these treatments
Document 2:::
This is a list of allergies, which includes the allergen, potential reactions, and a brief description of the cause where applicable.
Allergens
Food
Medical
case of dying
Environmental
Contact
Many substances can cause an allergic reaction when in contact with the human integumentary system.
See also
Allergic inflammation
Elimination diet
Food intolerance
Oral allergy syndrome
Sweat allergy
List of inclusion bodies that aid in diagnosis of cutaneous conditions
List of cutaneous conditions
List of genes mutated in cutaneous conditions
List of target antigens in pemphigus
List of specialized glands within the human integumentary system
Document 3:::
Irritation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant. Irritants are typically thought of as chemical agents (for example phenol and capsaicin) but mechanical, thermal (heat), and radiative stimuli (for example ultraviolet light or ionising radiations) can also be irritants. Irritation also has non-clinical usages referring to bothersome physical or psychological pain or discomfort.
Irritation can also be induced by some allergic response due to exposure of some allergens for example contact dermatitis, irritation of mucosal membranes and pruritus. Mucosal membrane is the most common site of irritation because it contains secretory glands that release mucous which attracts the allergens due to its sticky nature.
Chronic irritation is a medical term signifying that afflictive health conditions have been present for a while. There are many disorders that can cause chronic irritation, the majority involve the skin, vagina, eyes and lungs.
Irritation in organisms
In higher organisms, an allergic response may be the cause of irritation. An allergen is defined distinctly from an irritant, however, as allergy requires a specific interaction with the immune system and is thus dependent on the (possibly unique) sensitivity of the organism involved while an irritant, classically, acts in a non-specific manner.
It is a form of stress, but conversely, if one is stressed by unrelated matters, mild imperfections can cause more irritation than usual: one is irritable; see also sensitivity (human).
In more basic organisms, the status of pain is the perception of the being stimulated, which is not observable although it may be shared (see gate control theory of pain).
It is not proven that oysters can feel pain, but it is known that they react to irritants. When an irritating object becomes trapped within an oyster's shell, it deposits laye
Document 4:::
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis.
Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust, or mold. Inherited genetics and environmental exposures contribute to the development of allergies. Growing up on a farm and having multiple siblings decreases this risk. The underlying mechanism involves IgE antibodies that attach to an allergen, and subsequently result in the release of inflammatory chemicals such as histamine from mast cells. It causes mucous membranes in the nose, eyes and throat to become inflamed and itchy as they work to eject the allergen. Diagnosis is typically based on a combination of symptoms and a skin prick test or blood tests for allergen-specific IgE antibodies. These tests, however, can give false positives. The symptoms of allergies resemble those of the common cold; however, they often last for more than two weeks and, despite the common name, typically do not include a fever.
Exposure to animals early in life might reduce the risk of developing these specific allergies. Several different types of medications reduce allergic symptoms, including nasal steroids, antihistamines, such as diphenhydramine, cromolyn sodium, and leukotriene receptor antagonists such as montelukast. Oftentimes, medications do not completely control symptoms, and they may also have side effects. Exp
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
While collecting wildflowers, a student begins to sneeze and has itchy, watery eyes. What bodily system causes this reaction?
A. immune
B. nervous
C. muscular
D. circulatory
Answer:
|
|
sciq-1718
|
multiple_choice
|
What is the most important element to life?
|
[
"hydrogen",
"nitrogen",
"oxygen",
"carbon"
] |
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:::
Carbon is a primary component of all known life on Earth, representing approximately 45–50% of all dry biomass. Carbon compounds occur naturally in great abundance on Earth. Complex biological molecules consist of carbon atoms bonded with other elements, especially oxygen and hydrogen and frequently also nitrogen, phosphorus, and sulfur (collectively known as CHNOPS).
Because it is lightweight and relatively small in size, carbon molecules are easy for enzymes to manipulate. It is frequently assumed in astrobiology that if life exists elsewhere in the Universe, it will also be carbon-based. Critics refer to this assumption as carbon chauvinism.
Characteristics
Carbon is capable of forming a vast number of compounds, more than any other element, with almost ten million compounds described to date, and yet that number is but a fraction of the number of theoretically possible compounds under standard conditions. The enormous diversity of carbon-containing compounds, known as organic compounds, has led to a distinction between them and compounds that do not contain carbon, known as inorganic compounds. The branch of chemistry that studies organic compounds is known as organic chemistry.
Carbon is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass, after hydrogen, helium, and oxygen. Carbon's widespread abundance, its ability to form stable bonds with numerous other elements, and its unusual ability to form polymers at the temperatures commonly encountered on Earth enables it to serve as a common element of all known living organisms. In a 2018 study, carbon was found to compose approximately 550 billion tons of all life on Earth. It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.
The most important characteristics of carbon as a basis for the chemistry of life are that each carbon atom is capable of forming up to four valence bonds with other atoms simultaneously
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:::
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.
What is the most important element to life?
A. hydrogen
B. nitrogen
C. oxygen
D. carbon
Answer:
|
|
sciq-8659
|
multiple_choice
|
A common age-related bone disease in which bone density and strength is decreased is know as what?
|
[
"allergies",
"osteoporosis",
"fibrosis",
"Stomach"
] |
B
|
Relavent Documents:
Document 0:::
FRAX (Fracture Risk Assessment Tool) is a diagnostic tool used to evaluate the 10-year probability of bone fracture risk. It was developed by the University of Sheffield. FRAX integrates clinical risk factors and bone mineral density at the femoral neck to calculate the 10-year probability of hip fracture and the 10-year probability of a major osteoporotic fracture (clinical spine, forearm, hip or shoulder fracture). The models used to develop the FRAX diagnostic tool were derived from studying patient populations in North America, Europe, Latin America, Asia and Australia.
Components
The parameters included in a FRAX assessment are:
Country
Age
Sex
Weight
Height
Previous fracture
Hip fracture in the subject's mother or father
Smoking
Glucocorticoid treatment
Rheumatoid arthritis
Disease strongly associated with osteoporosis
Alcohol intake of 3 or more standard drinks per day
Bone mineral density (BMD) of the femoral neck
Trabecular bone score (optional)
Availability and usage
FRAX is freely accessible online, and commercially available as a desktop application, in paper-form as a FRAX Pad, as an iPhone application, and as an Android application. The tool is compatible with 58 models for 53 countries, and is available in 28 languages.
FRAX is incorporated into many national guidelines around the world, including those of Belgium, Canada, Japan, Netherlands, Poland, Sweden, Switzerland, UK (NOGG), and US (NOF). FRAX assessments are intended to provide guidance for determining access to treatment in healthcare systems.
Adjustments
Glucocorticoid use is included FRAX as a dichotomous variable, whereas the increased risk for fractures seen with glucocorticoid use is dependent on glucocorticoid dose and duration of use. Several methods have been proposed how to adjust FRAX accordingly.
Though known to be a risk factor for fractures, Type 2 Diabetes is not included as such in FRAX. Some clinicians choose rheumatoid arthritis as an equivalent risk factor instead.
Document 1:::
Senile osteoporosis has been recently recognized as a geriatric syndrome with a particular pathophysiology. There are different classification of osteoporosis: primary, in which bone loss is a result of aging and secondary, in which bone loss occurs from various clinical and lifestyle factors. Primary, or involuntary osteoporosis, can further be classified into Type I or Type II. Type I refers to postmenopausal osteoporosis and is caused by the deficiency of estrogen. While senile osteoporosis is categorized as an involuntary, Type II, and primary osteoporosis, which affects both men and women over the age of 70 years. It is accompanied by vitamin D deficiency, body's failure to absorb calcium, and increased parathyroid hormone.
Research over the years has shown that senile osteoporosis is the product of a skeleton in an advanced stage of life and can be caused by a deficiency caused by calcium. However, physicians are also coming to the conclusion that multiple mechanisms in the development stages of the disease interact together resulting in an osteoporotic bone, regardless of age. Still, elderly people make up the fastest growing population in the world. As bone mass declines with age, the risk of fractures increases. Annual incidence of osteoporotic fractures is more than 1.5 million in the US and notably 20% of people die during the first year after a hip fracture.
It costs the US health system around $17 billion annually, with the cost projecting to $50 billion by 2040. These costs represent a higher burden compared to other disease states, such as breast cancer, stroke, diabetes, or chronic lung disease. Although there are cost effective and well-tolerated treatments, 23% of the diagnosed are women over 67 have received either bone mineral density (BMD) tests or prescription for treatment after fracture. The clinical and economic burdens indicate there should be more effort in assessment of risk, prevention, and early intervention when it comes to osteoporo
Document 2:::
Orthopedic pathology, also known as bone pathology is a subspecialty of surgical pathology which deals with the diagnosis and feature of many bone diseases, specifically studying the cause and effects of disorders of the musculoskeletal system. It uses gross and microscopic findings along with the findings of in vivo radiological studies, and occasionally, specimen radiographs to diagnose diseases of the bones.
Causes and effects
Orthopaedic disorders may be congenital and there may be hereditary and environmental factors that can affect the normal functioning of the bones, joints, or muscles. Other causes of bone diseases include severe impacts/injuries and weakness in bones/bone loss.
The effects of bone disorders will vary with disease. The effects can occur physically, mentally and financially as well as impact the individuals quality of life. Orthopaedic disorders can drastically affect an individual's functional ability. Individuals who have had bone diseases can experience complications such as extreme pain, fractures, height loss and the ability to be mobile. They can also be more susceptible to other issues, for example, a urinary tract infection (UTI) or pneumonia. Many of these bone disorders could lead to declines in both mental and physical health. In addition to a physical impact, bone disorders can also give rise to psychological ramifications and reflect negatively on an individual's mindset, body image as well as self-esteem, which may result in the individual feeling helpless and yield fears of falling.
To care for bone diseases and disorders is quite expensive. These costs can include both direct and indirect medical expenses as well as possible job loss or productivity loss for the patient. The chances of death vary enormously between the bone disorders due to the differing degree of severity, however many bone diseases do increase an individual's susceptibility to other complications. These disorders depend on multiple factors such as geneti
Document 3:::
Arthritis of the knee is typically a particularly debilitating form of arthritis. The knee may become affected by almost any form of arthritis.
The word arthritis refers to inflammation of the joints. Types of arthritis include those related to wear and tear of cartilage, such as osteoarthritis, to those associated with inflammation resulting from an overactive immune system (such as rheumatoid arthritis).
Causes
It is not always certain why arthritis of the knee develops. The knee may become affected by almost any form of arthritis, including those related to mechanical damage of the structures of the knee (osteoarthritis, and post-traumatic arthritis), various autoimmune forms of arthritis (including; rheumatoid arthritis, juvenile arthritis, and SLE-related arthritis, psoriatic arthritis, and ankylosing spondylitis), arthritis due to infectious causes (including Lyme disease-related arthritis), gouty arthritis, or reactive arthritis.
Osteoarthritis of the knee
The knee is one of the joints most commonly affected by osteoarthritis. Cartilage in the knee may begin to break down after sustained stress, leaving the bones of the knee rubbing against each other and resulting in osteoarthritis. Nearly a third of US citizens are affected by osteoarthritis of the knee by age 70.
Obesity is a known and very significant risk factor for the development of osteoarthritis. Risk increases proportionally to body weight. Obesity contributes to OA development, not only by increasing the mechanical stress exerted upon the knees when standing, but also leads to increased production of compounds that may cause joint inflammation.
Parity is associated with an increased risk of knee OA and likelihood of knee replacement. The risk increases in proportion to the number of children the woman has birthed. This may be due to weight gain after pregnancy, or increased body weight and consequent joint stress during pregnancy.
Flat feet are a significant risk factor for the development
Document 4:::
Osteosclerosis is a disorder that is characterized by abnormal hardening of bone and an elevation in bone density. It may predominantly affect the medullary portion and/or cortex of bone. Plain radiographs are a valuable tool for detecting and classifying osteosclerotic disorders. It can manifest in localized or generalized osteosclerosis. Localized osteosclerosis can be caused by Legg–Calvé–Perthes disease, sickle-cell disease and osteoarthritis among others. Osteosclerosis can be classified in accordance with the causative factor into acquired and hereditary.
Types
Acquired osteosclerosis
Osteogenic bone metastasis caused by carcinoma of prostate and breast
Paget's disease of bone
Myelofibrosis (primary disorder or secondary to intoxication or malignancy)
Osteosclerosing types of chronic osteomyelitis
Hypervitaminosis D
hyperparathyroidism
Schnitzler syndrome
Mastocytosis
Skeletal fluorosis
Monoclonal IgM Kappa cryoglobulinemia
Hepatitis C.
Hereditary osteosclerosis
Malignant infantile osteopetrosis
Neuropathic infantile osteopetrosis
Infantile osteopetrosis with renal tubular acidosis
Infantile osteopetrosis with immunodeficiency
IO with leukocyte adhesion deficiency syndrome (LAD-III)
Intermediate osteopetrosis
Autosomal dominant osteopetrosis (Albers-Schonberg)
Pyknodysostosis (osteopetrosis acro-osteolytica)
Osteopoikilosis (Buschke–Ollendorff syndrome)
Osteopathia striata with cranial sclerosis
Mixed sclerosing bone dysplasia
Progressive diaphyseal dysplasia (Camurati–Engelmann disease)
SOST-related sclerosing bone dysplasias
Diagnosis
Osteosclerosis can be detected with a simple radiography. There are white portions of the bone which appear due to the increased number of bone trabeculae.
Animals
In the animal kingdom, there also exists a non-pathological form of osteosclerosis, resulting in unusually solid bone structure with little to no marrow. It is often seen in aquatic vertebrates, especially those living in shallow waters
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A common age-related bone disease in which bone density and strength is decreased is know as what?
A. allergies
B. osteoporosis
C. fibrosis
D. Stomach
Answer:
|
|
sciq-2206
|
multiple_choice
|
Magnetite crystals of different ages and on different continents pointed to different spots. the simplest explanation is that the continents have done what?
|
[
"changed",
"reacted",
"evolved",
"moved"
] |
D
|
Relavent Documents:
Document 0:::
The cataclysmic pole shift hypothesis is a pseudo-scientific claim that there have been recent, geologically rapid shifts in the axis of rotation of Earth, causing calamities such as floods and tectonic events or relatively rapid climate changes.
There is evidence of precession and changes in axial tilt, but this change is on much longer time-scales and does not involve relative motion of the spin axis with respect to the planet. However, in what is known as true polar wander, the Earth rotates with respect to a fixed spin axis. Research shows that during the last 200 million years a total true polar wander of some 30° has occurred, but that no rapid shifts in Earth's geographic axial pole were found during this period. A characteristic rate of true polar wander is 1° or less per million years. Between approximately 790 and 810 million years ago, when the supercontinent Rodinia existed, two geologically rapid phases of true polar wander may have occurred. In each of these, the magnetic poles of Earth shifted by approximately 55° due to a large shift in the crust.
Definition and clarification
The geographic poles are defined by the points on the surface of Earth that are intersected by the axis of rotation. The pole shift hypothesis describes a change in location of these poles with respect to the underlying surface – a phenomenon distinct from the changes in axial orientation with respect to the plane of the ecliptic that are caused by precession and nutation, and is an amplified event of a true polar wander. Geologically, a surface shift separate from a planetary shift, enabled by earth's molten core.
Pole shift hypotheses are not connected with plate tectonics, the well-accepted geological theory that Earth's surface consists of solid plates which shift over a viscous, or semifluid asthenosphere; nor with continental drift, the corollary to plate tectonics which maintains that locations of the continents have moved slowly over the surface of Earth, resulting
Document 1:::
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 2:::
Akilia Island is an island in southwestern Greenland, about 22 kilometers south of Nuuk. Akilia is the location of a rock formation that has been proposed to contain the oldest known sedimentary rocks on Earth, and perhaps the oldest evidence of life on Earth.
Geology
The rocks in question are part of a metamorphosed supracrustal sequence located at the south-western tip of the island. The sequence has been dated as no younger than 3.85 billion years old - that is, in the Hadean eon - based on the age of an igneous band that cuts the rock. The supracrustal sequence contains layers rich in iron and silica, which are variously interpreted as banded iron formation, chemical sediments from submarine hot springs, or hydrothermal vein deposits. Carbon in the rock, present as graphite, shows low levels of carbon-13, which may suggest an origin as isotopically light organic matter derived from living organisms.
However, this interpretation is complicated because of high-grade metamorphism that affected the Akilia rocks after their formation. The sedimentary origin, age and the carbon content of the rocks have been questioned.
If the Akilia rocks do show evidence of life by 3.85 Ga, it would challenge models which suggest that Earth would not be hospitable to life at this time.
See also
List of islands of Greenland
Origin of life
Document 3:::
Glacio-geological databases compile data on glacially associated sedimentary deposits and erosional activity from former and current ice-sheets, usually from published peer-reviewed sources. Their purposes are generally directed towards two ends: (Mode 1) compiling information about glacial landforms, which often inform about former ice-flow directions; and (Mode 2) compiling information which dates the absence or presence of ice.
These databases are used for a variety of purposes: (i) as bibliographic tools for researchers; (ii) as the quantitative basis of mapping of landforms or dates of ice presence/absence; and (iii) as quantitative databases which are used to constrain physically based mathematical models of ice-sheets.
Antarctic Ice Sheet: The AGGDB is a Mode 2 glacio-geological database for the Antarctic ice-sheet using information from around 150 published sources, covering glacial activity mainly from the past 30,000 years. It is available online, and aims to be comprehensive to the end of 2007.
British Ice Sheet: BRITICE is a Mode 1 database which aims to map all glacial landforms of Great Britain.
Eurasian Ice Sheet: DATED-1 is a Mode 2 database for the Eurasian ice-sheet. Its sister-project DATED-2 uses the information in DATED-1 to map the retreat of the Eurasian ice-sheet since the Last Glacial Maximum.
See also
Glacial landforms
Sediment
Geology
Ice sheet
Exposure Age Dating
Radio-carbon dating
Document 4:::
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.
Magnetite crystals of different ages and on different continents pointed to different spots. the simplest explanation is that the continents have done what?
A. changed
B. reacted
C. evolved
D. moved
Answer:
|
|
sciq-5452
|
multiple_choice
|
In biology, a relationship that benefits both entities is known as what?
|
[
"mutualism",
"predatory",
"altruism",
"naturalism"
] |
A
|
Relavent Documents:
Document 0:::
Generalized exchange is a type of social exchange in which a desired outcome that is sought by an individual is not dependent on the resources provided by that individual. It is assumed to be a fundamental social mechanism that stabilizes relations in society by unilateral resource giving in which one's giving is not necessarily reciprocated by the recipient, but by a third party. Thus, in contrast to direct or restricted exchange or reciprocity, in which parties exchange resources with each other, generalized exchange naturally involves more than two parties. Examples of generalized exchange include; matrilateral cross-cousin marriage and helping a stranded driver on a desolate road.
Reciprocity Norm
All forms of social exchange occur within structures of mutual dependence, that is, structures in which actors are mutually, or reciprocally dependent on one another for valued outcomes. A structure of mutual or reciprocal dependence is defining characteristic of all social relations based on exchange.
The mutual or reciprocal dependence can be either direct (restricted) or indirect (generalized). Both of them rest on a norm of reciprocity which provides guidance to both parties: takers are obliged to be givers. In direct dyadic exchange, the norm of reciprocity insists that takers give gifts to those who gave to them. Generalized exchange, also, insists that takers give, but to somebody else. The recipient is not defined and creates opportunities of exploitation if actors explicitly reject the guiding norm of reciprocity. The purest form of indirect, generalized exchange, is the chain-generalized form, first documented by the classical anthropologists: Lévi-Strauss (1969) and Malinowski (1922). In chain-generalized exchange, benefits flow in one direction in a circle of giving that eventually returns benefit to the giver. In direct exchange, actors instead engage in individual actions that benefit another. Reciprocal exchanges evolve gradually, as beneficial acts p
Document 1:::
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
Document 2:::
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
Document 3:::
A heterarchy is a system of organization where the elements of the organization are unranked (non-hierarchical) or where they possess the potential to be ranked a number of different ways. Definitions of the term vary among the disciplines: in social and information sciences, heterarchies are networks of elements in which each element shares the same "horizontal" position of power and authority, each playing a theoretically equal role. In biological taxonomy, however, the requisite features of heterarchy involve, for example, a species sharing, with a species in a different family, a common ancestor which it does not share with members of its own family. This is theoretically possible under principles of "horizontal gene transfer".
A heterarchy may be parallel to a hierarchy, subsumed to a hierarchy, or it may contain hierarchies; the two kinds of structure are not mutually exclusive. In fact, each level in a hierarchical system is composed of a potentially heterarchical group which contains its constituent elements.
The concept of heterarchy was first employed in a modern context by cybernetician Warren McCulloch in 1945. As Carole L. Crumley has summarised, "[h]e examined alternative cognitive structure(s), the collective organization of which he termed heterarchy. He demonstrated that the human brain, while reasonably orderly was not organized hierarchically. This understanding revolutionized the neural study of the brain and solved major problems in the fields of artificial intelligence and computer design."
General principles, operationalization, and evidence
In a group of related items, heterarchy is a state wherein any pair of items is likely to be related in two or more differing ways. Whereas hierarchies sort groups into progressively smaller categories and subcategories, heterarchies divide and unite groups variously, according to multiple concerns that emerge or recede from view according to perspective. Crucially, no one way of dividing a heterarchica
Document 4:::
Evolutionary biologists have developed various theoretical models to explain the evolution of food-sharing behavior—"[d]efined as the unresisted transfer of food" from one food-motivated individual to another—among humans and other animals.
Models of food-sharing are based upon general evolutionary theory. When applied to human behavior, these models are considered a branch of human behavioral ecology. Researchers have developed several types of food-sharing models, involving phenomena such as kin selection, reciprocal altruism, tolerated theft, group cooperation, and costly signaling. Kin-selection and reciprocal-altruism models of food-sharing are based upon evolutionary concepts of kin selection and altruism. Since the theoretical basis of these models involves reproductive fitness, one underlying assumption of these models is that greater resource-accumulation increases reproductive fitness. Food-sharing has been theorized as an important development in early human evolution.
Kin selection models
W. D. Hamilton was among the first to propose an explanation for natural selection of altruistic behaviors among related individuals. According to his model, natural selection will favor altruistic behavior towards kin when the benefit (as a contributing factor to reproductive fitness) towards the recipient (scaled based upon Wright's coefficient of genetic relatedness between donor and recipient) outweighs the cost of giving. In other words, kin selection implies that food will be given when there is a great benefit to the recipient with low cost to the donor. An example of this would be sharing food among kin during a period of surplus. The implications of kin-selection is that natural selection will also favor the development of ways of determining kin from non-kin and close kin from distant kin. When Hamilton's rule is applied to food-sharing behavior, a simple expectation of the model is that close kin should receive food shares either more frequently or in lar
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In biology, a relationship that benefits both entities is known as what?
A. mutualism
B. predatory
C. altruism
D. naturalism
Answer:
|
|
sciq-8276
|
multiple_choice
|
Birds adapted wings and weathers for flight during what process?
|
[
"variation",
"migration",
"emergence",
"evolution"
] |
D
|
Relavent Documents:
Document 0:::
Tinbergen's four questions, named after 20th century biologist Nikolaas Tinbergen, are complementary categories of explanations for animal behaviour. These are also commonly referred to as levels of analysis. It suggests that an integrative understanding of behaviour must include ultimate (evolutionary) explanations, in particular:
behavioural adaptive functions
phylogenetic history; and the proximate explanations
underlying physiological mechanisms
ontogenetic/developmental history.
Four categories of questions and explanations
When asked about the purpose of sight in humans and animals, even elementary-school children can answer that animals have vision to help them find food and avoid danger (function/adaptation). Biologists have three additional explanations: sight is caused by a particular series of evolutionary steps (phylogeny), the mechanics of the eye (mechanism/causation), and even the process of an individual's development (ontogeny).
This schema constitutes a basic framework of the overlapping behavioural fields of ethology, behavioural ecology, comparative psychology, sociobiology, evolutionary psychology, and anthropology. Julian Huxley identified the first three questions. Niko Tinbergen gave only the fourth question, as Huxley's questions failed to distinguish between survival value and evolutionary history; Tinbergen's fourth question helped resolve this problem.
Evolutionary (ultimate) explanations
First question: Function (adaptation)
Darwin's theory of evolution by natural selection is the only scientific explanation for why an animal's behaviour is usually well adapted for survival and reproduction in its environment. However, claiming that a particular mechanism is well suited to the present environment is different from claiming that this mechanism was selected for in the past due to its history of being adaptive.
The literature conceptualizes the relationship between function and evolution in two ways. On the one hand, function
Document 1:::
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life forms on Earth. Evolution holds that all species are related and gradually change over generations. In a population, the genetic variations affect the phenotypes (physical characteristics) of an organism. These changes in the phenotypes will be an advantage to some organisms, which will then be passed onto their offspring. Some examples of evolution in species over many generations are the peppered moth and flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology.
The investigational range of current research has widened to encompass the genetic architecture of adaptation, molecular evolution, and the different forces that contribute to evolution, such as sexual selection, genetic drift, and biogeography. Moreover, the newer field of evolutionary developmental biology ("evo-devo") investigates how embryogenesis is controlled, thus yielding a wider synthesis that integrates developmental biology with the fields of study covered by the earlier evolutionary synthesis.
Subfields
Evolution is the central unifying concept in biology. Biology can be divided into various ways. One way is by the level of biological organization, from molecular to cell, organism to population. Another way is by perceived taxonomic group, with fields such as zoology, botany, and microbiology, reflecting what was once seen as the major divisions of life. A third way is by approaches, such as field biology, theoretical biology, experimental evolution, and paleontology. These alternative ways of dividing up the subject have been combined with evolution
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
The history of life on Earth seems to show a clear trend; for example, it seems intuitive that there is a trend towards increasing complexity in living organisms. More recently evolved organisms, such as mammals, appear to be much more complex than organisms, such as bacteria, which have existed for a much longer period of time. However, there are theoretical and empirical problems with this claim. From a theoretical perspective, it appears that there is no reason to expect evolution to result in any largest-scale trends, although small-scale trends, limited in time and space, are expected (Gould, 1997). From an empirical perspective, it is difficult to measure complexity and, when it has been measured, the evidence does not support a largest-scale trend (McShea, 1996).
History
Many of the founding figures of evolution supported the idea of Evolutionary progress which has fallen from favour, but the work of Francisco J. Ayala and Michael Ruse suggests is still influential.
Hypothetical largest-scale trends
McShea (1998) discusses eight features of organisms that might indicate largest-scale trends in evolution: entropy, energy intensiveness, evolutionary versatility, developmental depth, structural depth, adaptedness, size, complexity. He calls these "live hypotheses", meaning that trends in these features are currently being considered by evolutionary biologists. McShea observes that the most popular hypothesis, among scientists, is that there is a largest-scale trend towards increasing complexity.
Evolutionary theorists agree that there are local trends in evolution, such as increasing brain size in hominids, but these directional changes do not persist indefinitely, and trends in opposite directions also occur (Gould, 1997). Evolution causes organisms to adapt to their local environment; when the environment changes, the direction of the trend may change. The question of whether there is evolutionary progress is better formulated as the question of whether
Document 4:::
Exaptation and the related term co-option describe a shift in the function of a trait during evolution. For example, a trait can evolve because it served one particular function, but subsequently it may come to serve another. Exaptations are common in both anatomy and behaviour.
Bird feathers are a classic example. Initially they may have evolved for temperature regulation, but later were adapted for flight. When feathers were first used to aid in flight, that was an exaptive use. They have since then been shaped by natural selection to improve flight, so in their current state they are best regarded as adaptations for flight. So it is with many structures that initially took on a function as an exaptation: once molded for a new function, they become further adapted for that function.
Interest in exaptation relates to both the process and products of evolution: the process that creates complex traits and the products (functions, anatomical structures, biochemicals, etc.) that may be imperfectly developed. The term "exaptation" was proposed by Stephen Jay Gould and Elisabeth Vrba, as a replacement for 'pre-adaptation', which they considered to be a teleologically loaded term.
History and definitions
The idea that the function of a trait might shift during its evolutionary history originated with Charles Darwin (). For many years the phenomenon was labeled "preadaptation", but since this term suggests teleology in biology, appearing to conflict with natural selection, it has been replaced by the term exaptation.
The idea had been explored by several scholars when in 1982 Stephen Jay Gould and Elisabeth Vrba introduced the term "exaptation". However, this definition had two categories with different implications for the role of adaptation.
(1) A character, previously shaped by natural selection for a particular function (an adaptation), is coopted for a new use—cooptation.
(2) A character whose origin cannot be ascribed to the direct action of natural selection (
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Birds adapted wings and weathers for flight during what process?
A. variation
B. migration
C. emergence
D. evolution
Answer:
|
|
sciq-11338
|
multiple_choice
|
Individuals with sickle cell anemia have crescent-shaped what?
|
[
"glial cells",
"red blood cells",
"nerve cells",
"white blood cells"
] |
B
|
Relavent Documents:
Document 0:::
Hematopoietic stem cells (HSCs) have high regenerative potentials and are capable of differentiating into all blood and immune system cells. Despite this impressive potential, HSCs have limited potential to produce more multipotent stem cells. This limited self-renewal potential is protected through maintenance of a quiescent state in HSCs. Stem cells maintained in this quiescent state are known as long term HSCs (LT-HSCs). During quiescence, HSCs maintain a low level of metabolic activity and do not divide. LT-HSCs can be signaled to proliferate, producing either myeloid or lymphoid progenitors. Production of these progenitors does not come without a cost: When grown under laboratory conditions that induce proliferation, HSCs lose their ability to divide and produce new progenitors. Therefore, understanding the pathways that maintain proliferative or quiescent states in HSCs could reveal novel pathways to improve existing therapeutics involving HSCs.
Background
All adult stem cells can undergo two types of division: symmetric and asymmetric. When a cell undergoes symmetric division, it can either produce two differentiated cells or two new stem cells. When a cell undergoes asymmetric division, it produces one stem and one differentiated cell. Production of new stem cells is necessary to maintain this population within the body. Like all cells, hematopoietic stem cells undergo metabolic shifts to meet their bioenergetic needs throughout development. These metabolic shifts play an important role in signaling, generating biomass, and protecting the cell from damage. Metabolic shifts also guide development in HSCs and are one key factor in determining if an HSC will remain quiescent, symmetrically divide, or asymmetrically divide. As mentioned above, quiescent cells maintain a low level of oxidative phosphorylation and primarily rely on glycolysis to generate energy. Fatty acid beta-oxidation has been shown to influence fate decisions in HSCs. In contrast, proliferat
Document 1:::
Lymph node stromal cells are essential to the structure and function of the lymph node whose functions include: creating an internal tissue scaffold for the support of hematopoietic cells; the release of small molecule chemical messengers that facilitate interactions between hematopoietic cells; the facilitation of the migration of hematopoietic cells; the presentation of antigens to immune cells at the initiation of the adaptive immune system; and the homeostasis of lymphocyte numbers. Stromal cells originate from multipotent mesenchymal stem cells.
Structure
Lymph nodes are enclosed in an external fibrous capsule, from which thin walls of sinew called trabeculae penetrate into the lymph node, partially dividing it. Beneath the external capsule and along the courses of the trabeculae, are peritrabecular and subcapsular sinuses. These sinuses are cavities containing macrophages (specialised cells which help to keep the extracellular matrix in order).
The interior of the lymph node has two regions: the cortex and the medulla. In the cortex, lymphoid tissue is organized into nodules. In the nodules, T lymphocytes are located in the T cell zone. B lymphocytes are located in the B cell follicle. The primary B cell follicle matures in germinal centers. In the medulla are hematopoietic cells (which contribute to the formation of the blood) and stromal cells.
Near the medulla is the hilum of lymph node. This is the place where blood vessels enter and leave the lymph node and lymphatic vessels leave the lymph node. Lymph vessels entering the node do so along the perimeter (outer surface).
Function
The lymph nodes, the spleen and Peyer's patches, together are known as secondary lymphoid organs. Lymph nodes are found between lymphatic ducts and blood vessels. Afferent lymphatic vessels bring lymph fluid from the peripheral tissues to the lymph nodes. The lymph tissue in the lymph nodes consists of immune cells (95%), for example lymphocytes, and stromal cells (1% to
Document 2:::
bEnd.3 is a mouse brain cell line derived from BALB/c mice. The cell line is commonly used in vascular research and studies of endothelial brain tissue. In particular, bEnd.3 cells can serve as blood–brain barrier models for ischemia.
Document 3:::
In haematology atypical localization of immature precursors (ALIP) refers to finding of atypically localized precursors (myeloblasts and promyelocytes) on bone marrow biopsy. In healthy humans, precursors are rare and are found localized near the endosteum, and consist of 1-2 cells. In some cases of myelodysplastic syndromes, immature precursors might be located in the intertrabecular region and occasionally aggregate as clusters of 3 ~ 5 cells. The presence of ALIPs is associated with worse prognosis of MDS . Recently, in bone marrow sections of patients with acute myeloid leukemia cells similar to ALIPs were defined as ALIP-like clusters. The presence of ALIP-like clusters in AML patients within remission was reported to be associated with early relapse of the disease.
Document 4:::
Left shift or blood shift is an increase in the number of immature cell types among the blood cells in a sample of blood. Many (perhaps most) clinical mentions of left shift refer to the white blood cell lineage, particularly neutrophil-precursor band cells, thus signifying bandemia. Less commonly, left shift may also refer to a similar phenomenon in the red blood cell lineage in severe anemia, when increased reticulocytes and immature erythrocyte-precursor cells appear in the peripheral circulation.
Definition
The standard definition of a left shift is an absolute band form count greater than 7700/microL. There are competing explanations for the origin of the phrase "left shift," including the left-most button arrangement of early cell sorting machines and a 1920s publication by Josef Arneth, containing a graph in which immature neutrophils, with fewer segments, shifted the median left. In the latter view, the name reflects a curve's preponderance shifting to the left on a graph of hematopoietic cellular differentiations.
Morphology
It is usually noted on microscopic examination of a blood smear. This systemic effect of inflammation is most often seen in the course of an active infection and during other severe illnesses such as hypoxia and shock. Döhle bodies may also be present in the neutrophil's cytoplasm in the setting of sepsis or severe inflammatory responses.
Pathogenesis
It is believed that cytokines (including IL-1 and TNF) accelerate the release of cells from the postmitotic reserve pool in the bone marrow, leading to an increased number of immature cells.
See also
Leukocytosis
Reticulocyte
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Individuals with sickle cell anemia have crescent-shaped what?
A. glial cells
B. red blood cells
C. nerve cells
D. white blood cells
Answer:
|
|
ai2_arc-307
|
multiple_choice
|
Many types of motion occur in our solar system. Which type of motion describes one Earth year?
|
[
"the revolution of the sun around Earth",
"the revolution of Earth around the sun",
"the rotation of the sun around Earth",
"the rotation of Earth around the sun"
] |
B
|
Relavent Documents:
Document 0:::
Solar rotation varies with latitude. The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy. The rate of surface rotation is observed to be the fastest at the equator (latitude ) and to decrease as latitude increases. The solar rotation period is 24.47 days at the equator and almost 38 days at the poles. The average rotation is 28 days.
Current Carrington Rotation: CR []
Surface rotation as an equation
The differential rotation rate is usually described by the equation:
where is the angular velocity in degrees per day, is the solar latitude, A is angular velocity at the equator, and B, C are constants controlling the decrease in velocity with increasing latitude. The values of A, B, and C differ depending on the techniques used to make the measurement, as well as the time period studied. A current set of accepted average values is:
A= 14.713 ± 0.0491 °/day
B= −2.396 ± 0.188 °/day
C= −1.787 ± 0.253 °/day
Sidereal rotation
At the equator, the solar rotation period is 24.47 days. This is called the sidereal rotation period, and should not be confused with the synodic rotation period of 26.24 days, which is the time for a fixed feature on the Sun to rotate to the same apparent position as viewed from Earth (the earth's orbital rotation is in the same direction as the sun's rotation). The synodic period is longer because the Sun must rotate for a sidereal period plus an extra amount due to the orbital motion of Earth around the Sun. Note that astrophysical literature does not typically use the equatorial rotation period, but instead often uses the definition of a Carrington rotation: a synodic rotation period of 27.2753 days or a sidereal period of 25.38 days. This chosen period roughly corresponds to the prograde rotation at a latitude of 26° north or south, which is consistent with the typical latitude of sunspot
Document 1:::
In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular arc. It can be uniform, with a constant rate of rotation and constant tangential speed, or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves the circular motion of its parts. The equations of motion describe the movement of the center of mass of a body, which remains at a constant distance from the axis of rotation. In circular motion, the distance between the body and a fixed point on its surface remains the same, i.e., the body is assumed rigid.
Examples of circular motion include: special satellite orbits around the Earth (circular orbits), a ceiling fan's blades rotating around a hub, a stone that is tied to a rope and is being swung in circles, a car turning through a curve in a race track, an electron moving perpendicular to a uniform magnetic field, and a gear turning inside a mechanism.
Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion.
Uniform circular motion
In physics, uniform circular motion describes the motion of a body traversing a circular path at a constant speed. Since the body describes circular motion, its distance from the axis of rotation remains constant at all times. Though the body's speed is constant, its velocity is not constant: velocity, a vector quantity, depends on both the body's speed and its direction of travel. This changing velocity indicates the presence of an acceleration; this centripetal acceleration is of constant magnitude and directed at all times toward the axis of rotation. This acceleration is, in turn, produced by a centripetal force which is also constant in magnitude and directed toward the axis of
Document 2:::
A fundamental ephemeris of the Solar System is a model of the objects of the system in space, with all of their positions and motions accurately represented. It is intended to be a high-precision primary reference for prediction and observation of those positions and motions, and which provides a basis for further refinement of the model. It is generally not intended to cover the entire life of the Solar System; usually a short-duration time span, perhaps a few centuries, is represented to high accuracy. Some long ephemerides cover several millennia to medium accuracy.
They are published by the Jet Propulsion Laboratory as Development Ephemeris. The latest releases include DE430 which covers planetary and lunar ephemeris from Dec 21, 1549 to Jan 25, 2650 with high precision and is intended for general use for modern time periods . DE431 was created to cover a longer time period Aug 15, -13200 to March 15, 17191 with slightly less precision for use with historic observations and far reaching forecasted positions. DE432 was released as a minor update to DE430 with improvements to the Pluto barycenter in support of the New Horizons mission.
Description
The set of physical laws and numerical constants used in the calculation of the ephemeris must be self-consistent and precisely specified. The ephemeris must be calculated strictly in accordance with this set, which represents the most current knowledge of all relevant physical forces and effects. Current fundamental ephemerides are typically released with exact descriptions of all mathematical models, methods of computation, observational data, and adjustment to the observations at the time of their announcement. This may not have been the case in the past, as fundamental ephemerides were then computed from a collection of methods derived over a span of decades by many researchers.
The independent variable of the ephemeris is always time. In the case of the most current ephemerides, it is a relativistic coordinate t
Document 3:::
The angular momentum problem is a problem in astrophysics identified by Leon Mestel in 1965.
It was found that the angular momentum of a protoplanetary disk is misappropriated when compared to models during stellar birth. The Sun and other stars are predicted by models to be rotating considerably faster than they actually are. The Sun, for example, only accounts for about 0.3 percent of the total angular momentum of the Solar System while about 60% is attributed to Jupiter.
See also
History of Solar System formation and evolution hypotheses
Document 4:::
Earth's rotation or Earth's spin is the rotation of planet Earth around its own axis, as well as changes in the orientation of the rotation axis in space. Earth rotates eastward, in prograde motion. As viewed from the northern polar star Polaris, Earth turns counterclockwise.
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where Earth's axis of rotation meets its surface. This point is distinct from Earth's North Magnetic Pole. The South Pole is the other point where Earth's axis of rotation intersects its surface, in Antarctica.
Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes and 4 seconds with respect to other distant stars (see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation. Atomic clocks show that the modern day is longer by about 1.7 milliseconds than a century ago, slowly increasing the rate at which UTC is adjusted by leap seconds. Analysis of historical astronomical records shows a slowing trend; the length of a day increased by about 2.3 milliseconds per century since the 8th century BCE.
Scientists reported that in 2020 Earth had started spinning faster, after consistently spinning slower than 86,400 seconds per day in the decades before. On June 29, 2022, Earth's spin was completed in 1.59 milliseconds under 24 hours, setting a new record. Because of that trend, engineers worldwide are discussing a 'negative leap second' and other possible timekeeping measures.
This increase in speed is thought to be due to various factors, including the complex motion of its molten core, oceans, and atmosphere, the effect of celestial bodies such as the Moon, and possibly climate change, which is causing the ice at Earth's poles to melt. The masses of ice account for the Earth's shape being that of an oblate spheroid, bulging around t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Many types of motion occur in our solar system. Which type of motion describes one Earth year?
A. the revolution of the sun around Earth
B. the revolution of Earth around the sun
C. the rotation of the sun around Earth
D. the rotation of Earth around the sun
Answer:
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|
sciq-8060
|
multiple_choice
|
In addition to insects, what large invertebrate phylum includes animals such as spiders, centipedes, and lobsters?
|
[
"onychophora",
"ostracods",
"fungi",
"arthropoda"
] |
D
|
Relavent Documents:
Document 0:::
Invertebrate zoology is the subdiscipline of zoology that consists of the study of invertebrates, animals without a backbone (a structure which is found only in fish, amphibians, reptiles, birds and mammals).
Invertebrates are a vast and very diverse group of animals that includes sponges, echinoderms, tunicates, numerous different phyla of worms, molluscs, arthropods and many additional phyla. Single-celled organisms or protists are usually not included within the same group as invertebrates.
Subdivisions
Invertebrates represent 97% of all named animal species, and because of that fact, this subdivision of zoology has many further
subdivisions, including but not limited to:
Arthropodology - the study of arthropods, which includes
Arachnology - the study of spiders and other arachnids
Entomology - the study of insects
Carcinology - the study of crustaceans
Myriapodology - the study of centipedes, millipedes, and other myriapods
Cnidariology - the study of Cnidaria
Helminthology - the study of parasitic worms.
Malacology - the study of mollusks, which includes
Conchology - the study of Mollusk shells.
Limacology - the study of slugs.
Teuthology - the study of cephalopods.
Invertebrate paleontology - the study of fossil invertebrates
These divisions are sometimes further divided into more specific specialties. For example, within arachnology, acarology is the study of mites and ticks; within entomology, lepidoptery is the study of butterflies and moths, myrmecology is the study of ants and so on. Marine invertebrates are all those invertebrates that exist in marine habitats.
History
Early Modern Era
In the early modern period starting in the late 16th century, invertebrate zoology saw growth in the number of publications made and improvement in the experimental practices associated with the field. (Insects are one of the most diverse groups of organisms on Earth. They play important roles in ecosystems, including pollination, natural enemies, saprophytes, and
Document 1:::
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:::
Taxonomy of commonly fossilised invertebrates is a complex and evolving field that combines both traditional and modern paleozoological terminology. This article aims to provide a comprehensive overview of the various invertebrate taxa that are commonly found in the fossil record, from protists to arthropods. The taxonomy presented here is not intended to be exhaustive but focuses on invertebrates that are either popularly collected as fossils or are extinct. Special notations are used to highlight invertebrate groups that are important as fossils, very abundant in the fossil record, or have a large proportion of extinct species. These notations are explained below for clarity:
[ ! ]: Indicates clades that are important as fossils or very abundant in the fossil record.
[ – ]: Indicates clades that contain a large proportion of extinct species.
[ † ]: Indicates clades that are completely extinct.
The paleobiologic systematics that follow are not intended to be comprehensive, rather encompass invertebrates that (a) are popularly collected as fossils and/or (b) extinct. As a result, some groups of invertebrates are not listed.
If an invertebrate animal is mentioned below using its common (vernacular) name, it is an extant (living) taxon, but if it is cited by its scientific genus, then it is typically an extinct invertebrate known only from the fossil record.
Invertebrate clades that are important fossils (e.g. ostracods, frequently used as index fossils), and/or clades that are very abundant as fossils (e.g. crinoids, easily found in crinoidal limestone), are highlighted with a bracketed exclamation mark [ ! ].
Domain of Eukaryota/Eukarya
Eukaryotes; eukaryotes are cellular organisms bearing a central, organized nucleus with DNA.
most of the species which have been documented by biologists and paleontologists, extinct or extant, are eukaryotic.
includes: a wide variety of single-celled protists; all algae; most plankton; most molds; the green plants; all an
Document 3:::
Incertae sedis
Diplopoda
Callipodida
Platydesmida
Polyxenida
Siphoniulida
Siphonophorida
Spirostreptida
"Entognatha"
Entomobryomorpha
Poduromorpha
Symphypleona
Insecta
Malacostraca
Decapoda
Isopoda
Ostracoda
Symphyla
Scolopendrellidae
Mollusca
Cephalopoda
Ammonitida
Gastropoda
"Architaenioglossa"
Heterobranchia
Littorinimorpha
Neritimorpha
Bivalvia
Nematoda
Chromadorea
Rhab
Document 4:::
Endoparasites
Protozoan organisms
Helminths (worms)
Helminth organisms (also called helminths or intestinal worms) include:
Tapeworms
Flukes
Roundworms
Other organisms
Ectoparasites
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In addition to insects, what large invertebrate phylum includes animals such as spiders, centipedes, and lobsters?
A. onychophora
B. ostracods
C. fungi
D. arthropoda
Answer:
|
|
sciq-8085
|
multiple_choice
|
What does a theory need to be supported by?
|
[
"scientists",
"facts",
"peer reviewed journals",
"many observations"
] |
D
|
Relavent Documents:
Document 0:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 1:::
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:::
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 3:::
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 4:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does a theory need to be supported by?
A. scientists
B. facts
C. peer reviewed journals
D. many observations
Answer:
|
|
sciq-9107
|
multiple_choice
|
How can you prevent food allergy symptoms?
|
[
"avoid offending foods",
"antioxidants",
"stem cell therapy",
"antiviral drugs"
] |
A
|
Relavent Documents:
Document 0:::
An elimination diet, also known as exclusion diet, is a diagnostic procedure used to identify foods that an individual cannot consume without adverse effects. Adverse effects may be due to food allergy, food intolerance, other physiological mechanisms (such as metabolic or toxins), or a combination of these. Elimination diets typically involve entirely removing a suspected food from the diet for a period of time from two weeks to two months, and waiting to determine whether symptoms resolve during that time period. In rare cases, a health professional may wish to use an elimination diet, also referred to as an oligoantigenic diet, to relieve a patient of symptoms they are experiencing.
Common reasons for undertaking an elimination diet include suspected food allergies and suspected food intolerances. An elimination diet might remove one or more common foods, such as eggs or milk, or it might remove one or more minor or non-nutritive substances, such as artificial food colorings.
An elimination diet relies on trial and error to identify specific allergies and intolerances. Typically, if symptoms resolve after the removal of a food from the diet, then the food is reintroduced to see whether the symptoms reappear. This challenge–dechallenge–rechallenge approach has been claimed to be particularly useful in cases with intermittent or vague symptoms.
The exclusion diet can be a diagnostic tool or method used temporarily to determine whether a patient's symptoms are food-related. The term elimination diet is also used to describe a "treatment diet", which eliminates certain foods for a patient.
Adverse reactions to food can be due to several mechanisms. Correct identification of the type of reaction in an individual is important, as different approaches to management may be required. The area of food allergies and intolerances has been controversial and is currently a topic that is heavily researched. It has been characterised in the past by lack of universal acceptan
Document 1:::
Nutritional immunology is a field of immunology that focuses on studying the influence of nutrition on the immune system and its protective functions. Part of nutritional immunology involves studying the possible effects of diet on the prevention and management on developing autoimmune diseases, chronic diseases, allergy, cancer (diseases of affluence) and infectious diseases. Other related topics of nutritional immunology are: malnutrition, malabsorption and nutritional metabolic disorders including the determination of their immune products.
The Role of Nutrition on the Prevention and Management of Diseases
Autoimmune diseases
The development and progression of many autoimmune diseases are generally unknown. The "Western pattern diet" consists of high-fat, high-sugar, low-fiber meals with a surfeit of salt and highly processed food, which have pro-inflammatory effects. These effects may promote Th1- and Th17 - biased immunity and alter monocyte and neutrophil migration from bone marrow. A healthy diet contains a multitude of micronutrients that have anti-inflammatory and immune boosting effects that can help prevent or treat autoimmune diseases.
