id
stringlengths 6
15
| question_type
stringclasses 1
value | question
stringlengths 15
683
| choices
listlengths 4
4
| answer
stringclasses 5
values | explanation
stringclasses 481
values | prompt
stringlengths 1.75k
10.9k
|
|---|---|---|---|---|---|---|
sciq-10650
|
multiple_choice
|
In which specific organs are hormonal cells located?
|
[
"lymph nodes",
"mammary glands",
"spinal cord",
"endocrine glands"
] |
D
|
Relavent Documents:
Document 0:::
In the human endocrine system, a spongiocyte is a cell in the zona fasciculata of the adrenal cortex containing lipid droplets that show pronounced vacuolization, due to the way the cells are prepared for microscopic examination.
The lipid droplets contain neutral fats, fatty acids, cholesterol, and phospholipids; all of which are precursors to the steroid hormones secreted by the adrenal glands. The principal hormone secreted from the cells of the zona fasciculata are glucocorticoids, but some androgens are produced as well.
Document 1:::
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 2:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 3:::
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 4:::
Sudomotor function refers to the autonomic nervous system control of sweat gland activity in response to various environmental and individual factors. Sweat production is a vital thermoregulatory mechanism used by the body to prevent heat-related illness as the evaporation of sweat is the body’s most effective method of heat reduction and the only cooling method available when the air temperature rises above skin temperature. In addition, sweat plays key roles in grip, microbial defense, and wound healing.
Physiology
Human sweat glands are primarily classified as either eccrine or apocrine glands. Eccrine glands open directly onto the surface of the skin, while apocrine glands open into hair follicles. Eccrine glands are the predominant sweat gland in the human body with numbers totaling up to 4 million. They are located within the reticular dermal layer of the skin and distributed across nearly the entire surface of the body with the largest numbers occurring in the palms and soles.
Eccrine sweat is secreted in response to both emotional and thermal stimulation. Eccrine glands are primarily innervated by small-diameter, unmyelinated class C-fibers from postganglionic sympathetic cholinergic neurons. Increases in body and skin temperature are detected by visceral and peripheral thermoreceptors, which send signals via class C and Aδ-fiber afferent somatic neurons through the lateral spinothalamic tract to the preoptic nucleus of the hypothalamus for processing. In addition, there are warm-sensitive neurons located within the preoptic nucleus that detect increases in core body temperature. Efferent pathways then descend ipsilaterally from the hypothalamus through the pons and medulla to preganglionic sympathetic cholinergic neurons in the intermediolateral column of the spinal cord. The preganglionic neurons synapse with postganglionic cholinergic sudomotor (and to a lesser extent adrenergic) neurons in the paravertebral sympathetic ganglia. When the action potentia
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In which specific organs are hormonal cells located?
A. lymph nodes
B. mammary glands
C. spinal cord
D. endocrine glands
Answer:
|
|
sciq-3781
|
multiple_choice
|
What characteristic of reptile eggs allows them to be laid on land instead of in water?
|
[
"they are circular",
"they are dry",
"they are amniotic",
"they trap gas"
] |
C
|
Relavent Documents:
Document 0:::
An eggshell is the outer covering of a hard-shelled egg and of some forms of eggs with soft outer coats.
Worm eggs
Nematode eggs present a two layered structure: an external vitellin layer made of chitin that confers mechanical resistance and an internal lipid-rich layer that makes the egg chamber impermeable.
Insect eggs
Insects and other arthropods lay a large variety of styles and shapes of eggs. Some of them have gelatinous or skin-like coverings, others have hard eggshells. Softer shells are mostly protein. It may be fibrous or quite liquid. Some arthropod eggs do not actually have shells, rather, their outer covering is actually the outermost embryonic membrane, the choroid, which protects inner layers. This can be a complex structure, and it may have different layers, including an outermost layer called an exochorion. Eggs which must survive in dry conditions usually have hard eggshells, made mostly of dehydrated or mineralized proteins with pore systems to allow respiration. Arthropod eggs can have extensive ornamentation on their outer surfaces.
Fish, amphibian and reptile eggs
Fish and amphibians generally lay eggs which are surrounded by the extraembryonic membranes but do not develop a shell, hard or soft, around these membranes. Some fish and amphibian eggs have thick, leathery coats, especially if they must withstand physical force or desiccation. These types of eggs can also be very small and fragile.