The impact of diet is studied in relation to these autoimmune diseases:
Inflammatory bowel disease (IBD)
Type 1 diabetes (T1D)
Multiple sclerosis (MS)
Systemic lupus erythematosus (SLE)
Rheumatoid arthritis (RA)
Celiac disease
Allergies
Nutrition can help prevent or promote the development of food allergies. The hygiene hypothesis states that a child's early introduction to certain microorganisms can avert the onset of allergies. Breastfeeding is considered to be the main method of preventing food allergies. This is because breast milk contains oligosaccharides, secretory IgA, vitamins, antioxidants and possible transfer of microbiota. Conversely, a child's lack of exposure to specific microorganisms can establish a vulnerability to food allergies
Diabetes
Diabetes mellitus is a disease in which one's blo
Document 2:::
Corn allergy is a very rare food allergy. People with a true IgE-mediated allergy to corn develop symptoms such as swelling or hives when they eat corn or foods that contain corn. The allergy can be difficult to manage due to many food and non-food products that contain various forms of corn, such as corn starch and modified food starch, among many others. It is an allergy that often goes unrecognized.
Symptoms
As a result of a possible immunoglobulin E (IgE) allergy to corn, symptoms can resemble that of any other recognized allergy, including anaphylaxis. As with other food allergies, most people who are allergic to corn have mild symptoms.
Causes
Corn allergies is caused by certain proteins which are found within the corn kernel. Currently, the maize lipid transfer protein is known to cause corn allergies, The mechanisms of the allergy are unknown.
Management
As with other food allergies, there is no cure. Since the allergy is rarely reported, diagnosis of the allergen that causes the corn allergy has been difficult. Most people who are allergic to corn cannot eat corn or anything containing proteins from corn. Many people who are allergic to corn can still eat sugars purified from corn, such as corn syrup.
Epidemiology
See also
List of allergies
Food intolerance – another cause of illness after eating a particular food
Document 3:::
An allergist is a physician specially trained to manage and treat allergies, asthma and the other allergic diseases. They may also be called
immunologists.
Becoming an allergist
Becoming an allergist/immunologist requires completion of at least nine years of training. After completing medical school and graduating with a medical degree, a physician will then undergo three years of training in internal medicine (to become an internist) or pediatrics (to become a pediatrician). Once physicians have finished training in one of these specialties, they must pass the exam of either the American Board of Pediatrics (ABP) or the American Board of Internal Medicine (ABIM). Internists or pediatricians who wish to focus on the sub-specialty of allergy-immunology then complete at least an additional two years of study, called a fellowship, in an allergy/immunology training program.
Allergist/immunologists who are listed as ABAI-certified have successfully passed the certifying examination of the American Board of Allergy and Immunology (ABAI), following their fellowship.
In the United States physicians who hold certification by the American Board of Allergy and Immunology (ABAI) have successfully completed an accredited educational program and an evaluation process, including a secure, proctored examination to demonstrate the knowledge, skills, and experience to the provision of patient care in allergy and immunology.
In the United Kingdom, allergy is a subspecialty of general medicine or pediatrics. After obtaining postgraduate exams (MRCP or MRCPCH respectively) a doctor works for several years as a specialist registrar before qualifying for the General Medical Council specialist register. Allergy services may also be delivered by immunologists.
Absence of allergists
A 2003 Royal College of Physicians report presented a case for improvement of what were felt to be inadequate allergy services in the UK. In 2006, the House of Lords convened a subcommittee that reported i
Document 4:::
Sociedad Española de Inmunología Clínica, Alergología y Asma Pediátrica (SEICAP), the Spanish Society of Pediatric Allergy, Asthma and Clinical Immunology, is a scientific, non-profit organization, whose aims are to develop and disseminate the knowledge of allergic and immunologic diseases that affect children. Since June 2012 SEICAP has been recognized as a Public Interest Entity.
Their field of study includes childhood asthma, rhinitis and conjunctivitis, anaphylaxis, atopic dermatitis, contact dermatitis, urticaria and angioedema, food allergy, drug allergy, allergy to latex, allergy to insect stings, primary immunodeficiency, and other disorders.
These conditions are very frequent in children, especially in developed countries, and account for a considerable amount of healthcare spending, which has increased especially since the 1990s.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How can you prevent food allergy symptoms?
A. avoid offending foods
B. antioxidants
C. stem cell therapy
D. antiviral drugs
Answer:
|
|
sciq-7151
|
multiple_choice
|
Two events are defined to be simultaneous if an observer measures them as occurring at what?
|
[
"same time",
"opposite times",
"different times",
"midnight"
] |
A
|
Relavent Documents:
Document 0:::
Synchronism may refer to:
Synchronism (Davidovsky), compositions by Argentine-American composer Mario Davidovsky incorporating acoustic instruments and electroacoustic sounds
Chronological synchronism, an event that links two chronologies such as historical and datable astronomical events
Synchronization, the coordination of events to operate a system in unison
Film
Synchronized sound, film sound technologically coupled to image
Post-synchronization, the process of re-recording dialogue after the filming process
See also
Synchromism an early 20th-century art movement, commonly misspelled as "synchronism"
Synchronicity (disambiguation)
Synchronizer (disambiguation)
Synchrony (disambiguation)
Synchronization
Document 1:::
Output compare is the ability to trigger an output based on a timestamp in memory, without interrupting the execution of code by a processor or microcontroller. This is a functionality provided by many embedded systems.
The corresponding ability to record a timestamp in memory when an input occurs is called input capture.
Embedded systems
Microchip Documentation on Output Compare: DS39706A-page 16-1 - Section 16. Output Compare http://ww1.microchip.com/downloads/en/DeviceDoc/39706a.pdf
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In numerology, 11:11 is considered to be a significant moment in time for an event to occur. It is seen as an example of synchronicity, as well as a favorable sign or a suggestion towards the presence of spiritual influence. It is additionally thought that the repetition of numbers in the sequence adds "intensity" to them and increases the numerological effect.
Critics highlight the lack of substantial evidence for this assertion, and they gesture towards confirmation bias and post-hoc analysis as a scientific explanation for any claims related to the significance or importance of 11:11 and other such sequences. Through observations made in the study of statistics, specifically chaos theory and the law of truly large numbers, skeptics explain these anecdotal observations as a coincidence and an inevitability, rather than as any particular indication towards significance.
Significance in Christianity
Within Protestant Christianity, particularly in Pentecostal movements, the number 11 or 11:11 has been linked to the concept of transition.
Significance in dates
For various reasons, individuals are known to attribute significance to dates and numbers. One notable example is the significance given to "the eleventh hour of the eleventh day of the eleventh month," which corresponds to 11:00 a.m. (Paris time) on 11 November 1918. It marks the moment when the armistice ending World War I took effect.
On 11 November 2011, also known as "11/11/11," there was an increase in the number of marriages occurring in various regions worldwide, including the United States and across the Asian continent.
See also
Law of Fives
23 enigma
Apophenia
Document 3:::
Chronemics is an anthropological, philosophical, and linguistic subdiscipline that describes how time is perceived, coded, and communicated across a given culture. It is one of several subcategories to emerge from the study of nonverbal communication. According to the Encyclopedia of Special Education, "Chronemics includes time orientation, understanding and organisation, the use of and reaction to time pressures, the innate and learned awareness of time, by physically wearing or not wearing a watch, arriving, starting, and ending late or on time." A person's perception and values placed on time plays a considerable role in their communication process. The use of time can affect lifestyles, personal relationships, and work life. Across cultures, people usually have different time perceptions, and this can result in conflicts between individuals. Time perceptions include punctuality, interactions, and willingness to wait.
Definition
Chronemics is the study of the use of time in nonverbal communication. Time perceptions include punctuality, willingness to wait, and interactions. The use of time can affect lifestyles, daily agendas, speed of speech, movements, and how long people are willing to listen.
Thomas J. Bruneau, a professor in communication at Radford University who focused his studies on nonverbal communication, interpersonal communication, and intercultural communication, coined the term "chronemics" in the late 1970s to help define the function of time in human interaction:
Time can be used as an indicator of status. For example, in most companies the boss can interrupt progress to hold an impromptu meeting in the middle of the work day, yet the average worker would have to make an appointment to see the boss.
The way in which different cultures perceive time can influence communication as well.
Monochronic time
A monochronic time system means that things are done one at a time and time is segmented into small precise units. Under this system, time
Document 4:::
Clock angle problems are a type of mathematical problem which involve finding the angle between the hands of an analog clock.
Math problem
Clock angle problems relate two different measurements: angles and time. The angle is typically measured in degrees from the mark of number 12 clockwise. The time is usually based on a 12-hour clock.
A method to solve such problems is to consider the rate of change of the angle in degrees per minute. The hour hand of a normal 12-hour analogue clock turns 360° in 12 hours (720 minutes) or 0.5° per minute. The minute hand rotates through 360° in 60 minutes or 6° per minute.
Equation for the angle of the hour hand
where:
is the angle in degrees of the hand measured clockwise from the 12
is the hour.
is the minutes past the hour.
is the number of minutes since 12 o'clock.
Equation for the angle of the minute hand
where:
is the angle in degrees of the hand measured clockwise from the 12 o'clock position.
is the minute.
Example
The time is 5:24. The angle in degrees of the hour hand is:
The angle in degrees of the minute hand is:
Equation for the angle between the hands
The angle between the hands can be found using the following formula:
where
is the hour
is the minute
If the angle is greater than 180 degrees then subtract it from 360 degrees.
Example 1
The time is 2:20.
Example 2
The time is 10:16.
When are the hour and minute hands of a clock superimposed?
The hour and minute hands are superimposed only when their angle is the same.
is an integer in the range 0–11. This gives times of: 0:00, 1:05., 2:10., 3:16., 4:21., 5:27.. 6:32., 7:38., 8:43., 9:49.,
10:54., and 12:00.
(0. minutes are exactly 27. seconds.)
See also
Clock position
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Two events are defined to be simultaneous if an observer measures them as occurring at what?
A. same time
B. opposite times
C. different times
D. midnight
Answer:
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ai2_arc-493
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multiple_choice
|
The Ohio state tree is the buckeye. Which of these is a trait that is inherited by the buckeye tree in the reproduction process?
|
[
"number of leaves that fall during winter",
"change in leaf color during the autumn season",
"type of mineral that is absorbed from the soil",
"amount of water that is available for growth"
] |
B
|
Relavent Documents:
Document 0:::
Phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. Plant morphology is useful in the visual identification of plants. Recent studies in molecular biology started to investigate the molecular processes involved in determining the conservation and diversification of plant morphologies. In these studies transcriptome conservation patterns were found to mark crucial ontogenetic transitions during the plant life cycle which may result in evolutionary constraints limiting diversification.
Scope
Plant morphology "represents a study of the development, form, and structure of plants, and, by implication, an attempt to interpret these on the basis of similarity of plan and origin". There are four major areas of investigation in plant morphology, and each overlaps with another field of the biological sciences.
First of all, morphology is comparative, meaning that the morphologist examines structures in many different plants of the same or different species, then draws comparisons and formulates ideas about similarities. When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany.
Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive str
Document 1:::
A tree fork is a bifurcation in the trunk of a tree giving rise to two roughly equal diameter branches. These forks are a common feature of tree crowns. The wood grain orientation at the top of a tree fork is such that the wood's grain pattern most often interlocks to provide sufficient mechanical support. A common "malformation" of a tree fork is where bark has formed within the join, often caused by natural bracing occurring higher up in the crown of the tree, and these bark-included junctions often have a heightened risk of failure, especially when bracing branches are pruned out or are shaded out from the tree's crown.
Definition
In arboriculture, junctions in the crown structure of trees are frequently categorised as either branch-to-stem attachments or co-dominant stems. Co-dominant stems are where the two or more arising branches emerging from the junction are of near equal diameter and this type of junction in a tree is often referred to in layman's terms as 'a tree fork'.
There is actually no hard botanical division between these two forms of branch junction: they are topologically equivalent, and from their external appearance it is only a matter of the diameter ratio between the branches that are conjoined that separates a tree fork from being a branch-to-stem junction.
However, when a small branch joins to a tree trunk there is a knot that can be found to be embedded into the trunk of the tree, which was the initial base of the smaller branch. This is not the case in tree forks, as each branch is roughly equal in size and no substantial tissues from either branch is embedded into the other, so there is no reinforcing knot to supply the mechanical strength to the junction that will be needed to hold the branches aloft.
Anatomy and morphology
Research has shown that a unique wood grain pattern at the apex of forks in hazel trees (Corylus avellana L.) acts to hold together the branches in this species, and this is probably the case in most other
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Crown sprouting is the ability of a plant to regenerate its shoot system after destruction (usually by fire) by activating dormant vegetative structures to produce regrowth from the root crown (the junction between the root and shoot portions of a plant). These dormant structures take the form of lignotubers or basal epicormic buds. Plant species that can accomplish crown sprouting are called crown resprouters (distinguishing them from stem or trunk resprouters) and, like them, are characteristic of fire-prone habitats such as chaparral.
In contrast to plant fire survival strategies that decrease the flammability of the plant, or by requiring heat to germinate, crown sprouting allows for the total destruction of the above ground growth. Crown sprouting plants typically have extensive root systems in which they store nutrients allowing them to survive during fires and sprout afterwards. Early researchers suggested that crown sprouting species might lack species genetic diversity; however, research on Gondwanan shrubland suggests that crown sprouting species have similar genetic diversity to seed sprouters. Some genera, such as Arctostaphylos and Ceanothus, have species that are both resprouters and not, both adapted to fire.
California Buckeye, Aesculus californica, is an example of a western United States tree which can regenerate from its root crown after a fire event, but can also regenerate by seed.
See also
Fire ecology
Lignotuber
Notes
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Tree breeding is the application of genetic, reproductive biology and economics principles to the genetic improvement and management of forest trees. In contrast to the selective breeding of livestock, arable crops, and horticultural flowers over the last few centuries, the breeding of trees, with the exception of fruit trees, is a relatively recent occurrence.
A typical forest tree breeding program starts with selection of superior phenotypes (plus trees) in a natural or planted forest, often based on growth rate, tree form and site adaptation traits. This application of mass selection improves the mean performance of the forest. Offspring is obtained from selected trees and grown in test plantations that act as genetic trials. Based on such tests the best genotypes among the parents can be selected. Selected trees are typically multiplied by either seeds or grafting and seed orchards are established when the preferred output is improved seed. Alternatively, the best genotypes can be directly propagated by cuttings or in-vitro methods and used directly in clonal plantations. The first system is frequently used in pines and other conifers, while the second is typical in some broadleaves (poplars, eucalypts and others). The objectives of a tree breeding program range from yield improvement and adaptation to particular conditions, to pest- and disease-resistance, wood properties, etc. Currently, tree breeding is starting to take advantage of the fast development in plant genetics and genomics.
Optimisation
Tree breeders make efforts to get their operation efficient by optimising tree breeding. Scientists develop tools aimed at improvement of the efficiency of tree breeding programmes. Optimising can mean adapting strategies and methods to certain species, group of populations, structure of genetic variation and mode of inheritance of the important traits to obtain the highest benefit per unit of time. Optimising is usually carried out at the following levels: breedi
Document 4:::
Witch's broom or witches' broom is a deformity in a woody plant, typically a tree, where the natural structure of the plant is changed. A dense mass of shoots grows from a single point, with the resulting structure resembling a broom or a bird's nest. It is sometimes caused by pathogens.
Diseases with symptoms of witches' broom, caused by phytoplasmas or basidiomycetes, are economically important in a number of crop plants, including the cocoa tree Theobroma cacao, jujube (Ziziphus jujuba) and the timber tree Melia azedarach.
Causes
A tree's characteristic shape, or habit, is in part the product of auxins, hormones which control the growth of secondary apices. The growth of an offshoot is limited by the auxin, while that of the parent branch is not. In cases of witch's broom, the normal hierarchy of buds is interrupted, and apices grow indiscriminately. This can be caused by cytokinin, a phytohormone which interferes with growth regulation. The phenomenon can also be caused by other organisms, including fungi, oomycetes, insects, mites, nematodes, phytoplasmas, and viruses. The broom growths may last for many years, typically for the life of the host plant. If twigs of witch's brooms are grafted onto normal rootstocks, freak trees result, showing that the attacking organism has changed the inherited growth pattern of the twigs.
Ecological role
Witches' brooms provide nesting habitat for birds and mammals, such as the northern flying squirrel, which nests in them.
See also
Plant development § buds and shoots – atypical shoot development
Epicormic shoot – a shoot that develops from buds under the bark
Forest pathology
Longan witches broom-associated virus
Melampsora can cause different kinds of witch's brooms.
Moniliophthora perniciosa, cause of witch's broom disease in cacao
Phyllody, a related plant growth abnormality affecting flowers
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The Ohio state tree is the buckeye. Which of these is a trait that is inherited by the buckeye tree in the reproduction process?
A. number of leaves that fall during winter
B. change in leaf color during the autumn season
C. type of mineral that is absorbed from the soil
D. amount of water that is available for growth
Answer:
|
|
ai2_arc-66
|
multiple_choice
|
An astronomer is studying two stars that are the same distance from Earth. Star X appears brighter than star Y. Which statement best explains this observation?
|
[
"Star X is larger than star Y.",
"Star Y is larger than star X.",
"Star X reflects the Sun’s light better than star Y.",
"Star Y reflects the Sun’s light better than star X."
] |
A
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
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Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are." Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.
In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; and the origin and ultimate fate of the universe. Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.
History
Astronomy is an ancient science, long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthl
Document 3:::
Astronomy education or astronomy education research (AER) refers both to the methods currently used to teach the science of astronomy and to an area of pedagogical research that seeks to improve those methods. Specifically, AER includes systematic techniques honed in science and physics education to understand what and how students learn about astronomy and determine how teachers can create more effective learning environments.
Education is important to astronomy as it impacts both the recruitment of future astronomers and the appreciation of astronomy by citizens and politicians who support astronomical research. Astronomy has been taught throughout much of recorded human history, and has practical application in timekeeping and navigation. Teaching astronomy contributes to an understanding of physics and the origin of the world around us, a shared cultural background, and a sense of wonder and exploration. It includes education of the general public through planetariums, books, and instructive presentations, plus programs and tools for amateur astronomy, and University-level degree programs for professional astronomers. Astronomy organizations provide educational functions and societies in about 100 nation states around the world.
In schools, particularly at the collegiate level, astronomy is aligned with physics and the two are often combined to form a Department of Physics and Astronomy. Some parts of astronomy education overlap with physics education, however, astronomy education has its own arenas, practitioners, journals, and research. This can be demonstrated in the identified 20-year lag between the emergence of AER and physics education research. The body of research in this field are available through electronic sources such as the Searchable Annotated Bibliography of Education Research (SABER) and the American Astronomical Society's database of the contents of their journal "Astronomy Education Review" (see link below).
The National Aeronautics and
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
An astronomer is studying two stars that are the same distance from Earth. Star X appears brighter than star Y. Which statement best explains this observation?
A. Star X is larger than star Y.
B. Star Y is larger than star X.
C. Star X reflects the Sun’s light better than star Y.
D. Star Y reflects the Sun’s light better than star X.
Answer:
|
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sciq-9716
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multiple_choice
|
Where are the olfactory organs of snails located?
|
[
"their anus",
"their feet",
"their shell",
"their tentacles"
] |
D
|
Relavent Documents:
Document 0:::
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the eyestalks of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions.
A tentacle is similar to a cirrus, but a cirrus is an organ that usually lacks the tentacle's strength, size, flexibility, or sensitivity. A nautilus has cirri, but a squid has tentacles.
Invertebrates
Molluscs
Many molluscs have tentacles of one form or another. The most familiar are those of the pulmonate land snails, which usually have two sets of tentacles on the head: when extended the upper pair have eyes at their tips; the lower pair are chemoreceptors. Both pairs are fully retractable muscular hydrostats, but they are not used for manipulation or prey capture. Molluscs have one pair of tentacles close to their mouths that hold close to their captured prey before they can consume it.
Some marine snails such as abalone and top snails, Trochidae, have numerous small tentacles around the edge of the mantle. These are known as pallial tentacles.
Among cephalopods, squid have spectacular tentacles. They take the form of highly mobile muscular hydrostats with various appendages such as suction disks and sometimes thorny hooks. Up to the early twentieth century "tentacles" were interchangeably called "arms". These tentacles are made of stalks of axial nerve cords that are covered by circular transverse muscle tissue that contract in response to stimuli. There is a layer of helical muscle that helps each tentacle to twist or turn in any direction where the prey is sendsed.
Th
Document 1:::
Cement glands are small organs found in Acanthocephala that are used to temporarily close the posterior end of the female after copulation.
Cement glands are also mucus-secreting organs that can attach embryos or larvae to a solid substrate. These can be found in frogs such as those in the genus Xenopus, fish such as the Mexican tetra, and crustaceans.
Document 2:::
Cepaea is a genus of large air-breathing land snails, terrestrial pulmonate gastropod molluscs in the family Helicidae. The shells are often brightly colored and patterned with brown stripes. The two species in this genus, C. nemoralis and C. hortensis, are widespread and common in Western and Central Europe and have been introduced to North America. Both have been influential model species for ongoing studies of genetics and natural selection. Like many Helicidae, these snails use love darts during mating.
Species
For a long time, four species were classified in the genus Cepaea. However, molecular phylogenetic studies suggested that two of them should be placed in the genera Macularia and Caucasotachea, which are not immediate relatives either of Cepaea or each other:
Cepaea hortensis (O. F. Müller, 1774) – white-lipped snail or garden banded snail
Cepaea nemoralis (Linnaeus, 1758) – brown-lipped snail or grove snail
Cepaea sylvatica (Draparnaud, 1801), now Macularia sylvatica
Cepaea vindobonensis (Férussac, 1821), now Caucasotachea vindobonensis
Interspecific relations
The range of C. hortensis extends further north than that of C. nemoralis in Scotland and Scandinavia and it is the only one of the two species in Iceland. Likewise in the Swiss Alps C. hortensis is found as high as 2050 m, but C. nemoralis only up to 1600 m. Conversely, the southern edge of the range lies further north in C. hortensis; unlike C. nemoralis it does not occur in Italy, and in Spain it has a more restricted distribution (in the north-east corner).
Where the ranges overlap C. hortensis prefers cooler sites with longer and damper vegetation. But the two species often co-occur at a site, in which situation the densities of both affect each other's growth, fecundity and mortality. However, they differ somewhat in their behaviour: C. hortensis is more active at lower temperatures, aestivates higher on the vegetation and is more diurnal, although this appears to be independent of wh
Document 3:::
The organs of Bojanus or Bojanus organs are excretory glands that serve the function of kidneys in some of the molluscs. In other words, these are metanephridia that are found in some molluscs, for example in the bivalves. Some other molluscs have another type of organ for excretion called Keber's organ.
The Bojanus organ is named after Ludwig Heinrich Bojanus, who first described it. The excretory system of a bivalve consists of a pair of kidneys called the organ of bojanus. These are situated one of each side of the body below the pericardium. Each kidney consist of 2 part (1)- glandular part (2)- a thin walled ciliated urinary bladder.
Document 4:::
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.
Where are the olfactory organs of snails located?
A. their anus
B. their feet
C. their shell
D. their tentacles
Answer:
|
|
sciq-9016
|
multiple_choice
|
The carbon atoms are bonded together, with each carbon also being bonded to two of what kind of atoms?
|
[
"hydrogen",
"helium",
"calcium",
"ions"
] |
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, 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
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A chemical bonding model is a theoretical model used to explain atomic bonding structure, molecular geometry, properties, and reactivity of physical matter. This can refer to:
VSEPR theory, a model of molecular geometry.
Valence bond theory, which describes molecular electronic structure with localized bonds and lone pairs.
Molecular orbital theory, which describes molecular electronic structure with delocalized molecular orbitals.
Crystal field theory, an electrostatic model for transition metal complexes.
Ligand field theory, the application of molecular orbital theory to transition metal complexes.
Chemical bonding
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In molecular geometry, bond length or bond distance is defined as the average distance between nuclei of two bonded atoms in a molecule. It is a transferable property of a bond between atoms of fixed types, relatively independent of the rest of the molecule.
Explanation
Bond length is related to bond order: when more electrons participate in bond formation the bond is shorter. Bond length is also inversely related to bond strength and the bond dissociation energy: all other factors being equal, a stronger bond will be shorter. In a bond between two identical atoms, half the bond distance is equal to the covalent radius.
Bond lengths are measured in the solid phase by means of X-ray diffraction, or approximated in the gas phase by microwave spectroscopy. A bond between a given pair of atoms may vary between different molecules. For example, the carbon to hydrogen bonds in methane are different from those in methyl chloride. It is however possible to make generalizations when the general structure is the same.
Bond lengths of carbon with other elements
A table with experimental single bonds for carbon to other elements is given below. Bond lengths are given in picometers. By approximation the bond distance between two different atoms is the sum of the individual covalent radii (these are given in the chemical element articles for each element). As a general trend, bond distances decrease across the row in the periodic table and increase down a group. This trend is identical to that of the atomic radius.
Bond lengths in organic compounds
The bond length between two atoms in a molecule depends not only on the atoms but also on such factors as the orbital hybridization and the electronic and steric nature of the substituents. The carbon–carbon (C–C) bond length in diamond is 154 pm. It is generally considered the average length for a carbon–carbon single bond, but is also the largest bond length that exists for ordinary carbon covalent bonds. Since one atomic unit
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A carbon–nitrogen bond is a covalent bond between carbon and nitrogen and is one of the most abundant bonds in organic chemistry and biochemistry.
Nitrogen has five valence electrons and in simple amines it is trivalent, with the two remaining electrons forming a lone pair. Through that pair, nitrogen can form an additional bond to hydrogen making it tetravalent and with a positive charge in ammonium salts. Many nitrogen compounds can thus be potentially basic but its degree depends on the configuration: the nitrogen atom in amides is not basic due to delocalization of the lone pair into a double bond and in pyrrole the lone pair is part of an aromatic sextet.
Similar to carbon–carbon bonds, these bonds can form stable double bonds, as in imines; and triple bonds, such as nitriles. Bond lengths range from 147.9 pm for simple amines to 147.5 pm for C-N= compounds such as nitromethane to 135.2 pm for partial double bonds in pyridine to 115.8 pm for triple bonds as in nitriles.
A CN bond is strongly polarized towards nitrogen (the electronegativities of C and N are 2.55 and 3.04, respectively) and subsequently molecular dipole moments can be high: cyanamide 4.27 D, diazomethane 1.5 D, methyl azide 2.17, pyridine 2.19. For this reason many compounds containing CN bonds are water-soluble. N-philes are group of radical molecules which are specifically attracted to the C=N bonds.
Carbon-nitrogen bond can be analyzed by X-ray photoelectron spectroscopy (XPS). Depending on the bonding states the peak positions differ in N1s XPS spectra.
Nitrogen functional groups
See also
Cyanide
Other carbon bonds with group 15 elements: carbon–nitrogen bonds, carbon–phosphorus bonds
Other carbon bonds with period 2 elements: carbon–lithium bonds, carbon–beryllium bonds, carbon–boron bonds, carbon–carbon bonds, carbon–nitrogen bonds, carbon–oxygen bonds, carbon–fluorine bonds
Carbon–hydrogen bond
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The carbon atoms are bonded together, with each carbon also being bonded to two of what kind of atoms?
A. hydrogen
B. helium
C. calcium
D. ions
Answer:
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sciq-5974
|
multiple_choice
|
Which types of compounds are more likely to burn easily?
|
[
"salty",
"hydroxyl",
"chlorophyll",
"covalent"
] |
D
|
Relavent Documents:
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
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Reduction
Reduction of ethyl acetoacetate gives ethyl 3-hydroxybutyrate.
Transesterification
Ethyl acetoacetate transesterifies to give benzyl acetoacetate via a mechanism involving acetylketene. Ethyl (and other) acetoacetates nitrosate readily with equimolar
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2-Nonenal is an unsaturated aldehyde. The colorless liquid is an important aroma component of aged beer and buckwheat.
Odor characteristics
The odor of this substance is perceived as orris, fat and cucumber. Its odor has been associated with human body odor alterations during aging.
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Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, clear or white crystalline substance, which is solid at room temperature and melts slightly above.
The main form of menthol occurring in nature is (−)-menthol, which is assigned the (1R,2S,5R) configuration. Menthol has local anesthetic and counterirritant qualities, and it is widely used to relieve minor throat irritation. Menthol also acts as a weak κ-opioid receptor agonist.
Structure
Natural menthol exists as one pure stereoisomer, nearly always the (1R,2S,5R) form (bottom left corner of the diagram below). The eight possible stereoisomers are:
In the natural compound, the isopropyl group is in the trans orientation to both the methyl and hydroxyl groups. Thus, it can be drawn in any of the ways shown:
The (+)- and (−)-enantiomers of menthol are the most stable among these based on their cyclohexane conformations. With the ring itself in a chair conformation, all three bulky groups can orient in equatorial positions.
The two crystal forms for racemic menthol have melting points of 28 °C and 38 °C. Pure (−)-menthol has four crystal forms, of which the most stable is the α form, the familiar broad needles.
Biological properties
Menthol's ability to chemically trigger the cold-sensitive TRPM8 receptors in the skin is responsible for the well-known cooling sensation it provokes when inhaled, eaten, or applied to the skin. In this sense, it is similar to capsaicin, the chemical responsible for the spiciness of hot chilis (which stimulates heat sensors, also without causing an actual change in temperature).
Menthol's analgesic properties are mediated through a selective activation of κ-opioid receptors. Menthol blocks calcium channels and voltage-sensitive sodium channels, reducing neural activity that may stimulate muscles.
Some studies show that menthol acts as a GABAA receptor positive al
Document 4:::
Chlorthiamide is an organic compound with the chemical formula C7H5Cl2NS used as an herbicide.
Chloroarenes
Herbicides
Thioamides
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which types of compounds are more likely to burn easily?
A. salty
B. hydroxyl
C. chlorophyll
D. covalent
Answer:
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sciq-5985
|
multiple_choice
|
The major classes of living members of this phylum include gastropods, bivalves, and cephalopods?
|
[
"crustaceans",
"insects",
"invertebrates",
"mollusks"
] |
D
|
Relavent Documents:
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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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Incertae sedis
Diplopoda
Callipodida
Platydesmida
Polyxenida
Siphoniulida
Siphonophorida
Spirostreptida
"Entognatha"
Entomobryomorpha
Poduromorpha
Symphypleona
Insecta
Malacostraca
Decapoda
Isopoda
Ostracoda
Symphyla
Scolopendrellidae
Mollusca
Cephalopoda
Ammonitida
Gastropoda
"Architaenioglossa"
Heterobranchia
Littorinimorpha
Neritimorpha
Bivalvia
Nematoda
Chromadorea
Rhab
Document 2:::
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. As of 2022, 2.16 million living animal species have been described—of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are around 7.77 million animal species. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and the chordates, the latter including the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on ad
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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
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Euphylliidae (Greek eu-, true; Greek phyllon, leaf) are known as a family of polyped stony corals under the order Scleractinia.
This family consists of multiple genera (more than one genus) and various species which are found among the ocean floor. These coral may be sparse or conspicuous in the wild. However, they are commonly kept in home-aquariums to be enjoyed for their beauty and protection by many fish and their owners.
Classification
Marine organisms are studied and classified just as any other member of the animal kingdom. However, marine taxa are observed and therefore classified differently than reptiles or mammals would be. When any marine animal is classified, there are a group of main characteristics that are observed and used to differentiate between phylum, class, (potentially subclass), order, family, and of course species. The key characteristics that scientists look for are categorized by body type, (symmetry, presence of segments, limbs, head or tail) reproduction, digestion,
As of the year 2000, the order Scleractinia was divided into 18 artificial families, known as the Acroporidae, Astrocoeniidae, Pocilloporidae, Euphyllidae, Oculinidae, Meandrinidae, Siderastreidae, Agariciidae, Fungiidae, Rhizangiidae, Pectiniidae, Merulinidae, Dendrophylliidae, Caryophylliidae, Mussidae, Faviidae, Trachyphylliidae, and Poritidae (sensu Veron 2000). During this time, only 11 families were known to contain corals that can be classified as truly reef-building. All scleractinian families considered here are zooxanthellates (contain photo-endo-symbiontic zooxanthellae). However, in 2022 there are more than 30 families determined under the Scleractinia (according to the World Register of Marine Species) order and 845 species of coral which are known to be reef-building.
Among the countless organisms in the Animalia kingdom, the families of coral will always remain as a unique group. Although they are stationary and stony structures, they belong in the same Cn
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The major classes of living members of this phylum include gastropods, bivalves, and cephalopods?
A. crustaceans
B. insects
C. invertebrates
D. mollusks
Answer:
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|
ai2_arc-1053
|
multiple_choice
|
Which characteristic of a bird most likely aids in obtaining food found in small places?
|
[
"webbed feet",
"large body",
"soft feathers",
"skinny beak"
] |
D
|
Relavent Documents:
Document 0:::
The following is a glossary of common English language terms used in the description of birds—warm-blooded vertebrates of the class Aves and the only living dinosaurs, characterized by , the ability to in all but the approximately 60 extant species of flightless birds, toothless, , the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart and a strong yet lightweight skeleton.
Among other details such as size, proportions and shape, terms defining bird features developed and are used to describe features unique to the class—especially evolutionary adaptations that developed to aid flight. There are, for example, numerous terms describing the complex structural makeup of feathers (e.g., , and ); types of feathers (e.g., , and feathers); and their growth and loss (e.g., , and ).
There are thousands of terms that are unique to the study of birds. This glossary makes no attempt to cover them all, concentrating on terms that might be found across descriptions of multiple bird species by bird enthusiasts and ornithologists. Though words that are not unique to birds are also covered, such as or , they are defined in relation to other unique features of external bird anatomy, sometimes called . As a rule, this glossary does not contain individual entries on any of the approximately 9,700 recognized living individual bird species of the world.
A
B
C
D
{| border="1"
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|carnivores (sometimes called faunivores): birds that predominantly forage for the meat of vertebrates—generally hunters as in certain birds of prey—including eagles, owls and shrikes, though piscivores, insectivores and crustacivores may be called specialized types of carnivores.
|-
|crustacivores: birds that forage for and eat crustaceans, such as crab-plovers and some rails.
|-
|detritivores: birds that forage for and eat decomposing material, such as vultures. It is usually used as a more general term than "saprovore" (defined below), which often connotes the eating of de
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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
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Significant work has gone into analyzing the effects of climate change on birds. Like other animal groups, birds are affected by anthropogenic (human-caused) climate change. The research includes tracking the changes in species' life cycles over decades in response to the changing world, evaluating the role of differing evolutionary pressures and even comparing museum specimens with modern birds to track changes in appearance and body structure. Predictions of range shifts caused by the direct and indirect impacts of climate change on bird species are amongst the most important, as they are crucial for informing animal conservation work, required to minimize extinction risk from climate change.
Climate change mitigation options can also have varying impacts on birds. However, even the environmental impact of wind power is estimated to be much less threatening to birds than the continuing effects of climate change.
Causes
Climate change has raised the temperature of the Earth by about since the Industrial Revolution. As the extent of future greenhouse gas emissions and mitigation actions determines the climate change scenario taken, warming may increase from present levels by less than with rapid and comprehensive mitigation (the Paris Agreement goal) to around ( from the preindustrial) by the end of the century with very high and continually increasing greenhouse gas emissions.
Effects
Physical changes
Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
Climate change has already altered the appearance of some birds by facilitating changes to their feathers. A comparison of museum specimens of juvenile passerines from 1800s with juveniles of the same species today had shown that these birds now complete the switch from their nesting feathers to adult feathers ea
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Around 350 BCE, Aristotle and other philosophers of the time attempted to explain the aerodynamics of avian flight. Even after the discovery of the ancestral bird Archaeopteryx which lived over 150 million years ago, debates still persist regarding the evolution of flight. There are three leading hypotheses pertaining to avian flight: Pouncing Proavis model, Cursorial model, and Arboreal model.
In March 2018, scientists reported that Archaeopteryx was likely capable of flight, but in a manner substantially different from that of modern birds.
Flight characteristics
For flight to occur, four physical forces (thrust and drag, lift and weight) must be favorably combined. In order for birds to balance these forces, certain physical characteristics are required. Asymmetrical wing feathers, found on all flying birds with the exception of hummingbirds, help in the production of thrust and lift. Anything that moves through the air produces drag due to friction. The aerodynamic body of a bird can reduce drag, but when stopping or slowing down a bird will use its tail and feet to increase drag. Weight is the largest obstacle birds must overcome in order to fly. An animal can more easily attain flight by reducing its absolute weight. Birds evolved from other theropod dinosaurs that had already gone through a phase of size reduction during the Middle Jurassic, combined with rapid evolutionary changes. Flying birds during their evolution further reduced relative weight through several characteristics such as the loss of teeth, shrinkage of the gonads out of mating season, and fusion of bones. Teeth were replaced by a lightweight bill made of keratin, the food being processed by the bird's gizzard. Other advanced physical characteristics evolved for flight are a keel for the attachment of flight muscles and an enlarged cerebellum for fine motor coordination. These were gradual changes, though, and not strict conditions for flight: the first birds had teeth, at best a small keel
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Bird flight is the primary mode of locomotion used by most bird species in which birds take off and fly. Flight assists birds with feeding, breeding, avoiding predators, and migrating.
Bird flight is one of the most complex forms of locomotion in the animal kingdom. Each facet of this type of motion, including hovering, taking off, and landing, involves many complex movements. As different bird species adapted over millions of years through evolution for specific environments, prey, predators, and other needs, they developed specializations in their wings, and acquired different forms of flight.
Various theories exist about how bird flight evolved, including flight from falling or gliding (the trees down hypothesis), from running or leaping (the ground up hypothesis), from wing-assisted incline running or from proavis (pouncing) behavior.
Basic mechanics of bird flight
Lift, drag and thrust
The fundamentals of bird flight are similar to those of aircraft, in which the aerodynamic forces sustaining flight are lift, drag, and thrust. Lift force is produced by the action of air flow on the wing, which is an airfoil. The airfoil is shaped such that the air provides a net upward force on the wing, while the movement of air is directed downward. Additional net lift may come from airflow around the bird's body in some species, especially during intermittent flight while the wings are folded or semi-folded (cf. lifting body).
Aerodynamic drag is the force opposite to the direction of motion, and hence the source of energy loss in flight. The drag force can be separated into two portions, lift-induced drag, which is the inherent cost of the wing producing lift (this energy ends up primarily in the wingtip vortices), and parasitic drag, including skin friction drag from the friction of air and body surfaces and form drag from the bird's frontal area. The streamlining of bird's body and wings reduces these forces. Unlike aircraft, which have engines to produce thrust, bi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which characteristic of a bird most likely aids in obtaining food found in small places?
A. webbed feet
B. large body
C. soft feathers
D. skinny beak
Answer:
|
|
sciq-3271
|
multiple_choice
|
What element is released into the atmosphere by the burning of fossil fuels?
|
[
"oxygen",
"carbon",
"helium",
"sulfur"
] |
D
|
Relavent Documents:
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Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities (vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
The sources of volcanic gases on Earth include:
primordial and recycled constituents from the Earth's mantle,
assimilated constituents from the Earth's crust,
groundwater and the Earth's atmosphere.
Substances that may become gaseous or give off gases when heated are termed volatile substances.
Composition
The principal components of volcanic gases are water vapor (H2O), carbon dioxide (CO2), sulfur either as sulfur dioxide (SO2) (high-temperature volcanic gases) or hydrogen sulfide (H2S) (low-temperature volcanic gases), nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen (meteoric), hydrogen chloride, hydrogen fluoride, hydrogen bromide, sulfur hexafluoride, carbonyl sulfide, and organic compounds. Exotic trace compounds include mercury, halocarbons (including CFCs), and halogen oxide radicals.
The abundance of gases varies considerably from volcano to volcano, with volcanic activity and with tectonic setting. Water vapour is consistently the most abundant volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions.
Volcanoes located at convergent plate boundaries emit more water vapor and chlorine than volcanoes at hot spots or divergent plate boundaries. This is caused by the addition of seawater into magmas formed at subduction zones. Convergent plate boundary volcanoes also have higher H2O/H2, H2O/CO2, CO2/He and N2/He ratios than hot spot or divergent plate boundary volcanoes.
Magmatic gases and high-temperature volcanic gases
Magma contains dissolved volatile componen
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Carbon is a primary component of all known life on Earth, representing approximately 45–50% of all dry biomass. Carbon compounds occur naturally in great abundance on Earth. Complex biological molecules consist of carbon atoms bonded with other elements, especially oxygen and hydrogen and frequently also nitrogen, phosphorus, and sulfur (collectively known as CHNOPS).
Because it is lightweight and relatively small in size, carbon molecules are easy for enzymes to manipulate. It is frequently assumed in astrobiology that if life exists elsewhere in the Universe, it will also be carbon-based. Critics refer to this assumption as carbon chauvinism.
Characteristics
Carbon is capable of forming a vast number of compounds, more than any other element, with almost ten million compounds described to date, and yet that number is but a fraction of the number of theoretically possible compounds under standard conditions. The enormous diversity of carbon-containing compounds, known as organic compounds, has led to a distinction between them and compounds that do not contain carbon, known as inorganic compounds. The branch of chemistry that studies organic compounds is known as organic chemistry.
Carbon is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass, after hydrogen, helium, and oxygen. Carbon's widespread abundance, its ability to form stable bonds with numerous other elements, and its unusual ability to form polymers at the temperatures commonly encountered on Earth enables it to serve as a common element of all known living organisms. In a 2018 study, carbon was found to compose approximately 550 billion tons of all life on Earth. It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.
The most important characteristics of carbon as a basis for the chemistry of life are that each carbon atom is capable of forming up to four valence bonds with other atoms simultaneously
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Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (), which causes ocean acidification as atmospheric levels increase.
It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.025%. Burning fossil fuels is the primary cause of these increased concentrations and also the primary cause of climate change.
Its concentration in Earth's pre-industrial atmosphere since late in the Precambrian was regulated by organisms and geological phenomena. Plants, algae and cyanobacteria use energy from sunlight to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis, which produces oxygen as a waste product. In turn, oxygen is consumed and is released as waste by all aerobic organisms when they metabolize organic compounds to produce energy by respiration. is released from organic materials when they decay or combust, such as in forest fires. Since plants require for photosynthesis, and humans and animals depend on plants for food, is necessary for the survival of life on earth.
Carbon dioxide is 53% more dense than dry air, but is long lived and thoroughly mixes in the atmosphere. About half of excess emissions to the atmosphere are absorbed by land and ocean carbon sinks. These sinks can become saturated and are volatile, as decay and wildfires result i
Document 3:::
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules.
The atmosphere of Earth is composed of nitrogen (78 %), oxygen (21 %), argon (0.9 %), carbon dioxide (0.04 %) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, solar wind, and cosmic rays to protect organisms from genetic damage. The current composition of the atmosphere of the Earth is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.
Composition
The initial gaseous composition of an atmosphere is determined by the chemistry and temperature of the local solar nebula from which a planet is formed, and the subsequent escape of some gases from the interior of the atmosphere proper. The original atmosphere of the planets originated from a rotating disc of gases, which collapsed onto itself and then divided into a series of spaced rings of gas and matter that, which later condensed to form the planets of the Solar System. The atmospheres of the planets Venus and Mars are principally composed of carbon dioxide and nitrogen, argon and oxygen.
The composition of Earth's atmosphere is determined by the by-products of the life that it sustains. Dry air (mixture of gases) from Earth's atmosphere contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and traces of hydrogen,
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What element is released into the atmosphere by the burning of fossil fuels?
A. oxygen
B. carbon
C. helium
D. sulfur
Answer:
|
|
sciq-2578
|
multiple_choice
|
What part of a spider is equipped with poison glands?
|
[
"vacuole",
"baleen",
"pedipalps",
"chelicerae"
] |
D
|
Relavent Documents:
Document 0:::
Spider behavior refers to the range of behaviors and activities performed by spiders. Spiders are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms which is reflected in their large diversity of behavior.
Diet
Almost all known spider species are predators, mostly preying on insects and on other spiders, although a few species also take vertebrates such as frogs, lizards, fish, and even birds and bats. Spiders' guts are too narrow to take solids, and they liquidize their food by flooding it with digestive enzymes and grinding it with the bases of their pedipalps, as they do not have true jaws.
Though most known spiders are almost exclusively carnivorous, a few species, primarily of jumping spiders, supplement their diet with plant matter such as sap, nectar, and pollen. However, most of these spiders still need a mostly carnivorous diet to survive, and lab studies have shown that they become unhealthy when fed only plants. One exception is a species of jumping spider called Bagheera kiplingi, which is largely herbivorous, feeding mainly on the sugar rich Beltian bodies produced by acacia plants.
Capturing prey
Many spiders, but not all, build webs. Other spiders use a wide variety of methods to capture prey.
Web: There are several recognised types of spider web
Spiral orb webs, associated primarily with the family Araneidae
Tangle webs or cobwebs, associated with the family Theridiidae
Funnel webs,
Tubular webs, which run up the bases of trees or along the ground
Sheet webs
The net-casting spider weaves a small net which it attaches to its front legs. It then lurks in wait for potential prey and when such prey arrives, lunges forward to wrap its victim in the net, bite and paralyze it. Hence, this spider expends less energy catching prey than a primitive hunter and also avoids the energy loss of
Document 1:::
This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids.
Links within the glossary are shown .
Terms
A
Abdomen or opisthosoma: One of the two main body parts (tagmata), located towards the posterior end; see also Abdomen § Other animals
Accessory claw: Modified at the tip of the in web-building spiders; used with to grip strands of the web
Anal tubercle: A small protuberance (tubercule) above the through which the anus opens
Apodeme: see
Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male : see
Atrium (plural atria): An internal chamber at the entrance to the in female haplogyne spiders
B
Bidentate: Having two
Book lungs: Respiratory organs on the ventral side (underside) of the , in front of the , opening through narrow slits; see also Book lungs
Branchial operculum: see
Bulbus: see
C
Calamistrum (plural calamistra): Modified setae (bristles) on the of the fourth leg of spiders with a , arranged in one or more rows or in an oval shape, used to comb silk produced by the cribellum; see also Calamistrum
Caput (plural capita): see
Carapace: A hardened plate (sclerite) covering the upper (dorsal) portion of the ; see also Carapace
Carpoblem: The principal on the male ; also just called the tibial apophysis
Cephalic region or caput: The front part of the , separated from the thoracic region by the
Cephalothorax or prosoma: One of the two main body parts (tagmata), located towards the anterior end, composed of the head ( or caput) and the thorax (thoracic region), the two regions being separated by the ; covered by the and bearing the , legs, and mouthparts
Cervical groove: A shallow U-shaped groove, separating the and thoracic regions of the
Chelate: A description of a where the closes against a tooth-like process
Chelic
Document 2:::
Spider silk is a protein fibre or silk spun by spiders. Spiders use silk to make webs or other structures that function as adhesive traps to catch prey, to entangle and restrain prey before biting, to transmit tactile information, or as nests or cocoons to protect their offspring. They can also use the silk to suspend themselves from height, to float through the air, or to glide away from predators. Most spiders vary the thickness and adhesiveness of their silk for different uses.
In some cases, spiders may even use silk as a source of food. While methods have been developed to collect silk from a spider by force, it is difficult to gather silk from many spiders compared to silk-spinning organisms such as silkworms.
All spiders produce silk, and even in non-web-building spiders, silk is intimately tied to courtship and mating. Silk produced by females provides a transmission channel for male vibratory courtship signals, while webs and draglines provide a substrate for female sex pheromones. Observations of male spiders producing silk during sexual interactions are also common across phylogenetically widespread taxa. However, the function of male-produced silk in mating has received very little study.
Properties
Structural
Silks, like many other biomaterials, have a hierarchical structure. The primary structure is the amino acid sequence of its proteins (spidroin), mainly consisting of highly repetitive glycine and alanine blocks, which is why silks are often referred to as a block co-polymer. On a secondary structure level, the short side chained alanine is mainly found in the crystalline domains (beta sheets) of the nanofibril, glycine is mostly found in the so-called amorphous matrix consisting of helical and beta turn structures. It is the interplay between the hard crystalline segments, and the strained elastic semi-amorphous regions, that gives spider silk its extraordinary properties. Various compounds other than protein are used to enhance the fibre's pr
Document 3:::
The pathophysiology of a spider bite is due to the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites inject venom – a dry bite, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. Some spider bites do leave a large enough wound that infection may be a concern. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider will typically inject when biting.
Only a small percentage of species have bites that pose a danger to people. Many spiders do not have mouthparts capable of penetrating human skin. While venoms are by definition toxic substances, most spiders do not have venom that is toxic to humans (in the quantities delivered) to require medical attention. Of those that do, fatal outcomes are exceedingly rare.
Spider venoms work on one of two fundamental principles; they are either neurotoxic (impairing the nervous system) or necrotic (dissolving tissues surrounding the bite). In some cases, the venom targets vital organs and systems.
Neurotoxic venom
Spiders paralyze prey with neurotoxic venom of some sort. A few have a venom that cross reacts with mammalian nervous system, though the specific manner in which the nervous system is attacked varies from spider to spider. When motor neurons are excited the symptoms include muscle spasms, cramps, and twitching. When autonomic nerves are involved sweating, drooling, gooseflesh. In the extreme unstable blood pressure and heart rate can result.
Widow spider venom contains components known as latrotoxins, which cause the massive release of the neurotransmitters causing muscle contractions, sweating, and gooseflesh. This can affect the body in several ways, including causing painful
Document 4:::
Venom optimization hypothesis, also known as venom metering, is a biological hypothesis which postulates that venomous animals have physiological control over their production and use of venoms. It explains the economic use of venom because venom is a metabolically expensive product, and that there is a biological mechanism for controlling their specific use. The hypothetical concept was proposed by Esther Wigger, Lucia Kuhn-Nentwig, and Wolfgang Nentwig of the Zoological Institute at the University of Bern, Switzerland, in 2002.
A number of venomous animals have been experimentally found to regulate the amount of venom they use during predation or defensive situations. Species of anemones, jellyfish, ants, scorpions, spiders, and snakes are found to use their venoms frugally depending on the situation and size of their preys or predators.
Development
Venom optimization hypothesis was postulated by Wigger, Kuhn-Nentwig, and Nentwig from their studies of the amount of venom used by a wandering spider Cupiennius salei. This spider produces a neurotoxic peptide called CsTx-1 for paralysing its prey. It does not weave webs for trapping preys, and therefore, entirely depends on its venom for predation. It is known to prey on a variety of insects including butterflies, moths, earwigs, cockroaches, flies and grasshoppers. Its venom glands store only about 10 μl of crude venom. Refilling of the glands takes 2–3 days and the lethal efficacy of the venom is, initially, very low for several days, requiring 8 to 18 days for full effect. It was found that the amount of venom released differed for each specific prey. For example, for bigger and stronger insects like beetles, the spider uses the entire amount of its venom; while for small ones, it uses only a small amount, thus economizing its costly venom. In fact, experiments show that the amount of venom released is just sufficient (at the lethal dose) to paralyze the target organism depending on the size or strength, and is
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What part of a spider is equipped with poison glands?
A. vacuole
B. baleen
C. pedipalps
D. chelicerae
Answer:
|
|
sciq-7143
|
multiple_choice
|
What makes the halogen group so diverse?
|
[
"three different states of matter",
"bonds easily",
"a single state of matter",
"contains alloys"
] |
A
|
Relavent Documents:
Document 0:::
In chemistry, a halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. Like a hydrogen bond, the result is not a formal chemical bond, but rather a strong electrostatic attraction. Mathematically, the interaction can be decomposed in two terms: one describing an electrostatic, orbital-mixing charge-transfer and another describing electron-cloud dispersion. Halogen bonds find application in supramolecular chemistry; drug design and biochemistry; crystal engineering and liquid crystals; and organic catalysis.
Definition
Halogen bonds occur when a halogen atom is electrostatically attracted to a partial negative charge. Necessarily, the atom must be covalently bonded in an antipodal σ-bond; the electron concentration associated with that bond leaves a positively charged "hole" on the other side. Although all halogens can theoretically participate in halogen bonds, the σ-hole shrinks if the electron cloud in question polarizes poorly or the halogen is so electronegative as to polarize the associated σ-bond. Consequently halogen-bond propensity follows the trend F < Cl < Br < I.
There is no clear distinction between halogen bonds and expanded octet partial bonds; what is superficially a halogen bond may well turn out to be a full bond in an unexpectedly relevant resonance structure.
Donor characteristics
A halogen bond is almost collinear with the halogen atom's other, conventional bond, but the geometry of the electron-charge donor may be much more complex.
Multi-electron donors such as ethers and amines prefer halogen bonds collinear with the lone pair and donor nucleus.
Pyridine derivatives tend to donate halogen bonds approximately coplanar with the ring, and the two CN \cdots X angles are about 120°.
Carbonyl, thiocarbonyl-, and selenocarbonyl groups, with a trigonal planar geometry
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:::
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.
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:::
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 makes the halogen group so diverse?
A. three different states of matter
B. bonds easily
C. a single state of matter
D. contains alloys
Answer:
|
|
sciq-8297
|
multiple_choice
|
What does the geiger counter detect?
|
[
"moisture",
"radiation",
"convection",
"vibration"
] |
B
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 2:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 3:::
Geiger counter is a colloquial name for any hand-held radiation measuring device in civil defense, but most civil defense devices were ion-chamber radiological survey meters capable of measuring only high levels of radiation that would be present after a major nuclear event.
Most Geiger and ion-chamber survey meters were issued by governmental civil defense organizations in several countries from the 1950s in the midst of the Cold War in an effort to help prepare citizens for a nuclear attack.
Many of these same instruments are still in use today by some states, Texas amongst them, under the jurisdiction of the Texas Bureau of Radiation Control. They are regularly maintained, calibrated and deployed to fire departments and other emergency services.
US models
CD Counters came in a variety of different models, each with specific capabilities. Each of these models has an analog meter from 1 to 5, with 1/10 tick marks. Thus, at X10, the meter reads from 1 to 50.
CD meters were produced by a number of different firms under contract. Victoreen, Lionel, Electro Neutronics, Nuclear Measurements, Chatham Electronics, International Pump and Machine Works, Universal Atomics, Anton Electronic Laboratories; Landers, Frary, & Clark; El Tronics, Jordan, and Nuclear Chicago are among the many manufacturers contracted.
Regardless of producer, most counters exhibit the same basic physical characteristics, albeit with slight variations between some production runs: a yellow case with black knobs and meter bezels. Most US meters had a "CD" sticker on the side of the case.
True Geiger counters
These are instruments which use the Geiger principle of detection.
Type CD V-700
The CD V-700 is a Geiger counter employing a probe equipped with a Geiger–Müller tube manufactured by several companies under contract to US federal civil defense agencies in the 1950s and 1960s. This unit is quite sensitive and can be used to measure low levels of gamma radiation and detect beta radiation.
Document 4:::
An item bank Or Question Bank is a term for a repository of test items that belong to a testing program, as well as all information pertaining to those items. In most applications of testing and assessment, the items are of multiple choice format, but any format can be used. Items are pulled from the bank and assigned to test forms for publication either as a paper-and-pencil test or some form of e-assessment.
Types of information
An item bank will not only include the text of each item, but also extensive information regarding test development and psychometric characteristics of the items. Examples of such information include:
Item author
Date written
Item status (e.g., new, pilot, active, retired)
Angoff ratings
Correct answer
Item format
Classical test theory statistics
Item response theory statistics
Linkage to test blueprint
Item history (e.g., usage date(s) and reviews)
User-defined fields
In India the Popular Question Bank is Oswaal Question Bank which covers All Indian Board And Competitive Exam Such as CBSE,CISCE,Pre-university course- State board and JEE,NEET,CLAT and CUET
Item banking software
Because an item bank is essentially a simple database, it can be stored in database software or even a spreadsheet such as Microsoft Excel. However, there are several dozen commercially-available software programs specifically designed for item banking. The advantages that these provide are related to assessment. For example, items are presented on the computer screen as they would appear to a test examinee, and item response theory parameters can be translated into item response functions or information functions. Additionally, there are functionalities for publication, such as formatting a set of items to be printed as a paper-and-pencil test.
Some item banks also have test administration functionalities, such as being able to deliver e-assessment or process "bubble" answer sheets.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does the geiger counter detect?
A. moisture
B. radiation
C. convection
D. vibration
Answer:
|
|
sciq-2935
|
multiple_choice
|
What property of certain states of matter can be given in units of millimeters of mercury?
|
[
"velocity",
"gravity",
"pressure",
"solvency"
] |
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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The constants listed here are known values of physical constants expressed in SI units; that is, physical quantities that are generally believed to be universal in nature and thus are independent of the unit system in which they are measured. Many of these are redundant, in the sense that they obey a known relationship with other physical constants and can be determined from them.
Table of physical constants
Uncertainties
While the values of the physical constants are independent of the system of units in use, each uncertainty as stated reflects our lack of knowledge of the corresponding value as expressed in SI units, and is strongly dependent on how those units are defined. For example, the atomic mass constant is exactly known when expressed using the dalton (its value is exactly 1 Da), but the kilogram is not exactly known when using these units, the opposite of when expressing the same quantities using the kilogram.
Technical constants
Some of these constants are of a technical nature and do not give any true physical property, but they are included for convenience. Such a constant gives the correspondence ratio of a technical dimension with its corresponding underlying physical dimension. These include the Boltzmann constant , which gives the correspondence of the dimension temperature to the dimension of energy per degree of freedom, and the Avogadro constant , which gives the correspondence of the dimension of amount of substance with the dimension of count of entities (the latter formally regarded in the SI as being dimensionless). By implication, any product of powers of such constants is also such a constant, such as the molar gas constant .
See also
List of mathematical constants
Physical constant
List of particles
Notes
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This article gives a list of conversion factors for several physical quantities. A number of different units (some only of historical interest) are shown and expressed in terms of the corresponding SI unit.
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10−6 metre). Within each table, the units are listed alphabetically, and the SI units (base or derived) are highlighted.
The following quantities are considered: length, area, volume, plane angle, solid angle, mass, density, time, frequency, velocity, volumetric flow rate, acceleration, force, pressure (or mechanical stress), torque (or moment of force), energy, power (or heat flow rate), action, dynamic viscosity, kinematic viscosity, electric current, electric charge, electric dipole, electromotive force (or electric potential difference), electrical resistance, capacitance, magnetic flux, magnetic flux density, inductance, temperature, information entropy, luminous intensity, luminance, luminous flux, illuminance, radiation.
Length
Area
Volume
Plane angle
Solid angle
Mass
Notes:
See Weight for detail of mass/weight distinction and conversion.
Avoirdupois is a system of mass based on a pound of 16 ounces, while Troy weight is the system of mass where 12 troy ounces equals one troy pound.
The symbol is used to denote standard gravity in order to avoid confusion with the (upright) g symbol for gram.
Density
Time
Frequency
Speed or velocity
A velocity consists of a speed combined with a direction; the speed part of the velocity takes units of speed.
Flow (volume)
Acceleration
Force
Pressure or mechanical stress
Torque or moment of force
Energy
Power or heat flow rate
Action
Dynamic viscosity
Kinematic viscosity
Electric current
Electric charge
Electric dipole
Elec
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Metrologia is a bimonthly journal dealing with the scientific aspects of metrology. It has been running since 1965 and has been published by the International Bureau of Weights and Measures since 1991. Since 2003 the journal has been published by IOP Publishing on behalf of the bureau. The journal covers the fundamentals of measurements, in particular those dealing with the seven base units of the International System of Units (metre, kilogram, second, ampere, kelvin, candela, mole) or proposals to replace them.
The editors-in-chief are Sten Bergstrand (RISE Research Institutes of Sweden) and Janet Miles (International Bureau of Weights and Measures).
Abstracting and indexing
This journal is indexed by the following databases:
Science Citation Index Expanded
Scopus
Inspec
Chemical Abstracts Service
Compendex
GeoRef
MathSciNet
Astrophysics Data System
VINITI Abstracts Journal
External links
Physics journals
IOP Publishing academic journals
Academic journals established in 1962
English-language journals
Metrology
Bimonthly journals
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Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L (pronounced "osmolar"), in the same way that the molarity of a solution is expressed as "M" (pronounced "molar"). Whereas molarity measures the number of moles of solute per unit volume of solution, osmolarity measures the number of osmoles of solute particles per unit volume of solution. This value allows the measurement of the osmotic pressure of a solution and the determination of how the solvent will diffuse across a semipermeable membrane (osmosis) separating two solutions of different osmotic concentration.
Unit
The unit of osmotic concentration is the osmole. This is a non-SI unit of measurement that defines the number of moles of solute that contribute to the osmotic pressure of a solution. A milliosmole (mOsm) is 1/1,000 of an osmole. A microosmole (μOsm) (also spelled micro-osmole) is 1/1,000,000 of an osmole.
Types of solutes
Osmolarity is distinct from molarity because it measures osmoles of solute particles rather than moles of solute. The distinction arises because some compounds can dissociate in solution, whereas others cannot.
Ionic compounds, such as salts, can dissociate in solution into their constituent ions, so there is not a one-to-one relationship between the molarity and the osmolarity of a solution. For example, sodium chloride (NaCl) dissociates into Na+ and Cl− ions. Thus, for every 1 mole of NaCl in solution, there are 2 osmoles of solute particles (i.e., a 1 mol/L NaCl solution is a 2 osmol/L NaCl solution). Both sodium and chloride ions affect the osmotic pressure of the solution.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What property of certain states of matter can be given in units of millimeters of mercury?
A. velocity
B. gravity
C. pressure
D. solvency
Answer:
|
|
sciq-2700
|
multiple_choice
|
When your body digests food, it breaks down the molecules of nutrients and releases what?
|
[
"waste materials",
"energy",
"gas",
"calories"
] |
B
|
Relavent Documents:
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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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Animal nutrition focuses on the dietary nutrients needs of animals, primarily those in agriculture and food production, but also in zoos, aquariums, and wildlife management.
Constituents of diet
Macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and lipids from which cell membranes and some signaling molecules are built) and energy. Some of the structural material can be used to generate energy internally, though the net energy depends on such factors as absorption and digestive effort, which vary substantially from instance to instance. Vitamins, minerals, fiber, and water do not provide energy, but are required for other reasons. A third class dietary material, fiber (i.e., non-digestible material such as cellulose), seems also to be required, for both mechanical and biochemical reasons, though the exact reasons remain unclear.
Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple monosaccharides (glucose, fructose, galactose) to complex polysaccharides (starch). Fats are triglycerides, made of assorted fatty acid monomers bound to glycerol backbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body. Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are nitrogen-containing amino acids. Essential amino acids cannot be made by the animal. Some of the amino acids are convertible (with the expenditure of energy) to glucose and can be used for energy production just as ordinary glucose. By breaking down existing protein, some glucose can be produced internally; the remaining amino acids are discarded, primarily as urea in urine. This occurs normally only during prolonged starvation.
Other dietary substances found in plant foods (phytochemicals, polyphenols) are not identified as essential nutrients but appear to impact healt
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Relatively speaking, the brain consumes an immense amount of energy in comparison to the rest of the body. The mechanisms involved in the transfer of energy from foods to neurons are likely to be fundamental to the control of brain function. Human bodily processes, including the brain, all require both macronutrients, as well as micronutrients.
Insufficient intake of selected vitamins, or certain metabolic disorders, may affect cognitive processes by disrupting the nutrient-dependent processes within the body that are associated with the management of energy in neurons, which can subsequently affect synaptic plasticity, or the ability to encode new memories.
Macronutrients
The human brain requires nutrients obtained from the diet to develop and sustain its physical structure and cognitive functions. Additionally, the brain requires caloric energy predominately derived from the primary macronutrients to operate. The three primary macronutrients include carbohydrates, proteins, and fats. Each macronutrient can impact cognition through multiple mechanisms, including glucose and insulin metabolism, neurotransmitter actions, oxidative stress and inflammation, and the gut-brain axis. Inadequate macronutrient consumption or proportion could impair optimal cognitive functioning and have long-term health implications.
Carbohydrates
Through digestion, dietary carbohydrates are broken down and converted into glucose, which is the sole energy source for the brain. Optimal brain function relies on adequate carbohydrate consumption, as carbohydrates provide the quickest source of glucose for the brain. Glucose deficiencies such as hypoglycaemia reduce available energy for the brain and impair all cognitive processes and performance. Additionally, situations with high cognitive demand, such as learning a new task, increase brain glucose utilization, depleting blood glucose stores and initiating the need for supplementation.
Complex carbohydrates, especially those with high d
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An energy budget is a balance sheet of energy income against expenditure. It is studied in the field of Energetics which deals with the study of energy transfer and transformation from one form to another. Calorie is the basic unit of measurement. An organism in a laboratory experiment is an open thermodynamic system, exchanging energy with its surroundings in three ways - heat, work and the potential energy of biochemical compounds.
Organisms use ingested food resources (C=consumption) as building blocks in the synthesis of tissues (P=production) and as fuel in the metabolic process that power this synthesis and other physiological processes (R=respiratory loss). Some of the resources are lost as waste products (F=faecal loss, U=urinary loss). All these aspects of metabolism can be represented in energy units. The basic model of energy budget may be shown as:
P = C - R - U - F or
P = C - (R + U + F) or
C = P + R + U + F
All the aspects of metabolism can be represented in energy units (e.g. joules (J);1 calorie = 4.2 kJ).
Energy used for metabolism will be
R = C - (F + U + P)
Energy used in the maintenance will be
R + F + U = C - P
Endothermy and ectothermy
Energy budget allocation varies for endotherms and ectotherms. Ectotherms rely on the environment as a heat source while endotherms maintain their body temperature through the regulation of metabolic processes. The heat produced in association with metabolic processes facilitates the active lifestyles of endotherms and their ability to travel far distances over a range of temperatures in the search for food. Ectotherms are limited by the ambient temperature of the environment around them but the lack of substantial metabolic heat production accounts for an energetically inexpensive metabolic rate. The energy demands for ectotherms are generally one tenth of that required for endotherms.
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Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and good health. Poor nutrition is a chronic problem often linked to poverty, food security, or a poor understanding of nutritional requirements. Malnutrition and its consequences are large contributors to deaths, physical deformities, and disabilities worldwide. Good nutrition is necessary for children to grow physically and mentally, and for normal human biological development.
Overview
The human body contains chemical compounds such as water, carbohydrates, amino acids (found in proteins), fatty acids (found in lipids), and nucleic acids (DNA and RNA). These compounds are composed of elements such as carbon, hydrogen, oxygen, nitrogen, and phosphorus. Any study done to determine nutritional status must take into account the state of the body before and after experiments, as well as the chemical composition of the whole diet and of all the materials excreted and eliminated from the body (including urine and feces).
Nutrients
The seven major classes of nutrients are carbohydrates, fats, fiber, minerals, proteins, vitamins, and water. Nutrients can be grouped as either macronutrients or micronutrients (needed in small quantities). Carbohydrates, fats, and proteins are macronutrients, and provide energy. Water and fiber are macronutrients but do not provide energy. The micronutrients are minerals and vitamins.
The macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and lipids from which cell membranes and some signaling molecules are built), and energy. Some of the structural material can also be used to generate energy internally, and in either case it is measured in Joules or kilocalories (often called "Calories" and written with a capital 'C' to distinguish them from little 'c' calories). Carbohydrates and proteins provide 17 kJ approximately (4 kcal) of energy per gram, while fats prov
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When your body digests food, it breaks down the molecules of nutrients and releases what?
A. waste materials
B. energy
C. gas
D. calories
Answer:
|
|
scienceQA-6471
|
multiple_choice
|
Select the mammal below.
|
[
"kangaroo",
"loon",
"great crested newt",
"poison dart frog"
] |
A
|
A kangaroo is a mammal. It has fur and feeds its young milk.
Kangaroos hop to move around. They use their large tails for balance while hopping.
A loon is a bird. It has feathers, two wings, and a beak.
Loons usually live near lakes. They dive in the water to hunt for food.
A great crested newt is an amphibian. It has moist skin and begins its life in water.
Some newts live in water. Other newts live on land but lay their eggs in water.
A poison dart frog is an amphibian. It has moist skin and begins its life in water.
Poison dart frogs come in many bright colors. Their bright color warns other animals that these frogs are poisonous.
|
Relavent Documents:
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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 1:::
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 2:::
Kangaroos, Wallabies and other Macropodidae have become emblems and symbols of Australia, as well as appearing in popular culture both internationally and within Australia itself.
Kangaroos are part of cultural and spiritual significance for many Indigenous Australians. Since its European discovery, Kangaroos have since become an emblem of Australia, appearing in their coat of arms and in many state and city coat of arms, Australian logos such as the Qantas logo, names of Australian sport teams, mascots such as the Boxing Kangaroo and in public art. Kangaroos are also well represented in film, television, songs, toys and souvenirs around the world.
European first encounters
The kangaroo was considered a unique oddity when Captain Cook's HMB Endeavour arrived back in England in 1771 with a specimen on board. Over time it has come to symbolise Australia and Australian values.
Joseph Banks, the naturalist on the Endeavour voyage, commissioned George Stubbs to paint a portrait of the kangaroo specimen. When the official account of the voyage was published in 1773, it was illustrated with an engraving of Stubbs' kangaroo. From that time on, the kangaroo quickly came to symbolise the Australian continent, appearing in exhibitions, collections, art and printed works across Europe.
Kangaroo status
It took a long time for the kangaroo to achieve official recognition in Australia. Despite being a "declared noxious animal" because of its reputation for damaging crops and fences and competing with domestic animals for resources, the kangaroo finally achieved official recognition with its inclusion on Australia's coat of arms in 1908. The kangaroo is now popularly regarded as Australia's unofficial animal emblem.
Kangaroo emblems and logos
The kangaroo and emu are bearers on the Australian Coat of Arms. It has been claimed these animals were chosen to signify a country moving 'forward' because of a common belief that neither can move backward.
Two red kangaroos serve as
Document 3:::
Where Do Camels Belong? is a book by biologist Ken Thompson.
The book examines the science and history of invasive species. The book describes itself as 'an examination of the whole question of native and alien species, and what might be called an alien invasions industry - and its implications'.
The title of the book is in reference to a question posed on its first page, questioning the reader as to 'where camels belong?' as a native species; while pointing out that whilst most associated with the Middle East, camels actually first evolved in North America, are most diverse in South America, and have their only truly wild extant population in Australia.
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The following is a list of megafauna discovered by science since the beginning of the 19th century (with their respective date of discovery). Some of these may have been known to native peoples or reported anecdotally but had not been generally acknowledged as confirmed by the scientific world, until conclusive evidence was obtained for formal studies. In other cases, certain animals were initially considered hoaxes – similar to the initial reception of mounted specimens of the duck-billed platypus (Ornithorhynchus anatinus) in late 18th-century Europe.
The definition of megafauna varies, but this list includes some of the more notable examples.
Megafauna believed extinct, but rediscovered
Burchell's zebra (Equus quagga burchellii), 2004
Megafauna previously unknown from the fossil record
Western grey kangaroo Notamacropus fuliginosus (1817)
Malayan tapir Tapirus indicus (1819)
Red kangaroo Osphranter rufus (1822)
Lowland anoa Bubalus depressicornis (1827)
Mountain tapir Tapirus pinchaque (1829)
Baird's tapir Tapirus bairdii (1865)
Bonobo Pan paniscus (1928)
Kouprey Bos sauveli (1937)
Saola Pseudoryx nghetinhensis (1993)
Megafauna initially believed to have been fictitious or hoaxes
Przewalski's horse Equus ferus przewalskii (1881 - current wild population descended from zoo breeding since 1945)
Okapi Okapia johnstoni (1901)
See also
Mammalia
List of mammals described in the 2000s
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the mammal below.
A. kangaroo
B. loon
C. great crested newt
D. poison dart frog
Answer:
|
sciq-8202
|
multiple_choice
|
Gametes are products through meiosis in which organs?
|
[
"gonads",
"cones",
"hormones",
"kidneys"
] |
A
|
Relavent Documents:
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Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes, or by mitosis. For example, plants produce gametes through mitosis in gametophytes. The gametophytes grow from haploid spores after sporic meiosis. The existence of a multicellular, haploid phase in the life cycle between meiosis and gametogenesis is also referred to as alternation of generations.
It is the biological process of gametogenesis; cells that are haploid or diploid divide to create other cells. matured haploid gametes. It can take place either through mitosis or meiotic division of diploid gametocytes into different depending on an organism's biological life cycle, gametes. For instance, gametophytes in plants undergo mitosis to produce gametes. Both male and female have different forms.
In animals
Animals produce gametes directly through meiosis from diploid mother cells in organs called gonads (testis in males and ovaries in females). In mammalian germ cell development, sexually dimorphic gametes differentiates into primordial germ cells from pluripotent cells during initial mammalian development. Males and females of a species that reproduce sexually have different forms of gametogenesis:
spermatogenesis (male): Immature germ cells are produced in a man's testes. To mature into sperms, males' immature germ cells, or spermatogonia, go through spermatogenesis during adolescence. Spermatogonia are diploid cells that become larger as they divide through mitosis. These primary spermatocytes. These diploid cells undergo meiotic division to create secondary spermatocytes. These secondary spermatocytes undergo a second meiotic division to produce immature sperms or spermatids. These spermatids undergo spermiogenesis in order to develop into sperm. LH, FSH, GnRH
Document 1:::
Microgametogenesis is the process in plant reproduction where a microgametophyte develops in a pollen grain to the three-celled stage of its development. In flowering plants it occurs with a microspore mother cell inside the anther of the plant.
When the microgametophyte is first formed inside the pollen grain four sets of fertile cells called sporogenous cells are apparent. These cells are surrounded by a wall of sterile cells called the tapetum, which supplies food to the cell and eventually becomes the cell wall for the pollen grain. These sets of sporogenous cells eventually develop into diploid microspore mother cells. These microspore mother cells, also called microsporocytes, then undergo meiosis and become four microspore haploid cells. These new microspore cells then undergo mitosis and form a tube cell and a generative cell. The generative cell then undergoes mitosis one more time to form two male gametes, also called sperm.
See also
Gametogenesis
Document 2:::
Reproductive biology includes both sexual and asexual reproduction.
Reproductive biology includes a wide number of fields:
Reproductive systems
Endocrinology
Sexual development (Puberty)
Sexual maturity
Reproduction
Fertility
Human reproductive biology
Endocrinology
Human reproductive biology is primarily controlled through hormones, which send signals to the human reproductive structures to influence growth and maturation. These hormones are secreted by endocrine glands, and spread to different tissues in the human body. In humans, the pituitary gland synthesizes hormones used to control the activity of endocrine glands.
Reproductive systems
Internal and external organs are included in the reproductive system. There are two reproductive systems including the male and female, which contain different organs from one another. These systems work together in order to produce offspring.
Female reproductive system
The female reproductive system includes the structures involved in ovulation, fertilization, development of an embryo, and birth.
These structures include:
Ovaries
Oviducts
Uterus
Vagina
Mammary Glands
Estrogen is one of the sexual reproductive hormones that aid in the sexual reproductive system of the female.
Male reproductive system
The male reproductive system includes testes, rete testis, efferent ductules, epididymis, sex accessory glands, sex accessory ducts and external genitalia.
Testosterone, an androgen, although present in both males and females, is relatively more abundant in males. Testosterone serves as one of the major sexual reproductive hormones in the male reproductive system However, the enzyme aromatase is present in testes and capable of synthesizing estrogens from androgens. Estrogens are present in high concentrations in luminal fluids of the male reproductive tract. Androgen and estrogen receptors are abundant in epithelial cells of the male reproductive tract.
Animal Reproductive Biology
Animal reproduction oc
Document 3:::
Germ-Soma Differentiation is the process by which organisms develop distinct germline and somatic cells. The development of cell differentiation has been one of the critical aspects of the evolution of multicellularity and sexual reproduction in organisms. Multicellularity has evolved upwards of 25 times, and due to this there is great possibility that multiple factors have shaped the differentiation of cells. There are three general types of cells: germ cells, somatic cells, and stem cells. Germ cells lead to the production of gametes, while somatic cells perform all other functions within the body. Within the broad category of somatic cells, there is further specialization as cells become specified to certain tissues and functions. In addition, stem cell are undifferentiated cells which can develop into a specialized cell and are the earliest type of cell in a cell lineage. Due to the differentiation in function, somatic cells are found ony in multicellular organisms, as in unicellular ones the purposes of somatic and germ cells are consolidated in one cell.
All organisms with germ-soma differentiation are eukaryotic, and represent an added level of specialization to multicellular organisms. Pure germ-soma differentiation has developed in a select number of eukaryotes (called Weismannists), included in this category are vertebrates and arthropods- however land plants, green algae, red algae, brown algae, and fungi have partial differentiation. While a significant portion of organisms with germ-soma differentiation are asexual, this distinction has been imperative in the development of sexual reproduction; the specialization of certain cells into germ cells is fundamental for meiosis and recombination.
Weismann barrier
The strict division between somatic and germ cells is called the Weismann barrier, in which genetic information passed onto offspring is found only in germ cells. This occurs only in select organisms, however some without a Weismann barrier do pre
Document 4:::
In cellular biology, a somatic cell (), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Somatic cells compose the body of an organism and divide through the process of binary fission and mitotic division.
In contrast, gametes are cells that fuse during sexual reproduction and germ cells are cells that give rise to gametes. Stem cells also can divide through mitosis, but are different from somatic in that they differentiate into diverse specialized cell types.
In mammals, somatic cells make up all the internal organs, skin, bones, blood and connective tissue, while mammalian germ cells give rise to spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, which divides and differentiates into the cells of an embryo. There are approximately 220 types of somatic cell in the human body.
Theoretically, these cells are not germ cells (the source of gametes); they transmit their mutations, to their cellular descendants (if they have any), but not to the organism's descendants. However, in sponges, non-differentiated somatic cells form the germ line and, in Cnidaria, differentiated somatic cells are the source of the germline. Mitotic cell division is only seen in diploid somatic cells. Only some cells like germ cells take part in reproduction.
Evolution
As multicellularity was theorized to be evolved many times, so did sterile somatic cells. The evolution of an immortal germline producing specialized somatic cells involved the emergence of mortality, and can be viewed in its simplest version in volvocine algae. Those species with a separation between sterile somatic cells and a germline are called Weismannists. Weismannist development is relatively rare (e.g., vertebrates, arthropods, Volvox), as many species have the capacity for somatic embryogenesis (e.g., land plants, most algae, and numerous invertebrates).
Genetics and chrom
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Gametes are products through meiosis in which organs?
A. gonads
B. cones
C. hormones
D. kidneys
Answer:
|
|
sciq-486
|
multiple_choice
|
How many different types of stresses are there?
|
[
"five",
"seven",
"three",
"four"
] |
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:::
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 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:::
Progress tests are longitudinal, feedback oriented educational assessment tools for the evaluation of development and sustainability of cognitive knowledge during a learning process. A progress test is a written knowledge exam (usually involving multiple choice questions) that is usually administered to all students in the "A" program at the same time and at regular intervals (usually twice to four times yearly) throughout the entire academic program. The test samples the complete knowledge domain expected of new graduates upon completion of their courses, regardless of the year level of the student). The differences between students’ knowledge levels show in the test scores; the further a student has progressed in the curriculum the higher the scores. As a result, these resultant scores provide a longitudinal, repeated measures, curriculum-independent assessment of the objectives (in knowledge) of the entire programme.
History
Since its inception in the late 1970s at both Maastricht University and the University of Missouri–Kansas City independently, the progress test of applied knowledge has been increasingly used in medical and health sciences programs across the globe. They are well established and increasingly used in medical education in both undergraduate and postgraduate medical education. They are used formatively and summatively.
Use in academic programs
The progress test is currently used by national progress test consortia in the United Kingdom, Italy, The Netherlands, in Germany (including Austria), and in individual schools in Africa, Saudi Arabia, South East Asia, the Caribbean, Australia, New Zealand, Sweden, Finland, UK, and the USA. The National Board of Medical Examiners in the USA also provides progress testing in various countries The feasibility of an international approach to progress testing has been recently acknowledged and was first demonstrated by Albano et al. in 1996, who compared test scores across German, Dutch and Italian medi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How many different types of stresses are there?
A. five
B. seven
C. three
D. four
Answer:
|
|
sciq-9207
|
multiple_choice
|
What term describes scientists who debate the origin of the earliest plants?
|
[
"specialists",
"protobotanists",
"archaebotanists",
"paleobotanists"
] |
D
|
Relavent Documents:
Document 0:::
Ethnobotany is the study of a region's plants and their practical uses through the traditional knowledge of a local culture and people. An ethnobotanist thus strives to document the local customs involving the practical uses of local flora for many aspects of life, such as plants as medicines, foods, intoxicants and clothing. Richard Evans Schultes, often referred to as the "father of ethnobotany", explained the discipline in this way:
Ethnobotany simply means ... investigating plants used by societies in various parts of the world.
Since the time of Schultes, the field of ethnobotany has grown from simply acquiring ethnobotanical knowledge to that of applying it to a modern society, primarily in the form of pharmaceuticals. Intellectual property rights and benefit-sharing arrangements are important issues in ethnobotany.
History
The idea of ethnobotany was first proposed by the early 20th century botanist John William Harshberger. While Harshberger did perform ethnobotanical research extensively, including in areas such as North Africa, Mexico, Scandinavia, and Pennsylvania, it was not until Richard Evans Schultes began his trips into the Amazon that ethnobotany became a more well known science. However, the practice of ethnobotany is thought to have much earlier origins in the first century AD when a Greek physician by the name of Pedanius Dioscorides wrote an extensive botanical text detailing the medical and culinary properties of "over 600 mediterranean plants" named De Materia Medica. Historians note that Dioscorides wrote about traveling often throughout the Roman empire, including regions such as "Greece, Crete, Egypt, and Petra", and in doing so obtained substantial knowledge about the local plants and their useful properties. European botanical knowledge drastically expanded once the New World was discovered due to ethnobotany. This expansion in knowledge can primarily be attributed to the substantial influx of new plants from the Americas, including c
Document 1:::
Plant taxonomy is the science that finds, identifies, describes, classifies, and names plants. It is one of the main branches of taxonomy (the science that finds, describes, classifies, and names living things).
Plant taxonomy is closely allied to plant systematics, and there is no sharp boundary between the two. In practice, "plant systematics" involves relationships between plants and their evolution, especially at the higher levels, whereas "plant taxonomy" deals with the actual handling of plant specimens. The precise relationship between taxonomy and systematics, however, has changed along with the goals and methods employed.
Plant taxonomy is well known for being turbulent, and traditionally not having any close agreement on circumscription and placement of taxa. See the list of systems of plant taxonomy.
Background
Classification systems serve the purpose of grouping organisms by characteristics common to each group. Plants are distinguished from animals by various traits: they have cell walls made of cellulose, polyploidy, and they exhibit sedentary growth. Where animals have to eat organic molecules, plants are able to change energy from light into organic energy by the process of photosynthesis. The basic unit of classification is species, a group able to breed amongst themselves and bearing mutual resemblance, a broader classification is the genus. Several genera make up a family, and several families an order.
History of classification
The botanical term "angiosperm", from Greek words ( 'bottle, vessel') and ( 'seed'), was coined in the form "Angiospermae" by Paul Hermann in 1690 but he used this term to refer to a group of plants which form only a subset of what today are known as angiosperms. Hermannn's Angiospermae including only flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, which were flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded
Document 2:::
The Pollen Analysis Circular was a mimeographed publication that maintained communications among scientists working on either side of the Atlantic Ocean during World War II and aided the early development of the field of palynology. It was initiated by Paul Sears in 1943 and published somewhat regularly until May 1949 (No. 17), by which time scientific meetings had again become feasible. Publication was made possible by contributions and the efforts of many individuals at various institutions. It provided comments and discussion on the field, progress reports on research projects, lists and addresses of researchers in the field, bibliographies, obituaries, and other news items. A final issue, No. 18, was printed in January 1954.
History
The international scientific cooperation on which the field of palynology depended was interrupted by the onset of World War II. The Pollen Analysis Circular was a response to increased handicaps to travel during the late stages of World War II. Because palynology was a well established trans-Atlantic field by the time World War II broke out, workers in the United States, Britain, and Germany in particular, had difficulty maintaining contact with one another. The Pollen Analysis Circular allowed researchers in the United States to maintain contact with one another and maintain publication lists that had, until then, been published by Gunnar Erdtman as "Literature on Pollen Statistics and Related Topics".
The first issue of the Pollen Analysis Circular was dated May 5, 1943 and published by Paul B. Sears (Oberlin College). Subsequent issues were generally edited by Sears, sometimes in cooperation with L.R. Wilson.
In January 1945, the Pollen Analysis Circular was renamed the Pollen and Spore Circular to more accurately reflect its scope. After 1954, the Circular was incorporated into the Micropaleontologist, soon renamed Micropaleontology, published by the American Museum of Natural History. The last issue of the Pollen and Spore C
Document 3:::
Botany is a natural science concerned with the study of plants.The main branches of botany (also referred to as "plant science") are commonly divided into three groups: core topics, concerned with the study of the fundamental natural phenomena and processes of plant life, the classification and description of plant diversity; applied topics which study the ways in which plants may be used for economic benefit in horticulture, agriculture and forestry; and organismic topics which focus on plant groups such as algae, mosses or flowering plants.'''
Core topics
Cytology – cell structure
Epigenetics – Control of gene expression
Paleobotany – Study of fossil plants and plant evolution
Palynology – Pollen and spores
Plant biochemistry – Chemical processes of primary and secondary metabolism
Phenology – the timing of germination, flowering and fruiting
Phytochemistry – Plant secondary chemistry and chemical processes
Phytogeography – Plant Biogeography, the study of plant distributions
Phytosociology – Plant communities and interactions
Plant anatomy – Structure of plant cells and tissues
Plant ecology – Role and function of plants in the environment
Plant evolutionary developmental biology – Plant development from an evolutionary perspective
Plant genetics – Genetic inheritance in plants
Plant morphology – Structure of plants
Plant physiology – Life functions of plants
Plant reproduction – Processes of plant reproduction
Plant systematics – Classification and naming of plants
Plant taxonomy – Classification and naming of plants
Applied topics
Agronomy – Application of plant science to crop production
Arboriculture – Culture and propagation of trees
Astrobotany - The study of plants in space
Biotechnology – Use of plants to synthesize products
Dendrology – Study of woody plants, shrubs, trees and lianas
Economic botany – Study of plants of economic use or value
Ethnobotany – Plants and people. Use and selection of plants by humans
Forestry –
Document 4:::
A plantsman is an enthusiastic and knowledgeable gardener (amateur or professional), nurseryman or nurserywoman. "Plantsman" can refer to a male or female person, though the terms plantswoman, or even plantsperson, are sometimes used. The word is sometimes said to be synonymous with "botanist" or "horticulturist", but that would indicate a professional involvement, whereas "plantsman" reflects an attitude to (and perhaps even an obsession with) plants. A horticulturist may be a plantsman, but a plantsman is not necessarily a horticulturist.
Defining the word
In the first edition (June 1979) of The Plantsman (a specialist magazine, published by the Royal Horticultural Society from 1994 until June 2019, when it was announced that the title would be changed to The Plant Review), Sandra Raphael (then a senior editor in the Dictionary Department of the Oxford University Press) contributed a short article on the history and meaning of the word. Her first example came from an issue of the Gardeners' Chronicle of 1881, when it seemed to mean "A nurseryman, a florist" (in the early sense of "florist" as a grower and breeder of flowers, rather than the more recent meaning of someone who sells or arranges them). She added that a modern definition should point out that "plantsman"
"…is usually intended to mean a connoisseur of plants or an expert gardener."
In her article, Raphael also quotes botanist David McClintock (writing in the Botanical Society of the British Isles' BSBI News, December 1976) on how to distinguish a botanist from a plantsman, beginning with the simple definition:
"A plantsman is one who loves plants for their own sake and knows how to cherish them. This… concept… may include a botanist: it certainly includes a host of admirable amateurs who may not know what a chromosome looks like or what taxonomy means, but they know the growing plant, wild or cultivated, first-hand. To my mind they are the cream of those in the plant world, a fund of invaluable firs
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term describes scientists who debate the origin of the earliest plants?
A. specialists
B. protobotanists
C. archaebotanists
D. paleobotanists
Answer:
|
|
sciq-4647
|
multiple_choice
|
What occurs when waves interact with other waves?
|
[
"interference",
"resurgence",
"vibration",
"frequency"
] |
A
|
Relavent Documents:
Document 0:::
This is a list of wave topics.
0–9
21 cm line
A
Abbe prism
Absorption spectroscopy
Absorption spectrum
Absorption wavemeter
Acoustic wave
Acoustic wave equation
Acoustics
Acousto-optic effect
Acousto-optic modulator
Acousto-optics
Airy disc
Airy wave theory
Alfvén wave
Alpha waves
Amphidromic point
Amplitude
Amplitude modulation
Animal echolocation
Antarctic Circumpolar Wave
Antiphase
Aquamarine Power
Arrayed waveguide grating
Artificial wave
Atmospheric diffraction
Atmospheric wave
Atmospheric waveguide
Atom laser
Atomic clock
Atomic mirror
Audience wave
Autowave
Averaged Lagrangian
B
Babinet's principle
Backward wave oscillator
Bandwidth-limited pulse
beat
Berry phase
Bessel beam
Beta wave
Black hole
Blazar
Bloch's theorem
Blueshift
Boussinesq approximation (water waves)
Bow wave
Bragg diffraction
Bragg's law
Breaking wave
Bremsstrahlung, Electromagnetic radiation
Brillouin scattering
Bullet bow shockwave
Burgers' equation
Business cycle
C
Capillary wave
Carrier wave
Cherenkov radiation
Chirp
Ernst Chladni
Circular polarization
Clapotis
Closed waveguide
Cnoidal wave
Coherence (physics)
Coherence length
Coherence time
Cold wave
Collimated light
Collimator
Compton effect
Comparison of analog and digital recording
Computation of radiowave attenuation in the atmosphere
Continuous phase modulation
Continuous wave
Convective heat transfer
Coriolis frequency
Coronal mass ejection
Cosmic microwave background radiation
Coulomb wave function
Cutoff frequency
Cutoff wavelength
Cymatics
D
Damped wave
Decollimation
Delta wave
Dielectric waveguide
Diffraction
Direction finding
Dispersion (optics)
Dispersion (water waves)
Dispersion relation
Dominant wavelength
Doppler effect
Doppler radar
Douglas Sea Scale
Draupner wave
Droplet-shaped wave
Duhamel's principle
E
E-skip
Earthquake
Echo (phenomenon)
Echo sounding
Echolocation (animal)
Echolocation (human)
Eddy (fluid dynamics)
Edge wave
Eikonal equation
Ekman layer
Ekman spiral
Ekman transport
El Niño–Southern Oscillation
El
Document 1:::
A crest point on a wave is the maximum value of upward displacement within a cycle. A crest is a point on a surface wave where the displacement of the medium is at a maximum. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.
When the crests and troughs of two sine waves of equal amplitude and frequency intersect or collide, while being in phase with each other, the result is called constructive interference and the magnitudes double (above and below the line). When in antiphase – 180° out of phase – the result is destructive interference: the resulting wave is the undisturbed line having zero amplitude.
See also
Crest factor
Superposition principle
Wave
Document 2:::
In physics, a mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves can be produced only in media which possess elasticity and inertia. There are three types of mechanical waves: transverse waves, longitudinal waves, and surface waves. Some of the most common examples of mechanical waves are water waves, sound waves, and seismic waves.
Like all waves, mechanical waves transport energy. This energy propagates in the same direction as the wave. A wave requires an initial energy input; once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, electromagnetic waves require no medium, but can still travel through one.
Transverse wave
A transverse wave is the form of a wave in which particles of medium vibrate about their mean position perpendicular to the direction of the motion of the wave.
To see an example, move an end of a Slinky (whose other end is fixed) to the left-and-right of the Slinky, as opposed to to-and-fro. Light also has properties of a transverse wave, although it is an electromagnetic wave.
Longitudinal wave
Longitudinal waves cause the medium to vibrate parallel to the direction of the wave. It consists of multiple compressions and rarefactions. The rarefaction is the farthest distance apart in the longitudinal wave and the compression is the closest distance together. The speed of the longitudinal wave is increased in higher index of refraction, due to the closer proximity of the atoms in the medium that is being compressed. Sound is a longitudinal wave.
Surface waves
This type of wave travels along the surface or interface between two media. An example of a surface wave would be waves in a pool, or in an ocean
Document 3:::
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.
Document 4:::
In physics, a transverse wave is a wave that oscillates perpendicularly to the direction of the wave's advance. In contrast, a longitudinal wave travels in the direction of its oscillations. All waves move energy from place to place without transporting the matter in the transmission medium if there is one. Electromagnetic waves are transverse without requiring a medium. The designation “transverse” indicates the direction of the wave is perpendicular to the displacement of the particles of the medium through which it passes, or in the case of EM waves, the oscillation is perpendicular to the direction of the wave.
A simple example is given by the waves that can be created on a horizontal length of string by anchoring one end and moving the other end up and down. Another example is the waves that are created on the membrane of a drum. The waves propagate in directions that are parallel to the membrane plane, but each point in the membrane itself gets displaced up and down, perpendicular to that plane. Light is another example of a transverse wave, where the oscillations are the electric and magnetic fields, which point at right angles to the ideal light rays that describe the direction of propagation.
Transverse waves commonly occur in elastic solids due to the shear stress generated; the oscillations in this case are the displacement of the solid particles away from their relaxed position, in directions perpendicular to the propagation of the wave. These displacements correspond to a local shear deformation of the material. Hence a transverse wave of this nature is called a shear wave. Since fluids cannot resist shear forces while at rest, propagation of transverse waves inside the bulk of fluids is not possible. In seismology, shear waves are also called secondary waves or S-waves.
Transverse waves are contrasted with longitudinal waves, where the oscillations occur in the direction of the wave. The standard example of a longitudinal wave is a sound wave or "
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What occurs when waves interact with other waves?
A. interference
B. resurgence
C. vibration
D. frequency
Answer:
|
|
sciq-4012
|
multiple_choice
|
Upon reaching the postsynaptic membrane, what type of chemical messenger binds to and activates a specific receptor?
|
[
"neurotransmitter",
"pheromone",
"neuropeptide",
"hormone"
] |
A
|
Relavent Documents:
Document 0:::
Neurotransmission (Latin: transmissio "passage, crossing" from transmittere "send, let through") is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), and bind to and react with the receptors on the dendrites of another neuron (the postsynaptic neuron) a short distance away. A similar process occurs in retrograde neurotransmission, where the dendrites of the postsynaptic neuron release retrograde neurotransmitters (e.g., endocannabinoids; synthesized in response to a rise in intracellular calcium levels) that signal through receptors that are located on the axon terminal of the presynaptic neuron, mainly at GABAergic and glutamatergic synapses.
Neurotransmission is regulated by several different factors: the availability and rate-of-synthesis of the neurotransmitter, the release of that neurotransmitter, the baseline activity of the postsynaptic cell, the number of available postsynaptic receptors for the neurotransmitter to bind to, and the subsequent removal or deactivation of the neurotransmitter by enzymes or presynaptic reuptake.
In response to a threshold action potential or graded electrical potential, a neurotransmitter is released at the presynaptic terminal. The released neurotransmitter may then move across the synapse to be detected by and bind with receptors in the postsynaptic neuron. Binding of neurotransmitters may influence the postsynaptic neuron in either an inhibitory or excitatory way. The binding of neurotransmitters to receptors in the postsynaptic neuron can trigger either short term changes, such as changes in the membrane potential called postsynaptic potentials, or longer term changes by the activation of signaling cascades.
Neurons form complex biological neural networks through which nerve impulses (action potentials) travel. Neurons do not touch each other (except in the case of an electrical synapse through a gap junction); instead, neurons intera
Document 1:::
A neurotransmitter receptor (also known as a neuroreceptor) is a membrane receptor protein that is activated by a neurotransmitter. Chemicals on the outside of the cell, such as a neurotransmitter, can bump into the cell's membrane, in which there are receptors. If a neurotransmitter bumps into its corresponding receptor, they will bind and can trigger other events to occur inside the cell. Therefore, a membrane receptor is part of the molecular machinery that allows cells to communicate with one another. A neurotransmitter receptor is a class of receptors that specifically binds with neurotransmitters as opposed to other molecules.
In postsynaptic cells, neurotransmitter receptors receive signals that trigger an electrical signal, by regulating the activity of ion channels. The influx of ions through ion channels opened due to the binding of neurotransmitters to specific receptors can change the membrane potential of a neuron. This can result in a signal that runs along the axon (see action potential) and is passed along at a synapse to another neuron and possibly on to a neural network. On presynaptic cells, there are receptors known as autoreceptors that are specific to the neurotransmitters released by that cell, which provide feedback and mediate excessive neurotransmitter release from it.
There are two major types of neurotransmitter receptors: ionotropic and metabotropic. Ionotropic means that ions can pass through the receptor, whereas metabotropic means that a second messenger inside the cell relays the message (i.e. metabotropic receptors do not have channels). There are several kinds of metabotropic receptors, including G protein-coupled receptors. Ionotropic receptors are also called ligand-gated ion channels and they can be activated by neurotransmitters (ligands) like glutamate and GABA, which then allow specific ions through the membrane. Sodium ions (that are, for example, allowed passage by the glutamate receptor) excite the post-synaptic cell
Document 2:::
A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals.