While many reptiles lay eggs with flexible, calcified eggshells, there are some that lay hard eggs. Eggs laid by snakes generally have leathery shells which often adhere to one another. Depending on the species, turtles and tortoises lay hard or soft eggs. Several species lay eggs which are nearly indistinguishable from bird eggs.
Bird eggs
The bird egg is a fertilized gamete (or, in the case of some birds, such as chickens, possibly unfertilized) located on the yolk surface and surrounded by albumen, or egg white. The albumen in turn is surro
Document 1:::
The anamniotes are an informal group of craniates comprising all fishes and amphibians, which lay their eggs in aquatic environments. They are distinguished from the amniotes (reptiles, birds and mammals), which can reproduce on dry land either by laying shelled eggs or by carrying fertilized eggs within the female. Older sources, particularly before the 20th century, may refer to anamniotes as "lower vertebrates" and amniotes as "higher vertebrates", based on the antiquated idea of the evolutionary great chain of being.
The name "anamniote" is a back-formation word created by adding the prefix an- to the word amniote, which in turn refers to the amnion, an extraembryonic membrane present during the amniotes' embryonic development which serves as a biochemical barrier that shields the embryo from environmental fluctuations by regulating the oxygen, carbon dioxide and metabolic waste exchanges and secreting a cushioning fluid. As the name suggests, anamniote embryos lack an amnion during embryonic development, and therefore rely on the presence of external water to provide oxygen and help dilute and excrete waste products (particularly ammonia) via diffusion in order for the embryo to complete development without being intoxicated by their own metabolites. This means anamniotes are almost always dependent on an aqueous (or at least very moist) environment for reproduction and are thus restricted to spawning in or near water bodies. They are also highly sensitive to chemical and temperature variation in the surrounding water, and are also more vulnerable to egg predation and parasitism.
During their life cycle, all anamniote classes pass through a completely aquatic egg stage, as well as an aquatic larval stage during which all hatchlings are gill-dependent and morphologically resemble tiny finless fish (known as a fry or a tadpole for fish and amphibians, respectively), before metamorphosizing into juvenile and adult forms (which might be aquatic, semiaquatic or e
Document 2:::
An associated reproductive pattern is a seasonal change in reproduction which is highly correlated with a change in gonad and associated hormone.
Notable Model Organisms
Parthenogenic Whiptail Lizards
Document 3:::
In oviparous biology, a hatchling is a newly hatched fish, amphibian, reptile, or bird. A group of mammals called monotremes lay eggs, and their young are hatchlings as well.
Fish
Fish hatchlings generally do not receive parental care, similar to reptiles. Like reptiles, fish hatchlings can be affected by xenobiotic compounds. For example, exposure to xenoestrogens can feminize fish. As well, hatchlings raised in water with high levels of carbon dioxide demonstrate unusual behaviour, such as being attracted to the scent of predators. This change could be reversed by immersion into gabazine water, leading to the hypothesis that acidic waters affect hatchling brain chemistry.
Amphibians
The behavior of an amphibian hatchling, commonly referred to as a tadpole, is controlled by a few thousand neurons. 99% of a Xenopus hatchling's first day after hatching is spent hanging from a thread of mucus secreted from near its mouth will eventually form; if it becomes detached from this thread, it will swim back and become reattached, usually within ten seconds. While newt hatchlings are only able to swim for a few seconds, Xenopus tadpoles may be able to swim for minutes as long as they do not bump into anything. The tadpole live from remaining yolk-mass in the gut for a period, before it swims off to find food.
Reptiles
The reptile hatchling is quite the opposite of an altricial bird hatchling. Most hatchling reptiles are born with the same instincts as their parents and leave to live on their own immediately after leaving the egg. When first hatched, hatchlings can be several times smaller than their adult forms: Pine Snakes weigh 30 grams when they first hatch, but can grow up to 1,400 grams as adults. This appears to have been the case even in dinosaurs. In sea turtles, hatchling sex is determined by incubation temperature. In species in which eggs are laid then buried in sand, indentations in the sand can be a clue to imminent hatching. In sea turtles, this usually occ
Document 4:::
A trophic egg is an egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an unfertilised egg. The production of trophic eggs has been observed in a highly diverse range of species, including fish, amphibians, spiders and insects. The function is not limited to any particular level of parental care, but occurs in some sub-social species of insects, the spider A. ferox, and a few other species like the frogs Leptodactylus fallax and Oophaga, and the catfish Bagrus meridionalis.
Parents of some species deliver trophic eggs directly to their offspring, whereas some other species simply produce the trophic eggs after laying the viable eggs; they then leave the trophic eggs where the viable offspring are likely to find them.
The mackerel sharks present the most extreme example of proximity between reproductive eggs and trophic eggs; their viable offspring feed on trophic eggs in utero.
Despite the diversity of species and life strategies in which trophic eggs occur, all trophic egg functions are similarly derived from similar ancestral functions, which once amounted to the sacrifice of potential future offspring in order to provide food for the survival of rival (usually earlier) offspring. In more derived examples the trophic eggs are not viable, being neither fertilised, nor even fully formed in some cases, so they do not represent actually potential offspring, although they still represent parental investment corresponding to the amount of food it took to produce them.
Morphology
Trophic eggs are not always morphologically distinct from normal reproductive eggs; however if there is no physical distinction there tends to be some kind of specialised behaviour in the way that trophic eggs are delivered by the parents.
In some beetles, trophic eggs are paler in colour and softer in texture than reproductive eggs, with a smooth
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What characteristic of reptile eggs allows them to be laid on land instead of in water?
A. they are circular
B. they are dry
C. they are amniotic
D. they trap gas
Answer:
|
|
sciq-5779
|
multiple_choice
|
What does increasing a solute's temperature do?
|
[
"increases its solubility",
"no change",
"decrease its solubility",
"increases its viscosity"
] |
A
|
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:::
Boiling-point elevation describes the phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as water. The boiling point can be measured accurately using an ebullioscope.
Explanation
The boiling point elevation is a colligative property, which means that it is dependent on the presence of dissolved particles and their number, but not their identity. It is an effect of the dilution of the solvent in the presence of a solute. It is a phenomenon that happens for all solutes in all solutions, even in ideal solutions, and does not depend on any specific solute–solvent interactions. The boiling point elevation happens both when the solute is an electrolyte, such as various salts, and a nonelectrolyte. In thermodynamic terms, the origin of the boiling point elevation is entropic and can be explained in terms of the vapor pressure or chemical potential of the solvent. In both cases, the explanation depends on the fact that many solutes are only present in the liquid phase and do not enter into the gas phase (except at extremely high temperatures).
Put in vapor pressure terms, a liquid boils at the temperature when its vapor pressure equals the surrounding pressure. For the solvent, the presence of the solute decreases its vapor pressure by dilution. A nonvolatile solute has a vapor pressure of zero, so the vapor pressure of the solution is less than the vapor pressure of the solvent. Thus, a higher temperature is needed for the vapor pressure to reach the surrounding pressure, and the boiling point is elevated.
Put in chemical potential terms, at the boiling point, the liquid phase and the gas (or vapor) phase have the same chemical potential (or vapor pressure) meaning that they are energetically equivalent. The chemical potential is dependent on the temper
Document 2:::
Superheated water is liquid water under pressure at temperatures between the usual boiling point, and the critical temperature, . It is also known as "subcritical water" or "pressurized hot water". Superheated water is stable because of overpressure that raises the boiling point, or by heating it in a sealed vessel with a headspace, where the liquid water is in equilibrium with vapour at the saturated vapor pressure. This is distinct from the use of the term superheating to refer to water at atmospheric pressure above its normal boiling point, which has not boiled due to a lack of nucleation sites (sometimes experienced by heating liquids in a microwave).
Many of water's anomalous properties are due to very strong hydrogen bonding. Over the superheated temperature range the hydrogen bonds break, changing the properties more than usually expected by increasing temperature alone. Water becomes less polar and behaves more like an organic solvent such as methanol or ethanol. Solubility of organic materials and gases increases by several orders of magnitude and the water itself can act as a solvent, reagent, and catalyst in industrial and analytical applications, including extraction, chemical reactions and cleaning.
Change of properties with temperature
All materials change with temperature, but superheated water exhibits greater changes than would be expected from temperature considerations alone. Viscosity and surface tension of water drop and diffusivity increases with increasing temperature.