Prominent neurochemicals
Neurotransmitters and neuromodulators
Glutamate is the most common neurotransmitter. Most neurons secrete with glutamate or GABA. Glutamate is excitatory, meaning that the release of glutamate by one cell usually causes adjacent cells to fire an action potential. (Note: Glutamate is chemically identical to the MSG commonly used to flavor food.)
GABA is an example of an inhibitory neurotransmitter.
Monoamine neurotransmitters:
Dopamine is a monoamine neurotransmitter. It plays a key role in the functioning of the limbic system, which is involved in emotional function and control. It also is involved in cognitive processes associated with movement, arousal, executive function, body temperature regulation, and pleasure and reward, and other processes.
Norepinephrine, also known as noradrenaline, is a monoamine neurotransmitter that is involved in arousal, pain perception, executive function, body temperature regulation, and other processes.
Epinephrine, also known as adrenaline, is a monoamine neurotransmitter that plays in fight-or-flight response, increases blood flow to muscles, output of the heart, pupil dilation, and glucose.
Serotonin is a monoamine neurotransmitter that plays a regulatory role in mood, sleep, appetite, body temperature regulation, and other processes.
Histamine is a monoamine neurotransmitter that is involved in arousal, pain, body temperature regulation, and appetite.
Trace amines act as neuromodulators in monoamine neurons via binding to TAAR1.
Acetylcholine assists motor function and is involved in memory.
Nitric oxide functions as a neurotransmitter, despite being a gas. It is not grouped with the other neurotransmitters because it is not released in the same way.
Endocannabinoids act in the endocannabinoid system to control neurotransmitter release
Document 3:::
The adequate stimulus is a property of a sensory receptor that determines the type of energy to which a sensory receptor responds with the initiation of sensory transduction. Sensory receptor are specialized to respond to certain types of stimuli. The adequate stimulus is the amount and type of energy required to stimulate a specific sensory organ.
Many of the sensory stimuli are categorized by the mechanics by which they are able to function and their purpose. Sensory receptors that are present within the body typically are made to respond to a single stimulus. Sensory receptors are present all throughout the body, and they take a certain amount of a stimulus to trigger these receptors. The use of these sensory receptors allows the brain to interpret the signals to the body which allow a person to respond to the stimulus if the stimulus reaches a minimum threshold to signal the brain. The sensory receptors will activate the sensory transduction system which will in turn send an electrical or chemical stimulus to a cell, and the cell will then respond with electrical signals to the brain which were produced from action potentials. The minuscule signals, which result from the stimuli, enter the cells must be amplified and turned into an sufficient signal that will be sent to the brain.
A sensory receptor's adequate stimulus is determined by the signal transduction mechanisms and ion channels incorporated in the sensory receptor's plasma membrane. Adequate stimulus are often used in relation with sensory thresholds and absolute thresholds to describe the smallest amount of a stimulus needed to activate a feeling within the sensory organ.
Categorizations of receptors
They are categorized through the stimuli to which they respond. Adequate stimulus are also often categorized based on their purpose and locations within the body. The following are the categorizations of receptors within the body:
Visual – These are found in the visual organs of species and are respon
Document 4:::
In physiology, a stimulus is a detectable change in the physical or chemical structure of an organism's internal or external environment. The ability of an organism or organ to detect external stimuli, so that an appropriate reaction can be made, is called sensitivity (excitability). Sensory receptors can receive information from outside the body, as in touch receptors found in the skin or light receptors in the eye, as well as from inside the body, as in chemoreceptors and mechanoreceptors. When a stimulus is detected by a sensory receptor, it can elicit a reflex via stimulus transduction. An internal stimulus is often the first component of a homeostatic control system. External stimuli are capable of producing systemic responses throughout the body, as in the fight-or-flight response. In order for a stimulus to be detected with high probability, its level of strength must exceed the absolute threshold; if a signal does reach threshold, the information is transmitted to the central nervous system (CNS), where it is integrated and a decision on how to react is made. Although stimuli commonly cause the body to respond, it is the CNS that finally determines whether a signal causes a reaction or not.
Types
Internal
Homeostatic imbalances
Homeostatic outbalances are the main driving force for changes of the body. These stimuli are monitored closely by receptors and sensors in different parts of the body. These sensors are mechanoreceptors, chemoreceptors and thermoreceptors that, respectively, respond to pressure or stretching, chemical changes, or temperature changes. Examples of mechanoreceptors include baroreceptors which detect changes in blood pressure, Merkel's discs which can detect sustained touch and pressure, and hair cells which detect sound stimuli. Homeostatic imbalances that can serve as internal stimuli include nutrient and ion levels in the blood, oxygen levels, and water levels. Deviations from the homeostatic ideal may generate a homeostatic emotio
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Upon reaching the postsynaptic membrane, what type of chemical messenger binds to and activates a specific receptor?
A. neurotransmitter
B. pheromone
C. neuropeptide
D. hormone
Answer:
|
|
sciq-9656
|
multiple_choice
|
Genetic traits are characteristics encoded in what?
|
[
"rna",
"nuclei",
"bacteria",
"dna"
] |
D
|
Relavent Documents:
Document 0:::
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
Document 1:::
Genetics is the study of genes and tries to explain what they are and how they work. Genes are how living organisms inherit features or traits from their ancestors; for example, children usually look like their parents because they have inherited their parents' genes. Genetics tries to identify which traits are inherited and to explain how these traits are passed from generation to generation.
Some traits are part of an organism's physical appearance, such as eye color, height or weight. Other sorts of traits are not easily seen and include blood types or resistance to diseases. Some traits are inherited through genes, which is the reason why tall and thin people tend to have tall and thin children. Other traits come from interactions between genes and the environment, so a child who inherited the tendency of being tall will still be short if poorly nourished. The way our genes and environment interact to produce a trait can be complicated. For example, the chances of somebody dying of cancer or heart disease seems to depend on both their genes and their lifestyle.
Genes are made from a long molecule called DNA, which is copied and inherited across generations. DNA is made of simple units that line up in a particular order within it, carrying genetic information. The language used by DNA is called genetic code, which lets organisms read the information in the genes. This information is the instructions for the construction and operation of a living organism.
The information within a particular gene is not always exactly the same between one organism and another, so different copies of a gene do not always give exactly the same instructions. Each unique form of a single gene is called an allele. As an example, one allele for the gene for hair color could instruct the body to produce much pigment, producing black hair, while a different allele of the same gene might give garbled instructions that fail to produce any pigment, giving white hair. Mutations are random
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The Bateson Lecture is an annual genetics lecture held as a part of the John Innes Symposium since 1972, in honour of the first Director of the John Innes Centre, William Bateson.
Past Lecturers
Source: John Innes Centre
1951 Sir Ronald Fisher - "Statistical methods in Genetics"
1953 Julian Huxley - "Polymorphic variation: a problem in genetical natural history"
1955 Sidney C. Harland - "Plant breeding: present position and future perspective"
1957 J.B.S. Haldane - "The theory of evolution before and after Bateson"
1959 Kenneth Mather - "Genetics Pure and Applied"
1972 William Hayes - "Molecular genetics in retrospect"
1974 Guido Pontecorvo - "Alternatives to sex: genetics by means of somatic cells"
1976 Max F. Perutz - "Mechanism of respiratory haemoglobin"
1979 J. Heslop-Harrison - "The forgotten generation: some thoughts on the genetics and physiology of Angiosperm Gametophytes "
1982 Sydney Brenner - "Molecular genetics in prospect"
1984 W.W. Franke - "The cytoskeleton - the insoluble architectural framework of the cell"
1986 Arthur Kornberg - "Enzyme systems initiating replication at the origin of the E. coli chromosome"
1988 Gottfried Schatz - "Interaction between mitochondria and the nucleus"
1990 Christiane Nusslein-Volhard - "Axis determination in the Drosophila embryo"
1992 Frank Stahl - "Genetic recombination: thinking about it in phage and fungi"
1994 Ira Herskowitz - "Violins and orchestras: what a unicellular organism can do"
1996 R.J.P. Williams - "An Introduction to Protein Machines"
1999 Eugene Nester - "DNA and Protein Transfer from Bacteria to Eukaryotes - the Agrobacterium story"
2001 David Botstein - "Extracting biological information from DNA Microarray Data"
2002 Elliot Meyerowitz
2003 Thomas Steitz - "The Macromolecular machines of gene expression"
2008 Sean Carroll - "Endless flies most beautiful: the role of cis-regulatory sequences in the evolution of animal form"
2009 Sir Paul Nurse - "Genetic transmission through
Document 3:::
A geneticist is a biologist or physician who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic processes or develop genetic technologies to aid in the pharmaceutical or and agriculture industries. Some geneticists perform experiments in model organisms such as Drosophila, C. elegans, zebrafish, rodents or humans and analyze data to interpret the inheritance of biological traits. A basic science geneticist is a scientist who usually has earned a PhD in genetics and undertakes research and/or lectures in the field. A medical geneticist is a physician who has been trained in medical genetics as a specialization and evaluates, diagnoses, and manages patients with hereditary conditions or congenital malformations; and provides genetic risk calculations and mutation analysis.
Education
Geneticists participate in courses from many areas, such as biology, chemistry, physics, microbiology, cell biology, bioinformatics, and mathematics. They also participate in more specific genetics courses such as molecular genetics, transmission genetics, population genetics, quantitative genetics, ecological genetics, epigenetics, and genomics.
Careers
Geneticists can work in many different fields, doing a variety of jobs. There are many careers for geneticists in medicine, agriculture, wildlife, general sciences, or many other fields.
Listed below are a few examples of careers a geneticist may pursue.
Research and Development
Genetic counseling
Clinical Research
Medical genetics
Gene therapy
Pharmacogenomics
Molecular ecology
Animal breeding
Genomics
Biotechnology
Proteomics
Microbial genetics
Teaching
Molecular diagnostics
Sales and Marketing of scientific products
Science Journalism
Patent Law
Paternity testing
Forensic DNA
Agriculture
Document 4:::
Genome-wide complex trait analysis (GCTA) Genome-based restricted maximum likelihood (GREML) is a statistical method for heritability estimation in genetics, which quantifies the total additive contribution of a set of genetic variants to a trait. GCTA is typically applied to common single nucleotide polymorphisms (SNPs) on a genotyping array (or "chip") and thus termed "chip" or "SNP" heritability.
GCTA operates by directly quantifying the chance genetic similarity of unrelated individuals and comparing it to their measured similarity on a trait; if two unrelated individuals are relatively similar genetically and also have similar trait measurements, then the measured genetics are likely to causally influence that trait, and the correlation can to some degree tell how much. This can be illustrated by plotting the squared pairwise trait differences between individuals against their estimated degree of relatedness. GCTA makes a number of modeling assumptions and whether/when these assumptions are satisfied continues to be debated.
The GCTA framework has also been extended in a number of ways: quantifying the contribution from multiple SNP categories (i.e. functional partitioning); quantifying the contribution of Gene-Environment interactions; quantifying the contribution of non-additive/non-linear effects of SNPs; and bivariate analyses of multiple phenotypes to quantify their genetic covariance (co-heritability or genetic correlation).
GCTA estimates have implications for the potential for discovery from Genome-wide Association Studies (GWAS) as well as the design and accuracy of polygenic scores. GCTA estimates from common variants are typically substantially lower than other estimates of total or narrow-sense heritability (such as from twin or kinship studies), which has contributed to the debate over the Missing heritability problem.
History
Estimation in biology/animal breeding using standard ANOVA/REML methods of variance components such as heritability,
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Genetic traits are characteristics encoded in what?
A. rna
B. nuclei
C. bacteria
D. dna
Answer:
|
|
sciq-8483
|
multiple_choice
|
What larger theory is einstein's equation part of?
|
[
"cycle of relativity",
"excess of relativity",
"law of relativity",
"theory of relativity"
] |
D
|
Relavent Documents:
Document 0:::
Beyond Einstein: The Cosmic Quest for the Theory of the Universe is a book by Michio Kaku, a theoretical physicist from the City College of New York, and Jennifer Trainer Thompson. It focuses on the development of superstring theory, which might become the unified field theory of the strong force, the weak force, electromagnetism and gravity. The book was initially published on February 1, 1987, by Bantam Books.
Overview
Beyond Einstein tries to explain the basics of superstring theory. Michio Kaku analyzes the history of theoretical physics and the struggle to formulate a unified field theory. He posits that the superstring theory might be the only theory that can unite quantum mechanics and general relativity in one theory.
Document 1:::
This is a list of mathematical topics in relativity, by Wikipedia page.
Special relativity
Foundational issues
principle of relativity
speed of light
faster-than-light
biquaternion
conjugate diameters
four-vector
four-acceleration
four-force
four-gradient
four-momentum
four-velocity
hyperbolic orthogonality
hyperboloid model
light-like
Lorentz covariance
Lorentz group
Lorentz transformation
Lorentz–FitzGerald contraction hypothesis
Minkowski diagram
Minkowski space
Poincaré group
proper length
proper time
rapidity
relativistic wave equations
relativistic mass
split-complex number
unit hyperbola
world line
General relativity
black holes
no-hair theorem
Hawking radiation
Hawking temperature
Black hole entropy
charged black hole
rotating black hole
micro black hole
Schwarzschild black hole
Schwarzschild metric
Schwarzschild radius
Reissner–Nordström black hole
Immirzi parameter
closed timelike curve
cosmic censorship hypothesis
chronology protection conjecture
Einstein–Cartan theory
Einstein's field equation
geodesic
gravitational redshift
Penrose–Hawking singularity theorems
Pseudo-Riemannian manifold
stress–energy tensor
worm hole
Cosmology
anti-de Sitter space
Ashtekar variables
Batalin–Vilkovisky formalism
Big Bang
Cauchy horizon
cosmic inflation
cosmic microwave background
cosmic variance
cosmological constant
dark energy
dark matter
de Sitter space
Friedmann–Lemaître–Robertson–Walker metric
horizon problem
large-scale structure of the cosmos
Randall–Sundrum model
warped geometry
Weyl curvature hypothesis
Relativity
Mathematics
Document 2:::
The Meaning of Relativity: Four Lectures Delivered at Princeton University, May 1921 is a book published by Princeton University Press in 1922 that compiled the 1921 Stafford Little Lectures at Princeton University, given by Albert Einstein. The lectures were translated into English by Edwin Plimpton Adams. The lectures and the subsequent book were Einstein's last attempt to provide a comprehensive overview of his theory of relativity and is his only book that provides an accessible overview of the physics and mathematics of general relativity. Einstein explained his goal in the preface of the book's German edition by stating he "wanted to summarize the principal thoughts and mathematical methods of relativity theory" and that his "principal aim was to let the fundamentals in the entire train of thought of the theory emerge clearly". Among other reviews, the lectures were the subject of the 2017 book The Formative Years of Relativity: The History and Meaning of Einstein's Princeton Lectures by Hanoch Gutfreund and Jürgen Renn.
Background
The book contains four of Einstein's Stafford Little Lectures that were given at Princeton University in 1921. The lectures follow a series of 1915 publications by Einstein developing the theory of general relativity. During this time, there were still many controversial issues surrounding the theories and he was still defending several of his views. The lectures and the subsequent book were Einstein's last attempt to provide a comprehensive overview of his theory of relativity. It is also his only book that provides an overview of the physics and mathematics of general relativity in a comprehensive manner that was accessible to non-specialists. Einstein explained his goal in the preface of the book's German edition by stating he "wanted to summarize the principal thoughts and mathematical methods of relativity theory" and that his "principal aim was to let the fundamentals in the entire train of thought of the theory emerge clea
Document 3:::
Following is a list of the frequently occurring equations in the theory of special relativity.
Postulates of Special Relativity
To derive the equations of special relativity, one must start with two other
The laws of physics are invariant under transformations between inertial frames. In other words, the laws of physics will be the same whether you are testing them in a frame 'at rest', or a frame moving with a constant velocity relative to the 'rest' frame.
The speed of light in a perfect classical vacuum () is measured to be the same by all observers in inertial frames and is, moreover, finite but nonzero. This speed acts as a supremum for the speed of local transmission of information in the universe.
In this context, "speed of light" really refers to the speed supremum of information transmission or of the movement of ordinary (nonnegative mass) matter, locally, as in a classical vacuum. Thus, a more accurate description would refer to rather than the speed of light per se. However, light and other massless particles do theoretically travel at under vacuum conditions and experiment has nonfalsified this notion with fairly high precision. Regardless of whether light itself does travel at , though does act as such a supremum, and that is the assumption which matters for Relativity.
From these two postulates, all of special relativity follows.
In the following, the relative velocity v between two inertial frames is restricted fully to the x-direction, of a Cartesian coordinate system.
Kinematics
Lorentz transformation
The following notations are used very often in special relativity:
Lorentz factor
where and v is the relative velocity between two inertial frames.
For two frames at rest, γ = 1, and increases with relative velocity between the two inertial frames. As the relative velocity approaches the speed of light, γ → ∞.
Time dilation (different times t and t''' at the same position x in same inertial frame)
{| class="toccolours collapsible
Document 4:::
The Einstein Theory of Relativity (1923) is a silent animated short film directed by Dave Fleischer and released by Fleischer Studios.
History
In August 1922, Scientific American published an article explaining their position that a silent film would be unsuccessful in presenting the theory of relativity to the general public, arguing that only as part of a broader educational package including lecture and text would such film be successful. Scientific American then went on to review frames from an unnamed German film reported to be financially successful.
Six months later, on February 8, 1923, the Fleischers released their relativity film, produced in collaboration with popular science journalist Garrett P. Serviss to accompany his book on the same topic. Two versions of the Fleischer film are reported to exist – a shorter two-reel (20 minute) edit intended for general theater audiences, and a longer five-reel (50 minute) version intended for educational use.
The Fleischers lifted footage from the German predecessor, Die Grundlagen der Einsteinschen Relativitäts-Theorie, directed by Hanns-Walter Kornblum, for inclusion into their film. Presented here are images from the Fleischer film and German film. If actual footage was not recycled into The Einstein Theory of Relativity, these images and text from the Scientific American article suggest that original visual elements from the German film were.
This film, like much of the Fleischer's work, has fallen into the public domain. Unlike Fleischer Studio's Superman or Betty Boop cartoons, The Einstein Theory of Relativity has very few existing prints and is available in 16mm from only a few specialized film preservation organizations.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What larger theory is einstein's equation part of?
A. cycle of relativity
B. excess of relativity
C. law of relativity
D. theory of relativity
Answer:
|
|
sciq-8037
|
multiple_choice
|
What kind of atomic molecule is oxygen gas?
|
[
"symbiotic",
"diatomic",
"aromatic",
"dramatic"
] |
B
|
Relavent Documents:
Document 0:::
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.
Document 1:::
Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its chemical formula (•N=O or •NO). Nitric oxide is also a heteronuclear diatomic molecule, a class of molecules whose study spawned early modern theories of chemical bonding.
An important intermediate in industrial chemistry, nitric oxide forms in combustion systems and can be generated by lightning in thunderstorms. In mammals, including humans, nitric oxide is a signaling molecule in many physiological and pathological processes. It was proclaimed the "Molecule of the Year" in 1992. The 1998 Nobel Prize in Physiology or Medicine was awarded for discovering nitric oxide's role as a cardiovascular signalling molecule.
Nitric oxide should not be confused with nitrogen dioxide (NO2), a brown gas and major air pollutant, or with nitrous oxide (N2O), an anesthetic gas.
Physical properties
Electronic configuration
The ground state electronic configuration of NO is, in united atom notation:
The first two orbitals are actually pure atomic 1sO and 1sN from oxygen and nitrogen respectively and therefore are usually not noted in the united atom notation. Orbitals noted with an asterisk are antibonding. The ordering of 5σ and 1π according to their binding energies is subject to discussion. Removal of a 1π electron leads to 6 states whose energies span over a range starting at a lower level than a 5σ electron an extending to a higher level. This is due to the different orbital momentum couplings between a 1π and a 2π electron.
The lone electron in the 2π orbital makes NO a doublet (X ²Π) in its ground state whose degeneracy is split in the fine structure from spin-orbit coupling with a total momentum J= or J=.
Dipole
The dipole of NO has been measured experimentally to 0.15740 D and is oriented from O to N (⁻NO⁺) due to the transf
Document 2:::
Atomicity is the total number of atoms present in a molecule. For example, each molecule of oxygen (O2) is composed of two oxygen atoms. Therefore, the atomicity of oxygen is 2.
In older contexts, atomicity is sometimes equivalent to valency. Some authors also use the term to refer to the maximum number of valencies observed for an element.
Classifications
Based on atomicity, molecules can be classified as:
Monoatomic (composed of one atom). Examples include He (helium), Ne (neon), Ar (argon), and Kr (krypton). All noble gases are monoatomic.
Diatomic (composed of two atoms). Examples include H2 (hydrogen), N2 (nitrogen), O2 (oxygen), F2 (fluorine), and Cl2 (chlorine). Halogens are usually diatomic.
Triatomic (composed of three atoms). Examples include O3 (ozone).
Polyatomic (composed of three or more atoms). Examples include S8.
Atomicity may vary in different allotropes of the same element.
The exact atomicity of metals, as well as some other elements such as carbon, cannot be determined because they consist of a large and indefinite number of atoms bonded together. They are typically designated as having an atomicity of 1.
The atomicity of homonuclear molecule can be derived by dividing the molecular weight by the atomic weight. For example, the molecular weight of oxygen is 31.999, while its atomic weight is 15.879; therefore, its atomicity is approximately 2 (31.999/15.879 ≈ 2).
Examples
The most common values of atomicity for the first 30 elements in the periodic table are as follows:
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:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of atomic molecule is oxygen gas?
A. symbiotic
B. diatomic
C. aromatic
D. dramatic
Answer:
|
|
sciq-5903
|
multiple_choice
|
What part of the eye controls the size of the pupil?
|
[
"avis",
"debis",
"iris",
"lens"
] |
C
|
Relavent Documents:
Document 0:::
The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil. The size of the pupil is controlled by the iris, and varies depending on many factors, the most significant being the amount of light in the environment. The term "pupil" was coined by Gerard of Cremona.
In humans, the pupil is circular, but its shape varies between species; some cats, reptiles, and foxes have vertical slit pupils, goats have horizontally oriented pupils, and some catfish have annular types. In optical terms, the anatomical pupil is the eye's aperture and the iris is the aperture stop. The image of the pupil as seen from outside the eye is the entrance pupil, which does not exactly correspond to the location and size of the physical pupil because it is magnified by the cornea. On the inner edge lies a prominent structure, the collarette, marking the junction of the embryonic pupillary membrane covering the embryonic pupil.
Function
The iris is a contractile structure, consisting mainly of smooth muscle, surrounding the pupil. Light enters the eye through the pupil, and the iris regulates the amount of light by controlling the size of the pupil. This is known as the pupillary light reflex.
The iris contains two groups of smooth muscles; a circular group called the sphincter pupillae, and a radial group called the dilator pupillae. When the sphincter pupillae contract, the iris decreases or constricts the size of the pupil. The dilator pupillae, innervated by sympathetic nerves from the superior cervical ganglion, cause the pupil to dilate when they contract. These muscles are sometimes referred to as intrinsic eye muscles.
The sensory pathway (rod or cone, bipolar, ganglion) is linked with its counterpart in the other eye by a partial
Document 1:::
The stroma of the iris is a fibrovascular layer of tissue. It is the upper layer of two in the iris.
Structure
The stroma is a delicate interlacement of fibres. Some circle the circumference of the iris and the majority radiate toward the pupil. Blood vessels and nerves intersperse this mesh.
In dark eyes, the stroma often contains pigment granules. Blue eyes and the eyes of albinos, however, lack pigment.
The stroma connects to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. The back surface is covered by a commonly, heavily pigmented epithelial layer that is two cells thick (the iris pigment epithelium), but the front surface has no epithelium. This anterior surface projects as the muscles dilate.
Document 2:::
The pupil magnification of an optical system is the ratio of the diameter of the exit pupil to the diameter of the entrance pupil. The pupil magnification is used in calculations of the effective f-number, which affects a number of important elements related to optics, such as exposure, diffraction, and depth of field. For all symmetric lenses, and for many conventional photographic lenses, the pupils appear the same size and so the pupil magnification is approximately 1.
See also
Magnification
External links
Photo.net lens tutorial
Geometrical optics
Document 3:::
The orbitalis muscle is a vestigial or rudimentary nonstriated muscle (smooth muscle) that crosses from the infraorbital groove and sphenomaxillary fissure and is intimately united with the periosteum of the orbit. It was described by Heinrich Müller and is often called Müller's muscle. It lies at the back of the orbit and spans the infraorbital fissure. It is a thin layer of smooth muscle that bridges the inferior orbital fissure. It is supplied by sympathetic nerves, and its function is unknown.
Function
The muscle forms an important part of the lateral orbital wall in some animals and can act to change the wall's volume in lower mammals, while in humans it is not known to have any significant function, but its contraction may possibly produce a slight forward protrusion of the eyeball. Several sources have suggested a role in the autonomic regulation of the vascular system due to the pattern of innervation of the orbitalis.
Pathology
Horner's syndrome causes paralysis of the structures of the eye and orbit that receive sympathetic innervation. The signs of Horner's syndrome are ptosis, miosis, anhydrosis, and (apparent) enophthalmos. While some attribute the enophthalmos of Horner's Syndrome to paralysis of the orbitalis muscle, this is inaccurate. Enophthalmos in Horner's syndrome is an illusion created by the subtle ptosis of the upper eyelid caused by paralysis of the superior tarsal muscle.
Sinking in of the eye (true enophthalmos) is possibly caused by paralysis of the smooth (orbitalis) muscle in the floor of the orbit.
Eponym
While the orbitalis muscle is also known as Müller's muscle, the use of this term should be discouraged to avoid confusion with the superior tarsal muscle and the circular fibres of the ciliary muscle.
Document 4:::
Glands of Zeis are unilobar sebaceous glands located on the margin of the eyelid. The glands of Zeis service the eyelash. These glands produce an oily substance that is issued through the excretory ducts of the sebaceous lobule into the middle portion of the hair follicle. In the same area of the eyelid, near the base of the eyelashes are apocrine glands called the "glands of Moll".
If eyelashes are not kept clean, conditions such as folliculitis may take place, and if the sebaceous gland becomes infected, it can lead to abscesses and styes. The glands of Zeis are named after German ophthalmologist Eduard Zeis (1807–68).
See also
Meibomian gland
Moll's gland
List of specialized glands within the human integumentary system
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What part of the eye controls the size of the pupil?
A. avis
B. debis
C. iris
D. lens
Answer:
|
|
sciq-10073
|
multiple_choice
|
When a solvent with a gas dissolved in it is heated, the kinetic energy of both the solvent and solute _________?
|
[
"decreases",
"generates",
"evaporates",
"increases"
] |
D
|
Relavent Documents:
Document 0:::
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be "miscible in all proportions" (or just "miscible").
The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations, and a solid or liquid can be "dissolved" in a gas only by passing into the gaseous state first.
The solubility mainly depends on the composition of solute and solvent (including their pH and the presence of other dissolved substances) as well as on temperature and pressure. The dependency can often be explained in terms of interactions between the particles (atoms, molecules, or ions) of the two substances, and of thermodynamic concepts such as enthalpy and entropy.
Under certain conditions, the concentration of the solute can exceed its usual solubility limit. The result is a supersaturated solution, which is metastable and will rapidly exclude the excess solute if a suitable nucleation site appears.
The concept of solubility does not apply when there is an irreversible chemical reaction between the two substances, such as the reaction of calcium hydroxide with hydrochloric acid; even though one might say, informally, that one "dissolved" the other. The solubility is also not the same as the rate of solution, which is how fast a solid solute dissolves in a liquid solvent. This property de
Document 1:::
The Stefan flow, occasionally called Stefan's flow, is a transport phenomenon concerning the movement of a chemical species by a flowing fluid (typically in the gas phase) that is induced to flow by the production or removal of the species at an interface. Any process that adds the species of interest to or removes it from the flowing fluid may cause the Stefan flow, but the most common processes include evaporation, condensation, chemical reaction, sublimation, ablation, adsorption, absorption, and desorption. It was named after the Slovenian physicist, mathematician, and poet Josef Stefan for his early work on calculating evaporation rates.
The Stefan flow is distinct from diffusion as described by Fick's law, but diffusion almost always also occurs in multi-species systems that are experiencing the Stefan flow. In systems undergoing one of the species addition or removal processes mentioned previously, the addition or removal generates a mean flow in the flowing fluid as the fluid next to the interface is displaced by the production or removal of additional fluid by the processes occurring at the interface. The transport of the species by this mean flow is the Stefan flow. When concentration gradients of the species are also present, diffusion transports the species relative to the mean flow. The total transport rate of the species is then given by a summation of the Stefan flow and diffusive contributions.
An example of the Stefan flow occurs when a droplet of liquid evaporates in air. In this case, the vapor/air mixture surrounding the droplet is the flowing fluid, and liquid/vapor boundary of the droplet is the interface. As heat is absorbed by the droplet from the environment, some of the liquid evaporates into vapor at the surface of the droplet, and flows away from the droplet as it is displaced by additional vapor evaporating from the droplet. This process causes the flowing medium to move away from the droplet at some mean speed that is dependent on
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
In fluid thermodynamics, nucleate boiling is a type of boiling that takes place when the surface temperature is hotter than the saturated fluid temperature by a certain amount but where the heat flux is below the critical heat flux. For water, as shown in the graph below, nucleate boiling occurs when the surface temperature is higher than the saturation temperature () by between . The critical heat flux is the peak on the curve between nucleate boiling and transition boiling. The heat transfer from surface to liquid is greater than that in film boiling.
Nucleate boiling is common in electric kettles and is responsible for the noise that occurs before boiling occurs. It also occurs in water boilers where water is rapidly heated.
Mechanism
Two different regimes may be distinguished in the nucleate boiling range. When the temperature difference is between approximately above TS, isolated bubbles form at nucleation sites and separate from the surface. This separation induces considerable fluid mixing near the surface, substantially increasing the convective heat transfer coefficient and the heat flux. In this regime, most of the heat transfer is through direct transfer from the surface to the liquid in motion at the surface and not through the vapor bubbles rising from the surface.
Between above TS, a second flow regime may be observed. As more nucleation sites become active, increased bubble formation causes bubble interference and coalescence. In this region the vapor escapes as jets or columns which subsequently merge into slugs of vapor.
Interference between the densely populated bubbles inhibits the motion of liquid near the surface. This is observed on the graph as a change in the direction of the gradient of the curve or an inflection in the boiling curve. After this point, the heat transfer coefficient starts to reduce as the surface temperature is further increased although the product of the heat transfer coefficient and the temperature difference (t
Document 4:::
In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid, but it can also be applied to liquids and gases dissolved in a liquid. A supersaturated solution is in a metastable state; it may return to equilibrium by separation of the excess of solute from the solution, by dilution of the solution by adding solvent, or by increasing the solubility of the solute in the solvent.
History
Early studies of the phenomenon were conducted with sodium sulfate, also known as Glauber's Salt because, unusually, the solubility of this salt in water may decrease with increasing temperature. Early studies have been summarised by Tomlinson. It was shown that the crystallization of a supersaturated solution does not simply come from its agitation, (the previous belief) but from solid matter entering and acting as a "starting" site for crystals to form, now called "seeds". Expanding upon this, Gay-Lussac brought attention to the kinematics of salt ions and the characteristics of the container having an impact on the supersaturation state. He was also able to expand upon the number of salts with which a supersaturated solution can be obtained. Later Henri Löwel came to the conclusion that both nuclei of the solution and the walls of the container have a catalyzing effect on the solution that cause crystallization. Explaining and providing a model for this phenomenon has been a task taken on by more recent research. Désiré Gernez contributed to this research by discovering that nuclei must be of the same salt that is being crystallized in order to promote crystallization.
Occurrence and examples
Solid precipitate, liquid solvent
A solution of a chemical compound in a liquid will become supersaturated when the temperature of the saturated solution is changed. In most cases solubility decreases wit
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When a solvent with a gas dissolved in it is heated, the kinetic energy of both the solvent and solute _________?
A. decreases
B. generates
C. evaporates
D. increases
Answer:
|
|
sciq-10625
|
multiple_choice
|
What allows the electrons to move in an electrochemical system.
|
[
"magnetism",
"conduction",
"mass",
"conductor"
] |
D
|
Relavent Documents:
Document 0:::
Bioelectrochemistry is a branch of electrochemistry and biophysical chemistry concerned with electrophysiological topics like cell electron-proton transport, cell membrane potentials and electrode reactions of redox enzymes.
History
The beginnings of bioelectrochemistry, as well as those of electrochemistry, are closely related to physiology through the works of Luigi Galvani and then Alessandro Volta.
The first modern work in this field is considered that of the German physiologist Julius Bernstein (1902) concerning the source of biopotentials due to different ion concentration through the cell's membrane.
The domain of bioelectrochemistry has grown considerably over the past century, maintaining the close connections to various medical and biological and engineering disciplines like electrophysiology, biomedical engineering, and enzyme kinetics. The achievements in this field have been awarded several Nobel prizes for Physiology or Medicine. Among prominent electrochemists who have contributed to this field one could mention John Bockris.
See also
Biomedical engineering
Bioelectronics
Bioelectrochemical reactor
Biomagnetism
Enzymatic biofuel cell
Protein Film Voltammetry
Saltatory conduction
Notes
External links
Johann Wilhelm Ritter contribution to the field
Electrochemistry
Document 1:::
A solvated electron is a free electron in (solvated in) a solution, and is the smallest possible anion. Solvated electrons occur widely. Often, discussions of solvated electrons focus on their solutions in ammonia, which are stable for days, but solvated electrons also occur in water and other solvents in fact, in any solvent that mediates outer-sphere electron transfer. The solvated electron is responsible for a great deal of radiation chemistry.
Ammonia solutions
Liquid ammonia will dissolve all of the alkali metals and other electropositive metals such as Ca, Sr, Ba, Eu, and Yb (also Mg using an electrolytic process), giving characteristic blue solutions. For alkali metals in liquid ammonia, the solution is blue when dilute and copper-colored when more concentrated (> 3 molar). These solutions conduct electricity. The blue colour of the solution is due to ammoniated electrons, which absorb energy in the visible region of light. The diffusivity of the solvated electron in liquid ammonia can be determined using potential-step chronoamperometry.
Solvated electrons in ammonia are the anions of salts called electrides.
Na + 6 NH3 → [Na(NH3)6]+e−
The reaction is reversible: evaporation of the ammonia solution produces a film of metallic sodium.
Case study: Li in NH3
A lithium–ammonia solution at −60 °C is saturated at about 15 mol% metal (MPM). When the concentration is increased in this range electrical conductivity increases from 10−2 to 104 Ω−1cm−1 (larger than liquid mercury). At around 8 MPM, a "transition to the metallic state" (TMS) takes place (also called a "metal-to-nonmetal transition" (MNMT)). At 4 MPM a liquid-liquid phase separation takes place: the less dense gold-colored phase becomes immiscible from a denser blue phase. Above 8 MPM the solution is bronze/gold-colored. In the same concentration range the overall density decreases by 30%.
Other solvents
Alkali metals also dissolve in some small primary amines, such as methylamine and ethylami
Document 2:::
In physics, electrical engineering and materials science, electromaterials are the set of materials which store, controllably convert, exchange and conduct electrically charged particles. The term electromaterial can refer to any electronically or ionically active material. While this definition is quite broad, the term is typically used in the context of properties and/or applications in which atomic electronic transition is pertinent. The word electromaterials is a compound form of the Ancient Greek term, ἤλεκτρον ēlektron, "Amber", and the Latin term, materia, "Matter".
Properties
Electromaterials enable the transport of charged species (electrons and/or ions) as well as facilitate the exchange of charge to other materials. For atomic and molecule systems, this is observed as atomic electronic transition between discrete orbitals, while for bulk semiconductor materials electronic bands determine which transitions may occur. Metals, in which the conduction band is permanently populated, may also be considered electromaterials, although this is typically outside the category compared to other conduction mechanisms such as for a degenerate semiconductor (transparent conductive oxides) or polaron hopping (organic conductor). Materials which can be ionised (i.e. electrons either added or stripped away) may also be considered electronically active.
Electromaterials have a number of properties broadly, including:
Opto-electronic properties
Photoelectric properties
Exotic phenomena such as super-conductive properties
Partial charge transfer, adsorption of species leading to change in electronic properties of material
Ion conductive materials
Applications
In the application of electromaterials, ions or electrons are used to carry out a specific function. For example, the oxidation or reduction (loss or gain of electrons, respectively) of another species. Materials such as metals, metal particles, conducting polymers, conducting carbon, e.g. CNTs, graphene, carbo
Document 3:::
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 4:::
Electrical mobility is the ability of charged particles (such as electrons or protons) to move through a medium in response to an electric field that is pulling them. The separation of ions according to their mobility in gas phase is called ion mobility spectrometry, in liquid phase it is called electrophoresis.
Theory
When a charged particle in a gas or liquid is acted upon by a uniform electric field, it will be accelerated until it reaches a constant drift velocity according to the formula
where
is the drift velocity (SI units: m/s),
is the magnitude of the applied electric field (V/m),
is the mobility (m2/(V·s)).
In other words, the electrical mobility of the particle is defined as the ratio of the drift velocity to the magnitude of the electric field:
For example, the mobility of the sodium ion (Na+) in water at 25 °C is . This means that a sodium ion in an electric field of 1 V/m would have an average drift velocity of . Such values can be obtained from measurements of ionic conductivity in solution.
Electrical mobility is proportional to the net charge of the particle. This was the basis for Robert Millikan's demonstration that electrical charges occur in discrete units, whose magnitude is the charge of the electron.
Electrical mobility is also inversely proportional to the Stokes radius of the ion, which is the effective radius of the moving ion including any molecules of water or other solvent that move with it. This is true because the solvated ion moving at a constant drift velocity is subject to two equal and opposite forces: an electrical force and a frictional force , where is the frictional coefficient, is the solution viscosity. For different ions with the same charge such as Li+, Na+ and K+ the electrical forces are equal, so that the drift speed and the mobility are inversely proportional to the radius . In fact, conductivity measurements show that ionic mobility increases from Li+ to Cs+, and therefore that Stokes radius decrease
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What allows the electrons to move in an electrochemical system.
A. magnetism
B. conduction
C. mass
D. conductor
Answer:
|
|
sciq-3451
|
multiple_choice
|
This series of life stages and events that a sexually reproducing organism goes through is called its what?
|
[
"maturation cycle",
"development cycle",
"formative period",
"life cycle"
] |
D
|
Relavent Documents:
Document 0:::
Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. However, puberty is the process of biological sexual maturation, while the concept of adulthood is generally based on broader cultural definitions.
Most multicellular organisms are unable to sexually reproduce at birth (animals) or germination (e.g. plants): depending on the species, it may be days, weeks, or years until they have developed enough to be able to do so. Also, certain cues may trigger an organism to become sexually mature. They may be external, such as drought (certain plants), or internal, such as percentage of body fat (certain animals). (Such internal cues are not to be confused with hormones, which directly produce sexual maturity – the production/release of those hormones is triggered by such cues.)
Role of reproductive organs
Sexual maturity is brought about by a maturing of the reproductive organs and the production of gametes. It may also be accompanied by a growth spurt or other physical changes which distinguish the immature organism from its adult form. In animals these are termed secondary sex characteristics, and often represent an increase in sexual dimorphism.
After sexual maturity is achieved, some organisms become infertile, or even change their sex. Some organisms are hermaphrodites and may or may not be able to "completely" mature and/or to produce viable offspring. Also, while in many organisms sexual maturity is strongly linked to age, many other factors are involved, and it is possible for some to display most or all of the characteristics of the adult form without being sexually mature. Conversely it is also possible for the "immature" form of an organism to reproduce. This is called progenesis, in which sexual development occurs faster than other physiological development (in contrast, the term neoteny refers to when non-sexual development is slowed – but the result is the same - the retention of juvenile c
Document 1:::
In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion.
"The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction.
In some organisms, different "generations" of the species succeed each other during the life cycle. For plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or more), rather than two.
Life cycles that include sexual reproduction involve alternating haploid (n) and diploid (2n) stages, i.e., a change of ploidy is involved. To return from a diploid stage to a haploid stage, meiosis must occur. In regard to changes of ploidy, there are three types of cycles:
haplontic life cycle — the haploid stage is multicellular and the diploid stage is a single cell, meiosis is "zygotic".
diplontic life cycle — the diploid stage is multicellular and haploid gametes are formed, meiosis is "gametic".
haplodiplontic life cycle (also referred to as diplohaplontic, diplobiontic, or dibiontic life cycle) — multicellular diploid and haploid stages occur, meiosis is "sporic".
The cycles differ in when mitosis (growth) occurs. Zygotic meiosis and gametic meiosis have one mitotic stage: mitosis occurs during the n phase in zygotic meiosis and during the 2n phase in gametic meiosis. Therefore, zygotic and gametic meiosis are collectively termed "haplobiontic" (single mitotic phase, not to be confused with ha
Document 2:::
This glossary of developmental biology is a list of definitions of terms and concepts commonly used in the study of developmental biology and related disciplines in biology, including embryology and reproductive biology, primarily as they pertain to vertebrate animals and particularly to humans and other mammals. The developmental biology of invertebrates, plants, fungi, and other organisms is treated in other articles; e.g. terms relating to the reproduction and development of insects are listed in Glossary of entomology, and those relating to plants are listed in Glossary of botany.
This glossary is intended as introductory material for novices; for more specific and technical detail, see the article corresponding to each term. Additional terms relevant to vertebrate reproduction and development may also be found in Glossary of biology, Glossary of cell biology, Glossary of genetics, and Glossary of evolutionary biology.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
See also
Introduction to developmental biology
Outline of developmental biology
Outline of cell biology
Glossary of biology
Glossary of cell biology
Glossary of genetics
Glossary of evolutionary biology
Document 3:::
Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. In particular, a sequential hermaphrodite produces eggs (female gametes) and sperm (male gametes) at different stages in life. Sequential hermaphroditism occurs in many fish, gastropods, and plants. Species that can undergo these changes do so as a normal event within their reproductive cycle, usually cued by either social structure or the achievement of a certain age or size. In some species of fish, sequential hermaphroditism is much more common than simultaneous hermaphroditism.
In animals, the different types of change are male to female (protandry or protandrous hermaphroditism), female to male (protogyny or protogynous hermaphroditism), and bidirectional (serial or bidirectional hermaphroditism). Both protogynous and protandrous hermaphroditism allow the organism to switch between functional male and functional female. Bidirectional hermaphrodites have the capacity for sex change in either direction between male and female or female and male, potentially repeatedly during their lifetime. These various types of sequential hermaphroditism may indicate that there is no advantage based on the original sex of an individual organism. Those that change gonadal sex can have both female and male germ cells in the gonads or can change from one complete gonadal type to the other during their last life stage.
In plants, individual flowers are called dichogamous if their function has the two sexes separated in time, although the plant as a whole may have functionally male and functionally female flowers open at any one moment. A flower is protogynous if its function is first female, then male, and protandrous if its function is male then female. It used to be thought that this reduced inbreeding, but it may be a more general mechanism for reducing pollen-
Document 4:::
A juvenile is an individual organism (especially an animal) that has not yet reached its adult form, sexual maturity or size. Juveniles can look very different from the adult form, particularly in colour, and may not fill the same niche as the adult form. In many organisms the juvenile has a different name from the adult (see List of animal names).
Some organisms reach sexual maturity in a short metamorphosis, such as ecdysis in many insects and some other arthropods. For others, the transition from juvenile to fully mature is a more prolonged process—puberty in humans and other species (like higher primates and whales), for example. In such cases, juveniles during this transformation are sometimes called subadults.
Many invertebrates cease development upon reaching adulthood. The stages of such invertebrates are larvae or nymphs.
In vertebrates and some invertebrates (e.g. spiders), larval forms (e.g. tadpoles) are usually considered a development stage of their own, and "juvenile" refers to a post-larval stage that is not fully grown and not sexually mature. In amniotes, the embryo represents the larval stage. Here, a "juvenile" is an individual in the time between hatching/birth/germination and reaching maturity.
Examples
For animal larval juveniles, see larva
Juvenile birds or bats can be called fledglings
For cat juveniles, see kitten
For dog juveniles, see puppy
For human juvenile life stages, see childhood and adolescence, an intermediary period between the onset of puberty and full physical, psychological, and social adulthood
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
This series of life stages and events that a sexually reproducing organism goes through is called its what?
A. maturation cycle
B. development cycle
C. formative period
D. life cycle
Answer:
|
|
sciq-3475
|
multiple_choice
|
The abnormal cells cannot carry oxygen properly and can get stuck where?
|
[
"Viens",
"capillaries",
"Arteries",
"muscles"
] |
B
|
Relavent Documents:
Document 0:::
Lymph node stromal cells are essential to the structure and function of the lymph node whose functions include: creating an internal tissue scaffold for the support of hematopoietic cells; the release of small molecule chemical messengers that facilitate interactions between hematopoietic cells; the facilitation of the migration of hematopoietic cells; the presentation of antigens to immune cells at the initiation of the adaptive immune system; and the homeostasis of lymphocyte numbers. Stromal cells originate from multipotent mesenchymal stem cells.
Structure
Lymph nodes are enclosed in an external fibrous capsule, from which thin walls of sinew called trabeculae penetrate into the lymph node, partially dividing it. Beneath the external capsule and along the courses of the trabeculae, are peritrabecular and subcapsular sinuses. These sinuses are cavities containing macrophages (specialised cells which help to keep the extracellular matrix in order).
The interior of the lymph node has two regions: the cortex and the medulla. In the cortex, lymphoid tissue is organized into nodules. In the nodules, T lymphocytes are located in the T cell zone. B lymphocytes are located in the B cell follicle. The primary B cell follicle matures in germinal centers. In the medulla are hematopoietic cells (which contribute to the formation of the blood) and stromal cells.
Near the medulla is the hilum of lymph node. This is the place where blood vessels enter and leave the lymph node and lymphatic vessels leave the lymph node. Lymph vessels entering the node do so along the perimeter (outer surface).
Function
The lymph nodes, the spleen and Peyer's patches, together are known as secondary lymphoid organs. Lymph nodes are found between lymphatic ducts and blood vessels. Afferent lymphatic vessels bring lymph fluid from the peripheral tissues to the lymph nodes. The lymph tissue in the lymph nodes consists of immune cells (95%), for example lymphocytes, and stromal cells (1% to
Document 1:::
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue.
Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries.
These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues throughout the body.
Structure
The endothelium is a thin layer of single flat (squamous) cells that line the interior surface of blood vessels and lymphatic vessels.
Endothelium is of mesodermal origin. Both blood and lymphatic capillaries are composed of a single layer of endothelial cells called a monolayer. In straight sections of a blood vessel, vascular endothelial cells typically align and elongate in the direction of fluid flow.
Terminology
The foundational model of anatomy, an index of terms used to describe anatomical structures, makes a distinction between endothelial cells and epithelial cells on the basis of which tissues they develop from, and states that the presence of vimentin rather than keratin filaments separates these from epithelial cells. Many considered the endothelium a specialized epithelial tissue.
Function
The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. This forms a barrier between v
Document 2:::
In haematology atypical localization of immature precursors (ALIP) refers to finding of atypically localized precursors (myeloblasts and promyelocytes) on bone marrow biopsy. In healthy humans, precursors are rare and are found localized near the endosteum, and consist of 1-2 cells. In some cases of myelodysplastic syndromes, immature precursors might be located in the intertrabecular region and occasionally aggregate as clusters of 3 ~ 5 cells. The presence of ALIPs is associated with worse prognosis of MDS . Recently, in bone marrow sections of patients with acute myeloid leukemia cells similar to ALIPs were defined as ALIP-like clusters. The presence of ALIP-like clusters in AML patients within remission was reported to be associated with early relapse of the disease.
Document 3:::
Outline
h1.00: Cytology
h2.00: General histology
H2.00.01.0.00001: Stem cells
H2.00.02.0.00001: Epithelial tissue
H2.00.02.0.01001: Epithelial cell
H2.00.02.0.02001: Surface epithelium
H2.00.02.0.03001: Glandular epithelium
H2.00.03.0.00001: Connective and supportive tissues
H2.00.03.0.01001: Connective tissue cells
H2.00.03.0.02001: Extracellular matrix
H2.00.03.0.03001: Fibres of connective tissues
H2.00.03.1.00001: Connective tissue proper
H2.00.03.1.01001: Ligaments
H2.00.03.2.00001: Mucoid connective tissue; Gelatinous connective tissue
H2.00.03.3.00001: Reticular tissue
H2.00.03.4.00001: Adipose tissue
H2.00.03.5.00001: Cartilage tissue
H2.00.03.6.00001: Chondroid tissue
H2.00.03.7.00001: Bone tissue; Osseous tissue
H2.00.04.0.00001: Haemotolymphoid complex
H2.00.04.1.00001: Blood cells
H2.00.04.1.01001: Erythrocyte; Red blood cell
H2.00.04.1.02001: Leucocyte; White blood cell
H2.00.04.1.03001: Platelet; Thrombocyte
H2.00.04.2.00001: Plasma
H2.00.04.3.00001: Blood cell production
H2.00.04.4.00001: Postnatal sites of haematopoiesis
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
Document 4:::
Hemogenic endothelium is a special subset of endothelial cells scattered within blood vessels that can differentiate into haematopoietic cells.