Self-ionization of water increases with temperature, and the pKw of water at 250 °C is closer to 11 than the more familiar 14 at 25 °C. This means the concentration of hydronium ion () and the concentration of hydroxide () are increased while the pH remains neutral. Specific heat capacity at constant pressure also increases with temperature, from 4.187 kJ/kg at 25 °C to 8.138 kJ/kg at 350 °C. A significant effect on the behaviour of water at high temperatures is decreased di
Document 3:::
In chemistry, solvent effects are the influence of a solvent on chemical reactivity or molecular associations. Solvents can have an effect on solubility, stability and reaction rates and choosing the appropriate solvent allows for thermodynamic and kinetic control over a chemical reaction.
A solute dissolves in a solvent when solvent-solute interactions are more favorable than solute-solute interaction.
Effects on stability
Different solvents can affect the equilibrium constant of a reaction by differential stabilization of the reactant or product. The equilibrium is shifted in the direction of the substance that is preferentially stabilized.
Stabilization of the reactant or product can occur through any of the different non-covalent interactions with the solvent such as H-bonding, dipole-dipole interactions, van der Waals interactions etc.
Acid-base equilibria
The ionization equilibrium of an acid or a base is affected by a solvent change. The effect of the solvent is not only because of its acidity or basicity but also because of its dielectric constant and its ability to preferentially solvate and thus stabilize certain species in acid-base equilibria. A change in the solvating ability or dielectric constant can thus influence the acidity or basicity.
In the table above, it can be seen that water is the most polar-solvent, followed by DMSO, and then acetonitrile. Consider the following acid dissociation equilibrium:
HA A− + H+
Water, being the most polar-solvent listed above, stabilizes the ionized species to a greater extent than does DMSO or Acetonitrile. Ionization - and, thus, acidity - would be greatest in water and lesser in DMSO and Acetonitrile, as seen in the table below, which shows pKa values at 25 °C for acetonitrile (ACN) and dimethyl sulfoxide (DMSO) and water.
Keto–enol equilibria
Many carbonyl compounds exhibit keto–enol tautomerism. This effect is especially pronounced in 1,3-dicarbonyl compounds that can form hydrogen-bonded enols. The e
Document 4:::
A characteristic property is a chemical or physical property that helps identify and classify substances. The characteristic properties of a substance are always the same whether the sample being observed is large or small. Thus, conversely, if the property of a substance changes as the sample size changes, that property is not a characteristic property. Examples of physical properties that are not characteristic properties are mass and volume. Examples of characteristic properties include melting points, boiling points, density, viscosity, solubility, crystal shape, and color. Substances with characteristic properties can be separated. For example, in fractional distillation, liquids are separated using the boiling point. The water Boiling point is 212 degrees Fahrenheit.
Identifying a substance
Every characteristic property is unique to one given substance. Scientists use characteristic properties to identify unknown substances. However, characteristic properties are most useful for distinguishing between two or more substances, not identifying a single substance. For example, isopropanol and water can be distinguished by the characteristic property of odor. Characteristic properties are used because the sample size and the shape of the substance does not matter. For example, 1 gram of lead is the same color as 100 tons of lead.
See also
Intensive and extensive properties
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does increasing a solute's temperature do?
A. increases its solubility
B. no change
C. decrease its solubility
D. increases its viscosity
Answer:
|
|
sciq-3600
|
multiple_choice
|
An electromagnetic wave begins with what movement by an electrically charged particle?
|
[
"acceleration",
"diffusion",
"momentum",
"vibration"
] |
D
|
Relavent Documents:
Document 0:::
Relativistic electromagnetism is a physical phenomenon explained in electromagnetic field theory due to Coulomb's law and Lorentz transformations.
Electromechanics
After Maxwell proposed the differential equation model of the electromagnetic field in 1873, the mechanism of action of fields came into question, for instance in the Kelvin’s master class held at Johns Hopkins University in 1884 and commemorated a century later.
The requirement that the equations remain consistent when viewed from various moving observers led to special relativity, a geometric theory of 4-space where intermediation is by light and radiation. The spacetime geometry provided a context for technical description of electric technology, especially generators, motors, and lighting at first. The Coulomb force was generalized to the Lorentz force. For example, with this model transmission lines and power grids were developed and radio frequency communication explored.
An effort to mount a full-fledged electromechanics on a relativistic basis is seen in the work of Leigh Page, from the project outline in 1912 to his textbook Electrodynamics (1940) The interplay (according to the differential equations) of electric and magnetic field as viewed over moving observers is examined. What is charge density in electrostatics becomes proper charge density and generates a magnetic field for a moving observer.
A revival of interest in this method for education and training of electrical and electronics engineers broke out in the 1960s after Richard Feynman’s textbook.
Rosser’s book Classical Electromagnetism via Relativity was popular, as was Anthony French’s treatment in his textbook which illustrated diagrammatically the proper charge density. One author proclaimed, "Maxwell — Out of Newton, Coulomb, and Einstein".
The use of retarded potentials to describe electromagnetic fields from source-charges is an expression of relativistic electromagnetism.
Principle
The question of how an electric field
Document 1:::
Melde's experiment is a scientific experiment carried out in 1859 by the German physicist Franz Melde on the standing waves produced in a tense cable originally set oscillating by a tuning fork, later improved with connection to an electric vibrator. This experiment, "a lecture-room standby", attempted to demonstrate that mechanical waves undergo interference phenomena. In the experiment, mechanical waves traveled in opposite directions form immobile points, called nodes. These waves were called standing waves by Melde since the position of the nodes and loops (points where the cord vibrated) stayed static.
Standing waves were first discovered by Franz Melde, who coined the term "standing wave" around 1860. Melde generated parametric oscillations in a string by employing a tuning fork to periodically vary the tension at twice the resonance frequency of the string.
History
Wave phenomena in nature have been investigated for centuries, some being some of the most controverted themes in the history of science, and so the case is with the wave nature of light. In the 17th century, Sir Isaac Newton described light through a corpuscular theory. The English physicist Thomas Young later contrasted Newton's theories in the 18th century and established the scientific basis upon which rest the wave theories. At the end of the 19th century, at the peak of the Second Industrial Revolution, the creation of electricity as the technology of the era offered a new contribution to the wave theories. This advance allowed Franz Melde to recognize the phenomena of wave interference and the creation of standing waves. Later, the Scottish physicist James Clerk Maxwell in his study of the wave nature of light succeeded in expressing waves and the electromagnetic spectrum in a mathematical formula.
Principle
A string undergoing transverse vibration illustrates many features common to all vibrating acoustic systems, whether these are the vibrations of a guitar string or the standing wave
Document 2:::
There are various mathematical descriptions of the electromagnetic field that are used in the study of electromagnetism, one of the four fundamental interactions of nature. In this article, several approaches are discussed, although the equations are in terms of electric and magnetic fields, potentials, and charges with currents, generally speaking.
Vector field approach
The most common description of the electromagnetic field uses two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates. As such, they are often written as (electric field) and (magnetic field).
If only the electric field (E) is non-zero, and is constant in time, the field is said to be an electrostatic field. Similarly, if only the magnetic field (B) is non-zero and is constant in time, the field is said to be a magnetostatic field. However, if either the electric or magnetic field has a time-dependence, then both fields must be considered together as a coupled electromagnetic field using Maxwell's equations.
Maxwell's equations in the vector field approach
The behaviour of electric and magnetic fields, whether in cases of electrostatics, magnetostatics, or electrodynamics (electromagnetic fields), is governed by Maxwell-Heaviside's equations:
{| class="toccolours collapsible" width="400px" style="background-color:#ECFCF4; padding:6; cellpadding=6;text-align:left;border:2px solid #50C878"
|-
|text-align="center" colspan="2"|Maxwell's equations (vector fields)
|-
| || Gauss's law
|-
| || Gauss's law for magnetism
|-
| || Faraday's law
|-
| || Ampère–Maxwell law
|}
where ρ is the charge density, which can (and often does) depend on time and position, ε0 is the electric constant, μ0 is the magnetic constant, and J is the current per unit area, also a function of time and position. The equations
Document 3:::
The invention of radio communication was preceded by many decades of establishing theoretical underpinnings, discovery and experimental investigation of radio waves, and engineering and technical developments related to their transmission and detection. These developments allowed Guglielmo Marconi to turn radio waves into a wireless communication system.
The idea that the wires needed for electrical telegraph could be eliminated, creating a wireless telegraph, had been around for a while before the establishment of radio-based communication. Inventors attempted to build systems based on electric conduction, electromagnetic induction, or on other theoretical ideas. Several inventors/experimenters came across the phenomenon of radio waves before its existence was proven; it was written off as electromagnetic induction at the time.