The development of hematopoietic cells in the embryo proceeds sequentially from mesoderm through the hemangioblast to the hemogenic endothelium and hematopoietic progenitors.
See also
Hemangioblast
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The abnormal cells cannot carry oxygen properly and can get stuck where?
A. Viens
B. capillaries
C. Arteries
D. muscles
Answer:
|
|
ai2_arc-521
|
multiple_choice
|
A student is measuring the boiling point of a salt and water mixture. He takes one temperature measurement of 105°C. Which is the best way to ensure the results are valid?
|
[
"repeat the investigation",
"change the volume of water",
"add more salt to the mixture",
"do the investigation without salt"
] |
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:::
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 2:::
Test equating traditionally refers to the statistical process of determining comparable scores on different forms of an exam. It can be accomplished using either classical test theory or item response theory.
In item response theory, equating is the process of placing scores from two or more parallel test forms onto a common score scale. The result is that scores from two different test forms can be compared directly, or treated as though they came from the same test form. When the tests are not parallel, the general process is called linking. It is the process of equating the units and origins of two scales on which the abilities of students have been estimated from results on different tests. The process is analogous to equating degrees Fahrenheit with degrees Celsius by converting measurements from one scale to the other. The determination of comparable scores is a by-product of equating that results from equating the scales obtained from test results.
Purpose
Suppose that Dick and Jane both take a test to become licensed in a certain profession. Because the high stakes (you get to practice the profession if you pass the test) may create a temptation to cheat, the organization that oversees the test creates two forms. If we know that Dick scored 60% on form A and Jane scored 70% on form B, do we know for sure which one has a better grasp of the material? What if form A is composed of very difficult items, while form B is relatively easy? Equating analyses are performed to address this very issue, so that scores are as fair as possible.
Equating in item response theory
In item response theory, person "locations" (measures of some quality being assessed by a test) are estimated on an interval scale; i.e., locations are estimated in relation to a unit and origin. It is common in educational assessment to employ tests in order to assess different groups of students with the intention of establishing a common scale by equating the origins, and when appropri
Document 3:::
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 4:::
The Texas Math and Science Coaches Association or TMSCA is an organization for coaches of academic University Interscholastic League teams in Texas middle schools and high schools, specifically those that compete in mathematics and science-related tests.
Events
There are four events in the TMSCA at both the middle and high school level: Number Sense, General Mathematics, Calculator Applications, and General Science.
Number Sense is an 80-question exam that students are given only 10 minutes to solve. Additionally, no scratch work or paper calculations are allowed. These questions range from simple calculations such as 99+98 to more complicated operations such as 1001×1938. Each calculation is able to be done with a certain trick or shortcut that makes the calculations easier.
The high school exam includes calculus and other difficult topics in the questions also with the same rules applied as to the middle school version.
It is well known that the grading for this event is particularly stringent as errors such as writing over a line or crossing out potential answers are considered as incorrect answers.
General Mathematics is a 50-question exam that students are given only 40 minutes to solve. These problems are usually more challenging than questions on the Number Sense test, and the General Mathematics word problems take more thinking to figure out. Every problem correct is worth 5 points, and for every problem incorrect, 2 points are deducted. Tiebreakers are determined by the person that misses the first problem and by percent accuracy.
Calculator Applications is an 80-question exam that students are given only 30 minutes to solve. This test requires practice on the calculator, knowledge of a few crucial formulas, and much speed and intensity. Memorizing formulas, tips, and tricks will not be enough. In this event, plenty of practice is necessary in order to master the locations of the keys and develop the speed necessary. All correct questions are worth 5
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A student is measuring the boiling point of a salt and water mixture. He takes one temperature measurement of 105°C. Which is the best way to ensure the results are valid?
A. repeat the investigation
B. change the volume of water
C. add more salt to the mixture
D. do the investigation without salt
Answer:
|
|
sciq-6399
|
multiple_choice
|
The waste of cows releases a lot of which type of gas?
|
[
"carbon dioxide",
"methane",
"sulphur",
"oxygen"
] |
B
|
Relavent Documents:
Document 0:::
Cow dung, also known as cow pats, cow pies or cow manure, is the waste product (faeces) of bovine animal species. These species include domestic cattle ("cows"), bison ("buffalo"), yak, and water buffalo. Cow dung is the undigested residue of plant matter which has passed through the animal's gut. The resultant faecal matter is rich in minerals. Color ranges from greenish to blackish, often darkening soon after exposure to air.
Uses
Fuel
In many parts of the old world, and in the past in mountain regions of Europe, caked and dried cow dung is used as fuel. In India, it is dried into cake like shapes called or , and used as replacement for firewood for cooking in (traditional kitchen stove).
Dung may also be collected and used to produce biogas to generate electricity and heat. The gas is rich in methane and is used in rural areas of India and Pakistan and elsewhere to provide a renewable and stable (but unsustainable) source of electricity.
Fertilizer
Cow dung, which is usually a dark brown color, is often used as manure (agricultural fertilizer). If not recycled into the soil by species such as earthworms and dung beetles, cow dung can dry out and remain on the pasture, creating an area of grazing land which is unpalatable to livestock.
Cow dung is nowadays used for making flower and plant pots. It is plastic free, biodegradable and eco-friendly. Unlike plastic grow bags which harm nature, cow dung pots dissolves naturally and becomes excellent manure for the plant. From 20 July 2020, State Government of Chhattisgarh India started buying cow dung under the Godhan Nyay Yojana scheme. Cow dung procured under this scheme will be utilised for the production of vermicompost fertilizer.
Religious uses
Cow dung is used in Hindu yajna ritual as an important ingredient. Cow dung is also used in the making of pancha-gavya, for use in Hindu rituals. Several Hindu texts - including Yājñavalkya Smṛti and Manusmṛti - state that the pancha-gavya purifies many sins.
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:::
Enteric fermentation is a digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. Because of human agricultural reliance in many parts of the world on animals which digest by enteric fermentation, it is the second largest anthropogenic factor for the increase in methane emissions directly after fossil fuel use.
Ruminants
Ruminant animals are those that have a rumen. A rumen is a multichambered stomach found almost exclusively among some artiodactyl mammals, such as cattle, sheep, and deer, enabling them to eat cellulose-enhanced tough plants and grains that monogastric (i.e., "single-chambered stomached") animals, such as humans, dogs, and cats, cannot digest. Although camels are thought to be ruminants they are not true ruminants.
Enteric fermentation occurs when methane (CH4) is produced in the rumen as microbial fermentation takes place. Over 200 species of microorganisms are present in the rumen, although only about 10% of these play an important role in digestion. Most of the CH4 byproduct is belched by the animal. However, a small percentage of CH4 is also produced in the large intestine and passed out as flatulence.
Methane emissions are an important contribution to global greenhouse gas emissions. The IPCC reports that methane is more than twenty times as effective as CO2 at trapping heat in the atmosphere - though note that it is produced in substantially smaller amounts. Methane represents also a significant energy loss to the animal ranging from 2 to 12% of gross energy intake. So, decreasing the production of enteric CH4 from ruminants without altering animal production is desirable both as a strategy to reduce global greenhouse gas emissions and as a means of improving feed conversion efficiency. In Australia ruminant animals account for over half of their green house gas contribution from methane.
However, in Australia there are ruminant species of the ka
Document 3:::
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 4:::
Manure management refers to capture, storage, treatment, and utilization of animal manures in an environmentally sustainable manner. It can be retained in various holding facilities. Animal manure (also referred to as animal waste) can occur in a liquid, slurry, or solid form. It is utilized by distribution on fields in amounts that enrich soils without causing water pollution or unacceptably high levels of nutrient enrichment. Manure management is a component of nutrient management.
In confined spaces the gasses from manure can lethally asphyxiate humans. There is also a drowning danger.
Risks posed by gases in livestock manure
Livestock manure produces several gases including four main toxic gases, hydrogen sulfide, methane, ammonia and carbon dioxide. In animal housing it is very common in swine and beef breeding to have manure storage under the building's floor. In this setup low concentrations of these toxic gases are commonly noted throughout the year. The highest concentrations of these gases are noted during manure agitation, stirring the manure to homogenize the manure for pumping out of the storage. During these times the concentrations easily approach levels that can pose health issues to the workers and animals in the facilities.
Hydrogen sulfide
Hydrogen Sulfide (), is a naturally occurring gas that is flammable, colorless and poisonous. H2S has a characteristic rotten egg smell, though pungent at first it quickly deadens the sense of smell. People are typically only able to smell at low concentrations. is heavier than air causing the gas to travel close to the ground and collect in low-lying areas. Common names for hydrogen sulfide include hydrosulfuric acid (the product of it reacting with water), stink damp and sewer gas.
Sources of hydrogen sulfide exposure
Hydrogen sulfide naturally occurs in hot springs, crude petroleum and natural gas. is also produced from the bacterial breakdown of animal and human wastes and organic materials in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The waste of cows releases a lot of which type of gas?
A. carbon dioxide
B. methane
C. sulphur
D. oxygen
Answer:
|
|
sciq-3425
|
multiple_choice
|
What is the molten material deep within the earth?
|
[
"magma",
"lava",
"crystals",
"volcanic mass"
] |
A
|
Relavent Documents:
Document 0:::
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time scales of up to thousands of years or more. The crust and upper mantle are distinguished on the basis of chemistry and mineralogy.
Earth's lithosphere
Earth's lithosphere, which constitutes the hard and rigid outer vertical layer of the Earth, includes the crust and the lithospheric mantle (or mantle lithosphere), the uppermost part of the mantle that is not convecting. The lithosphere is underlain by the asthenosphere which is the weaker, hotter, and deeper part of the upper mantle that is able to convect. The lithosphere–asthenosphere boundary is defined by a difference in response to stress. The lithosphere remains rigid for very long periods of geologic time in which it deforms elastically and through brittle failure, while the asthenosphere deforms viscously and accommodates strain through plastic deformation.
The thickness of the lithosphere is thus considered to be the depth to the isotherm associated with the transition between brittle and viscous behavior. The temperature at which olivine becomes ductile (~) is often used to set this isotherm because olivine is generally the weakest mineral in the upper mantle.
The lithosphere is subdivided horizontally into tectonic plates, which often include terranes accreted from other plates.
History of the concept
The concept of the lithosphere as Earth's strong outer layer was described by the English mathematician A. E. H. Love in his 1911 monograph "Some problems of Geodynamics" and further developed by the American geologist Joseph Barrell, who wrote a series of papers about the concept and introduced the term "lithosphere". The concept was based on the presence of significant gravity anomalies over continental crust, from which he inferred that there must exist a strong, s
Document 1:::
The core–mantle boundary (CMB) of Earth lies between the planet's silicate mantle and its liquid iron–nickel outer core, at a depth of below Earth's surface. The boundary is observed via the discontinuity in seismic wave velocities at that depth due to the differences between the acoustic impedances of the solid mantle and the molten outer core. P-wave velocities are much slower in the outer core than in the deep mantle while S-waves do not exist at all in the liquid portion of the core. Recent evidence suggests a distinct boundary layer directly above the CMB possibly made of a novel phase of the basic perovskite mineralogy of the deep mantle named post-perovskite. Seismic tomography studies have shown significant irregularities within the boundary zone and appear to be dominated by the African and Pacific Large Low-Shear-Velocity Provinces (LLSVP).
The uppermost section of the outer core is thought to be about 500–1,800 K hotter than the overlying mantle, creating a thermal boundary layer. The boundary is thought to harbor topography, much like Earth's surface, that is supported by solid-state convection within the overlying mantle. Variations in the thermal properties of the core-mantle boundary may affect how the outer core's iron-rich fluids flow, which are ultimately responsible for Earth's magnetic field.
The D″ region
The approx. 200 km thick layer of the lower mantle directly above the boundary is referred to as the D″ region ("D double-prime" or "D prime prime") and is sometimes included in discussions regarding the core–mantle boundary zone. The D″ name originates from geophysicist Keith Bullen's designations for the Earth's layers. His system was to label each layer alphabetically, A through G, with the crust as 'A' and the inner core as 'G'. In his 1942 publication of his model, the entire lower mantle was the D layer. In 1949, Bullen found his 'D' layer to actually be two different layers. The upper part of the D layer, about 1800 km thick, was r
Document 2:::
The thermal history of Earth involves the study of the cooling history of Earth's interior. It is a sub-field of geophysics. (Thermal histories are also computed for the internal cooling of other planetary and stellar bodies.) The study of the thermal evolution of Earth's interior is uncertain and controversial in all aspects, from the interpretation of petrologic observations used to infer the temperature of the interior, to the fluid dynamics responsible for heat loss, to material properties that determine the efficiency of heat transport.
Overview
Observations that can be used to infer the temperature of Earth's interior range from the oldest rocks on Earth to modern seismic images of the inner core size. Ancient volcanic rocks can be associated with a depth and temperature of melting through their geochemical composition. Using this technique and some geological inferences about the conditions under which the rock is preserved, the temperature of the mantle can be inferred. The mantle itself is fully convective, so that the temperature in the mantle is basically constant with depth outside the top and bottom thermal boundary layers. This is not quite true because the temperature in any convective body under pressure must increase along an adiabat, but the adiabatic temperature gradient is usually much smaller than the temperature jumps at the boundaries. Therefore, the mantle is usually associated with a single or potential temperature that refers to the mid-mantle temperature extrapolated along the adiabat to the surface. The potential temperature of the mantle is estimated to be about 1350 C today. There is an analogous potential temperature of the core but since there are no samples from the core its present-day temperature relies on extrapolating the temperature along an adiabat from the inner core boundary, where the iron solidus is somewhat constrained.
Thermodynamics
The simplest mathematical formulation of the thermal history of Earth's interior i
Document 3:::
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, water, and θέρμη, heat ). Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's crust. In general, this occurs near volcanic activity, but can occur in the shallow to mid crust along deeply penetrating fault irregularities or in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. Hydrothermal circulation often results in hydrothermal mineral deposits.
Seafloor hydrothermal circulation
Hydrothermal circulation in the oceans is the passage of the water through mid-oceanic ridge systems.
The term includes both the circulation of the well-known, high-temperature vent waters near the ridge crests, and the much-lower-temperature, diffuse flow of water through sediments and buried basalts further from the ridge crests. The former circulation type is sometimes termed "active", and the latter "passive". In both cases, the principle is the same: Cold, dense seawater sinks into the basalt of the seafloor and is heated at depth whereupon it rises back to the rock-ocean water interface due to its lesser density. The heat source for the active vents is the newly formed basalt, and, for the highest temperature vents, the underlying magma chamber. The heat source for the passive vents is the still-cooling older basalts. Heat flow studies of the seafloor suggest that basalts within the oceanic crust take millions of years to completely cool as they continue to support passive hydrothermal circulation systems.
Hydrothermal vents are locations on the seafloor where hydrothermal fluids mix into the overlying ocean. Perhaps the best-known vent forms are the naturally occurring chimneys referred to as black smokers.
Volcanic and magma related hydrothermal circulation
Hydrothermal circulation is not limited to ocean ridge environments. Hydrothermal circulating convection cells can exist in
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the molten material deep within the earth?
A. magma
B. lava
C. crystals
D. volcanic mass
Answer:
|
|
ai2_arc-600
|
multiple_choice
|
The students observed a large crack found in a boulder with a tree growing out of it. Which process were the students observing?
|
[
"oxidizing",
"deposition",
"weathering",
"decomposition"
] |
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 geology, petrifaction or petrification () is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood typifies this process, but all organisms, from bacteria to vertebrates, can become petrified (although harder, more durable matter such as bone, beaks, and shells survive the process better than softer remains such as muscle tissue, feathers, or skin). Petrifaction takes place through a combination of two similar processes: permineralization and replacement. These processes create replicas of the original specimen that are similar down to the microscopic level.
Processes
Permineralization
One of the processes involved in petrifaction is permineralization. The fossils created through this process tend to contain a large amount of the original material of the specimen. This process occurs when groundwater containing dissolved minerals (most commonly quartz, calcite, apatite (calcium phosphate), siderite (iron carbonate), and pyrite), fills pore spaces and cavities of specimens, particularly bone, shell or wood. The pores of the organisms' tissues are filled when these minerals precipitate out of the water. Two common types of permineralization are silicification and pyritization.
Silicification
Silicification is the process in which organic matter becomes saturated with silica. A common source of silica is volcanic material. Studies have shown that in this process, most of the original organic matter is destroyed. Silicification most often occurs in two environments—either the specimen is buried in sediments of deltas and floodplains or organisms are buried in volcanic ash. Water must be present for silicification to occur because it reduces the amount of oxygen present and therefore reduces the deterioration of the organism by fungi, maintains organism shape, and allows for the transportation and deposition of silica. The process begins
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In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects.
Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing rocks. Metamorphic rocks are formed when existing rocks are subjected to such high pressures and temperatures that they are transformed without significant melting.
Humanity has made use of rocks since the earliest humans. This early period, called the Stone Age, saw the development of many stone tools. Stone was then used as a major component in the construction of buildings and early infrastructure. Mining developed to extract rocks from the Earth and obtain the minerals within them, including metals. Modern technology has allowed the development of new man-made rocks and rock-like substances, such as concrete.
Study
Geology is the study of Earth and its components, including the study of rock formations. Petrology is the study of the character and origin of rocks. Mineralogy is the study of the mineral components that create rocks. The study of rocks and their components has contributed to the geological understanding of Earth's history, the archaeological understanding of human history, and the
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National Computer Rank Examination (NCRE) is a national exam held by China Education Department to test the computer proficiency and programming skill of non-computer specialized students and practitioners. The programming language can be chosen by examinees, including C, C++, Java, Visual Basic and Python 3. NCRE is widely recognized by enterprises and organizations in China.
Education in China
Computer programming
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Materials science has shaped the development of civilizations since the dawn of mankind. Better materials for tools and weapons has allowed mankind to spread and conquer, and advancements in material processing like steel and aluminum production continue to impact society today. Historians have regarded materials as such an important aspect of civilizations such that entire periods of time have defined by the predominant material used (Stone Age, Bronze Age, Iron Age). For most of recorded history, control of materials had been through alchemy or empirical means at best. The study and development of chemistry and physics assisted the study of materials, and eventually the interdisciplinary study of materials science emerged from the fusion of these studies. The history of materials science is the study of how different materials were used and developed through the history of Earth and how those materials affected the culture of the peoples of the Earth. The term "Silicon Age" is sometimes used to refer to the modern period of history during the late 20th to early 21st centuries.
Prehistory
In many cases, different cultures leave their materials as the only records; which anthropologists can use to define the existence of such cultures. The progressive use of more sophisticated materials allows archeologists to characterize and distinguish between peoples. This is partially due to the major material of use in a culture and to its associated benefits and drawbacks. Stone-Age cultures were limited by which rocks they could find locally and by which they could acquire by trading. The use of flint around 300,000 BCE is sometimes considered the beginning of the use of ceramics. The use of polished stone axes marks a significant advance, because a much wider variety of rocks could serve as tools.
The innovation of smelting and casting metals in the Bronze Age started to change the way that cultures developed and interacted with each other. Starting around 5,500 BCE,
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The students observed a large crack found in a boulder with a tree growing out of it. Which process were the students observing?
A. oxidizing
B. deposition
C. weathering
D. decomposition
Answer:
|
|
sciq-1177
|
multiple_choice
|
What is a wall of rocks or concrete called?
|
[
"groin",
"knee",
"ankle",
"foot"
] |
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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In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
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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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The Mathematics Subject Classification (MSC) is an alphanumerical classification scheme that has collaboratively been produced by staff of, and based on the coverage of, the two major mathematical reviewing databases, Mathematical Reviews and Zentralblatt MATH. The MSC is used by many mathematics journals, which ask authors of research papers and expository articles to list subject codes from the Mathematics Subject Classification in their papers. The current version is MSC2020.
Structure
The MSC is a hierarchical scheme, with three levels of structure. A classification can be two, three or five digits long, depending on how many levels of the classification scheme are used.
The first level is represented by a two-digit number, the second by a letter, and the third by another two-digit number. For example:
53 is the classification for differential geometry
53A is the classification for classical differential geometry
53A45 is the classification for vector and tensor analysis
First level
At the top level, 64 mathematical disciplines are labeled with a unique two-digit number. In addition to the typical areas of mathematical research, there are top-level categories for "History and Biography", "Mathematics Education", and for the overlap with different sciences. Physics (i.e. mathematical physics) is particularly well represented in the classification scheme with a number of different categories including:
Fluid mechanics
Quantum mechanics
Geophysics
Optics and electromagnetic theory
All valid MSC classification codes must have at least the first-level identifier.
Second level
The second-level codes are a single letter from the Latin alphabet. These represent specific areas covered by the first-level discipline. The second-level codes vary from discipline to discipline.
For example, for differential geometry, the top-level code is 53, and the second-level codes are:
A for classical differential geometry
B for local differential geometry
C for glo
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Advanced Placement (AP) Calculus (also known as AP Calc, Calc AB / Calc BC or simply AB / BC) is a set of two distinct Advanced Placement calculus courses and exams offered by the American nonprofit organization College Board. AP Calculus AB covers basic introductions to limits, derivatives, and integrals. AP Calculus BC covers all AP Calculus AB topics plus additional topics (including integration by parts, Taylor series, parametric equations, vector calculus, and polar coordinate functions).
AP Calculus AB
AP Calculus AB is an Advanced Placement calculus course. It is traditionally taken after precalculus and is the first calculus course offered at most schools except for possibly a regular calculus class. The Pre-Advanced Placement pathway for math helps prepare students for further Advanced Placement classes and exams.
Purpose
According to the College Board:
Topic outline
The material includes the study and application of differentiation and integration, and graphical analysis including limits, asymptotes, and continuity. An AP Calculus AB course is typically equivalent to one semester of college calculus.
Analysis of graphs (predicting and explaining behavior)
Limits of functions (one and two sided)
Asymptotic and unbounded behavior
Continuity
Derivatives
Concept
At a point
As a function
Applications
Higher order derivatives
Techniques
Integrals
Interpretations
Properties
Applications
Techniques
Numerical approximations
Fundamental theorem of calculus
Antidifferentiation
L'Hôpital's rule
Separable differential equations
AP Calculus BC
AP Calculus BC is equivalent to a full year regular college course, covering both Calculus I and II. After passing the exam, students may move on to Calculus III (Multivariable Calculus).
Purpose
According to the College Board,
Topic outline
AP Calculus BC includes all of the topics covered in AP Calculus AB, as well as the following:
Convergence tests for series
Taylor series
Parametric equations
Polar functions (inclu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a wall of rocks or concrete called?
A. groin
B. knee
C. ankle
D. foot
Answer:
|
|
sciq-2009
|
multiple_choice
|
Whose laws of motion are the foundation of dynamics?
|
[
"einstein",
"bell",
"newton",
"aristotle"
] |
C
|
Relavent Documents:
Document 0:::
In physics, a number of noted theories of the motion of objects have developed. Among the best known are:
Classical mechanics
Newton's laws of motion
Euler's laws of motion
Cauchy's equations of motion
Kepler's laws of planetary motion
General relativity
Special relativity
Quantum mechanics
Motion (physics)
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Physics education research (PER) is a form of discipline-based education research specifically related to the study of the teaching and learning of physics, often with the aim of improving the effectiveness of student learning. PER draws from other disciplines, such as sociology, cognitive science, education and linguistics, and complements them by reflecting the disciplinary knowledge and practices of physics. Approximately eighty-five institutions in the United States conduct research in science and physics education.
Goals
One primary goal of PER is to develop pedagogical techniques and strategies that will help students learn physics more effectively and help instructors to implement these techniques. Because even basic ideas in physics can be confusing, together with the possibility of scientific misconceptions formed from teaching through analogies, lecturing often does not erase common misconceptions about physics that students acquire before they are taught physics. Research often focuses on learning more about common misconceptions that students bring to the physics classroom so that techniques can be devised to help students overcome these misconceptions.
In most introductory physics courses, mechanics is usually the first area of physics that is taught. Newton's laws of motion about interactions between forces and objects are central to the study of mechanics. Many students hold the Aristotelian misconception that a net force is required to keep a body moving; instead, motion is modeled in modern physics with Newton's first law of inertia, stating that a body will keep its state of rest or movement unless a net force acts on the body. Like students who hold this misconception, Newton arrived at his three laws of motion through empirical analysis, although he did it with an extensive study of data that included astronomical observations. Students can erase such as misconception in a nearly frictionless environment, where they find that
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Dynamics is the branch of classical mechanics that is concerned with the study of forces and their effects on motion. Isaac Newton was the first to formulate the fundamental physical laws that govern dynamics in classical non-relativistic physics, especially his second law of motion.
Principles
Generally speaking, researchers involved in dynamics study how a physical system might develop or alter over time and study the causes of those changes. In addition, Newton established the fundamental physical laws which govern dynamics in physics. By studying his system of mechanics, dynamics can be understood. In particular, dynamics is mostly related to Newton's second law of motion. However, all three laws of motion are taken into account because these are interrelated in any given observation or experiment.
Linear and rotational dynamics
The study of dynamics falls under two categories: linear and rotational. Linear dynamics pertains to objects moving in a line and involves such quantities as force, mass/inertia, displacement (in units of distance), velocity (distance per unit time), acceleration (distance per unit of time squared) and momentum (mass times unit of velocity). Rotational dynamics pertains to objects that are rotating or moving in a curved path and involves such quantities as torque, moment of inertia/rotational inertia, angular displacement (in radians or less often, degrees), angular velocity (radians per unit time), angular acceleration (radians per unit of time squared) and angular momentum (moment of inertia times unit of angular velocity). Very often, objects exhibit linear and rotational motion.
For classical electromagnetism, Maxwell's equations describe the kinematics. The dynamics of classical systems involving both mechanics and electromagnetism are described by the combination of Newton's laws, Maxwell's equations, and the Lorentz force.
Force
From Newton, force can be defined as an exertion or pressure which can cause an object to ac
Document 3:::
Physics education or physics teaching refers to the education methods currently used to teach physics. The occupation is called physics educator or physics teacher. Physics education research refers to an area of pedagogical research that seeks to improve those methods. Historically, physics has been taught at the high school and college level primarily by the lecture method together with laboratory exercises aimed at verifying concepts taught in the lectures. These concepts are better understood when lectures are accompanied with demonstration, hand-on experiments, and questions that require students to ponder what will happen in an experiment and why. Students who participate in active learning for example with hands-on experiments learn through self-discovery. By trial and error they learn to change their preconceptions about phenomena in physics and discover the underlying concepts. Physics education is part of the broader area of science education.
Ancient Greece
Aristotle wrote what is considered now as the first textbook of physics. Aristotle's ideas were taught unchanged until the Late Middle Ages, when scientists started making discoveries that didn't fit them. For example, Copernicus' discovery contradicted Aristotle's idea of an Earth-centric universe. Aristotle's ideas about motion weren't displaced until the end of the 17th century, when Newton published his ideas.
Today's physics students often think of physics concepts in Aristotelian terms, despite being taught only Newtonian concepts.
Hong Kong
High schools
In Hong Kong, physics is a subject for public examination. Local students in Form 6 take the public exam of Hong Kong Diploma of Secondary Education (HKDSE).
Compare to the other syllabus include GCSE, GCE etc. which learn wider and boarder of different topics, the Hong Kong syllabus is learning more deeply and more challenges with calculations. Topics are narrow down to a smaller amount compared to the A-level due to the insufficient teachi
Document 4:::
This article deals with the history of classical mechanics.
Precursors to classical mechanics
Antiquity
The ancient Greek philosophers, Aristotle in particular, were among the first to propose that abstract principles govern nature. Aristotle argued, in On the Heavens, that terrestrial bodies rise or fall to their "natural place" and stated as a law the correct approximation that an object's speed of fall is proportional to its weight and inversely proportional to the density of the fluid it is falling through. Aristotle believed in logic and observation but it would be more than eighteen hundred years before Francis Bacon would first develop the scientific method of experimentation, which he called a vexation of nature.
Aristotle saw a distinction between "natural motion" and "forced motion", and he believed that 'in a void' i.e.vacuum, a body at rest will remain at rest and a body in motion will continue to have the same motion. In this way, Aristotle was the first to approach something similar to the law of inertia. However, he believed a vacuum would be impossible because the surrounding air would rush in to fill it immediately. He also believed that an object would stop moving in an unnatural direction once the applied forces were removed. Later Aristotelians developed an elaborate explanation for why an arrow continues to fly through the air after it has left the bow, proposing that an arrow creates a vacuum in its wake, into which air rushes, pushing it from behind. Aristotle's beliefs were influenced by Plato's teachings on the perfection of the circular uniform motions of the heavens. As a result, he conceived of a natural order in which the motions of the heavens were necessarily perfect, in contrast to the terrestrial world of changing elements, where individuals come to be and pass away.
There is another tradition that goes back to the ancient Greeks where mathematics is used to analyze bodies at rest or in motion, which may found as early as the
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Whose laws of motion are the foundation of dynamics?
A. einstein
B. bell
C. newton
D. aristotle
Answer:
|
|
sciq-5091
|
multiple_choice
|
The earth's atmosphere, climate, and living things are effected by what feature that covers more than 70 percent of earth's surface?
|
[
"mountains",
"oceans",
"continents",
"rivers"
] |
B
|
Relavent Documents:
Document 0:::
Earth system science (ESS) is the application of systems science to the Earth. In particular, it considers interactions and 'feedbacks', through material and energy fluxes, between the Earth's sub-systems' cycles, processes and "spheres"—atmosphere, hydrosphere, cryosphere, geosphere, pedosphere, lithosphere, biosphere, and even the magnetosphere—as well as the impact of human societies on these components. At its broadest scale, Earth system science brings together researchers across both the natural and social sciences, from fields including ecology, economics, geography, geology, glaciology, meteorology, oceanography, climatology, paleontology, sociology, and space science. Like the broader subject of systems science, Earth system science assumes a holistic view of the dynamic interaction between the Earth's spheres and their many constituent subsystems fluxes and processes, the resulting spatial organization and time evolution of these systems, and their variability, stability and instability. Subsets of Earth System science include systems geology and systems ecology, and many aspects of Earth System science are fundamental to the subjects of physical geography and climate science.
Definition
The Science Education Resource Center, Carleton College, offers the following description: "Earth System science embraces chemistry, physics, biology, mathematics and applied sciences in transcending disciplinary boundaries to treat the Earth as an integrated system. It seeks a deeper understanding of the physical, chemical, biological and human interactions that determine the past, current and future states of the Earth. Earth System science provides a physical basis for understanding the world in which we live and upon which humankind seeks to achieve sustainability".
Earth System science has articulated four overarching, definitive and critically important features of the Earth System, which include:
Variability: Many of the Earth System's natural 'modes' and variab
Document 1:::
Land cover is the physical material at the surface of Earth. Land covers include grass, asphalt, trees, bare ground, water, etc. Earth cover is the expression used by ecologist Frederick Edward Clements that has its closest modern equivalent being vegetation. The expression continues to be used by the United States Bureau of Land Management.
There are two primary methods for capturing information on land cover: field survey, and analysis of remotely sensed imagery. Land change models can be built from these types of data to assess changes in land cover over time.
One of the major land cover issues (as with all natural resource inventories) is that every survey defines similarly named categories in different ways. For instance, there are many definitions of "forest"—sometimes within the same organisation—that may or may not incorporate a number of different forest features (e.g., stand height, canopy cover, strip width, inclusion of grasses, and rates of growth for timber production). Areas without trees may be classified as forest cover "if the intention is to re-plant" (UK and Ireland), while areas with many trees may not be labelled as forest "if the trees are not growing fast enough" (Norway and Finland).
Distinction from "land use"
"Land cover" is distinct from "land use", despite the two terms often being used interchangeably. Land use is a description of how people utilize the land and of socio-economic activity. Urban and agricultural land uses are two of the most commonly known land use classes. At any one point or place, there may be multiple and alternate land uses, the specification of which may have a political dimension. The origins of the "land cover/land use" couplet and the implications of their confusion are discussed in Fisher et al. (2005).
Types
Following table is Land Cover statistics by Food and Agriculture Organization (FAO) with 14 classes.
Mapping
Land cover change detection using remote sensing and geospatial data provides baselin
Document 2:::
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
Document 3:::
Bioclimatology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or longer (in contrast to biometeorology).
Examples of relevant processes
Climate processes largely control the distribution, size, shape and properties of living organisms on Earth. For instance, the general circulation of the atmosphere on a planetary scale broadly determines the location of large deserts or the regions subject to frequent precipitation, which, in turn, greatly determine which organisms can naturally survive in these environments. Furthermore, changes in climates, whether due to natural processes or to human interferences, may progressively modify these habitats and cause overpopulation or extinction of indigenous species.
The biosphere, for its part, and in particular continental vegetation, which constitutes over 99% of the total biomass, has played a critical role in establishing and maintaining the chemical composition of the Earth's atmosphere, especially during the early evolution of the planet (See History of Earth for more details on this topic). Currently, the terrestrial vegetation exchanges some 60 billion tons of carbon with the atmosphere on an annual basis (through processes of carbon fixation and carbon respiration), thereby playing a critical role in the carbon cycle. On a global and annual basis, small imbalances between these two major fluxes, as do occur through changes in land cover and land use, contribute to the current increase in atmospheric carbon dioxide.
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At the global scale sustainability and environmental management involves managing the oceans, freshwater systems, land and atmosphere, according to sustainability principles.
Land use change is fundamental to the operations of the biosphere because alterations in the relative proportions of land dedicated to urbanisation, agriculture, forest, woodland, grassland and pasture have a marked effect on the global water, carbon and nitrogen biogeochemical cycles. Management of the Earth's atmosphere involves assessment of all aspects of the carbon cycle to identify opportunities to address human-induced climate change and this has become a major focus of scientific research because of the potential catastrophic effects on biodiversity and human communities. Ocean circulation patterns have a strong influence on climate and weather and, in turn, the food supply of both humans and other organisms.
Atmosphere
In March 2009, at a meeting of the Copenhagen Climate Council, 2,500 climate experts from 80 countries issued a keynote statement that there is now "no excuse" for failing to act on global warming and without strong carbon reduction targets "abrupt or irreversible" shifts in climate may occur that "will be very difficult for contemporary societies to cope with". Management of the global atmosphere now involves assessment of all aspects of the carbon cycle to identify opportunities to address human-induced climate change and this has become a major focus of scientific research because of the potential catastrophic effects on biodiversity and human communities.
Other human impacts on the atmosphere include the air pollution in cities, the pollutants including toxic chemicals like nitrogen oxides, sulphur oxides, volatile organic compounds and airborne particulate matter that produce photochemical smog and acid rain, and the chlorofluorocarbons that degrade the ozone layer. Anthropogenic particulates such as sulfate aerosols in the atmosphere reduce the direct irradianc
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The earth's atmosphere, climate, and living things are effected by what feature that covers more than 70 percent of earth's surface?
A. mountains
B. oceans
C. continents
D. rivers
Answer:
|
|
sciq-10178
|
multiple_choice
|
Name the two types of water turtles live in.
|
[
"arctic water and ice water",
"ocean water and fresh water",
"ocean water and sea water",
"river water and lake water"
] |
B
|
Relavent Documents:
Document 0:::
The Turtle Taxonomy Working Group (TTWG) is an informal working group of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group (TFTSG). It is composed of a number of leading turtle taxonomists, with varying participation by individual participants over the years, some dropping out and others joining.
Works
The TTWG has produced an annual checklist of living and recently extinct turtles since 2007, deliberates on proposed changes to turtle taxonomy, and describes its consideration whether to accept, reject, or suspend adoption of proposed changes in a series of annotations to the checklist. Recent versions of the checklist have included full primary synonymies and citations to all original descriptions of recent turtle taxa, as well as CITES and IUCN Red List status of each species as applicable.
Document 1:::
Aquatic science is the study of the various bodies of water that make up our planet including oceanic and freshwater environments. Aquatic scientists study the movement of water, the chemistry of water, aquatic organisms, aquatic ecosystems, the movement of materials in and out of aquatic ecosystems, and the use of water by humans, among other things. Aquatic scientists examine current processes as well as historic processes, and the water bodies that they study can range from tiny areas measured in millimeters to full oceans. Moreover, aquatic scientists work in Interdisciplinary groups. For example, a physical oceanographer might work with a biological oceanographer to understand how physical processes, such as tropical cyclones or rip currents, affect organisms in the Atlantic Ocean. Chemists and biologists, on the other hand, might work together to see how the chemical makeup of a certain body of water affects the plants and animals that reside there. Aquatic scientists can work to tackle global problems such as global oceanic change and local problems, such as trying to understand why a drinking water supply in a certain area is polluted.
There are two main fields of study that fall within the field of aquatic science. These fields of study include oceanography and limnology.
Oceanography
Oceanography refers to the study of the physical, chemical, and biological characteristics of oceanic environments. Oceanographers study the history, current condition, and future of the planet's oceans. They also study marine life and ecosystems, ocean circulation, plate tectonics, the geology of the seafloor, and the chemical and physical properties of the ocean.
Oceanography is interdisciplinary. For example, there are biological oceanographers and marine biologists. These scientists specialize in marine organisms. They study how these organisms develop, their relationship with one another, and how they interact and adapt to their environment. Biological oceanographers
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The Hoàn Kiếm turtle, also Rafetus leloii, was an obsolete or controversial taxon of turtle from Southeast Asia, based on specimens from Hoàn Kiếm Lake in Hanoi, Vietnam. Most experts classify this turtle as synonymous with the rare Yangtze giant softshell turtle (Rafetus swinhoei), although some Vietnamese biologists asserted that R. leloii is a distinct species. If the two taxa are to be considered distinct, R. leloii may be considered extinct.
The last known turtle, affectionately known to locals as "Cụ Rùa", meaning “great grandfather turtle” in Vietnamese, was reported dead on 19 January 2016. A local man saw the body of the turtle floating in the water and reported it to the authorities. The last time the turtle was spotted alive was on 21 December 2015.
Classification
Most authorities classify leloii as a junior synonym of the Yangtze giant softshell turtle, based a study by Farkas et al. However, some Vietnamese biologists, such as Hà Đình Đức, who first described leloii, and Le Tran Binh, insist that the two turtles are not the same species. Le points out genetic differences as well as differences in morphology, re-describing the Hoan Kiem turtle as Rafetus vietnamensis. However, Farkas et al. repeated their 2003 conclusion in 2011, stating that differences between specimens may be due to age. They also pointed out that Le et al. did not adequately describe their methods for DNA sequencing, and that the genetic sequences used were never sent to GenBank. They also criticized the fact that Le et al. violated ICZN Code by renaming the species from leloii to vietnamensis on the grounds of “appropriateness”. Another genetic analysis was purportedly when the turtle was rescued and cleaned, which allegedly showed it to be female and distinct from the R. swinhoei of China and Đồng Mô, Vietnam. However, the results were not formally announced or ever published in a peer-reviewed research article, and some skepticism has been cast on the results.
Đức has also h
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The Cowardin classification system is a system for classifying wetlands, devised by Lewis M. Cowardin et al. in 1979 for the United States Fish and Wildlife Service. The system includes five main types of wetlands:
Marine wetlands- which are areas exposed to the open ocean
Estuarine wetlands- partially enclosed by land and also exposed to a mixture of fresh and salt water bodies of water
Riverine wetlands- associated with flowing water
Lacustrine wetlands- associated with a lake or other body of fresh water
Palustrine wetlands- freshwater wetlands not associated with a river or lake.
The primary purpose of this ecological classification system was to establish consistent terms and definitions used in inventory of wetlands and to provide standard measurements for mapping these lands.
See also
Wetland conservation
Wetlands of the United States
Document 4:::
Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is observed in reptiles and teleost fish, with some reports of it occurring in species of shrimp.TSD differs from the chromosomal sex-determination systems common among vertebrates. It is the most studied type of environmental sex determination (ESD). Some other conditions, e.g. density, pH, and environmental background color, are also observed to alter sex ratio, which could be classified either as temperature-dependent sex determination or temperature-dependent sex differentiation, depending on the involved mechanisms. As sex-determining mechanisms, TSD and genetic sex determination (GSD) should be considered in an equivalent manner, which can lead to reconsidering the status of fish species that are claimed to have TSD when submitted to extreme temperatures instead of the temperature experienced during development in the wild, since changes in sex ratio with temperature variation are ecologically and evolutionally relevant.
While TSD has been observed in many reptile and fish species, the genetic differences between sexes and molecular mechanisms of TSD have not been determined. The cortisol-mediated pathway and epigenetic regulatory pathway are thought to be the potential mechanisms involved in TSD.
The eggs are affected by the temperature at which they are incubated during the middle one-third of embryonic development. This critical period of incubation is known as the thermosensitive period. The specific time of sex-commitment is known due to several authors resolving histological chronology of sex differentiation in the gonads of turtles with TSD.
Thermosensitive period
The thermosensitive, or temperature-sensitive, period is the period during development when sex is irreversibly determined. It is used in reference to species with temperature-dependent
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Name the two types of water turtles live in.
A. arctic water and ice water
B. ocean water and fresh water
C. ocean water and sea water
D. river water and lake water
Answer:
|
|
sciq-9798
|
multiple_choice
|
Strong bands of dense, regular connective tissue that connect muscles to bones are called what?
|
[
"cartilage",
"veins",
"tendons",
"membranes"
] |
C
|
Relavent Documents:
Document 0:::
Dense regular connective tissue (DRCT) provides connection between different tissues in the human body. The collagen fibers in dense regular connective tissue are bundled in a parallel fashion. DRCT is divided into white fibrous connective tissue and yellow fibrous connective tissue, both of which occur in two forms: cord arrangement and sheath arrangement.
In cord arrangement, bundles of collagen and matrix are distributed in regular alternate patterns. In sheath arrangement, collagen bundles and matrix are distributed in irregular patterns, sometimes in the form of a network. It is similar to areolar tissue, but in DRCT elastic fibers are completely absent.
Structures formed
An example of their use is in tendons, which connect muscle to bone and derive their strength from the regular, longitudinal arrangement of bundles of collagen fibers.
Ligaments bind bone to bone and are similar in structure to tendons.
Aponeuroses are layers of flat, broad tendons that join muscles and the body parts the muscles act upon, whether it be bone or muscle.
Functions
Dense regular connective tissue has great tensile strength that resists pulling forces especially well in one direction.
DRCT has a very poor blood supply, which is why damaged tendons and ligaments are slow to heal.
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Outline
h1.00: Cytology
h2.00: General histology
H2.00.01.0.00001: Stem cells
H2.00.02.0.00001: Epithelial tissue
H2.00.02.0.01001: Epithelial cell
H2.00.02.0.02001: Surface epithelium
H2.00.02.0.03001: Glandular epithelium
H2.00.03.0.00001: Connective and supportive tissues
H2.00.03.0.01001: Connective tissue cells
H2.00.03.0.02001: Extracellular matrix
H2.00.03.0.03001: Fibres of connective tissues
H2.00.03.1.00001: Connective tissue proper
H2.00.03.1.01001: Ligaments
H2.00.03.2.00001: Mucoid connective tissue; Gelatinous connective tissue
H2.00.03.3.00001: Reticular tissue
H2.00.03.4.00001: Adipose tissue
H2.00.03.5.00001: Cartilage tissue
H2.00.03.6.00001: Chondroid tissue
H2.00.03.7.00001: Bone tissue; Osseous tissue
H2.00.04.0.00001: Haemotolymphoid complex
H2.00.04.1.00001: Blood cells
H2.00.04.1.01001: Erythrocyte; Red blood cell
H2.00.04.1.02001: Leucocyte; White blood cell
H2.00.04.1.03001: Platelet; Thrombocyte
H2.00.04.2.00001: Plasma
H2.00.04.3.00001: Blood cell production
H2.00.04.4.00001: Postnatal sites of haematopoiesis
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
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Soft tissue is all the tissue in the body that is not hardened by the processes of ossification or calcification such as bones and teeth. Soft tissue connects, surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, fat, fibrous tissue, lymph and blood vessels, fasciae, and synovial membranes.
It is sometimes defined by what it is not – such as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia".
Composition
The characteristic substances inside the extracellular matrix of soft tissue are the collagen, elastin and ground substance. Normally the soft tissue is very hydrated because of the ground substance. The fibroblasts are the most common cell responsible for the production of soft tissues' fibers and ground substance. Variations of fibroblasts, like chondroblasts, may also produce these substances.
Mechanical characteristics
At small strains, elastin confers stiffness to the tissue and stores most of the strain energy. The collagen fibers are comparatively inextensible and are usually loose (wavy, crimped). With increasing tissue deformation the collagen is gradually stretched in the direction of deformation. When taut, these fibers produce a strong growth in tissue stiffness. The composite behavior is analogous to a nylon stocking, whose rubber band does the role of elastin as the nylon does the role of collagen. In soft tissues, the collagen limits the deformation and protects the tissues from injury.
Human soft tissue is highly deformable, and its mechanical properties vary significantly from one person to another. Impact testing results showed that the stiffness and the damping resistance of a test subject’s tissue are correlated with the mass, velocity, and size of the striking object. Such properties may be useful for forensics investigation when contusions were induced. When a solid object impacts a human soft tissue, the energy of the impact will be absorbed by the tissues
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Vertebrates
Tendon cells, or tenocytes, are elongated fibroblast type cells. The cytoplasm is stretched between the collagen fibres of the tendon. They have a central cell nucleus with a prominent nucleolus. Tendon cells have a well-developed rough endoplasmic reticulum and they are responsible for synthesis and turnover of tendon fibres and ground substance.
Invertebrates
Tendon cells form a connecting epithelial layer between the muscle and shell in molluscs. In gastropods, for example, the retractor muscles connect to the shell via tendon cells. Muscle cells are attached to the collagenous myo-tendon space via hemidesmosomes. The myo-tendon space is then attached to the base of the tendon cells via basal hemidesmosomes, while apical hemidesmosomes, which sit atop microvilli, attach the tendon cells to a thin layer of collagen. This is in turn attached to the shell via organic fibres which insert into the shell. Molluscan tendon cells appear columnar and contain a large basal cell nucleus. The cytoplasm is filled with granular endoplasmic reticulum and sparse golgi. Dense bundles of microfilaments run the length of the cell connecting the basal to the apical hemidesmosomes.
See also
List of human cell types derived from the germ layers
List of distinct cell types in the adult human body
Document 4:::
Stroma () is the part of a tissue or organ with a structural or connective role. It is made up of all the parts without specific functions of the organ - for example, connective tissue, blood vessels, ducts, etc. The other part, the parenchyma, consists of the cells that perform the function of the tissue or organ.
There are multiple ways of classifying tissues: one classification scheme is based on tissue functions and another analyzes their cellular components. Stromal tissue falls into the "functional" class that contributes to the body's support and movement. The cells which make up stroma tissues serve as a matrix in which the other cells are embedded. Stroma is made of various types of stromal cells.
Examples of stroma include:
stroma of iris
stroma of cornea
stroma of ovary
stroma of thyroid gland
stroma of thymus
stroma of bone marrow
lymph node stromal cell
multipotent stromal cell (mesenchymal stem cell)
Structure
Stromal connective tissues are found in the stroma; this tissue belongs to the group connective tissue proper. The function of connective tissue proper is to secure the parenchymal tissue, including blood vessels and nerves of the stroma, and to construct organs and spread mechanical tension to reduce localised stress. Stromal tissue is primarily made of extracellular matrix containing connective tissue cells. Extracellular matrix is primarily composed of ground substance - a porous, hydrated gel, made mainly from proteoglycan aggregates - and connective tissue fibers. There are three types of fibers commonly found within the stroma: collagen type I, elastic, and reticular (collagen type III) fibres.
Cells
Wandering cells - cells that migrate into the tissue from blood stream in response to a variety of stimuli; for example, immune system blood cells causing inflammatory response.
Fixed cells - cells that are permanent inhabitants of the tissue.
Fibroblast - produce and secrete the organic parts of the ground substance and extrace
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Strong bands of dense, regular connective tissue that connect muscles to bones are called what?