The discovery of electromagnetic waves, including radio waves, by Heinrich Rudolf Hertz in the 1880s came after theoretical development on the connection between electricity and magnetism that started in the early 1800s. This work culminated in a theory of electromagnetic radiation developed by James Clerk Maxwell by 1873, which Hertz demonstrated experimentally. Hertz considered electromagnetic waves to be of little practical value. Other experimenters, such as Oliver Lodge and Jagadish Chandra Bose, explored the physical properties of electromagnetic waves, and they developed electric devices and methods to improve the transmission and detection of electromagnetic waves. But they did not apparently see the value in developing a communication system based on electromagnetic waves.
In the mid-1890s, building on techniques physicists were using to study electromagnetic waves, Guglielmo Marconi developed the first apparatus for long-distance radio communication. On 23 December 1900, the Canadian inventor Reginald A. Fessenden became the first person to send audio (wireless telephony) by means of electromagnetic waves, successfully transmitt
Document 4:::
This is a list of electrical phenomena. Electrical phenomena are a somewhat arbitrary division of electromagnetic phenomena.
Some examples are:
Biefeld–Brown effect — Thought by the person who coined the name, Thomas Townsend Brown, to be an anti-gravity effect, it is generally attributed to electrohydrodynamics (EHD) or sometimes electro-fluid-dynamics, a counterpart to the well-known magneto-hydrodynamics.
Bioelectrogenesis — The generation of electricity by living organisms.
Capacitive coupling — Transfer of energy within an electrical network or between distant networks by means of displacement current.
Contact electrification — The phenomenon of electrification by contact. When two objects were touched together, sometimes the objects became spontaneously charged (οne negative charge, one positive charge).
Corona effect — Build-up of charges in a high-voltage conductor (common in AC transmission lines), which ionizes the air and produces visible light, usually purple.
Dielectric polarization — Orientation of charges in certain insulators inside an external static electric field, such as when a charged object is brought close, which produces an electric field inside the insulator.
Direct Current — (old: Galvanic Current) or "continuous current"; The continuous flow of electricity through a conductor such as a wire from high to low potential.
Electromagnetic induction — Production of a voltage by a time-varying magnetic flux.
Electroluminescence — The phenomenon wherein a material emits light in response to an electric current passed through it, or to a strong electric field.
Electrostatic induction — Redistribution of charges in a conductor inside an external static electric field, such as when a charged object is brought close.
Electrical conduction — The movement of electrically charged particles through transmission medium.
Electric shock — Physiological reaction of a biological organism to the passage of electric current through its body.
Ferranti effect
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
An electromagnetic wave begins with what movement by an electrically charged particle?
A. acceleration
B. diffusion
C. momentum
D. vibration
Answer:
|
|
ai2_arc-81
|
multiple_choice
|
A "widow's peak" hairline in humans is coded by the dominant allele W. A straight hairline is coded by the recessive allele w. A man with a homozygous dominant WW produces a zygote with a woman with a heterozygous dominant Ww for the trait. Which allele combinations could occur in the zygote?
|
[
"WW or ww",
"WW or Ww",
"WW only",
"Ww only"
] |
B
|
Relavent Documents:
Document 0:::
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (de novo) or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance, such as incomplete dominance, in which a gene variant has a partial effect compared to when it is present on both chromosomes, and co-dominance, in which different variants on each chromosome both show their associated traits.
Dominance is a key concept in Mendelian inheritance and classical genetics. Letters and Punnett squares are used to demonstrate the principles of dominance in teaching, and the use of upper-case letters for dominant alleles and lower-case letters for recessive alleles is a widely followed convention. A classic example of dominance is the inheritance of seed shape in peas. Peas may be round, associated with allele R, or wrinkled, associated with allele r. In this case, three combinations of alleles (genotypes) are possible: RR, Rr, and rr. The RR (homozygous) individuals have round peas, and the rr (homozygous) individuals have wrinkled peas. In Rr (heterozygous) individuals, the R allele masks the presence of the r allele, so these individuals also have round peas. Thus, allele R is d
Document 1:::
Allele frequency, or gene frequency, is the relative frequency of an allele (variant of a gene) at a particular locus in a population, expressed as a fraction or percentage. Specifically, it is the fraction of all chromosomes in the population that carry that allele over the total population or sample size. Microevolution is the change in allele frequencies that occurs over time within a population.
Given the following:
A particular locus on a chromosome and a given allele at that locus
A population of N individuals with ploidy n, i.e. an individual carries n copies of each chromosome in their somatic cells (e.g. two chromosomes in the cells of diploid species)
The allele exists in i chromosomes in the population
then the allele frequency is the fraction of all the occurrences i of that allele and the total number of chromosome copies across the population, i/(nN).