A. cartilage
B. veins
C. tendons
D. membranes
Answer:
|
|
ai2_arc-952
|
multiple_choice
|
Two balls rolled down two identical inclined planes. The balls were exactly the same mass and size, but one ball rolled down the inclined plane faster. Identify a possible reason that one ball rolled faster than the other ball.
|
[
"One ball was red and the other ball was blue.",
"One ball was new and the other ball was old.",
"One ball was shiny and the other ball was dull.",
"One ball was sticky and the other ball was smooth."
] |
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
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Adaptive comparative judgement is a technique borrowed from psychophysics which is able to generate reliable results for educational assessment – as such it is an alternative to traditional exam script marking. In the approach, judges are presented with pairs of student work and are then asked to choose which is better, one or the other. By means of an iterative and adaptive algorithm, a scaled distribution of student work can then be obtained without reference to criteria.
Introduction
Traditional exam script marking began in Cambridge 1792 when, with undergraduate numbers rising, the importance of proper ranking of students was growing. So in 1792 the new Proctor of Examinations, William Farish, introduced marking, a process in which every examiner gives a numerical score to each response by every student, and the overall total mark puts the students in the final rank order. Francis Galton (1869) noted that, in an unidentified year about 1863, the Senior Wrangler scored 7,634 out of a maximum of 17,000, while the Second Wrangler scored 4,123. (The 'Wooden Spoon' scored only 237.)
Prior to 1792, a team of Cambridge examiners convened at 5pm on the last day of examining, reviewed the 19 papers each student had sat – and published their rank order at midnight. Marking solved the problems of numbers and prevented unfair personal bias, and its introduction was a step towards modern objective testing, the format it is best suited to. But the technology of testing that followed, with its major emphasis on reliability and the automatisation of marking, has been an uncomfortable partner for some areas of educational achievement: assessing writing or speaking, and other kinds of performance need something more qualitative and judgemental.
The technique of Adaptive Comparative Judgement is an alternative to marking. It returns to the pre-1792 idea of sorting papers according to their quality, but retains the guarantee of reliability and fairness. It is by far the most rel
Document 2:::
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
Document 4:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Two balls rolled down two identical inclined planes. The balls were exactly the same mass and size, but one ball rolled down the inclined plane faster. Identify a possible reason that one ball rolled faster than the other ball.
A. One ball was red and the other ball was blue.
B. One ball was new and the other ball was old.
C. One ball was shiny and the other ball was dull.
D. One ball was sticky and the other ball was smooth.
Answer:
|
|
sciq-8662
|
multiple_choice
|
Intestinal cells combine with proteins to create what?
|
[
"amino acids",
"chondrocytes",
"lipoproteins",
"chylomicrons"
] |
D
|
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
Document 1:::
Cellular components are the complex biomolecules and structures of which cells, and thus living organisms, are composed. Cells are the structural and functional units of life. The smallest organisms are single cells, while the largest organisms are assemblages of trillions of cells. DNA, double stranded macromolecule that carries the hereditary information of the cell and found in all living cells; each cell carries chromosome(s) having a distinctive DNA sequence.
Examples include macromolecules such as proteins and nucleic acids, biomolecular complexes such as a ribosome, and structures such as membranes, and organelles. While the majority of cellular components are located within the cell itself, some may exist in extracellular areas of an organism.
Cellular components may also be called biological matter or biological material. Most biological matter has the characteristics of soft matter, being governed by relatively small energies. All known life is made of biological matter. To be differentiated from other theoretical or fictional life forms, such life may be called carbon-based, cellular, organic, biological, or even simply living – as some definitions of life exclude hypothetical types of biochemistry.
See also
Cell (biology)
Cell biology
Biomolecule
Organelle
Tissue (biology)
External links
https://web.archive.org/web/20130918033010/http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_cell3.htm
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This is a list of topics in molecular biology. See also index of biochemistry articles.
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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
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Intestinal cells combine with proteins to create what?
A. amino acids
B. chondrocytes
C. lipoproteins
D. chylomicrons
Answer:
|
|
sciq-8681
|
multiple_choice
|
Which region is just posterior to the mouth?
|
[
"the duodenum",
"the pharynx",
"the diaphragm",
"the esophagus"
] |
B
|
Relavent Documents:
Document 0:::
Swallowing, sometimes called deglutition in scientific contexts, is the process in the human or animal body that allows for a substance to pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing is an important part of eating and drinking. If the process fails and the material (such as food, drink, or medicine) goes through the trachea, then choking or pulmonary aspiration can occur. In the human body the automatic temporary closing of the epiglottis is controlled by the swallowing reflex.
The portion of food, drink, or other material that will move through the neck in one swallow is called a bolus.
In colloquial English, the term "swallowing" is also used to describe the action of taking in a large mouthful of food without any biting, where the word gulping is more adequate.
In humans
Swallowing comes so easily to most people that the process rarely prompts much thought. However, from the viewpoints of physiology, of speech–language pathology, and of health care for people with difficulty in swallowing (dysphagia), it is an interesting topic with extensive scientific literature.
Coordination and control
Eating and swallowing are complex neuromuscular activities consisting essentially of three phases, an oral, pharyngeal and esophageal phase. Each phase is controlled by a different neurological mechanism. The oral phase, which is entirely voluntary, is mainly controlled by the medial temporal lobes and limbic system of the cerebral cortex with contributions from the motor cortex and other cortical areas. The pharyngeal swallow is started by the oral phase and subsequently is coordinated by the swallowing center on the medulla oblongata and pons. The reflex is initiated by touch receptors in the pharynx as a bolus of food is pushed to the back of the mouth by the tongue, or by stimulation of the palate (palatal reflex).
Swallowing is a complex mechanism using both skeletal muscle (tongue) and smooth muscles of the p
Document 1:::
A posterior or subscapular group of six or seven glands is placed along the lower margin of the posterior wall of the axilla in the course of the subscapular artery.
The afferents of this group drain the skin and muscles of the lower part of the back of the neck and of the posterior thoracic wall; their efferents pass to the central group of axillary glands.
Additional images
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The commissure is the corner of the mouth, where the vermillion border of the superior labium (upper lip) meets that of the inferior labium (lower lip).
The commissure is important in facial appearance, particularly during some functions, including smiling. As such it is of interest to dental surgeons.
Diseases that involve the commissure include angular chelitis.
See also
Commissure
Lips
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The palatopharyngeal arch (pharyngopalatine arch, posterior pillar of fauces) is larger and projects farther toward the middle line than the palatoglossal arch; it runs downward, lateralward, and backward to the side of the pharynx, and is formed by the projection of the palatopharyngeal muscle, covered by mucous membrane.
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The retrovisceral space is divided into the retropharyngeal space and the danger space by the alar fascia. It is of particular clinical importance because it is a main route by which oropharyngeal infections can spread into the mediastinum.
Some sources say the retrovisceral space is the same as the retropharyngeal space.
Other sources say that the retrovisceral space is "continuous superiorly" with the retropharyngeal space.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which region is just posterior to the mouth?
A. the duodenum
B. the pharynx
C. the diaphragm
D. the esophagus
Answer:
|
|
sciq-6222
|
multiple_choice
|
What regulates the cell cycle only when they are tightly bound to cdks?
|
[
"cyclins",
"hormones",
"kinases",
"subclades"
] |
A
|
Relavent Documents:
Document 0:::
Cyclin-dependent kinases (CDKs) are the families of protein kinases first discovered for their role in regulating the cell cycle. They are also involved in regulating transcription, mRNA processing, and the differentiation of nerve cells. They are present in all known eukaryotes, and their regulatory function in the cell cycle has been evolutionarily conserved. In fact, yeast cells can proliferate normally when their CDK gene has been replaced with the homologous human gene. CDKs are relatively small proteins, with molecular weights ranging from 34 to 40 kDa, and contain little more than the kinase domain. By definition, a CDK binds a regulatory protein called a cyclin. Without cyclin, CDK has little kinase activity; only the cyclin-CDK complex is an active kinase but its activity can be typically further modulated by phosphorylation and other binding proteins, like p27. CDKs phosphorylate their substrates on serines and threonines, so they are serine-threonine kinases. The consensus sequence for the phosphorylation site in the amino acid sequence of a CDK substrate is [S/T*]PX[K/R], where S/T* is the phosphorylated serine or threonine, P is proline, X is any amino acid, K is lysine, and R is arginine.
Types
CDKs and cyclins in the cell cycle
Most of the known cyclin-CDK complexes regulate the progression through the cell cycle. Animal cells contain at least nine CDKs, four of which, CDK1, 2, 3, and 4, are directly involved in cell cycle regulation. In mammalian cells, CDK1, with its partners cyclin A2 and B1, alone can drive the cell cycle. Another one, CDK7, is involved indirectly as the CDK-activating kinase. Cyclin-CDK complexes phosphorylate substrates appropriate for the particular cell cycle phase. Cyclin-CDK complexes of earlier cell-cycle phase help activate cyclin-CDK complexes in later phase.
Document 1:::
Cyclin-dependent kinase 1 also known as CDK1 or cell division cycle protein 2 homolog is a highly conserved protein that functions as a serine/threonine protein kinase, and is a key player in cell cycle regulation. It has been highly studied in the budding yeast S. cerevisiae, and the fission yeast S. pombe, where it is encoded by genes cdc28 and cdc2, respectively. With its cyclin partners, Cdk1 forms complexes that phosphorylate a variety of target substrates (over 75 have been identified in budding yeast); phosphorylation of these proteins leads to cell cycle progression.
Structure
Cdk1 is a small protein (approximately 34 kilodaltons), and is highly conserved. The human homolog of Cdk1, CDK1, shares approximately 63% amino-acid identity with its yeast homolog. Furthermore, human CDK1 is capable of rescuing fission yeast carrying a cdc2 mutation. Cdk1 is comprised mostly by the bare protein kinase motif, which other protein kinases share. Cdk1, like other kinases, contains a cleft in which ATP fits. Substrates of Cdk1 bind near the mouth of the cleft, and Cdk1 residues catalyze the covalent bonding of the γ-phosphate to the oxygen of the hydroxyl serine/threonine of the substrate.
In addition to this catalytic core, Cdk1, like other cyclin-dependent kinases, contains a T-loop, which, in the absence of an interacting cyclin, prevents substrate binding to the Cdk1 active site. Cdk1 also contains a PSTAIRE helix, which, upon cyclin binding, moves and rearranges the active site, facilitating Cdk1 kinase activities.
Function
When bound to its cyclin partners, Cdk1 phosphorylation leads to cell cycle progression. Cdk1 activity is best understood in S. cerevisiae, so Cdk1 S. cerevisiae activity is described here.
In the budding yeast, initial cell cycle entry is controlled by two regulatory complexes, SBF (SCB-binding factor) and MBF (MCB-binding factor). These two complexes control G1/S gene transcription; however, they are normally inactive. SBF is inh
Document 2:::
A list of CDKs with their regulator protein, cyclin or other:
CDK1; cyclin A, cyclin B
CDK2; cyclin A, cyclin E
; cyclin C
CDK4; cyclin D1, cyclin D2, cyclin D3
Document 3:::
Cyclin A is a member of the cyclin family, a group of proteins that function in regulating progression through the cell cycle. The stages that a cell passes through that culminate in its division and replication are collectively known as the cell cycle Since the successful division and replication of a cell is essential for its survival, the cell cycle is tightly regulated by several components to ensure the efficient and error-free progression through the cell cycle. One such regulatory component is cyclin A which plays a role in the regulation of two different cell cycle stages.
Types
Cyclin A was first identified in 1983 in sea urchin embryos. Since its initial discovery, homologues of cyclin A have been identified in numerous eukaryotes including Drosophila, Xenopus, mice, and in humans but has not been found in lower eukaryotes like yeast. The protein exists in both an embryonic form and somatic form. A single cyclin A gene has been identified in Drosophila while Xenopus, mice and humans contain two distinct types of cyclin A: A1, the embryonic-specific form, and A2, the somatic form. Cyclin A1 is prevalently expressed during meiosis and early on in embryogenesis. Cyclin A2 is expressed in dividing somatic cells.
Role in cell cycle progression
Cyclin A, along with the other members of the cyclin family, regulates cell cycle progression through physically interacting with cyclin-dependent kinases (CDKs), which thereby activates the enzymatic activity of its CDK partner.
CDK partner association
The interaction between the cyclin box, a region conserved across cyclins, and a region of the CDK, called the PSTAIRE, confers the foundation of the cyclin-CDK complex. Cyclin A is the only cyclin that regulates multiple steps of the cell cycle. Cyclin A can regulate multiple cell cycle steps because it associates with, and thereby activates, two distinct CDKs – CDK2 and CDK1. Depending on which CDK partner cyclin A binds, the cell will continue through the S phase o
Document 4:::
Cyclin-dependent kinase 2, also known as cell division protein kinase 2, or Cdk2, is an enzyme that in humans is encoded by the CDK2 gene. The protein encoded by this gene is a member of the cyclin-dependent kinase family of Ser/Thr protein kinases. This protein kinase is highly similar to the gene products of S. cerevisiae cdc28, and S. pombe cdc2, also known as Cdk1 in humans. It is a catalytic subunit of the cyclin-dependent kinase complex, whose activity is restricted to the G1-S phase of the cell cycle, where cells make proteins necessary for mitosis and replicate their DNA. This protein associates with and is regulated by the regulatory subunits of the complex including cyclin E or A. Cyclin E binds G1 phase Cdk2, which is required for the transition from G1 to S phase while binding with Cyclin A is required to progress through the S phase. Its activity is also regulated by phosphorylation. Multiple alternatively spliced variants and multiple transcription initiation sites of this gene have been reported. The role of this protein in G1-S transition has been recently questioned as cells lacking Cdk2 are reported to have no problem during this transition.
Dispensability in normally functioning tissue
Original cell-culture based experiments demonstrated cell cycle arrest at the G1-S transition resulting from the deletion of Cdk2. Later experiments showed that Cdk2 deletions lengthened the G1 phase of the cell cycle in mouse embryo fibroblasts. However, they still entered S phase after this period and were able to complete the remaining phases of the cell cycle. When Cdk2 was deleted in mice, the animals remained viable despite a reduction in body size. However, meiotic function of both male and female mice was inhibited. This suggests that Cdk2 is non-essential for the cell cycle of healthy cells, but essential for meiosis and reproduction. Cells in Cdk2 knockout mice likely undergo fewer divisions, contributing to the reduction in body size. Germ cells also st
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What regulates the cell cycle only when they are tightly bound to cdks?
A. cyclins
B. hormones
C. kinases
D. subclades
Answer:
|
|
scienceQA-8427
|
multiple_choice
|
How long is a passenger airplane?
|
[
"200 miles",
"200 inches",
"200 yards",
"200 feet"
] |
D
|
The best estimate for the length of a passenger airplane is 200 feet.
200 inches is too short. 200 yards and 200 miles are too long.
|
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:::
A payload specialist (PS) was an individual selected and trained by commercial or research organizations for flights of a specific payload on a NASA Space Shuttle mission. People assigned as payload specialists included individuals selected by the research community, a company or consortium flying a commercial payload aboard the spacecraft, and non-NASA astronauts designated by international partners.
The term refers to both the individual and to the position on the Shuttle crew.
History
The National Aeronautics and Space Act of 1958 states that NASA should provide the "widest practicable and appropriate dissemination of information concerning its activities and the results thereof". The Naugle panel of 1982 concluded that carrying civilians—those not part of the NASA Astronaut Corps—on the Space Shuttle was part of "the purpose of adding to the public's understanding of space flight".
Payload specialists usually fly for a single specific mission. Chosen outside the standard NASA mission specialist selection process, they are exempt from certain NASA requirements such as colorblindness. Roger Crouch and Ulf Merbold are examples of those who flew in space despite not meeting NASA physical requirements; the agency's director of crew training Jim Bilodeau said in April 1981 "we'll be able to take everybody but the walking wounded". Payload specialists were not required to be United States citizens, but had to be approved by NASA and undergo rigorous but shorter training. In contrast, a Space Shuttle mission specialist was selected as a NASA astronaut first and then assigned to a mission.
Payload specialists on early missions were technical experts to join specific payloads such as a commercial or scientific satellite. On Spacelab and other missions with science components, payload specialists were scientists with expertise in specific experiments. The term also applied to representatives from partner nations who were given the opportunity of a first flight on boar
Document 2:::
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 3:::
Astronauts hold a variety of ranks and positions. Each of these roles carries responsibilities that are essential to the operation of a spacecraft. A spacecraft's cockpit, filled with sophisticated equipment, requires skills differing from those used to manage the scientific equipment on board, and so on.
NASA ranks and positions
Ranks
Members of the NASA Astronaut Corps hold one of two ranks. Astronaut Candidate is the rank of those training to be NASA astronauts.
Upon graduation, candidates are promoted to Astronaut and receive their Astronaut Pin. The pin is issued in two grades, silver and gold, with the silver pin awarded to candidates who have successfully completed astronaut training and the gold pin to astronauts who have flown in space.
Chief of the Astronaut Office is a position, not a rank.
Positions
Roscosmos and Soviet space program ranks and positions
Ranks
Cosmonauts are professional space travellers from Russia. After initial training, cosmonauts are assigned as either a test-cosmonaut (космонавт-испытатель, kosmonavt-ispytatel') or a research-cosmonaut (космонавт-исследователь, kosmonavt-issledovatel'). A test-cosmonaut has a more difficult preparation than a research-cosmonaut and can be the commander or the flight engineer of a spacecraft, while a research-cosmonaut cannot.
Higher ranks include pilot-cosmonaut, test-cosmonaut instructor, and research-cosmonaut instructor.
Pilot-Cosmonaut of the Russian Federation is a title that is presented to all cosmonauts who fly for the Russian space program.
Positions
China National Space Administration positions
Ranks
Similarly to NASA, members of the China National Space Administration (CNSA) hold one of two ranks. Astronaut Candidate is the rank of those training to be CNSA astronauts. The positions of Spacecraft Pilot, Flight Engineer, and Mission Payload Specialist were listed in the announcement for the Group 3 selection.
Upon graduation, candidates are promoted to Astronaut.
Position
Document 4:::
Wake turbulence categories and wake turbulence groups are defined by the International Civil Aviation Organization for the purpose of separating aircraft in flight, due to wake turbulence.
Wake turbulence categories
Since 2020, there are four categories, based on maximum certificated take-off mass:
Light (L) — aircraft types of 7,000 kg or less.
Medium (M) — aircraft types more than 7,000 kg but less than 136,000 kg; and
Heavy (H) — all aircraft types of 136 000 kg or more, with the exception of aircraft types in Super (J) category; and
Super (J) — aircraft types specified as such in ICAO Doc 8643, Aircraft Type Designators.
As of 2023, the only aircraft in Category J is the Airbus A380, with an MTOW of ). Before its destruction, the single Antonov An-225 (MTOW of ) was classified by the FAA as Super, although it is classified by ICAO as Heavy. The Antonov An-225 and the Antonov An-124 Ruslan are classified by the UK Civil Aviation Authority as Super, although they are classified by ICAO as Heavy.
Most wide-body aircraft are classified as Heavy. Not all aircraft variants of the same type have the same wake turbulence category. The narrow-bodied Boeing 707-100 is Medium but the 707-300 is Heavy.
Radio communication
The word "super" or "heavy" should be included by super or heavy aircraft immediately after the aircraft call-sign in initial radio contact with air traffic service (ATS) units, to warn ATS and other aircraft that they should leave additional separation to avoid this wake turbulence.
Distance-based separation minima
Distance-based separation minima for approach and departure are given by ICAO as follows:
Time-based separation minima
For landing aircraft, time-based separation minima are as follows:
HEAVY aircraft landing behind SUPER aircraft — 2 minutes
MEDIUM aircraft landing behind SUPER aircraft — 3 minutes
MEDIUM aircraft landing behind HEAVY aircraft — 2 minutes
LIGHT aircraft landing behind SUPER aircraft — 4 minutes
LIGHT aircra
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How long is a passenger airplane?
A. 200 miles
B. 200 inches
C. 200 yards
D. 200 feet
Answer:
|
sciq-9465
|
multiple_choice
|
What causes rivers to always flow downhill?
|
[
"slope",
"pressure",
"gravity",
"diffusion"
] |
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 hydrology, pipeflow is a type of subterranean water flow where water travels along cracks in the soil or old root systems found in above ground vegetation.
In such soils which have a high vegetation content water is able to travel along the 'pipes', allowing water to travel faster than throughflow. Here, water can move at speeds between 50 and 500 m/h.
Hydrology
Aquatic ecology
Document 2:::
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
Hydraulic engineering is the application of the principles of fluid mechanics to problems dealing with the collection, storage, control, transport, regulation, measurement, and use of water. Before beginning a hydraulic engineering project, one must figure out how much water is involved. The hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, and the occurrence of scour and deposition. "The hydraulic engineer actually develops conceptual designs for the various features which interact with water such as spillways and outlet works for dams, culverts for highways, canals and related structures for irrigation projects, and cooling-water facilities for thermal power plants."
Fundamental principles
A few examples of the fundamental principles of hydraulic engineering include fluid mechanics, fluid flow, behavior of real fluids, hydrology, pipelines, open channel hydraulics, mechanics of sediment transport, physical modeling, hydraulic machines, and drainage hydraulics.
Fluid mechanics
Fundamentals of Hydraulic Engineering defines hydrostatics as the study of fluids at rest. In a fluid at rest, there exists a force, known as pressure, that acts upon the fluid's surroundings. This pressure, measured in N/m2, is not constant throughout the body of fluid. Pressure, p, in a given body of fluid, increases with an increase in depth. Where the upward force on a body acts on the base and can be found by the equation:
where,
ρ = density of water
g = specific gravity
Document 3:::
Large woody debris (LWD) are the logs, sticks, branches, and other wood that falls into streams and rivers. This debris can influence the flow and the shape of the stream channel. Large woody debris, grains, and the shape of the bed of the stream are the three main providers of flow resistance, and are thus, a major influence on the shape of the stream channel. Some stream channels have less LWD than they would naturally because of removal by watershed managers for flood control and aesthetic reasons.
The study of woody debris is important for its forestry management implications. Plantation thinning can reduce the potential for recruitment of LWD into proximal streams. The presence of large woody debris is important in the formation of pools which serve as salmon habitat in the Pacific Northwest. Entrainment of the large woody debris in a stream can also cause erosion and scouring around and under the LWD. The amount of scouring and erosion is determined by the ratio of the diameter of the piece, to the depth of the stream, and the embedding and orientation of the piece.
Influence on stream flow around bends
Large woody debris slow the flow through a bend in the stream, while accelerating flow in the constricted area downstream of the obstruction.
See also
Beaver dam
Coarse woody debris
Driftwood
Log jam
Stream restoration
Document 4:::
In fluid dynamics, pipe network analysis is the analysis of the fluid flow through a hydraulics network, containing several or many interconnected branches. The aim is to determine the flow rates and pressure drops in the individual sections of the network. This is a common problem in hydraulic design.
Description
To direct water to many users, municipal water supplies often route it through a water supply network. A major part of this network will consist of interconnected pipes. This network creates a special class of problems in hydraulic design, with solution methods typically referred to as pipe network analysis. Water utilities generally make use of specialized software to automatically solve these problems. However, many such problems can also be addressed with simpler methods, like a spreadsheet equipped with a solver, or a modern graphing calculator.
Deterministic network analysis
Once the friction factors of the pipes are obtained (or calculated from pipe friction laws such as the Darcy-Weisbach equation), we can consider how to calculate the flow rates and head losses on the network. Generally the head losses (potential differences) at each node are neglected, and a solution is sought for the steady-state flows on the network, taking into account the pipe specifications (lengths and diameters), pipe friction properties and known flow rates or head losses.
The steady-state flows on the network must satisfy two conditions:
At any junction, the total flow into a junction equals the total flow out of that junction (law of conservation of mass, or continuity law, or Kirchhoff's first law)
Between any two junctions, the head loss is independent of the path taken (law of conservation of energy, or Kirchhoff's second law). This is equivalent mathematically to the statement that on any closed loop in the network, the head loss around the loop must vanish.
If there are sufficient known flow rates, so that the system of equations given by (1) and (2) abov
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What causes rivers to always flow downhill?
A. slope
B. pressure
C. gravity
D. diffusion
Answer:
|
|
ai2_arc-353
|
multiple_choice
|
A student investigated the percentage of energy obtained from several food sources for a population of eagles. Which format is the best way to display this data?
|
[
"a table",
"a pie chart",
"a bar graph",
"a line graph"
] |
B
|
Relavent Documents:
Document 0:::
A chart (sometimes known as a graph) is a graphical representation for data visualization, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart". A chart can represent tabular numeric data, functions or some kinds of quality structure and provides different info.
The term "chart" as a graphical representation of data has multiple meanings:
A data chart is a type of diagram or graph, that organizes and represents a set of numerical or qualitative data.
Maps that are adorned with extra information (map surround) for a specific purpose are often known as charts, such as a nautical chart or aeronautical chart, typically spread over several map sheets.
Other domain-specific constructs are sometimes called charts, such as the chord chart in music notation or a record chart for album popularity.
Charts are often used to ease understanding of large quantities of data and the relationships between parts of the data. Charts can usually be read more quickly than the raw data. They are used in a wide variety of fields, and can be created by hand (often on graph paper) or by computer using a charting application. Certain types of charts are more useful for presenting a given data set than others. For example, data that presents percentages in different groups (such as "satisfied, not satisfied, unsure") are often displayed in a pie chart, but maybe more easily understood when presented in a horizontal bar chart. On the other hand, data that represents numbers that change over a period of time (such as "annual revenue from 1990 to 2000") might be best shown as a line chart1
Features
A chart can take a large variety of forms. However, there are common features that provide the chart with its ability to extract meaning from data.
Typically the data in a chart is represented graphically since humans can infer meaning from pictures more quickly than from text. Thus, the text is generally used only to annota
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:::
This is a list of graphical methods with a mathematical basis.
Included are diagram techniques, chart techniques, plot techniques, and other forms of visualization.
There is also a list of computer graphics and descriptive geometry topics.
Simple displays
Area chart
Box plot
Dispersion fan diagram
Graph of a function
Logarithmic graph paper
Heatmap
Bar chart
Histogram
Line chart
Pie chart
Plotting
Scatterplot
Sparkline
Stemplot
Radar chart
Set theory
Venn diagram
Karnaugh diagram
Descriptive geometry
Isometric projection
Orthographic projection
Perspective (graphical)
Engineering drawing
Technical drawing
Graphical projection
Mohr's circle
Pantograph
Circuit diagram
Smith chart
Sankey diagram
Systems analysis
Binary decision diagram
Control-flow graph
Functional flow block diagram
Information flow diagram
IDEF
N2 chart
Sankey diagram
State diagram
System context diagram
Data-flow diagram
Cartography
Map projection
Orthographic projection (cartography)
Robinson projection
Stereographic projection
Dymaxion map
Topographic map
Craig retroazimuthal projection
Hammer retroazimuthal projection
Biological sciences
Cladogram
Punnett square
Systems Biology Graphical Notation
Physical sciences
Free body diagram
Greninger chart
Phase diagram
Wavenumber-frequency diagram
Bode plot
Nyquist plot
Dalitz plot
Feynman diagram
Carnot Plot
Business methods
Flowchart
Workflow
Gantt chart
Growth-share matrix (often called BCG chart)
Work breakdown structure
Control chart
Ishikawa diagram
Pareto chart (often used to prioritise outputs of an Ishikawa diagram)
Conceptual analysis
Mind mapping
Concept mapping
Conceptual graph
Entity-relationship diagram
Tag cloud, also known as word cloud
Statistics
Autocorrelation plot
Bar chart
Biplot
Box plot
Bullet graph
Chernoff faces
Control chart
Fan chart
Forest plot
Funnel plot
Galbraith plot
Histogram
Mosaic plot
Multidimensional scaling
np-chart
p-chart
Pie chart
Probability plot
Normal probability plot
Poincaré plot
Probability plot
Document 3:::
This is a list of software to create any kind of information graphics:
either includes the ability to create one or more infographics from a provided data set
either it is provided specifically for information visualization
Vector graphics
Vector graphics software can be used for manual graphing or for editing the output of another program. Please see:
:Category:Vector graphics editors
Comparison of vector graphics editors
A few online editors using vector graphics for specific needs have been created. This kind of creative interfaces work well together with data visualization tools like the ones above.
See also
:Category:Diagramming software
Comparison of numerical-analysis software
List of graphical methods
Document 4:::
A Gantt chart is a bar chart that illustrates a project schedule. It was designed and popularized by Henry Gantt around the years 1910–1915. Modern Gantt charts also show the dependency relationships between activities and the current schedule status.
Definition
A Gantt chart is a type of bar chart that illustrates a project schedule. This chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis. The width of the horizontal bars in the graph shows the duration of each activity. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements constitute the work breakdown structure of the project. Modern Gantt charts also show the dependency (i.e., precedence network) relationships between activities. Gantt charts can be used to show current schedule status using percent-complete shadings and a vertical "TODAY" line.
Gantt charts are sometimes equated with bar charts.
Gantt charts are usually created initially using an early start time approach, where each task is scheduled to start immediately when its prerequisites are complete. This method maximizes the float time available for all tasks.
History
Widely used in project planning in the present day, Gantt charts were considered revolutionary when introduced. The first known tool of this type was developed in 1896 by Karol Adamiecki, who called it a harmonogram. Adamiecki, however, published his chart only in Russian and Polish which limited both its adoption and recognition of his authorship.
In 1912, published what could be considered Gantt charts while discussing a construction project. Charts of the type published by Schürch appear to have been in common use in Germany at the time; however, the prior development leading to Schürch's work is unclear. Unlike later Gantt charts, Schürch's charts did not display interdependencies, leaving them to be inferred by the reader. These w
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A student investigated the percentage of energy obtained from several food sources for a population of eagles. Which format is the best way to display this data?
A. a table
B. a pie chart
C. a bar graph
D. a line graph
Answer:
|
|
sciq-6994
|
multiple_choice
|
Original atoms are called what type of isotopes?
|
[
"offspring",
"parent",
"component",
"product"
] |
B
|
Relavent Documents:
Document 0:::
Isotopes are distinct nuclear species (or nuclides, as technical term) of the same chemical element. They have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), but differ in nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei. While all isotopes of a given element have almost the same chemical properties, they have different atomic masses and physical properties.
The term isotope is formed from the Greek roots isos (ἴσος "equal") and topos (τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. It was coined by Scottish doctor and writer Margaret Todd in 1913 in a suggestion to the British chemist Frederick Soddy.
The number of protons within the atom's nucleus is called its atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.
For example, carbon-12, carbon-13, and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13, and 14, respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons so that the neutron numbers of these isotopes are 6, 7, and 8 respectively.
Isotope vs. nuclide
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over
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Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms. It is primarily concerned with the way in which electrons are arranged around the nucleus and
the processes by which these arrangements change. This comprises ions, neutral atoms and, unless otherwise stated, it can be assumed that the term atom includes ions.
The term atomic physics can be associated with nuclear power and nuclear weapons, due to the synonymous use of atomic and nuclear in standard English. Physicists distinguish between atomic physics—which deals with the atom as a system consisting of a nucleus and electrons—and nuclear physics, which studies nuclear reactions and special properties of atomic nuclei.
As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular, and optical physics. Physics research groups are usually so classified.
Isolated atoms
Atomic physics primarily considers atoms in isolation. Atomic models will consist of a single nucleus that may be surrounded by one or more bound electrons. It is not concerned with the formation of molecules (although much of the physics is identical), nor does it examine atoms in a solid state as condensed matter. It is concerned with processes such as ionization and excitation by photons or collisions with atomic particles.
While modelling atoms in isolation may not seem realistic, if one considers atoms in a gas or plasma then the time-scales for atom-atom interactions are huge in comparison to the atomic processes that are generally considered. This means that the individual atoms can be treated as if each were in isolation, as the vast majority of the time they are. By this consideration, atomic physics provides the underlying theory in plasma physics and atmospheric physics, even though
Document 2:::
A nuclide (or nucleide, from nucleus, also known as nuclear species) is a class of atoms characterized by their number of protons, Z, their number of neutrons, N, and their nuclear energy state.
The word nuclide was coined by Truman P. Kohman in 1947. Kohman defined nuclide as a "species of atom characterized by the constitution of its nucleus" containing a certain number of neutrons and protons. The term thus originally focused on the nucleus.
Nuclides vs isotopes
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, while the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear. The neutron number has large effects on nuclear properties, but its effect on chemical reactions is negligible for most elements. Even in the case of the very lightest elements, where the ratio of neutron number to atomic number varies the most between isotopes, it usually has only a small effect, but it matters in some circumstances. For hydrogen, the lightest element, the isotope effect is large enough to affect biological systems strongly. In the case of helium, helium-4 obeys Bose–Einstein statistics, while helium-3 obeys Fermi-Dirac statistics. Since isotope is the older term, it is better known than nuclide, and is still occasionally used in contexts in which nuclide might be more appropriate, such as nuclear technology and nuclear medicine.
Types of nuclides
Although the words nuclide and isotope are often used interchangeably, being isotopes is actually only one relation between nuclides. The following table names some other relations.
A set of nuclides with equal proton number (atomic number), i.e., of the same chemical element but different neutron numbers, are called isotopes of the element. Particular nuclides are still often loos
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The isotopic resonance hypothesis (IsoRes) postulates that certain isotopic compositions of chemical elements affect kinetics of chemical reactions involving molecules built of these elements. The isotopic compositions for which this effect is predicted are called resonance isotopic compositions.
Fundamentally, the IsoRes hypothesis relies on a postulate that less complex systems exhibit faster kinetics than equivalent but more complex systems. Furthermore, system's complexity is affected by its symmetry (more symmetric systems are simpler), and symmetry (in general meaning) of reactants may be affected by their isotopic composition.
The term “resonance” relates to the use of this term in nuclear physics, where peaks in the dependence of a reaction cross section upon energy are called “resonances”. Similarly, a sharp increase (or decrease) in the reaction kinetics as a function of the average isotopic mass of a certain element is called here a resonance.
History of formulation
The concept of isotopes developed from radioactivity. The pioneering work on radioactivity by Henri Becquerel, Marie Curie and Pierre Curie was awarded the Nobel Prize in Physics in 1903. Later Frederick Soddy would take radioactivity from physics to chemistry and shed light on the nature of isotopes, something with rendered him the Nobel Prize in Chemistry in 1921 (awarded in 1922).
The question of stable, non-radioactive isotopes was more difficult and required the development by Francis Aston of a high-resolution mass spectrograph, which allowed the separation of different stable isotopes of one and the same element. Francis Aston was awarded the 1922 Nobel Prize in Chemistry for this achievement. With his enunciation of the whole-number rule, Aston solved a problem that had riddled chemistry for a hundred years. The understanding was that different isotopes of a given element would be chemically identical.
It was discovered in the 1930s by Harold Urey in 1932 (awarded the Nobel Pri
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Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Original atoms are called what type of isotopes?
A. offspring
B. parent
C. component
D. product
Answer:
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|
sciq-9772
|
multiple_choice
|
How is a mammal developed if not inside of a placenta or a pouch?
|
[
"cloning",
"spawning or budding",
"hatched from eggs",
"mitosis"
] |
C
|
Relavent Documents:
Document 0:::
Mammalian embryogenesis is the process of cell division and cellular differentiation during early prenatal development which leads to the development of a mammalian embryo.
Difference from embryogenesis of lower chordates
Due to the fact that placental mammals and marsupials nourish their developing embryos via the placenta, the ovum in these species does not contain significant amounts of yolk, and the yolk sac in the embryo is relatively small in size, in comparison with both the size of the embryo itself and the size of yolk sac in embryos of comparable developmental age from lower chordates. The fact that an embryo in both placental mammals and marsupials undergoes the process of implantation, and forms the chorion with its chorionic villi, and later the placenta and umbilical cord, is also a difference from lower chordates.
The difference between a mammalian embryo and an embryo of a lower chordate animal is evident starting from blastula stage. Due to that fact, the developing mammalian embryo at this stage is called a blastocyst, not a blastula, which is more generic term.
There are also several other differences from embryogenesis in lower chordates. One such difference is that in mammalian embryos development of the central nervous system and especially the brain tends to begin at earlier stages of embryonic development and to yield more structurally advanced brain at each stage, in comparison with lower chordates. The evolutionary reason for such a change likely was that the advanced and structurally complex brain, characteristic of mammals, requires more time to develop, but the maximum time spent in utero is limited by other factors, such as relative size of the final fetus to the mother (ability of the fetus to pass mother's genital tract to be born), limited resources for the mother to nourish herself and her fetus, etc. Thus, to develop such a complex and advanced brain in the end, the mammalian embryo needed to start this process earlier and to
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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).
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Matrotrophy is a form of maternal care during organism development, associated with live birth (viviparity), in which the embryo of an animal or flowering plant is supplied with additional nutrition from the mother (e.g. through a placenta). This can be contrasted with lecithotrophy, in which the only source of nutrition for the embryo is yolk originally contained within its egg.
Vegetal matrotrophy
In plants, matrotrophy is considered a critical evolutionary development preceding the origin of embryophytes and therefore essential to the evolution of land plants. Matrotrophy is facilitated by cytological and ultrastructural modifications on one or both sides of the generational junction, a region called the placenta. Specialization of the placental cells pertains further to their cytological and ultrastructural characteristics: the cytoplasm is often dense and rich in lipids, the vacuole is typically reduced but large in Sphagnum, the endoplasmic reticulum extensive, mitochondria numerous and large, chloroplasts numerous, often less differentiated, rich in lipid-filled globuli and sometimes filled with starch.
Animal matrotrophy
While commonly associated with vertebrates and especially mammals, matrotrophy is found in 21 of 34 animal phyla, and is fairly common in 11 of those. It has arisen independently in more than 150 clades within Chordata and in more than 140 clades amongst invertebrates.
See also
Pregnancy (fish)
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In the field of developmental biology, regional differentiation is the process by which different areas are identified in the development of the early embryo. The process by which the cells become specified differs between organisms.
Cell fate determination
In terms of developmental commitment, a cell can either be specified or it can be determined. Specification is the first stage in differentiation. A cell that is specified can have its commitment reversed while the determined state is irreversible. There are two main types of specification: autonomous and conditional. A cell specified autonomously will develop into a specific fate based upon cytoplasmic determinants with no regard to the environment the cell is in. A cell specified conditionally will develop into a specific fate based upon other surrounding cells or morphogen gradients. Another type of specification is syncytial specification, characteristic of most insect classes.
Specification in sea urchins uses both autonomous and conditional mechanisms to determine the anterior/posterior axis. The anterior/posterior axis lies along the animal/vegetal axis set up during cleavage. The micromeres induce the nearby tissue to become endoderm while the animal cells are specified to become ectoderm. The animal cells are not determined because the micromeres can induce the animal cells to also take on mesodermal and endodermal fates. It was observed that β-catenin was present in the nuclei at the vegetal pole of the blastula. Through a series of experiments, one study confirmed the role of β-catenin in the cell-autonomous specification of vegetal cell fates and the micromeres inducing ability. Treatments of lithium chloride sufficient to vegetalize the embryo resulted in increases in nuclearly localized b-catenin. Reduction of expression of β-catenin in the nucleus correlated with loss of vegetal cell fates. Transplants of micromeres lacking nuclear accumulation of β-catenin were unable to induce a second axis.
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Gerd B. Müller (born 1953) is an Austrian biologist who is emeritus professor at the University of Vienna where he was the head of the Department of Theoretical Biology in the Center for Organismal Systems Biology. His research interests focus on vertebrate limb development, evolutionary novelties, evo-devo theory, and the Extended Evolutionary Synthesis. He is also concerned with the development of 3D based imaging tools in developmental biology.
Biography
Müller received an M.D. in 1979 and a Ph.D. in zoology in 1985, both from the University of Vienna. He has been a sabbatical fellow at the Department of Developmental Biology, Dalhousie University, Canada, (1988) and a visiting scholar at the Museum of Comparative Zoology, Harvard University, and received his Habilitation in Anatomy and Embryology in 1989. He is a founding member of the Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, Austria, of which he has been President since 1997. Müller is on the editorial boards of several scientific journals, including Biological Theory where he serves as an associate editor. He is editor-in-chief of the Vienna Series in Theoretical Biology, a book series devoted to theoretical developments in the biosciences, published by MIT Press.
Scientific contribution
Müller has published on developmental imaging, vertebrate limb development, the origins of phenotypic novelty, EvoDevo theory, and evolutionary theory.
With the cell and developmental biologist Stuart Newman, Müller co-edited the book Origination of Organismal Form (MIT Press, 2003). This book on evolutionary developmental biology is a collection of papers on generative mechanisms that were plausibly involved in the origination of disparate body forms during early periods of organismal life. Particular attention is given to epigenetic factors, such as physical determinants and environmental parameters, that may have led to the spontaneous emergence of bodyplans and organ forms during a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How is a mammal developed if not inside of a placenta or a pouch?
A. cloning
B. spawning or budding
C. hatched from eggs
D. mitosis
Answer:
|
|
sciq-5813
|
multiple_choice
|
Each root is made of dermal, ground, and what type of tissue?
|
[
"vascular",
"thermal",
"organic",
"circulatory"
] |
A
|
Relavent Documents:
Document 0:::
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
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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.
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Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
The cells in vascular tissue are typically long and slender. Since the xylem and phloem function in the conduction of water, minerals, and nutrients throughout the plant, it is not surprising that their form should be similar to pipes. The individual cells of phloem are connected end-to-end, just as the sections of a pipe might be. As the plant grows, new vascular tissue differentiates in the growing tips of the plant. The new tissue is aligned with existing vascular tissue, maintaining its connection throughout the plant. The vascular tissue in plants is arranged in long, discrete strands called vascular bundles. These bundles include both xylem and phloem, as well as supporting and protective cells. In stems and roots, the xylem typically lies closer to the interior of the stem with phloem towards the exterior of the stem. In the stems of some Asterales dicots, there may be phloem located inwardly from the xylem as well.
Between the xylem and phloem is a meristem called the vascular cambium. This tissue divides off cells that will become additional xylem and phloem. This growth increases the girth of the plant, rather than its length. As long as the vascular cambium continues to produce new cells, the plant will continue to grow more stout. In trees and other plants that develop wood, the vascular cambium allows the expansion of vascular tissue that produces woody growth. Because this growth ruptures the epidermis of the stem, woody plants also have a cork cambium that develops among the phloem. The cork cambium g
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A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
The stem is normally divided into nodes and internodes:
The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaves, conifer cones, or flowers). Adventitious roots may also be produced from the nodes. Vines may produce tendrils from nodes.
The internodes distance one node from another.
The term "shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other structures like leaves or flowers.
In most plants, stems are located above the soil surface, but some plants have underground stems.
Stems have several main functions:
Support for and the elevation of leaves, flowers, and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem.
Storage of nutrients.
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
Photosynthesis.
Stems have two pipe-like tissues called xylem and phloem. The xylem tissue arises from the cell facing inside and transports water by the action of transpiration pull, capillary action, and root pressure. The phloem tissue arises from the cell facing outside and consists of sieve tubes and their companion cells. The function of phloem tissue is to distribute food from photosynthetic tissue to other tissues. The two tissues are separated by cambium, a tis
Document 4:::
The ground tissue of plants includes all tissues that are neither dermal nor vascular. It can be divided into three types based on the nature of the cell walls. This tissue system is present between the dermal tissue and forms the main bulk of the plant body.
Parenchyma cells have thin primary walls and usually remain alive after they become mature. Parenchyma forms the "filler" tissue in the soft parts of plants, and is usually present in cortex, pericycle, pith, and medullary rays in primary stem and root.
Collenchyma cells have thin primary walls with some areas of secondary thickening. Collenchyma provides extra mechanical and structural support, particularly in regions of new growth.
Sclerenchyma cells have thick lignified secondary walls and often die when mature. Sclerenchyma provides the main structural support to a plant.
Parenchyma
Parenchyma is a versatile ground tissue that generally constitutes the "filler" tissue in soft parts of plants. It forms, among other things, the cortex (outer region) and pith (central region) of stems, the cortex of roots, the mesophyll of leaves, the pulp of fruits, and the endosperm of seeds. Parenchyma cells are often living cells and may remain meristematic, meaning that they are capable of cell division if stimulated. They have thin and flexible cellulose cell walls and are generally polyhedral when close-packed, but can be roughly spherical when isolated from their neighbors. Parenchyma cells are generally large. They have large central vacuoles, which allow the cells to store and regulate ions, waste products, and water. Tissue specialised for food storage is commonly formed of parenchyma cells.
Parenchyma cells have a variety of functions:
In leaves, they form two layers of mesophyll cells immediately beneath the epidermis of the leaf, that are responsible for photosynthesis and the exchange of gases. These layers are called the palisade parenchyma and spongy mesophyll. Palisade parenchyma cells can be either cu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Each root is made of dermal, ground, and what type of tissue?
A. vascular
B. thermal
C. organic
D. circulatory
Answer:
|
|
sciq-6471
|
multiple_choice
|
Who lack some of the defining traits of chordates?
|
[
"adult humans",
"Adult Mammals",
"Reptiles",
"Childern"
] |
A
|
Relavent Documents:
Document 0:::
Centroneuralia is a proposed clade of animals with bilateral symmetry as an embryo, consisting of the Chordata and Protostomia, united by the presence of a central nervous system. An alternative to the traditional protostome-deuterostome dichotomy, it has found weak support in several studies. Under this hypothesis, Centroneuralia would be sister to Xenambulacraria (Xenacoelomorpha + Ambulacraria) at the base of Bilateria.
Centroneuralia, as a proposed clade, originates in phylogenomics. More precisely, recent studies correlate support for Deuterostomia with simpler, site-homogeneous models, while more sophisticated and site-heterogeneous models recover Centroneuralia more often.
Phylogeny
Document 1:::
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:::
Caminalcules are a fictive group of animal-like life forms, which were created as a tool for better understanding phylogenetics in real organisms. They were created by Joseph H. Camin (University of Kansas) and consist of 29 living 'species' and 48 fossil forms.
The name of the taxon Caminalcules seems to come from Camin's last name and Antonie van Leeuwenhoek's animalcules.
History
Joseph H. Camin (1922–1979) drew the Caminalcules in the early 1960s or possibly even earlier to study the nature of taxonomic judgement. He assured that there was genetic continuity in the Caminalcules by the preservation of all characters except for changes that he desired in all successive animals. He did not keep track of the changes he made in the different species. The images of the Caminalcules were made using master stencils. The images of the living OTUs (29 species) were made available in the early 1960s; those of the fossil ones (48 species) later in the decade. These images were copied using xerography. Copies of all OTUs were in the possession of Dr. Paul A. Ehrlich (Stanford University), Dr. W. Wayne Moss (Philadelphia Academy of Sciences) and Robert R. Sokal (State University of New York at Stony Brook) in 1983. The original drawings by Joseph H. Camin have unfortunately been lost.
The Caminalcules first appeared in print in the journal Systematic Zoology (now Systematic Biology) in 1983, four years after Camin's death in 1979. Robert R. Sokal published four succeeding papers about them, titled "A Phylogenetic Analysis of the Caminalcules." These papers included the complete set of living and fossil species, as well as their cladogram, which Sokal had received from Camin in 1970.
At a symposium dedicated to Camin, Dr. W. Wayne Moss said that "his collaborative studies on methods and principles of systematics at Kansas in the 1960s resulted in the appearance of that delightful taxon, the Caminalcules", and that "his thoughts helped to launch the infant field of pheneti
Document 3:::
Roshd Biological Education is a quarterly science educational magazine covering recent developments in biology and biology education for a biology teacher Persian -speaking audience. Founded in 1985, it is published by The Teaching Aids Publication Bureau, Organization for Educational Planning and Research, Ministry of Education, Iran. Roshd Biological Education has an editorial board composed of Iranian biologists, experts in biology education, science journalists and biology teachers.
It is read by both biology teachers and students, as a way of launching innovations and new trends in biology education, and helping biology teachers to teach biology in better and more effective ways.
Magazine layout
As of Autumn 2012, the magazine is laid out as follows:
Editorial—often offering a view of point from editor in chief on an educational and/or biological topics.
Explore— New research methods and results on biology and/or education.
World— Reports and explores on biological education worldwide.
In Brief—Summaries of research news and discoveries.
Trends—showing how new technology is altering the way we live our lives.
Point of View—Offering personal commentaries on contemporary topics.
Essay or Interview—often with a pioneer of a biological and/or educational researcher or an influential scientific educational leader.
Muslim Biologists—Short histories of Muslim Biologists.
Environment—An article on Iranian environment and its problems.
News and Reports—Offering short news and reports events on biology education.
In Brief—Short articles explaining interesting facts.
Questions and Answers—Questions about biology concepts and their answers.
Book and periodical Reviews—About new publication on biology and/or education.
Reactions—Letter to the editors.
Editorial staff
Mohammad Karamudini, editor in chief
History
Roshd Biological Education started in 1985 together with many other magazines in other science and art. The first editor was Dr. Nouri-Dalooi, th
Document 4:::
Sphenacodontoidea is a node-based clade that is defined to include the most recent common ancestor of Sphenacodontidae and Therapsida and its descendants (including mammals). Sphenacodontoids are characterised by a number of synapomorphies concerning proportions of the bones of the skull and the teeth.
The sphenacodontoids evolved from earlier sphenacodonts such as Haptodus via a number of transitional stages of small, unspecialised pelycosaurs.
Classification
The following taxonomy follows Fröbisch et al. (2011) and Benson (2012) unless otherwise noted.
Class Synapsida
Sphenacodontoidea
Family †Sphenacodontidae
Therapsida
See also
Evolution of mammals
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Who lack some of the defining traits of chordates?
A. adult humans
B. Adult Mammals
C. Reptiles
D. Childern
Answer:
|
|
sciq-10275
|
multiple_choice
|
What is one problem with current methods of aluminum production?
|
[
"food shortages",
"competition",
"recycling is cheap",
"environmental contaminants"
] |
D
|
Relavent Documents:
Document 0:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
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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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The Oklahoma Energy Resources Board (abbreviated OERB) is an agency of the state of Oklahoma. Funded voluntarily by Oklahoma's oil and natural gas producers and royalty owners, the OERB conducts environmental restoration of orphaned and abandoned well sites, encourages the wise and efficient use of energy, and promotes energy education.
Unique is the OERB's funding process – though it is funded by a 0.1% assessment on oil and gas sales (not uncommon among similar agencies), it is a voluntary assessment. Any producer or royalty owner may opt out of the program by requesting OERB (between January 1 and March 31 of each year) for a refund of previously paid assessments. The OERB states that over 95% of participants remain in the program.
The Board is composed of 21 members. 7 members are appointed by the Governor of Oklahoma, 7 are appointed by the President pro tempore of the Oklahoma Senate, and 7 appointed by the Speaker of the Oklahoma House of Representatives. All members are either independent oil or natural gas producers or representatives of major oil companies that do business in Oklahoma. The Board, in turn, appoints an Executive Director to serve as the chief administrative officer of the Board.
The current board chairman is David Le Norman, Managing Partner & Founder of Reign Capital Holdings LLC.
OERB was created by the Oklahoma Legislature and energy industry leaders in 1993 during the term of Governor of Oklahoma David Walters.
Mission
The stated missions of the Oklahoma Energy Resources Board are:
to educate Oklahomans about the importance of petroleum (oil and natural gas) in their lives through traditional and non-traditional school curricula, advertising, and public relations
to environmentally restore abandoned well sites to productive land use
to promote environmentally sound production methods and technologies
to research and provide educational activities concerning the petroleum exploration and production industry
Leadership
OERB is unde
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The United States National Academy of Sciences' Board on Science, Technology, and Economic Policy (STEP) is a board of the United States National Academy of Sciences.
The mandate of the Board is to integrate understanding of scientific, technological, and economic elements in the formulation of national policies affecting the economic well-being of the United States. The program’s focus is on the dynamics of the macroeconomic and microeconomic variables, their relationship to the industrial structure of the economy, effect on high-technology manufacturing and service sectors, and influence on U.S. scientific and technological advancement through examination of trade, human resources, fiscal, research and development, intellectual property and other policies. Policymakers responsible for these areas in the executive branch and Congress are the audience for the STEP Board’s work in the form of consensus reports, conferences, and workshops. The current executive director is Stephen A. Merrill, Ph.D. and the Board Chair is Paul Joskow, president of the Sloan Foundation.
History and evolution
Establishment
The Academies began to address issues of U.S. competitiveness and innovation in the late 1970s and early 1980s through a series of industry studies by the NAE and broad policy studies by the Committee on Science, Engineering, and Public Policy (COSEPUP).
A leading NAS economist, Dale Jorgenson, and NAE industrialists Ralph Landau and George Hatsopoulos were concerned that this work, and national innovation policy more broadly, did not sufficiently reflect the contributions economics could make to understanding of trends and policy prescriptions to improve outcomes. They proposed to the National Research Council (NRC) Governing Board of Directors of the NAS to create a new standing committee as a forum for dialogue among economists, technologists, and industrial managers to those ends. The Board on Science, Technology, and Economic Policy (STEP) was established in 1
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is one problem with current methods of aluminum production?
A. food shortages
B. competition
C. recycling is cheap
D. environmental contaminants
Answer:
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|
sciq-3942
|
multiple_choice
|
Which cells change the accessibility, transcription, or translation of a gene?
|
[
"ribosomes",
"endogenous",
"eukaryotic",
"prokaryotic"
] |
C
|
Relavent Documents:
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The Process Molecular Gene Concept is an alternative definition of a gene that states that in order for synthesis of a polypeptide to occur you need non-DNA factors and regulatory regions to regulate gene expression on DNA and derived mRNA. This is important because a DNA sequence can code for multiple polypeptides, so it is these non-DNA factors that are present in order to help determine the polypeptide that is made.
Description
The definition was first proposed by Eva M. Neumann-Held, suggesting that a redefinition of our view of the "gene" in relation to developmental genetics. This concept claims that the definition is too general. We therefore need to either clarify its definition or stop using the term "gene". In the Cycles of Contingency, Neumann-Held states, "This empirical evidence shows that it is not only the presence of DNA sequence that determines the course of events that lead to the synthesis of a polypeptide but, in addition, specific non-DNA factors must act on DNA and derived mRNA to determine the particular processing mechanisms." The developmental state and tissue determine the outcome of the DNA.
An example Neumann-Held gives of this is RNA editing. Depending on the environmental and developmental state of the organism mRNA might enhance, delete, or even add nucleotides to create a different mRNA. So according to Neumann-Held the “gene” is the process that brings together the non-DNA elements to DNA in order to create a specific polypeptide. This process has specific interactions between certain DNA segments and certain non-DNA segments, specific mechanism for mRNA's resulting interactions with non-DNA entities, which in turn creates a specific polypeptide.
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Stem cell markers are genes and their protein products used by scientists to isolate and identify stem cells. Stem cells can also be identified by functional assays. Below is a list of genes/protein products that can be used to identify various types of stem cells, or functional assays that do the same. The initial version of the list below was obtained by mining the PubMed database as described in
Stem cell marker names
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This lecture, named in memory of Keith R. Porter, is presented to an eminent cell biologist each year at the ASCB Annual Meeting. The ASCB Program Committee and the ASCB President recommend the Porter Lecturer to the Porter Endowment each year.
Lecturers
Source: ASCB
See also
List of biology awards
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In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from altering the number of copies of RNA that are transcribed, to the temporal control of when the gene is transcribed. This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response. Some examples of this include producing the mRNA that encode enzymes to adapt to a change in a food source, producing the gene products involved in cell cycle specific activities, and producing the gene products responsible for cellular differentiation in multicellular eukaryotes, as studied in evolutionary developmental biology.
The regulation of transcription is a vital process in all living organisms. It is orchestrated by transcription factors and other proteins working in concert to finely tune the amount of RNA being produced through a variety of mechanisms. Bacteria and eukaryotes have very different strategies of accomplishing control over transcription, but some important features remain conserved between the two. Most importantly is the idea of combinatorial control, which is that any given gene is likely controlled by a specific combination of factors to control transcription. In a hypothetical example, the factors A and B might regulate a distinct set of genes from the combination of factors A and C. This combinatorial nature extends to complexes of far more than two proteins, and allows a very small subset (less than 10%) of the genome to control the transcriptional program of the entire cell.
In bacteria
Much of the early understanding of transcription came from bacteria, although the extent and complexity of transcriptional regulation is greater in eukaryotes. Bacterial transcription is governed by three main sequence elements:
Promoters are elements of DNA that may bind
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Cellular memory modules are a form of epigenetic inheritance that allow cells to maintain their original identity after a series of cell divisions and developmental processes. Cellular memory modules implement these preserved characteristics into transferred environments through transcriptional memory. Cellular memory modules are primarily found in Drosophila.
History
Cellular memory modules were discovered by François Jacob and Jaques Monod in 1961 at the Pasteur Institute in Paris. The discovery led to Jacob and Monod, along with André Lwoff, receiving The Nobel Prize in Physiology or Medicine in 1965 for their discoveries regarding genetic control of enzyme and virus synthesis. These experimental results mapped the complex processes in which self-regulating processes express or suppress genes. Monod and Jacob proved how genetic information conversion during the construction of proteins was done through a messenger which evinced RNA. Lwoff aided in the experiment that won the Nobel Prize but did not work on the series of experiments that led to the discovery of cellular memory modules, which is why he remains uncredited in its discovery.
Locations and mechanisms: experiment overviews
Cellular memory modules have the same general process of genes undergoing transcription, these genes being transferred to an unfamiliar environment, and then these genes reverting to their original characteristics preserved through transcriptional memory. Cellular memory modules preserve repressed and active chromatin states in the Polycomb group (PcG) and trithorax group (trxG) proteins by using Polycomb- and trithorax response elements, which are just DNA sequences. Transcription resets and alters epigenetic marks on chromosomal memory elements that are regulated by PcG and trxG proteins. PcG genes maintain silent expression states during the development of Hox genes while trxG proteins maintain Hox gene expression patterns. PcG proteins bind to Polycomb response elements (PREs
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which cells change the accessibility, transcription, or translation of a gene?
A. ribosomes
B. endogenous
C. eukaryotic
D. prokaryotic
Answer:
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sciq-1778
|
multiple_choice
|
Smooth, cardiac, and skeletal are all types of what?
|
[
"bone",
"hormones",
"teeth",
"muscle"
] |
D
|
Relavent Documents:
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Several universities have designed interdisciplinary courses with a focus on human biology at the undergraduate level. There is a wide variation in emphasis ranging from business, social studies, public policy, healthcare and pharmaceutical research.
Americas
Human Biology major at Stanford University, Palo Alto (since 1970)
Stanford's Human Biology Program is an undergraduate major; it integrates the natural and social sciences in the study of human beings. It is interdisciplinary and policy-oriented and was founded in 1970 by a group of Stanford faculty (Professors Dornbusch, Ehrlich, Hamburg, Hastorf, Kennedy, Kretchmer, Lederberg, and Pittendrigh). It is a very popular major and alumni have gone to post-graduate education, medical school, law, business and government.
Human and Social Biology (Caribbean)
Human and Social Biology is a Level 4 & 5 subject in the secondary and post-secondary schools in the Caribbean and is optional for the Caribbean Secondary Education Certification (CSEC) which is equivalent to Ordinary Level (O-Level) under the British school system. The syllabus centers on structure and functioning (anatomy, physiology, biochemistry) of human body and the relevance to human health with Caribbean-specific experience. The syllabus is organized under five main sections: Living organisms and the environment, life processes, heredity and variation, disease and its impact on humans, the impact of human activities on the environment.
Human Biology Program at University of Toronto
The University of Toronto offers an undergraduate program in Human Biology that is jointly offered by the Faculty of Arts & Science and the Faculty of Medicine. The program offers several major and specialist options in: human biology, neuroscience, health & disease, global health, and fundamental genetics and its applications.
Asia
BSc (Honours) Human Biology at All India Institute of Medical Sciences, New Delhi (1980–2002)
BSc (honours) Human Biology at AIIMS (New
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H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
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Animal science is described as "studying the biology of animals that are under the control of humankind". It can also be described as the production and management of farm animals. Historically, the degree was called animal husbandry and the animals studied were livestock species, like cattle, sheep, pigs, poultry, and horses. Today, courses available look at a broader area, including companion animals, like dogs and cats, and many exotic species. Degrees in Animal Science are offered at a number of colleges and universities. Animal science degrees are often offered at land-grant universities, which will often have on-campus farms to give students hands-on experience with livestock animals.
Education
Professional education in animal science prepares students for careers in areas such as animal breeding, food and fiber production, nutrition, animal agribusiness, animal behavior, and welfare. Courses in a typical Animal Science program may include genetics, microbiology, animal behavior, nutrition, physiology, and reproduction. Courses in support areas, such as genetics, soils, agricultural economics and marketing, legal aspects, and the environment also are offered.
Bachelor degree
At many universities, a Bachelor of Science (BS) degree in Animal Science allows emphasis in certain areas. Typical areas are species-specific or career-specific. Species-specific areas of emphasis prepare students for a career in dairy management, beef management, swine management, sheep or small ruminant management, poultry production, or the horse industry. Other career-specific areas of study include pre-veterinary medicine studies, livestock business and marketing, animal welfare and behavior, animal nutrition science, animal reproduction science, or genetics. Youth programs are also an important part of animal science programs.
Pre-veterinary emphasis
Many schools that offer a degree option in Animal Science also offer a pre-veterinary emphasis such as Iowa State University, th
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In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
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Outline
h1.00: Cytology
h2.00: General histology
H2.00.01.0.00001: Stem cells
H2.00.02.0.00001: Epithelial tissue
H2.00.02.0.01001: Epithelial cell
H2.00.02.0.02001: Surface epithelium
H2.00.02.0.03001: Glandular epithelium
H2.00.03.0.00001: Connective and supportive tissues
H2.00.03.0.01001: Connective tissue cells
H2.00.03.0.02001: Extracellular matrix
H2.00.03.0.03001: Fibres of connective tissues
H2.00.03.1.00001: Connective tissue proper
H2.00.03.1.01001: Ligaments
H2.00.03.2.00001: Mucoid connective tissue; Gelatinous connective tissue
H2.00.03.3.00001: Reticular tissue
H2.00.03.4.00001: Adipose tissue
H2.00.03.5.00001: Cartilage tissue
H2.00.03.6.00001: Chondroid tissue
H2.00.03.7.00001: Bone tissue; Osseous tissue
H2.00.04.0.00001: Haemotolymphoid complex
H2.00.04.1.00001: Blood cells
H2.00.04.1.01001: Erythrocyte; Red blood cell
H2.00.04.1.02001: Leucocyte; White blood cell
H2.00.04.1.03001: Platelet; Thrombocyte
H2.00.04.2.00001: Plasma
H2.00.04.3.00001: Blood cell production
H2.00.04.4.00001: Postnatal sites of haematopoiesis
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Smooth, cardiac, and skeletal are all types of what?
A. bone
B. hormones
C. teeth
D. muscle
Answer:
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sciq-7886
|
multiple_choice
|
What kind of light ranges from red to violet?
|
[
"x rays",
"visible light",
"infrared light",
"ultraviolet light"
] |
B
|
Relavent Documents:
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Green Light, green light, green-light or greenlight may refer to:
Green-colored light, part of the visible spectrum
Arts, entertainment, and media
Films and television
Green Light (1937 film), starring Errol Flynn
Green Light (2002 film), a Turkish film written and directed by Faruk Aksoy
"Green Light" (Breaking Bad), a third-season episode of Breaking Bad
Greenlight, formal approval of a project to move forward
Literature
Green Light, a 1935 novel by Lloyd C. Douglas
"Green Light", the final passage of F. Scott Fitzgerald's novel The Great Gatsby
Greenlights (book), a 2020 book by Matthew McConaughey
Music
Albums
Green Light (Bonnie Raitt album), 1982
Green Light (Cliff Richard album), 1978
The Green Light, a 2009 mixtape by Bow Wow
Songs
"Green Light" (Cliff Richard song) (1979)
"Green Light" (Beyoncé song) (2006)
"Green Light" (John Legend song) (2008)
"Green Light" (Roll Deep song) (2010)
"Green Light" (Lorde song) (2017)
"Green Light" (Valery Leontiev song) (1984)
"Green Light", by the American Breed from Bend Me, Shape Me (1968)
"Green Light", by Girls' Generation from Lion Heart
"Green Light", by Hank Thompson (1954)
"Green Light", by Lil Durk from Love Songs 4 the Streets 2
"Green Light", by R. Kelly from Write Me Back
"Green Light", by Sonic Youth from Evol
"Green Light", by the Bicycles from Oh No, It's Love
"Green Lights", by Aloe Blacc (2011)
"Greenlight" (Pitbull song) (2016)
"Green Lights", by Sarah Jarosz from Undercurrent (2016)
"Green Light", by Kylie Minogue from Tension (2023)
"Greenlight", by 5 Seconds of Summer from 5 Seconds of Summer
"Greenlight", by Enisa Nikaj which represented New York in the American Song Contest
"Greenlights" (song), by Krewella
Computing and technology
Greenlight (Internet service), a fiber-optic Internet service provided by the city of Wilson, North Carolina, US
Greenlight Networks, a fiber-optic Internet service in Rochester, New York, US
Steam Greenlight, a service part of Val
Document 1:::
A colorimeter is a device used in colorimetry that measures the absorbance of particular wavelengths of light by a specific solution. It is commonly used to determine the concentration of a known solute in a given solution by the application of the Beer–Lambert law, which states that the concentration of a solute is proportional to the absorbance.
Construction
The essential parts of a colorimeter are:
a light source (often an ordinary low-voltage filament lamp);
an adjustable aperture;
a set of colored filters;
a cuvette to hold the working solution;
a detector (usually a photoresistor) to measure the transmitted light;
a meter to display the output from the detector.
In addition, there may be:
a voltage regulator, to protect the instrument from fluctuations in mains voltage;
a second light path, cuvette and detector. This enables comparison between the working solution and a "blank", consisting of pure solvent, to improve accuracy.
There are many commercialized colorimeters as well as open source versions with construction documentation for education and for research.
Filters
Changeable optics filters are used in the colorimeter to select the wavelength which the solute absorbs the most, in order to maximize accuracy. The usual wavelength range is from 400 to 700 nm. If it is necessary to operate in the ultraviolet range then some modifications to the colorimeter are needed. In modern colorimeters the filament lamp and filters may be replaced by several (light-emitting diode) of different colors.
Cuvettes
In a manual colorimeter the cuvettes are inserted and removed by hand. An automated colorimeter (as used in an AutoAnalyzer) is fitted with a flowcell through which solution flows continuously.
Output
The output from a colorimeter may be displayed by an analogue or digital meter and may be shown as transmittance (a linear scale from 0 to 100%) or as absorbance (a logarithmic scale from zero to infinity). The useful range of the absorbance scale is
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The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared).
The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well.
The spectrum does not contain all the colors that the human visual system can distinguish. Unsaturated colors such as pink, or purple variations like magenta, for example, are absent because they can only be made from a mix of multiple wavelengths. Colors containing only one wavelength are also called pure colors or spectral colors.
Visible wavelengths pass largely unattenuated through the Earth's atmosphere via the "optical window" region of the electromagnetic spectrum. An example of this phenomenon is when clean air scatters blue light more than red light, and so the midday sky appears blue (apart from the area around the Sun which appears white because the light is not scattered as much). The optical window is also referred to as the "visible window" because it overlaps the human visible response spectrum. The near infrared (NIR) window lies just out of the human vision, as well as the medium wavelength infrared (MWIR) window, and the long-wavelength or far-infrared (LWIR or FIR) window, although other animals may perceive them.
Spectral colors
Colors that can be produced by visible light of a narrow band of wavelengths (monochromatic light) are called pure spectral colors. The various co
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Red light or redlight may refer to:
Science and technology
Red, any of a number of similar colors evoked by light in the wavelength range of 630–740 nm
Red light, a traffic light color signifying stop
Red light, a color of safelight used in photographic darkrooms
Red light therapy
Arts and entertainment
Red Lights (novel) (Feux Rouges), a 1953 book by Georges Simenon
Film
Red Lights (1923 film), a 1923 American silent film
Red Light (film), a 1949 crime film starring George Raft
Red Lights (2004 film) (Feux rouges), a French thriller directed by Cédric Kahn
Red Lights (2012 film), a thriller by Rodrigo Cortés
Redlight (film), a 2009 documentary film
Music
Red Light, a sublabel of Tunnel Records
Redlight (musician) (born 1980), British electronic musician
Albums
Red Light (Bladee album), 2018
Red Light (f(x) album), 2014
Redlight (Grails album), 2004
Redlight (The Slackers album), 1997
Red Light! (Indigo Swing album), 1999
Songs
"Red Light" (Linda Clifford song)
"Red Light" (David Nail song)
"Red Light" (Siouxsie and the Banshees song)
"Red Light" (U2 song)
"Red Light", by Fastball from Keep Your Wig On
"Red Light", by Jonny Lang from Long Time Coming
"Red Light", by Eddie Murphy, featuring Snoop Dogg
"Red Light", by The Strokes from First Impressions of Earth
"Red Light", by Wall of Voodoo from Dark Continent
"Redlight" (song), by Ian Carey
"Redlight", by Kelly Osbourne from Sleeping in the Nothing
"Red Lights" (song), by Tiësto
"Red Lights" (Stray Kids song)
"Red Lights", by Chloe x Halle from Sugar Symphony
Other uses
Redlight Children Campaign, an American non-profit organization
Common synonym for goals in ice hockey, derived from the red lamp behind the net activated to confirm a goal
André Racicot (born 1969), nicknamed "Red Light", retired ice hockey goalie
Operation Red Light II, a 2006 coalition military operation of the Iraq War
See also
Red-light district, a part of an urban area where there is a concentration o
Document 4:::
Cosmic ray visual phenomena, or light flashes (LF), also known as Astronaut's Eye, are spontaneous flashes of light visually perceived by some astronauts outside the magnetosphere of the Earth, such as during the Apollo program. While LF may be the result of actual photons of visible light being sensed by the retina, the LF discussed here could also pertain to phosphenes, which are sensations of light produced by the activation of neurons along the visual pathway.
Possible causes
Researchers believe that the LF perceived specifically by astronauts in space are due to cosmic rays (high-energy charged particles from beyond the Earth's atmosphere), though the exact mechanism is unknown. Hypotheses include Cherenkov radiation created as the cosmic ray particles pass through the vitreous humour of the astronauts' eyes, direct interaction with the optic nerve, direct interaction with visual centres in the brain, retinal receptor stimulation, and a more general interaction of the retina with radiation.
Conditions under which the light flashes were reported
Astronauts who had recently returned from space missions to the Hubble Space Telescope, the International Space Station and Mir Space Station reported seeing the LF under different conditions. In order of decreasing frequency of reporting in a survey, they saw the LF in the dark, in dim light, in bright light and one reported that he saw them regardless of light level and light adaptation. They were seen mainly before sleeping.
Types
Some LF were reported to be clearly visible, while others were not. They manifested in different colors and shapes. How often each type was seen varied across astronauts' experiences, as evident in a survey of 59 astronauts.
Colors
On Lunar missions, astronauts almost always reported that the flashes were white, with one exception where the astronaut observed "blue with a white cast, like a blue diamond." On other space missions, astronauts reported seeing other colors such as yellow and
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of light ranges from red to violet?
A. x rays
B. visible light
C. infrared light
D. ultraviolet light
Answer:
|
|
sciq-10014
|
multiple_choice
|
Momentum is directly related to both mass and?
|
[
"intensity",
"speed",
"velocity",
"mass"
] |
C
|
Relavent Documents:
Document 0:::
This is a list of topics that are included in high school physics curricula or textbooks.
Mathematical Background
SI Units
Scalar (physics)
Euclidean vector
Motion graphs and derivatives
Pythagorean theorem
Trigonometry
Motion and forces
Motion
Force
Linear motion
Linear motion
Displacement
Speed
Velocity
Acceleration
Center of mass
Mass
Momentum
Newton's laws of motion
Work (physics)
Free body diagram
Rotational motion
Angular momentum (Introduction)
Angular velocity
Centrifugal force
Centripetal force
Circular motion
Tangential velocity
Torque
Conservation of energy and momentum
Energy
Conservation of energy
Elastic collision
Inelastic collision
Inertia
Moment of inertia
Momentum
Kinetic energy
Potential energy
Rotational energy
Electricity and magnetism
Ampère's circuital law
Capacitor
Coulomb's law
Diode
Direct current
Electric charge
Electric current
Alternating current
Electric field
Electric potential energy
Electron
Faraday's law of induction
Ion
Inductor
Joule heating
Lenz's law
Magnetic field
Ohm's law
Resistor
Transistor
Transformer
Voltage
Heat
Entropy
First law of thermodynamics
Heat
Heat transfer
Second law of thermodynamics
Temperature
Thermal energy
Thermodynamic cycle
Volume (thermodynamics)
Work (thermodynamics)
Waves
Wave
Longitudinal wave
Transverse waves
Transverse wave
Standing Waves
Wavelength
Frequency
Light
Light ray
Speed of light
Sound
Speed of sound
Radio waves
Harmonic oscillator
Hooke's law
Reflection
Refraction
Snell's law
Refractive index
Total internal reflection
Diffraction
Interference (wave propagation)
Polarization (waves)
Vibrating string
Doppler effect
Gravity
Gravitational potential
Newton's law of universal gravitation
Newtonian constant of gravitation
See also
Outline of physics
Physics education
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Physics education research (PER) is a form of discipline-based education research specifically related to the study of the teaching and learning of physics, often with the aim of improving the effectiveness of student learning. PER draws from other disciplines, such as sociology, cognitive science, education and linguistics, and complements them by reflecting the disciplinary knowledge and practices of physics. Approximately eighty-five institutions in the United States conduct research in science and physics education.
Goals
One primary goal of PER is to develop pedagogical techniques and strategies that will help students learn physics more effectively and help instructors to implement these techniques. Because even basic ideas in physics can be confusing, together with the possibility of scientific misconceptions formed from teaching through analogies, lecturing often does not erase common misconceptions about physics that students acquire before they are taught physics. Research often focuses on learning more about common misconceptions that students bring to the physics classroom so that techniques can be devised to help students overcome these misconceptions.
In most introductory physics courses, mechanics is usually the first area of physics that is taught. Newton's laws of motion about interactions between forces and objects are central to the study of mechanics. Many students hold the Aristotelian misconception that a net force is required to keep a body moving; instead, motion is modeled in modern physics with Newton's first law of inertia, stating that a body will keep its state of rest or movement unless a net force acts on the body. Like students who hold this misconception, Newton arrived at his three laws of motion through empirical analysis, although he did it with an extensive study of data that included astronomical observations. Students can erase such as misconception in a nearly frictionless environment, where they find that
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In classical mechanics, impulse (symbolized by or Imp) is the change in momentum of an object. If the initial momentum of an object is , and a subsequent momentum is , the object has received an impulse :
Momentum is a vector quantity, so impulse is also a vector quantity.
Newton’s second law of motion states that the rate of change of momentum of an object is equal to the resultant force acting on the object:
so the impulse delivered by a steady force acting for time Δt is:
The impulse delivered by a varying force is the integral of the force with respect to time:
The SI unit of impulse is the newton second (N⋅s), and the dimensionally equivalent unit of momentum is the kilogram metre per second (kg⋅m/s). The corresponding English engineering unit is the pound-second (lbf⋅s), and in the British Gravitational System, the unit is the slug-foot per second (slug⋅ft/s).
Mathematical derivation in the case of an object of constant mass
Impulse produced from time to is defined to be
where is the resultant force applied from to .
From Newton's second law, force is related to momentum by
Therefore,
where is the change in linear momentum from time to . This is often called the impulse-momentum theorem (analogous to the work-energy theorem).
As a result, an impulse may also be regarded as the change in momentum of an object to which a resultant force is applied. The impulse may be expressed in a simpler form when the mass is constant:
where
is the resultant force applied,
and are times when the impulse begins and ends, respectively,
is the mass of the object,
is the final velocity of the object at the end of the time interval, and
is the initial velocity of the object when the time interval begins.
Impulse has the same units and dimensions as momentum. In the International System of Units, these are . In English engineering units, they are .
The term "impulse" is also used to refer to a fast-acting force or impact. This type of impulse is o
Document 3:::
The newton-second (also newton second; symbol: N⋅s or N s) is the unit of impulse in the International System of Units (SI). It is dimensionally equivalent to the momentum unit kilogram-metre per second (kg⋅m/s). One newton-second corresponds to a one-newton force applied for one second.
It can be used to identify the resultant velocity of a mass if a force accelerates the mass for a specific time interval.
Definition
Momentum is given by the formula:
is the momentum in newton-seconds (N⋅s) or "kilogram-metres per second" (kg⋅m/s)
is the mass in kilograms (kg)
is the velocity in metres per second (m/s)
Examples
This table gives the magnitudes of some momenta for various masses and speeds.
See also
Power factor
Newton-metre – SI unit of torque
Orders of magnitude (momentum) – examples of momenta
Document 4:::
Working mass, also referred to as reaction mass, is a mass against which a system operates in order to produce acceleration.
In the case of a chemical rocket, for example, the reaction mass is the product of the burned fuel shot backwards to provide propulsion. All acceleration requires an exchange of momentum, which can be thought of as the "unit of movement". Momentum is related to mass and velocity, as given by the formula P = mv, where P is the momentum, m the mass, and v the velocity. The velocity of a body is easily changeable, but in most cases the mass is not, which makes it important.
Rockets and rocket-like reaction engines
In rockets, the total velocity change can be calculated (using the Tsiolkovsky rocket equation) as follows:
Where:
v = ship velocity.
u = exhaust velocity.
M = ship mass, not including the working mass.
m = total mass ejected from the ship (working mass).
The term working mass is used primarily in the aerospace field. In more "down to earth" examples the working mass is typically provided by the Earth, which contains so much momentum in comparison to most vehicles that the amount it gains or loses can be ignored. However, in the case of an aircraft the working mass is the air, and in the case of a rocket, it is the rocket fuel itself. Most rocket engines use light-weight fuels (liquid hydrogen, oxygen, or kerosene) accelerated to super-sonic speeds. However, ion engines often use heavier elements like xenon as the reaction mass, accelerated to much higher speeds using electric fields.
In many cases the working mass is separate from the energy used to accelerate it. In a car the engine provides power to the wheels, which then accelerates the Earth backward to make the car move forward. This is not the case for most rockets however, where the rocket propellant is the working mass, as well as the energy source. This means that rockets stop accelerating as soon as they run out of fuel, regardless of other power sources they may have
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Momentum is directly related to both mass and?
A. intensity
B. speed
C. velocity
D. mass
Answer:
|
|
sciq-10534
|
multiple_choice
|
What of most species are resistant cells that can survive harsh conditions?
|
[
"zygotes",
"gonads",
"subtypes",
"phenotypes"
] |
A
|
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:::
This lecture, named in memory of Keith R. Porter, is presented to an eminent cell biologist each year at the ASCB Annual Meeting. The ASCB Program Committee and the ASCB President recommend the Porter Lecturer to the Porter Endowment each year.
Lecturers
Source: ASCB
See also
List of biology awards
Document 2:::
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 3:::
Allorecognition is the ability of an individual organism to distinguish its own tissues from those of another. It manifests itself in the recognition of antigens expressed on the surface of cells of non-self origin. Allorecognition has been described in nearly all multicellular phyla.
This article focuses on allorecognition from the standpoint of its significance in the evolution of multicellular organisms. For other articles which focus on its importance in medicine, molecular biology, and so forth, the following topics are recommended as well as those in the Categories links at the bottom of this page.
Immune system, Immunology
Transplant rejection
Tissue typing
Major histocompatibility complex (MHC)
The ability to discriminate between self and non-self is a fundamental requirement for life. At the most basic level, even single-celled organisms need to be able to distinguish between food and non-food, to respond appropriately to invading pathogens, and to avoid cannibalism. In sexually reproducing organisms, self/non-self discrimination is essential to ensuring species-specific egg/sperm interaction during fertilization. Hermaphroditic organisms, such as annelids and certain plants, require recognition mechanisms to prevent self-fertilization. Such functions are all carried out by the innate immune system, which employs evolutionarily conserved pattern recognition receptors to eliminate cells displaying "nonself markers."
Evolution of multicellularity
The evolution of multicellularity brought about various challenges, many of which could be met by increasingly sophisticated innate immune systems, but which also served as an evolutionary driving force for the development of adaptive immune systems. The adaptive or "specific" immune system in its fully qualified form (i.e. based on major histocompatibility complex (MHC), T-cell receptors (TCR), and antibodies) exists only in jawed vertebrates, but an independently evolved adaptive immune system has been iden
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 of most species are resistant cells that can survive harsh conditions?
A. zygotes
B. gonads
C. subtypes
D. phenotypes
Answer:
|
|
sciq-8128
|
multiple_choice
|
What is an example of a metaloid element?
|
[
"chlorine",
"fluorine",
"silicon",
"argon"
] |
C
|
Relavent Documents:
Document 0:::
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals. There is no standard definition of a metalloid and no complete agreement on which elements are metalloids. Despite the lack of specificity, the term remains in use in the literature of chemistry.
The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. Five elements are less frequently so classified: carbon, aluminium, selenium, polonium and astatine. On a standard periodic table, all eleven elements are in a diagonal region of the p-block extending from boron at the upper left to astatine at lower right. Some periodic tables include a dividing line between metals and nonmetals, and the metalloids may be found close to this line.
Typical metalloids have a metallic appearance, but they are brittle and only fair conductors of electricity. Chemically, they behave mostly as nonmetals. They can form alloys with metals. Most of their other physical properties and chemical properties are intermediate in nature. Metalloids are usually too brittle to have any structural uses. They and their compounds are used in alloys, biological agents, catalysts, flame retardants, glasses, optical storage and optoelectronics, pyrotechnics, semiconductors, and electronics.
The electrical properties of silicon and germanium enabled the establishment of the semiconductor industry in the 1950s and the development of solid-state electronics from the early 1960s.
The term metalloid originally referred to nonmetals. Its more recent meaning, as a category of elements with intermediate or hybrid properties, became widespread in 1940–1960. Metalloids are sometimes called semimetals, a practice that has been discouraged, as the term semimetal has a different meaning in physics than in chemistry. In physics, it refers to a specific kind of electronic band structure of a substance. In this context, only
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
A nonmetal is a chemical element that mostly lacks metallic properties. Seventeen elements are generally considered nonmetals, though some authors recognize more or fewer depending on the properties considered most representative of metallic or nonmetallic character. Some borderline elements further complicate the situation.
Nonmetals tend to have low density and high electronegativity (the ability of an atom in a molecule to attract electrons to itself). They range from colorless gases like hydrogen to shiny solids like the graphite form of carbon. Nonmetals are often poor conductors of heat and electricity, and when solid tend to be brittle or crumbly. In contrast, metals are good conductors and most are pliable. While compounds of metals tend to be basic, those of nonmetals tend to be acidic.
The two lightest nonmetals, hydrogen and helium, together make up about 98% of the observable ordinary matter in the universe by mass. Five nonmetallic elements—hydrogen, carbon, nitrogen, oxygen, and silicon—make up the overwhelming majority of the Earth's crust, atmosphere, oceans and biosphere.
The distinct properties of nonmetallic elements allow for specific uses that metals often cannot achieve. Elements like hydrogen, oxygen, carbon, and nitrogen are essential building blocks for life itself. Moreover, nonmetallic elements are integral to industries such as electronics, energy storage, agriculture, and chemical production.
Most nonmetallic elements were not identified until the 18th and 19th centuries. While a distinction between metals and other minerals had existed since antiquity, a basic classification of chemical elements as metallic or nonmetallic emerged only in the late 18th century. Since then nigh on two dozen properties have been suggested as single criteria for distinguishing nonmetals from metals.
Definition and applicable elements
Properties mentioned hereafter refer to the elements in their most stable forms in ambient conditions unless otherwise
Document 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:::
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 an example of a metaloid element?
A. chlorine
B. fluorine
C. silicon
D. argon
Answer:
|
|
sciq-337
|
multiple_choice
|
What are flagellate protozoa that cause giardiasis?
|
[
"plankton",
"fungus",
"giardia",
"diatoms"
] |
C
|
Relavent Documents:
Document 0:::
A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are known as flagellates.
A microorganism may have from one to many flagella. A gram-negative bacterium Helicobacter pylori for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell.
Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means "whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum.
Eukaryotic flagella and cilia are identical in structure but have different lengths and functions. Prokaryotic fimbriae and pili are smaller, and thinner appendages, with different functions.
Types
The three types of flagella are bacterial, archaeal, and eukaryotic.
The flagella in eukaryotes have dynein and microtubules that move with a bending mechanism. Bacteria and archaea do not have dynein or microtubules in their flagella, and they move using a rotary mechanism.
Other differences among these three types are:
Bacterial flagella are helical filaments, each with a rotary motor at its base which can turn clockwise or counterclockwise. They provide two of several kinds of bacterial motility.
Archaeal flagella (archaella) are superficially similar to bacterial flagella in that it also has a rotary motor, but are different in many details and considered non-homologous.
Eukaryotic flagella—those of animal, plant, and protist cells—are complex cellular projections tha
Document 1:::
The evolution of flagella is of great interest to biologists because the three known varieties of flagella – (eukaryotic, bacterial, and archaeal) each represent a sophisticated cellular structure that requires the interaction of many different systems.
Eukaryotic flagellum
There are two competing groups of models for the evolutionary origin of the eukaryotic flagellum (referred to as cilium below to distinguish it from its bacterial counterpart). Recent studies on the microtubule organizing center suggest that the most recent ancestor of all eukaryotes already had a complex flagellar apparatus.
Endogenous, autogenous and direct filiation models
These models argue that cilia developed from pre-existing components of the eukaryotic cytoskeleton (which has tubulin and dynein also used for other functions) as an extension of the mitotic spindle apparatus. The connection can still be seen, first in the various early-branching single-celled eukaryotes that have a microtubule basal body, where microtubules on one end form a spindle-like cone around the nucleus, while microtubules on the other end point away from the cell and form the cilium. A further connection is that the centriole, involved in the formation of the mitotic spindle in many (but not all) eukaryotes, is homologous to the cilium, and in many cases is the basal body from which the cilium grows.
An intermediate stage between spindle and cilium would be a non-swimming appendage made of microtubules with a function subject to natural selection, such as increasing surface area, helping the protozoan remain suspended in water, increasing the chances of bumping into bacteria to eat, or serving as a stalk attaching the cell to a solid substrate.
Regarding the origin of the individual protein components, a paper on the evolution of dyneins shows that the more complex protein family of ciliary dynein has an apparent ancestor in a simpler cytoplasmic dynein (which itself has evolved from the AAA protein family t
Document 2:::
Endoparasites
Protozoan organisms
Helminths (worms)
Helminth organisms (also called helminths or intestinal worms) include:
Tapeworms
Flukes
Roundworms
Other organisms
Ectoparasites
Document 3:::
Philasterides dicentrarchi is a marine protozoan ciliate that was first identified in 1995 after being isolated from infected European sea bass (Dicentrarchus labrax) reared in France. The species was also identified as the causative agent of outbreaks of scuticociliatosis that occurred between summer 1999 and spring 2000 in turbot (Scophthalmus maximus) cultivated in the Atlantic Ocean (Galicia, Northwest Spain). Infections caused by P. dicentrarchi have since been observed in turbot reared in both open flow and recirculating production systems. In addition, the ciliate has also been reported to cause infections in other flatfishes, such as the olive flounder (Paralichthys olivaceus) in Korea and the fine flounder (Paralichthys adspersus) in Peru, as well as in seadragons (Phyllopteryx taeniolatus and Phycodurus eques), seahorses (Hippocampus kuda and H. abdominalis), and several species of sharks in other parts of the world.
Biology and Pathology
P. dicentrarchi is included within the subclass Scuticociliatia, which includes about 20 species of ciliates that are typically microphagous bacteriovores and generally abundant in eutrophic habitats in lakes and in coastal marine habitats. Some of these ciliates, characterized by possessing a scutica (a transient kinetosomal structure that is present during stomatogenesis), can behave as endoparasites and are capable of producing serious infections in a wide variety of vertebrates, especially fish, and invertebrates such as crustaceans and echinoderms. P. dicentrarchi is a microaerophilic scuticociliate that lives at the sea bottom, at or below the oxycline or on the monimolimnion, where it feeds on bacteria. However, when it encounters a host it can also behave as an opportunistic histiophagous parasite. Survival of the species inside the host and adaptation to a parasitic lifestyle are attributed to the existence of physiological adaptations at the level of mitochondrial metabolism. Such adaptations include the prese
Document 4:::
Ministeria vibrans is a bacterivorous amoeba with filopodia that was originally described to be suspended by a flagellum-like stalk attached to the substrate. Molecular and experimental work later on demonstrated the stalk is indeed a flagellar apparatus.
The amoeboid protist Ministeria vibrans occupies a key position to understand animal origins. It is a member of the Filasterea, that is the sister-group to Choanoflagellatea and Metazoa. Two Ministeria amoebae species have been reported so far, both of them from coastal marine water samples: M. vibrans and M. marisola. However, there is currently only one culture available, that of Ministeria vibrans.
The life cycle of Ministeria remains unknown.
Microvilli in Ministeria suggest their presence in the common ancestor of Filasterea and Choanoflagellata. The kinetid structure of Ministeria is similar to that of the choanocytes of the most deep-branching sponges, differing essentially from the kinetid of choanoflagellates. Thus, kinetid and microvilli of Ministeria illustrate features of the common ancestor of three holozoan groups: Filasterea, Metazoa and Choanoflagellata.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are flagellate protozoa that cause giardiasis?
A. plankton
B. fungus
C. giardia
D. diatoms
Answer:
|
|
sciq-9825
|
multiple_choice
|
Dentists occasionally use metallic mixtures called amalgams for what?
|
[
"tools",
"anesthesia",
"fillings",
"braces"
] |
C
|
Relavent Documents:
Document 0:::
Dental anesthesiology is the specialty of dentistry that deals with the advanced use of general anesthesia, sedation and pain management to facilitate dental procedures.
In the United States, a dentist anesthesiologist is a dentist who has successfully completed an accredited postdoctoral anesthesiology residency program of three or more years duration, in accordance with the Commission on Dental Accreditation’s standards or meets the eligibility requirements for examination by the American Dental Board of Anesthesiology.
United States and Canada
Dental Anesthesiology is a recognized specialty of dentistry in both the United States and Canada. The American Dental Board of Anesthesiology (ADBA) examines and certifies dentists who complete an accredited program of anesthesiology training in the United States or Canada. Dentists may then apply for board certification through the ADBA which requires ongoing and continual post-graduate education for maintenance.
The American Society of Dentist Anesthesiologists is the only organization that represents dentists with three or more years of anesthesiology training.
Dental Anesthesiology was the first specialty of dentistry to be recognized by both the American Board of Dental Specialties and the National Commission on Recognition of Dental Specialties and Certifying Boards.
See also
Anesthesia
Dentistry
Document 1:::
The history of dental treatments dates back to thousands of years. The scope of this article is limited to the pre-1981 history.
The earliest known example of dental caries manipulation is found in a Paleolithic man, dated between 14,160 and 13,820 BP. The earliest known use of a filling after removal of decayed or infected pulp is found in a Paleolithic who lived near modern-day Tuscany, Italy, from 13,000 to 12,740 BP. Although inconclusive, researchers have suggested that rudimentary dental procedures have been performed as far back as 130,000 years ago by Neanderthals. Regarding implants, one of the milestone progress is osseointegration which was termed in 1981 by Tomas Albrektsson.
Dental implants
There is archeological evidence that humans have attempted to replace missing teeth with root form implants for thousands of years. Remains from ancient China (dating 4000 years ago) have carved bamboo pegs, tapped into the bone, to replace lost teeth, and 2000-year-old remains from ancient Egypt have similarly shaped pegs made of precious metals. Some Egyptian mummies were found to have transplanted human teeth, and in other instances, teeth made of ivory. Wilson Popenoe and his wife in 1931, at a site in Honduras dating back to 600 AD, found the lower mandible of a young Mayan woman, with three missing incisors replaced by pieces of sea shells, shaped to resemble teeth. Bone growth around two of the implants, and the formation of calculus, indicates that they were functional as well as esthetic. The fragment is currently part of the Osteological Collection of the Peabody Museum of Archaeology and Ethnology at Harvard University.
In modern times, a tooth replica implant was reported as early as 1969, but the polymethacrylate tooth analogue was encapsulated by soft tissue rather than osseointegrated.
The early part of the 20th century saw a number of implants made of a variety of materials. One of the earliest successful implants was the Greenfield implant sy
Document 2:::
Adhesive dentistry is a branch of dentistry which deals with adhesion or bonding to the natural substance of teeth, enamel and dentin. It studies the nature and strength of adhesion to dental hard tissues, properties of adhesive materials, causes and mechanisms of failure of the bonds, clinical techniques for bonding and newer applications for bonding such as bonding to the soft tissue. There is also direct composite bonding which uses tooth-colored direct dental composites to repair various tooth damages such as cracks or gaps.
Dental bonding is a dental procedure in which a dentist applies a tooth-colored resin material (a durable plastic material) and cures it with visible, blue light. This ultimately "bonds" the material to the tooth and improves the overall appearance of teeth. Tooth bonding techniques have various clinical applications including operative dentistry and preventive dentistry as well as cosmetic and pediatric dentistry, prosthodontics, and orthodontics.
History
Adhesive dentistry began in 1955 with a paper by Dr. Michael Buonocore on the benefits of acid etching. Technologies have changed multiple times since then, with generally recognized generations established in the literature. Dental bonding agents have evolved from no-etch to total-etch (4th- and 5th-generation) to self-etch (6th- and 7th-generation) systems. improved convenience and reduced sensitivity to operator errors. However, the best bonding and longevity was achieved with 4th generation agents (having separate etch, prime, and bond steps).
Irwin Smigel founder and current president of the American Society for Dental Aesthetics and diplomate of the American Board of Aesthetic Dentistry, was one of the first to broaden the usage of bonding by using it to close gaps between teeth, lengthen teeth as well as to re-contour the entire mouth rather than using crowns. Having done more extensive work on the process than any other dentist, Dr. Smigel lectures worldwide on aesthetic dentist
Document 3:::
Minimal intervention dentistry is a modern dental practice designed around the principal aim of preservation of as much of the natural tooth structure as possible. It uses a disease-centric philosophy that directs attention to first control and management of the disease that causes tooth decay—dental caries—and then to relief of the residual symptoms it has left behind—the decayed teeth. The approach uses similar principles for prevention of future caries, and is intended to be a complete management solution for tooth decay.
History
Classical restorative dentistry has traditionally followed the century-old approach of GV Black in classification and treatment of tooth decay. This was based on very limited knowledge at the time about the pathology of the underlying dental caries disease, and the need to specially prepare a cavity to repair a lesion (decayed area) with the limited available materials. Therefore, the only approach was to treat the symptoms—to remove the decay and restore the tooth surgically. Modern science has since allowed for better understanding of the pathology, thus opening the door for new methodologies and approaches to treatment. The practice of minimal intervention dentistry was designed to utilise these new possibilities by implementing a disease-centric philosophy to management of tooth decay. While advances in dental science are of course used in mainstream dental practice, MI dentistry has redesigned the treatment guidelines beginning with a new classification of caries lesions. This classification was intended to reflect the possibility of curing the disease and remineralising (hardening) early lesions before irreversible damage has been done. It was first published by Mount and Hume in 1997 and has subsequently been revised.
Some see minimally invasive dentistry as merely a philosophical change, but since the practice has been in mainstream discussion in the late 1990s, it has acquired some respectable international academic backing.
Document 4:::
This list is arranged by the main material of manufacture.
Where a manufacturer has produced different kits in different materials, they are duplicated under each material.
Polystyrene
Injection-moulded (high pressure)
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Dentists occasionally use metallic mixtures called amalgams for what?
A. tools
B. anesthesia
C. fillings
D. braces
Answer:
|
|
sciq-11051
|
multiple_choice
|
On insects, what are the openings on the sides of the abdomen that allows respiration to occur?
|
[
"chloroplasts",
"gills",
"spiracles",
"wings"
] |
C
|
Relavent Documents:
Document 0:::
The protocerebrum is the first segment of the panarthropod brain.
Recent studies suggest that it comprises two regions.
Region associated with the expression of six3
six3 is a transcription factor that marks the anteriormost part of the developing body in a whole host of Metazoa.
In the panarthropod brain, the anteriormost (rostralmost) part of the germband expresses six3. This region is described as medial, and corresponds to the annelid prostomium.
In arthropods, it contains the pars intercerebralis and pars lateralis.
six3 is associated with the euarthropod labrum and the onychophoran frontal appendages (antennae).
Region associated with the expression of orthodenticle
The other region expresses homologues of orthodenticle, Otx or otd. This region is more caudal and lateral, and bears the eyes.
Orthodenticle is associated with the protocerebral bridge, part of the central complex, traditionally a marker of the prosocerebrum.
In the annelid brain, Otx expression characterises the peristomium, but also creeps forwards into the regions of the prostomium that bear the larval eyes.
Names of regions
Inconsistent use of the terms archicerebrum and the prosocerebrum makes them confusing.
The regions were defined by Siewing (1963): the archicerebrum as containing the ocular lobes and the mushroom bodies (= corpora pedunculata), and the prosocerebrum as comprising the central complex.
The archicerebrum has traditionally been equated with the anteriormost, 'non-segmental' part of the protocerebrum, equivalent to the acron in older terminology.
The prosocerebrum is then equivalent to the 'segmental' part of the protocerebrum, bordered by segment polarity genes such as engrailed, and (on one interpretation) bearing modified segmental appendages (= camera-type eyes).
But Urbach and Technau (2003) complicate the matter by seeing the prosocerebrum (central complex) + labrum as the anteriormost region
Strausfeld 2016 identifies the anteriormost part of the b
Document 1:::
Aquatic respiration is the process whereby an aquatic organism exchanges respiratory gases with water, obtaining oxygen from oxygen dissolved in water and excreting carbon dioxide and some other metabolic waste products into the water.
Unicellular and simple small organisms
In very small animals, plants and bacteria, simple diffusion of gaseous metabolites is sufficient for respiratory function and no special adaptations are found to aid respiration. Passive diffusion or active transport are also sufficient mechanisms for many larger aquatic animals such as many worms, jellyfish, sponges, bryozoans and similar organisms. In such cases, no specific respiratory organs or organelles are found.
Higher plants
Although higher plants typically use carbon dioxide and excrete oxygen during photosynthesis, they also respire and, particularly during darkness, many plants excrete carbon dioxide and require oxygen to maintain normal functions. In fully submerged aquatic higher plants specialised structures such as stoma on leaf surfaces to control gas interchange. In many species, these structures can be controlled to be open or closed depending on environmental conditions. In conditions of high light intensity and relatively high carbonate ion concentrations, oxygen may be produced in sufficient quantities to form gaseous bubbles on the surface of leaves and may produce oxygen super-saturation in the surrounding water body.
Animals
All animals that practice truly aquatic respiration are poikilothermic. All aquatic homeothermic animals and birds including cetaceans and penguins are air breathing despite a fully aquatic life-style.
Echinoderms
Echinoderms have a specialised water vascular system which provides a number of functions including providing the hydraulic power for tube feet but also serves to convey oxygenated sea water into the body and carry waste water out again. In many genera, the water enters through a madreporite, a sieve like structure on the upper surfac
Document 2:::
A branchiostegal lung is a respiration organ used by some air-breathing arthropods. It is one of the most significant adaptations of some crabs and hermit crabs such as the coconut crab to their terrestrial habitats.
The branchiostegal (gill) tissue is supported by folds or other mechanisms to increase surface area and are of a similar tissue to that normally found in gills. In this case, the lung is more suited to the absorption of oxygen from air, rather than water.
Instead of branchiostegal lungs, some terrestrial hermit crabs (Coenobita) possess multiple gills and small lungs, with other varieties of gas diffusion methods supporting the transition from aquatic to terrestrial dwelling.
The developmental shift from water diffusion "gills" to air perfusion "lungs" may have been related to the need for reduced rates of water loss in air.
Document 3:::
The corpuscles of Herbst or Herbst corpuscles are nerve-endings similar to the Pacinian corpuscle, found in the mucous membrane of the tongue, in pits on the beak and in other parts of the bodies of birds. They differ from Pacinian corpuscles in being smaller and more elongated, in having thinner and more closely placed capsules, and in that the axis-cylinder in the central clear space is encircled by a continuous row of nuclei. They are named after the German embryologist Curt Alfred Herbst.
In many wading birds, a large number of Herbst corpuscles are found embedded in pits on the mandible that are believed to enable birds to sense prey under wet sand or soil.
Document 4:::
The fecal shield is a structure formed by the larvae of many species of beetles in the leaf beetle family, Chrysomelidae. It is composed of the frass of the insect and often its exuviae, or bits of shed exoskeleton. The beetle may carry the shield on its back or wield it upon its posterior end. The main function of the fecal shield is defense against predators. Other terms for the fecal shield noted in the literature include "larval clothing", "kotanhang" ("fecal appendage"), "faecal mask", "faecal pad", and "exuvio-faecal annex".
Ecology
Beetle larvae of the chrysomelid subfamilies Criocerinae and Galerucinae often wear their fecal shields in piles on their backs, regularly adding material as bits chip off. The shields of Cassidinae larvae are mobile. They are attached to the posterior end of the body and moved into position as needed, sometimes held in place above the larva like an umbrella. They may be raised and even swung to strike a predator.
When the shield is carried on the tip of the abdomen, it is secured to a double-lobed, spine-like process called the caudal furca, which is also known as the "anal fork". The larva constructs the shield by maneuvering its "muscular telescopic and highly protrusible anus", or "anal turret", which is positioned dorsally, on the back. It excretes an amount of feces, sometimes with a droplet of gluey secretion, and places it on the caudal furca using its anal turret. In the species Hemisphaerota cyanea, the larva constructs a shield which may be more descriptively called a "fecal thatch", because it is woven from narrow, coiled strands of frass. The larva begins feeding immediately upon emergence from the egg and within minutes it produces its first fecal strand. Within twelve hours, its thatch-shield is full-sized. The larva diligently repairs the shield with replacement strands when it is broken.
The fecal shield takes many forms across species. In some, it covers the entire body, while in others it is narrower. In some,
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
On insects, what are the openings on the sides of the abdomen that allows respiration to occur?
A. chloroplasts
B. gills
C. spiracles
D. wings
Answer:
|
|
sciq-8554
|
multiple_choice
|
Earth’s magnetic north and south poles are not the same as what?
|
[
"geographic poles",
"geographic currents",
"geographic hemispheres",
"equatorial planes"
] |
A
|
Relavent Documents:
Document 0:::
The geomagnetic poles are antipodal points where the axis of a best-fitting dipole intersects the surface of Earth. This theoretical dipole is equivalent to a powerful bar magnet at the center of Earth, and comes closer than any other point dipole model to describing the magnetic field observed at Earth's surface. In contrast, the magnetic poles of the actual Earth are not antipodal; that is, the line on which they lie does not pass through Earth's center.
Owing to motion of fluid in the Earth's outer core, the actual magnetic poles are constantly moving (secular variation). However, over thousands of years, their direction averages to the Earth's rotation axis. On the order of once every half a million years, the poles reverse (i.e., north switches place with south) although the time frame of this switching can be anywhere from every 10 thousand years to every 50 million years. The poles also swing in an oval of around in diameter daily due to solar wind deflecting the magnetic field.
Although the geomagnetic pole is only theoretical and cannot be located directly, it arguably is of more practical relevance than the magnetic (dip) pole. This is because the poles describe a great deal about the Earth's magnetic field, determining for example where auroras can be observed. The dipole model of the Earth's magnetic field consists of the location of geomagnetic poles and the dipole moment, which describes the strength of the field.
Definition
As a first-order approximation, the Earth's magnetic field can be modeled as a simple dipole (like a bar magnet), tilted about 9.6° with respect to the Earth's rotation axis (which defines the Geographic North and Geographic South Poles) and centered at the Earth's center. The North and South Geomagnetic Poles are the antipodal points where the axis of this theoretical dipole intersects the Earth's surface. Thus, unlike the actual magnetic poles, the geomagnetic poles always have an equal degree of latitude and supplementary de
Document 1:::
The north magnetic pole, also known as the magnetic north pole, is a point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downward (in other words, if a magnetic compass needle is allowed to rotate in three dimensions, it will point straight down). There is only one location where this occurs, near (but distinct from) the geographic north pole. The geomagnetic north pole is the northern antipodal pole of an ideal dipole model of the Earth's magnetic field, which is the most closely fitting model of Earth's actual magnetic field.
The north magnetic pole moves over time according to magnetic changes and flux lobe elongation in the Earth's outer core. In 2001, it was determined by the Geological Survey of Canada to lie west of Ellesmere Island in northern Canada at . It was situated at in 2005. In 2009, while still situated within the Canadian Arctic at , it was moving toward Russia at between per year. In 2013, the distance between the north magnetic pole and the geographic north pole was approximately . As of 2021, the pole is projected to have moved beyond the Canadian Arctic to .
Its southern hemisphere counterpart is the south magnetic pole. Since Earth's magnetic field is not exactly symmetric, the north and south magnetic poles are not antipodal, meaning that a straight line drawn from one to the other does not pass through the geometric center of Earth.
Earth's north and south magnetic poles are also known as magnetic dip poles, with reference to the vertical "dip" of the magnetic field lines at those points.
Polarity
All magnets have two poles, where lines of magnetic flux enter one pole and emerge from the other pole. By analogy with Earth's magnetic field, these are called the magnet's "north" and "south" poles. The north-seeking pole of a magnet was defined to have the north designation, according to their use in early compasses. Because opposite poles attract, this means that as a physical magne
Document 2:::
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo.
The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic field (because opposite magnetic poles attract and the north end of a magnet, like a compass needle, points toward Earth's South magnetic field, i.e., the North geomagnetic pole near the Geographic North Pole). As of 2015, the North geomagnetic pole was located on Ellesmere Island, Nunavut, Canada.
While the North and South magnetic poles are usually located near the geographic poles, they slowly and continuously move over geological time scales, but sufficiently slowly for ordinary compasses to remain useful for navigation. However, at irregular intervals averaging several hundred thousand years, Earth's field reverses and the North and South Magnetic Poles respectively, abruptly switch places. These reversals of the geomagnetic poles leave a record in rocks that are of value to paleomagnetists in calculating geomagnetic fields in the past. Such information in turn is helpful in studying the motions of continents and ocean floors in the process of plate tectonics.
The magnetosphere is the regio
Document 3:::
The south magnetic pole, also known as the magnetic south pole, is the point on Earth's Southern Hemisphere where the geomagnetic field lines are directed perpendicular to the nominal surface. The Geomagnetic South Pole, a related point, is the south pole of an ideal dipole model of the Earth's magnetic field that most closely fits the Earth's actual magnetic field.
For historical reasons, the "end" of a freely hanging magnet that points (roughly) north is itself called the "north pole" of the magnet, and the other end, pointing south, is called the magnet's "south pole". Because opposite poles attract, Earth's south magnetic pole is physically actually a magnetic north pole (see also ).
The south magnetic pole is constantly shifting due to changes in Earth's magnetic field.
As of 2005 it was calculated to lie at , placing it off the coast of Antarctica, between Adélie Land and Wilkes Land. In 2015 it lay at (est). That point lies outside the Antarctic Circle. Due to polar drift, the pole is moving northwest by about per year. Its current distance from the actual Geographic South Pole is approximately . The nearest permanent science station is Dumont d'Urville Station. While the north magnetic pole began wandering very quickly in the mid 1990s, the movement of the south magnetic pole did not show a matching change of speed.
Expeditions
Early unsuccessful attempts to reach the magnetic south pole included those of French explorer Dumont d'Urville (1837–40), American Charles Wilkes (expedition of 1838–42) and Briton James Clark Ross (expedition of 1839 to 1843).
The first calculation of the magnetic inclination to locate the magnetic South Pole was made on 23 January 1838 by the hydrographer , a member of the Dumont d'Urville expedition in Antarctica and Oceania on the corvettes L'Astrolabe and Zélée in 1837–1840, which discovered Adelie Land.
On 16 January 1909 three men (Douglas Mawson, Edgeworth David, and Alistair Mackay) from Sir Ernest Shackleton's Nimrod
Document 4:::
Magnetic dip, dip angle, or magnetic inclination is the angle made with the horizontal by the Earth's magnetic field lines. This angle varies at different points on the Earth's surface. Positive values of inclination indicate that the magnetic field of the Earth is pointing downward, into the Earth, at the point of measurement, and negative values indicate that it is pointing upward. The dip angle is in principle the angle made by the needle of a vertically held compass, though in practice ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The value can be measured more reliably with a special instrument typically known as a dip circle.
Dip angle was discovered by the German engineer Georg Hartmann in 1544. A method of measuring it with a dip circle was described by Robert Norman in England in 1581.
Explanation
Magnetic dip results from the tendency of a magnet to align itself with lines of magnetic field. As the Earth's magnetic field lines are not parallel to the surface, the north end of a compass needle will point upward in the southern hemisphere (negative dip) or downward in the northern hemisphere (positive dip) . The range of dip is from -90 degrees (at the South Magnetic Pole) to +90 degrees (at the North Magnetic Pole). Contour lines along which the dip measured at the Earth's surface is equal are referred to as isoclinic lines. The locus of the points having zero dip is called the magnetic equator or aclinic line.
Calculation for a given latitude
The inclination is defined locally for the magnetic field due to the Earth's core, and has a positive value if the field points below the horizontal (ie into the Earth). Here we show how to determine the value of at a given latitude, following the treatment given by Fowler.
Outside Earth's core we consider Maxwell's equations in a vacuum, and where and the subscript denotes the core as the origin of these fields. The first means we can introduc
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Earth’s magnetic north and south poles are not the same as what?
A. geographic poles
B. geographic currents
C. geographic hemispheres
D. equatorial planes
Answer:
|
|
sciq-3180
|
multiple_choice
|
What weakly scatters visible light?
|
[
"water",
"Reflection",
"air",
"space"
] |
C
|
Relavent Documents:
Document 0:::
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 1:::
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 2:::
The refractive index of water at 20 °C for visible light is 1.33. The refractive index of normal ice is 1.31 (from List of refractive indices). In general, an index of refraction is a complex number with real and imaginary parts, where the latter indicates the strength of absorption loss at a particular wavelength. In the visible part of the electromagnetic spectrum, the imaginary part of the refractive index is very small. However, water and ice absorb in infrared and close the infrared atmospheric window thereby contributing to the greenhouse effect ...
The absorption spectrum of pure water is used in numerous applications, including light scattering and absorption by ice crystals and cloud water droplets, theories of the rainbow, determination of the single-scattering albedo, ocean color, and many others.
Quantitative description of the refraction index
Over the wavelengths from 0.2 μm to 1.2 μm, and over temperatures from −12 °C to 500 °C, the real part of the index of refraction of water can be calculated by the following empirical expression:
Where:
,
, and
and the appropriate constants are
= 0.244257733, = 0.00974634476, = −0.00373234996, = 0.000268678472, = 0.0015892057, = 0.00245934259, = 0.90070492, = −0.0166626219, = 273.15 K, = 1000 kg/m3, = 589 nm, = 5.432937, and = 0.229202.
In the above expression, T is the absolute temperature of water (in K), is the wavelength of light in nm, is the density of the water in kg/m3, and n is the real part of the index of refraction of water.
Volumic mass of water
In the above formula, the density of water also varies with temperature and is defined by:
with:
= −3.983035 °C
= 301.797 °C
= 522528.9 °C2
= 69.34881 °C
= 999.974950 kg / m3
Refractive index (real and imaginary parts) for liquid water
The total refractive index of water is given as m = n + ik. The absorption coefficient α' is used in the Beer–Lambert law with the prime here signifying base e convention. Values are for water
Document 3:::
Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiation) in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections of radiation that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections. Originally, the term was confined to light scattering (going back at least as far as Isaac Newton in the 17th century). As more "ray"-like phenomena were discovered, the idea of scattering was extended to them, so that William Herschel could refer to the scattering of "heat rays" (not then recognized as electromagnetic in nature) in 1800. John Tyndall, a pioneer in light scattering research, noted the connection between light scattering and acoustic scattering in the 1870s. Near the end of the 19th century, the scattering of cathode rays (electron beams) and X-rays was observed and discussed. With the discovery of subatomic particles (e.g. Ernest Rutherford in 1911) and the development of quantum theory in the 20th century, the sense of the term became broader as it was recognized that the same mathematical frameworks used in light scattering could be applied to many other phenomena.
Scattering can refer to the consequences of particle-particle collisions between molecules, atoms, electrons, photons and other particles. Examples include: cosmic ray scattering in the Earth's upper atmosphere; particle collisions inside particle accelerators; electron scattering by gas atoms in fluorescent lamps; and neutron scattering inside nuclear reactors.
The types of non-uniformities which can cause scattering, sometimes known as scatterers or scattering centers, are too numerous to list, bu
Document 4:::
Akira Ishimaru (; born March 16, 1928) is a Japanese-American electrical engineer and professor emeritus at Department of Electrical and Computer Engineering at University of Washington. He is best known for his contributions to the theory of wave scattering in random media.
Biography
Akira Ishimaru was born on March 16, 1928, in Fukuoka, Japan. He received his bachelor's degree from University of Tokyo and Ph.D. degree in electrical engineering from University of Washington, respectively in 1951 and 1958. During his doctoral studies, he was supervised by Gedaliah Held. From 1951 to 1952, he worked at Electrotechnical Laboratory in Tanashi, Tokyo. In 1956, he was employed at Bell Labs. In 1958, he joined the faculty of the Department of Electrical Engineering of the University of Washington, where he was also an adjunct professor of applied mathematics. He became a professor emeritus at the institution in 1999.
In 1996, Ishimaru was elected as a member of National Academy of Engineering "for his contributions to the theory and application of wave propagation and scattering in random media." Ishimaru is also the recipient of IEEE Centennial Medal (1984), IEEE Heinrich Hertz Medal (1999) and IEEE Third Millennium Medal (2000). He is a fellow of IEEE, the Optical Society of America, the Acoustical Society of America, and the Institute of Physics. He was the editor of Radio Science from 1979 to 1983, as well as the founding editor of the journals Waves in Random Media and Waves in Random and Complex Media.
Research
Ishimaru's research has mainly focused on wave propagation and scattering in random and turbulent media; his research has contributed to advances in microwave remote sensing, ultrasound imaging, laser surgery, radar systems and astronomy, as well as wireless and optical communications. His other research interests object detection and imaging in cluttered environments, inverse problems, wave propagation and scattering in the atmosphere and the terrain, aco
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What weakly scatters visible light?
A. water
B. Reflection
C. air
D. space
Answer:
|
|
sciq-2572
|
multiple_choice
|
The temperature dependence of solubility can be exploited to prepare what solutions of certain compounds?
|
[
"mineralized",
"supersaturated",
"instantiated",
"isolated"
] |
B
|
Relavent Documents:
Document 0:::
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
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In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be "miscible in all proportions" (or just "miscible").
The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations, and a solid or liquid can be "dissolved" in a gas only by passing into the gaseous state first.
The solubility mainly depends on the composition of solute and solvent (including their pH and the presence of other dissolved substances) as well as on temperature and pressure. The dependency can often be explained in terms of interactions between the particles (atoms, molecules, or ions) of the two substances, and of thermodynamic concepts such as enthalpy and entropy.
Under certain conditions, the concentration of the solute can exceed its usual solubility limit. The result is a supersaturated solution, which is metastable and will rapidly exclude the excess solute if a suitable nucleation site appears.
The concept of solubility does not apply when there is an irreversible chemical reaction between the two substances, such as the reaction of calcium hydroxide with hydrochloric acid; even though one might say, informally, that one "dissolved" the other. The solubility is also not the same as the rate of solution, which is how fast a solid solute dissolves in a liquid solvent. This property de
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A breakthrough curve in adsorption is the course of the effluent adsorptive concentration at the outlet of a fixed bed adsorber. Breakthrough curves are important for adsorptive separation technologies and for the characterization of porous materials.
Importance
Since almost all adsorptive separation processes are dynamic -meaning, that they are running under flow - testing porous materials for those applications for their separation performance has to be tested under flow as well. Since separation processes run with mixtures of different components, measuring several breakthrough curves results in thermodynamic mixture equilibria - mixture sorption isotherms, that are hardly accessible with static manometric sorption characterization. This enables the determination of sorption selectivities in gaseous and liquid phase.
The determination of breakthrough curves is the foundation of many other processes, like the pressure swing adsorption. Within this process, the loading of one adsorber is equivalent to a breakthrough experiment.
Measurement
A fixed bed of porous materials (e.g. activated carbons and zeolites) is pressurized and purged with a carrier gas. After becoming stationary one or more adsorptives are added to the carrier gas, resulting in a step-wise change of the inlet concentration. This is in contrast to chromatographic separation processes, where pulse-wise changes of the inlet concentrations are used. The course of the adsorptive concentrations at the outlet of the fixed bed are monitored.
Results
Integration of the area above the entire breakthrough curve gives the maximum loading of the adsorptive material. Additionally, the duration of the breakthrough experiment until a certain threshold of the adsorptive concentration at the outlet can be measured, which enables the calculation of a technically usable sorption capacity. Up to this time, the quality of the product stream can be maintained. The shape of the breakthrough curves contains informat
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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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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.
The temperature dependence of solubility can be exploited to prepare what solutions of certain compounds?
A. mineralized
B. supersaturated
C. instantiated
D. isolated
Answer:
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|
sciq-2696
|
multiple_choice
|
What kind of anatomical structure consists of several types of tissues that together carry out particular functions?
|
[
"valve",
"frame",
"system",
"organ"
] |
D
|
Relavent Documents:
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In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
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Splanchnology is the study of the visceral organs, i.e. digestive, urinary, reproductive and respiratory systems.
The term derives from the Neo-Latin splanchno-, from the Greek σπλάγχνα, meaning "viscera". More broadly, splanchnology includes all the components of the Neuro-Endo-Immune (NEI) Supersystem. An organ (or viscus) is a collection of tissues joined in a structural unit to serve a common function. In anatomy, a viscus is an internal organ, and viscera is the plural form. Organs consist of different tissues, one or more of which prevail and determine its specific structure and function. Functionally related organs often cooperate to form whole organ systems.
Viscera are the soft organs of the body. There are organs and systems of organs that differ in structure and development but they are united for the performance of a common function. Such functional collection of mixed organs, form an organ system. These organs are always made up of special cells that support its specific function. The normal position and function of each visceral organ must be known before the abnormal can be ascertained.
Healthy organs all work together cohesively and gaining a better understanding of how, helps to maintain a healthy lifestyle. Some functions cannot be accomplished only by one organ. That is why organs form complex systems. The system of organs is a collection of homogeneous organs, which have a common plan of structure, function, development, and they are connected to each other anatomically and communicate through the NEI supersystem.
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Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine.
Anatomy is a complex and dynamic field that is constantly evolving as new discoveries are made. In recent years, there has been a significant increase in the use of advanced imaging techniques, such as MRI and CT scans, which allow for more detailed and accurate visualizations of the body's structures.
The discipline of anatomy is divided into macroscopic and microscopic parts. Macroscopic anatomy, or gross anatomy, is the examination of an animal's body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy. Microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology, and also in the study of cells.
The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th-century medical imaging techniques, including X-ray, ultrasound, and magnetic resonance imaging.
Etymology and definition
Derived from the Greek anatomē "dissection" (from anatémnō "I cut up, cut open" from ἀνά aná "up", and τέμνω té
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Instruments used in Anatomy dissections are as follows:
Instrument list
Image gallery
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A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways. A biological system is not to be confused with a living system, such as a living organism.
Organ and tissue systems
These specific systems are widely studied in human anatomy and are also present in many other animals.
Respiratory system: the organs used for breathing, the pharynx, larynx, bronchi, lungs and diaphragm.
Digestive system: digestion and processing food with salivary glands, oesophagus, stomach, liver, gallbladder, pancreas, intestines, rectum and anus.
Cardiovascular system (heart and circulatory system): pumping and channeling blood to and from the body and lungs with heart, blood and blood vessels.
Urinary system: kidneys, ureters, bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.
Integumentary system: skin, hair, fat, and nails.
Skeletal system: structural support and protection with bones, cartilage, ligaments and tendons.
Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid, parathyroid and adrenals, i.e., adrenal glands.
Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream; includes the lymph and the nodes and vessels. The lymphatic system includes functions including immune responses and development of antibodies.
Immune system: protects the organism from
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of anatomical structure consists of several types of tissues that together carry out particular functions?
A. valve
B. frame
C. system
D. organ
Answer:
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|
sciq-11243
|
multiple_choice
|
Like simple hormone pathways, hormone cascade pathways typically involve what kind of feedback?
|
[
"positive",
"effective",
"negative",
"neutral"
] |
C
|
Relavent Documents:
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The insulin transduction pathway is a biochemical pathway by which insulin increases the uptake of glucose into fat and muscle cells and reduces the synthesis of glucose in the liver and hence is involved in maintaining glucose homeostasis. This pathway is also influenced by fed versus fasting states, stress levels, and a variety of other hormones.
When carbohydrates are consumed, digested, and absorbed the pancreas senses the subsequent rise in blood glucose concentration and releases insulin to promote uptake of glucose from the bloodstream. When insulin binds to the insulin receptor, it leads to a cascade of cellular processes that promote the usage or, in some cases, the storage of glucose in the cell. The effects of insulin vary depending on the tissue involved, e.g., insulin is most important in the uptake of glucose by muscle and adipose tissue.
This insulin signal transduction pathway is composed of trigger mechanisms (e.g., autophosphorylation mechanisms) that serve as signals throughout the cell. There is also a counter mechanism in the body to stop the secretion of insulin beyond a certain limit. Namely, those counter-regulatory mechanisms are glucagon and epinephrine. The process of the regulation of blood glucose (also known as glucose homeostasis) also exhibits oscillatory behavior.
On a pathological basis, this topic is crucial to understanding certain disorders in the body such as diabetes, hyperglycemia and hypoglycemia.
Transduction pathway
The functioning of a signal transduction pathway is based on extra-cellular signaling that in turn creates a response that causes other subsequent responses, hence creating a chain reaction, or cascade. During the course of signaling, the cell uses each response for accomplishing some kind of a purpose along the way. Insulin secretion mechanism is a common example of signal transduction pathway mechanism.
Insulin is produced by the pancreas in a region called Islets of Langerhans. In the islets of Langerha
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SPIKE (Signaling Pathways Integrated Knowledge Engine) is a database of highly curated interactions for particular human pathways.
Development
SPIKE was developed by Ron Shamir's computational biology group in cooperation with the group of Yosef Shiloh, an Israel Prize recipient for his research in systems biology, and the group of Karen Avraham, a leading researcher of human deafness, all from Tel Aviv University.
See also
Signaling pathways
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Pulsatile secretion is a biochemical phenomenon observed in a wide variety of cell and tissue types, in which chemical products are secreted in a regular temporal pattern. The most common cellular products observed to be released in this manner are intercellular signaling molecules such as hormones or neurotransmitters. Examples of hormones that are secreted pulsatilely include insulin, thyrotropin, TRH, gonadotropin-releasing hormone (GnRH) and growth hormone (GH). In the nervous system, pulsatility is observed in oscillatory activity from central pattern generators. In the heart, pacemakers are able to work and secrete in a pulsatile manner. A pulsatile secretion pattern is critical to the function of many hormones in order to maintain the delicate homeostatic balance necessary for essential life processes, such as development and reproduction. Variations of the concentration in a certain frequency can be critical to hormone function, as evidenced by the case of GnRH agonists, which cause functional inhibition of the receptor for GnRH due to profound downregulation in response to constant (tonic) stimulation. Pulsatility may function to sensitize target tissues to the hormone of interest and upregulate receptors, leading to improved responses. This heightened response may have served to improve the animal's fitness in its environment and promote its evolutionary retention.
Pulsatile secretion in its various forms is observed in:
Hypothalamic-pituitary-gonadal axis (HPG) related hormones
Glucocorticoids
Insulin
Growth hormone
Parathyroid hormone
Neuroendocrine Pulsatility
Nervous system control over hormone release is based in the hypothalamus, from which the neurons that populate the pariventricular and arcuate nuclei originate. These neurons project to the median eminence, where they secrete releasing hormones into the hypophysial portal system connecting the hypothalamus with the pituitary gland. There, they dictate endocrine function via the four Hyp
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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
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In molecular biology, the crustacean neurohormone family of proteins is a family of neuropeptides expressed by arthropods. The family includes the following types of neurohormones:
Crustacean hyperglycaemic hormone (CHH). CHH is primarily involved in blood sugar regulation, but also plays a role in the control of moulting and reproduction.
Moult-inhibiting hormone (MIH). MIH inhibits Y-organs where moulting hormone (ecdysteroid) is secreted. A moulting cycle is initiated when MIH secretion diminishes or stops.
Gonad-inhibiting hormone (GIH), also known as vitellogenesis-inhibiting hormone (VIH) because of its role in inhibiting vitellogenesis in female animals.
Mandibular organ-inhibiting hormone (MOIH). MOIH represses the synthesis of methyl farnesoate, the precursor of insect juvenile hormone III in the mandibular organ.
Ion transport peptide (ITP) from locust. ITP stimulates salt and water reabsorption and inhibits acid secretion in the ileum of the locust.
Caenorhabditis elegans uncharacterised protein ZC168.2.
These neurohormones are peptides of 70 to 80 amino acid residues which are processed from larger precursors. They contain six conserved cysteines that are involved in disulfide bonds.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Like simple hormone pathways, hormone cascade pathways typically involve what kind of feedback?
A. positive
B. effective
C. negative
D. neutral
Answer:
|
|
sciq-7547
|
multiple_choice
|
The afferent arterioles service about 1.3 million of what in each kidney?
|
[
"neurons",
"nephrons",
"dendrites",
"axons"
] |
B
|
Relavent Documents:
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H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
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The renal circulation supplies the blood to the kidneys via the renal arteries, left and right, which branch directly from the abdominal aorta. Despite their relatively small size, the kidneys receive approximately 20% of the cardiac output.
Each renal artery branches into segmental arteries, dividing further into interlobar arteries, which penetrate the renal capsule and extend through the renal columns between the renal pyramids. The interlobar arteries then supply blood to the arcuate arteries that run through the boundary of the cortex and the medulla. Each arcuate artery supplies several interlobular arteries that feed into the afferent arterioles that supply the glomeruli.
After filtration occurs, the blood moves through a small network of venules that converge into interlobular veins. As with the arteriole distribution, the veins follow the same pattern: the interlobular provide blood to the arcuate veins then back to the interlobar veins, which come to form the renal vein exiting the kidney for transfusion for blood.
Structure
Arterial system
The table below shows the path that blood takes when it travels through the glomerulus, traveling "down" the arteries and "up" the veins. However, this model is greatly simplified for clarity and symmetry. Some of the other paths and complications are described at the bottom of the table. The interlobar artery and vein (not to be confused with interlobular) are between two renal lobes, also known as the renal column (cortex region between two pyramids).
Note 1: The renal artery also provides a branch to the inferior suprarenal artery to supply the adrenal gland.
Note 2: Also called the cortical radiate arteries. The interlobular artery also supplies to the stellate veins.
Note 3: The efferent arterioles do not directly drain into the interlobular vein, but rather they go to the peritubular capillaries first. The efferent arterioles of the juxtamedullary nephron drain into the vasa recta.
Segmental arteries
The
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A central or intermediate group of three or four large glands is imbedded in the adipose tissue near the base of the axilla.
Its afferent lymphatic vessels are the efferent vessels of all the preceding groups of axillary glands; its efferents pass to the subclavicular group.
Additional images
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The ovarian cortex is the outer portion of the ovary. The ovarian follicles are located within the ovarian cortex. The ovarian cortex is made up of connective tissue. Ovarian cortex tissue transplant has been performed to treat infertility.
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In haemodynamics, the body must respond to physical activities, external temperature, and other factors by homeostatically adjusting its blood flow to deliver nutrients such as oxygen and glucose to stressed tissues and allow them to function. Haemodynamic response (HR) allows the rapid delivery of blood to active neuronal tissues. The brain consumes large amounts of energy but does not have a reservoir of stored energy substrates. Since higher processes in the brain occur almost constantly, cerebral blood flow is essential for the maintenance of neurons, astrocytes, and other cells of the brain. This coupling between neuronal activity and blood flow is also referred to as neurovascular coupling.
Vascular anatomy overview
In order to understand how blood is delivered to cranial tissues, it is important to understand the vascular anatomy of the space itself. Large cerebral arteries in the brain split into smaller arterioles, also known as pial arteries. These consist of endothelial cells and smooth muscle cells, and as these pial arteries further branch and run deeper into the brain, they associate with glial cells, namely astrocytes. The intracerebral arterioles and capillaries are unlike systemic arterioles and capillaries in that they do not readily allow substances to diffuse through them; they are connected by tight junctions in order to form the blood brain barrier (BBB). Endothelial cells, smooth muscle, neurons, astrocytes, and pericytes work together in the brain order to maintain the BBB while still delivering nutrients to tissues and adjusting blood flow in the intracranial space to maintain homeostasis. As they work as a functional neurovascular unit, alterations in their interactions at the cellular level can impair HR in the brain and lead to deviations in normal nervous function.
Mechanisms
Various cell types play a role in HR, including astrocytes, smooth muscle cells, endothelial cells of blood vessels, and pericytes. These cells control whether th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The afferent arterioles service about 1.3 million of what in each kidney?
A. neurons
B. nephrons
C. dendrites
D. axons
Answer:
|
|
sciq-886
|
multiple_choice
|
What kind of reactions are involved in processes ranging from the contraction of muscles to the digestion of food?
|
[
"liquid",
"atomical",
"chemical",
"mineral"
] |
C
|
Relavent Documents:
Document 0:::
Analysis (: analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (384–322 B.C.), though analysis as a formal concept is a relatively recent development.
The word comes from the Ancient Greek (analysis, "a breaking-up" or "an untying;" from ana- "up, throughout" and lysis "a loosening"). From it also comes the word's plural, analyses.
As a formal concept, the method has variously been ascribed to Alhazen, René Descartes (Discourse on the Method), and Galileo Galilei. It has also been ascribed to Isaac Newton, in the form of a practical method of physical discovery (which he did not name).
The converse of analysis is synthesis: putting the pieces back together again in a new or different whole.
Applications
Science
The field of chemistry uses analysis in three ways: to identify the components of a particular chemical compound (qualitative analysis), to identify the proportions of components in a mixture (quantitative analysis), and to break down chemical processes and examine chemical reactions between elements of matter. For an example of its use, analysis of the concentration of elements is important in managing a nuclear reactor, so nuclear scientists will analyze neutron activation to develop discrete measurements within vast samples. A matrix can have a considerable effect on the way a chemical analysis is conducted and the quality of its results. Analysis can be done manually or with a device.
Types of Analysis:
A) Qualitative Analysis: It is concerned with which components are in a given sample or compound.
Example: Precipitation reaction
B) Quantitative Analysis: It is to determine the quantity of individual component present in a given sample or compound.
Example: To find concentration by uv-spectrophotometer.
Isotopes
Chemists can use isotope analysis to assist analysts with i
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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
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An elementary reaction is a chemical reaction in which one or more chemical species react directly to form products in a single reaction step and with a single transition state. In practice, a reaction is assumed to be elementary if no reaction intermediates have been detected or need to be postulated to describe the reaction on a molecular scale. An apparently elementary reaction may be in fact a stepwise reaction, i.e. a complicated sequence of chemical reactions, with reaction intermediates of variable lifetimes.
In a unimolecular elementary reaction, a molecule dissociates or isomerises to form the products(s)
At constant temperature, the rate of such a reaction is proportional to the concentration of the species
In a bimolecular elementary reaction, two atoms, molecules, ions or radicals, and , react together to form the product(s)
The rate of such a reaction, at constant temperature, is proportional to the product of the concentrations of the species and
The rate expression for an elementary bimolecular reaction is sometimes referred to as the Law of Mass Action as it was first proposed by Guldberg and Waage in 1864. An example of this type of reaction is a cycloaddition reaction.
This rate expression can be derived from first principles by using collision theory for ideal gases. For the case of dilute fluids equivalent results have been obtained from simple probabilistic arguments.
According to collision theory the probability of three chemical species reacting simultaneously with each other in a termolecular elementary reaction is negligible. Hence such termolecular reactions are commonly referred as non-elementary reactions and can be broken down into a more fundamental set of bimolecular reactions, in agreement with the law of mass action. It is not always possible to derive overall reaction schemes, but solutions based on rate equations are often possible in terms of steady-state or Michaelis-Menten approximations.
Notes
Chemical kinetics
Phy
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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
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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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What kind of reactions are involved in processes ranging from the contraction of muscles to the digestion of food?
A. liquid
B. atomical
C. chemical
D. mineral
Answer:
|
|
sciq-4256
|
multiple_choice
|
Solar cells create voltages directly from light, while thermoelectric devices create voltage from differences in what?
|
[
"wattage",
"wire width",
"temperature",
"oxygen"
] |
C
|
Relavent Documents:
Document 0:::
Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons. A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being admitted from the hot object.
As TPV systems generally work at lower temperatures than solar cells, their efficiencies tend to be low. Offsetting this through the use of multi-junction cells based on non-silicon materials is common, but generally very expensive. This currently limits TPV to niche roles like spacecraft power and waste heat collection from larger systems like steam turbines.
General concept
PV
Typical photovoltaics work by creating a p–n junction near the front surface of a thin semiconductor material. When photons above the bandgap energy of the material hit atoms within the bulk lower layer, below the junction, an electron is photoexcited and becomes free of its atom. The junction creates an electric field that accelerates the electron forward within the cell until it passes the junction and is free to move to the thin electrodes patterned on the surface. Connecting a wire from the front to the rear allows the electrons to flow back into the bulk and complete the circuit.
Photons with less energy than the bandgap do not eject electrons. Photons with energy above the bandgap will eject higher-energy electrons which tend to thermalize within the material and lose their extra energy as heat. If the cell's bandgap is raised, the electrons that are emitted will have higher energy when they reach the junction and thus result in a higher voltage, but this will reduce the number of electrons emitted as more photons will be below the bandgap energy and thus generate a lower current. As electrical power is the product of voltage and current, there is a sweet spot where the total output is maximized.
Terrestrial solar radiation is typically characterized by a standard known as Air M
Document 1:::
Thermophotonics (often abbreviated as TPX) is a concept for generating usable power from heat which shares some features of thermophotovoltaic (TPV) power generation. Thermophotonics was first publicly proposed by solar photovoltaic researcher Martin Green in 2000. However, no TPX device is known to have been demonstrated to date, apparently because of the stringent requirement on the emitter efficiency.
A TPX system consists of a light-emitting diode (LED) (though other types of emitters are conceivable), a photovoltaic (PV) cell, an optical coupling between the two, and an electronic control circuit. The LED is heated to a temperature higher than the PV temperature by an external heat source. If no power is applied to the LED, the system functions much like a very inefficient TPV system, but if a forward bias is applied at some fraction of the bandgap potential, an increased number of electron-hole pairs (EHPs) will be thermally excited to the bandgap energy. These EHPs can then recombine radiatively so that the LED emits light at a rate higher than the thermal radiation rate ("superthermal" emission). This light is then delivered to the cooler PV cell over the optical coupling and converted to electricity.
The control circuit presents a load to the PV cell (presumably at the maximum power point) and converts this voltage to a voltage level that can be used to sustain the bias of the emitter. Provided that the conversion efficiencies of electricity to light and light to electricity are sufficiently high, the power harnessed from the PV cell can exceed the power going into the bias circuit, and this small fraction of excess power (originating from the heat difference) can be utilized. It is thus in some sense a photonic heat engine.
Possible applications of thermophotonic generators include solar thermal electricity generation and utilization of waste heat. TPX systems may have the potential to generate power with useful levels of output at temperatures w
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
The Bernard Price Memorial Lecture is the premier annual lecture of the South African Institute of Electrical Engineers. It is of general scientific or engineering interest and is given by an invited guest, often from overseas, at several of the major centres on South Africa. The main lecture and accompanying dinner are usually held at the University of Witwatersrand and it is also presented in the space of one week at other centres, typically Cape Town, Durban, East London and Port Elizabeth.
The Lecture is named in memory of the eminent electrical engineer Bernard Price. The first Lecture was held in 1951 and it has occurred as an annual event ever since.
Lecturers
1951 Basil Schonland
1952 A M Jacobs
1953 H J Van Eck
1954 J M Meek
1955 Frank Nabarro
1956 A L Hales
1957 P G Game
1958 Colin Cherry
1959 Thomas Allibone
1960 M G Say
1961 Willis Jackson
1963 W R Stevens
1964 William Pickering
1965 G H Rawcliffe
1966 Harold Bishop
1967 Eric Eastwood
1968 F J Lane
1969 A H Reeves
1970 Andrew R Cooper
1971 Herbert Haslegrave
1972 W J Bray
1973 R Noser
1974 D Kind
1975 L Kirchmayer
1976 S Jones
1977 J Johnson
1978 T G E Cockbain
1979 A R Hileman
1980 James Redmond
1981 L M Muntzing
1982 K F Raby
1983 R Isermann
1984 M N John
1985 J W L de Villiers
1986 Derek Roberts
1987 Wolfram Boeck
1988 Karl Gehring
1989 Leonard Sagan
1990 GKF Heyner
1991 P S Blythin
1992 P M Neches
1993 P Radley
1994 P R Rosen
1995 F P Sioshansi
1996 J Taylor
1997 M Chamia
1998 C Gellings
1999 M W Kennedy
2000 John Midwinter
2001 Pragasen Pillay
2002 Polina Bayvel
2003 Case Rijsdijk
2004 Frank Larkins
2005 Igor Aleksander
2006 Kevin Warwick
2007 Skip Hatfield
2008 Sami Solanki
2009 William Gruver
2010 Glenn Ricart
2011 Philippe Paelinck
2012 Nick Frydas
2013 Vint Cerf
2014 Ian Jandrell
2015 Saurabh Sinha
2016 Tshilidzi Marwala
2017 Fulufhelo Nelwamondo
2018 Ian Craig
2019 Robert Metcalfe
2020 Roger Price
Document 4:::
A solar cell or photovoltaic cell (PV cell) is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect. It is a form of photoelectric cell, a device whose electrical characteristics (such as current, voltage, or resistance) vary when exposed to light. Individual solar cell devices are often the electrical building blocks of photovoltaic modules, known colloquially as "solar panels". The common single-junction silicon solar cell can produce a maximum open-circuit voltage of approximately 0.5 to 0.6 volts.
Photovoltaic cells may operate under sunlight or artificial light. In addition to producing energy, they can be used as a photodetector (for example infrared detectors), detecting light or other electromagnetic radiation near the visible range, or measuring light intensity.
The operation of a PV cell requires three basic attributes:
The absorption of light, generating excitons (bound electron-hole pairs), unbound electron-hole pairs (via excitons), or plasmons.
The separation of charge carriers of opposite types.
The separate extraction of those carriers to an external circuit.
In contrast, a solar thermal collector supplies heat by absorbing sunlight, for the purpose of either direct heating or indirect electrical power generation from heat. A "photoelectrolytic cell" (photoelectrochemical cell), on the other hand, refers either to a type of photovoltaic cell (like that developed by Edmond Becquerel and modern dye-sensitized solar cells), or to a device that splits water directly into hydrogen and oxygen using only solar illumination.
Photovoltaic cells and solar collectors are the two means of producing solar power.
Applications
Assemblies of solar cells are used to make solar modules that generate electrical power from sunlight, as distinguished from a "solar thermal module" or "solar hot water panel". A solar array generates solar power using solar energy.
Vehicular applications
Application
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Solar cells create voltages directly from light, while thermoelectric devices create voltage from differences in what?
A. wattage
B. wire width
C. temperature
D. oxygen
Answer:
|
|
sciq-4480
|
multiple_choice
|
Matter is always conserved in what type of reaction?
|
[
"developed reaction",
"chemical reaction",
"toxic reaction",
"Quick reaction"
] |
B
|
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:::
In physics and chemistry, the law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so the quantity can neither be added nor be removed. Therefore, the quantity of mass is conserved over time.
The law implies that mass can neither be created nor destroyed, although it may be rearranged in space, or the entities associated with it may be changed in form. For example, in chemical reactions, the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Thus, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants, or starting materials, must be equal to the mass of the products.
The concept of mass conservation is widely used in many fields such as chemistry, mechanics, and fluid dynamics. Historically, mass conservation in chemical reactions was primarily demonstrated in the 17th century and finally confirmed by Antoine Lavoisier in the late 18th century. The formulation of this law was of crucial importance in the progress from alchemy to the modern natural science of chemistry.
In reality, the conservation of mass only holds approximately and is considered part of a series of assumptions in classical mechanics. The law has to be modified to comply with the laws of quantum mechanics and special relativity under the principle of mass–energy equivalence, which states that energy and mass form one conserved quantity. For very energetic systems the conservation of mass only is shown not to hold, as is the case in nuclear reactions and particle-antiparticle annihilation in particle physics.
Mass is also not generally conserved in open systems. Such is the case when various forms of energy and matter are allowed into, or out of, the system. However, unless radioactivity or nuclear r
Document 2:::
In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite.
Classically, conservation of energy was distinct from conservation of mass. However, special relativity shows that mass is related to energy and vice versa by , the equation representing mass–energy equivalence, and science now takes the view that mass-energy as a whole is conserved. Theoretically, this implies that any object with mass can itself be converted to pure energy, and vice versa. However, this is believed to be possible only under the most extreme of physical conditions, such as likely existed in the universe very shortly after the Big Bang or when black holes emit Hawking radiation.
Given the stationary-action principle, conservation of energy can be rigorously proven by Noether's theorem as a consequence of continuous time translation symmetry; that is, from the fact that the laws of physics do not change over time.
A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist; that is to say, no system without an external energy supply can deliver an unlimited amount of energy to its surroundings. Depending on the definition of energy, conservation of energy can arguably be violated by general relativity on the cosmological scale.
History
Ancient philosophers as far back as Thales of Miletus 550 BCE had inklings of the conservation of some underlying substance of which ev
Document 3:::
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 4:::
In chemical thermodynamics, the reaction quotient (Qr or just Q) is a dimensionless quantity that provides a measurement of the relative amounts of products and reactants present in a reaction mixture for a reaction with well-defined overall stoichiometry, at a particular point in time. Mathematically, it is defined as the ratio of the activities (or molar concentrations) of the product species over those of the reactant species involved in the chemical reaction, taking stoichiometric coefficients of the reaction into account as exponents of the concentrations. In equilibrium, the reaction quotient is constant over time and is equal to the equilibrium constant.
A general chemical reaction in which α moles of a reactant A and β moles of a reactant B react to give ρ moles of a product R and σ moles of a product S can be written as
\it \alpha\,\rm A{} + \it \beta\,\rm B{} <=> \it \rho\,\rm R{} + \it \sigma\,\rm S{}.
The reaction is written as an equilibrium even though in many cases it may appear that all of the reactants on one side have been converted to the other side. When any initial mixture of A, B, R, and S is made, and the reaction is allowed to proceed (either in the forward or reverse direction), the reaction quotient Qr, as a function of time t, is defined as
where {X}t denotes the instantaneous activity of a species X at time t.
A compact general definition is
where Пj denotes the product across all j-indexed variables, aj(t) is the activity of species j at time t, and νj is the stoichiometric number (the stoichiometric coefficient multiplied by +1 for products and –1 for starting materials).
Relationship to K (the equilibrium constant)
As the reaction proceeds with the passage of time, the species' activities, and hence the reaction quotient, change in a way that reduces the free energy of the chemical system. The direction of the change is governed by the Gibbs free energy of reaction by the relation
,
where K is a constant independent of initi
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Matter is always conserved in what type of reaction?
A. developed reaction
B. chemical reaction
C. toxic reaction
D. Quick reaction
Answer:
|
|
sciq-4673
|
multiple_choice
|
Huge calderas form when the mountain above an empty chamber of what collapses?
|
[
"mercury",
"magma",
"coal",
"gas"
] |
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:::
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 mid-24th century BCE climate anomaly is the period, between 2354–2345 BCE, of consistently, reduced annual temperatures that are reconstructed from consecutive abnormally narrow, Irish oak tree rings. These tree rings are indicative of a period of catastrophically reduced growth in Irish trees during that period. This range of dates also matches the transition from the Neolithic to the Bronze Age in the British Isles and a period of widespread societal collapse in the Near East. It has been proposed that this anomalous downturn in the climate might have been the result of comet debris suspended in the atmosphere.
In 1997, Marie-Agnès Courty proposed that a natural disaster involving wildfires, floods, and an air blast of over 100 megatons power occurred about 2350 BCE. This proposal is based on unusual "dust" deposits which have been reported from archaeological sites in Mesopotamia that are a few hundred kilometres from each other. In later papers, Courty subsequently revised the date of this event from 2350 BCE to 2000 BCE.
Based only upon the analysis of satellite imagery, Umm al Binni lake in southern Iraq has been suggested as a possible extraterrestrial impact crater and possible cause of this natural disaster. More recent sources have argued for a formation of the lake through the subsidence of the underlying basement fault blocks. Baillie and McAneney's 2015 discussion of this climate anomaly discusses its abnormally narrow Irish tree rings and the anomalous dust deposits of Courty. However, this paper lacks any mention of Umm al Binni lake.
See also
4.2-kiloyear event, c. 2200 BCE
Great Flood (China), c. 2300 BCE
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.
Huge calderas form when the mountain above an empty chamber of what collapses?
A. mercury
B. magma
C. coal
D. gas
Answer:
|
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