The allele frequency is distinct from the genotype frequency, although they are related, and allele frequencies can be calculated from genotype frequencies.
In population genetics, allele frequencies are used to describe the amount of variation at a particular locus or across multiple loci. When considering the ensemble of allele frequencies for many distinct loci, their distribution is called the allele frequency spectrum.
Calculation of allele frequencies from genotype frequencies
The actual frequency calculations depend on the ploidy of the species for autosomal genes.
Monoploids
The frequency (p) of an allele A is the fraction of the number of copies (i) of the A allele and the population or sample size (N), so
Diploids
If , , and are the frequencies of the three genotypes at a locus with two alleles, then the frequency p of the A-allele and the frequency q of the B-allele in the population are obtained by counting alleles.
Because p and q are the frequencies of the only two alleles present at that locus, they must sum to 1. To check this:
and
If there are more than two different alle
Document 2:::
The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach in 1905. The diagram is used by biologists to determine the probability of an offspring having a particular genotype. The Punnett square is a tabular summary of possible combinations of maternal alleles with paternal alleles. These tables can be used to examine the genotypical outcome probabilities of the offspring of a single trait (allele), or when crossing multiple traits from the parents. The Punnett square is a visual representation of Mendelian inheritance. For multiple traits, using the "forked-line method" is typically much easier than the Punnett square. Phenotypes may be predicted with at least better-than-chance accuracy using a Punnett square, but the phenotype that may appear in the presence of a given genotype can in some instances be influenced by many other factors, as when polygenic inheritance and/or epigenetics are at work.
Zygosity
Zygosity refers to the grade of similarity between the alleles that determine one specific trait in an organism. In its simplest form, a pair of alleles can be either homozygous or heterozygous. Homozygosity, with homo relating to same while zygous pertains to a zygote, is seen when a combination of either two dominant or two recessive alleles code for the same trait. Recessive are always lowercase letters. For example, using 'A' as the representative character for each allele, a homozygous dominant pair's genotype would be depicted as 'AA', while homozygous recessive is shown as 'aa'. Heterozygosity, with hetero associated with different, can only be 'Aa' (the capital letter is always presented first by convention). The phenotype of a homozygous dominant pair is 'A', or dominant, while the opposite is true for homozygous recessive. Heterozygous pairs always have a dominant phenotype. To a lesser degree, hemizygosity and nullizygosit
Document 3:::
In statistical genetics, inclusive composite interval mapping (ICIM) has been proposed as an approach to QTL (quantitative trait locus) mapping for populations derived from bi-parental crosses. QTL mapping is based on genetic linkage map and phenotypic data to attempt to locate individual genetic factors on chromosomes and to estimate their genetic effects.
Additive and dominance QTL mapping
Two genetic assumptions used in ICIM are (1) the genotypic value of an individual is the summation of effects from all genes affecting the trait of interest; and (2) linked QTL are separated by at least one blank marker interval. Under the two assumptions, they proved that additive effect of the QTL located in a marker interval can be completely absorbed by the regression coefficients of the two flanking markers, while the QTL dominance effect causes marker dominance effects, as well as additive by additive and dominance by dominance interactions between the two flanking markers. By including two multiplication variables between flanking markers, the additive and dominance effects of one QTL can be completely absorbed. As a consequence, an inclusive linear model of phenotype regressing on all genetic markers (and marker multiplications) can be used to fit the positions and additive (and dominance) effects of all QTL in the genome. A two-step strategy was adopted in ICIM for additive and dominance QTL mapping. In the first step, stepwise regression was applied to identify the most significant marker variables in the linear model. In the second step, one-dimensional scanning or interval mapping was conducted for detecting QTL and estimating its additive and dominance effects, based on the phenotypic values adjusted by the regression model in the first step.
Genetic and statistical properties in additive QTL mapping
Computer simulations were used to study the asymptotic properties of ICIM in additive QTL mapping. The test statistic LOD score linearly increases as the increase in
Document 4:::
In genetics, pseudolinkage is a characteristic of a heterozygote for a reciprocal translocation, in which genes located near the translocation breakpoint behave as if they are linked even though they originated on nonhomologous chromosomes.
Linkage is the proximity of two or more markers on a chromosome; the closer together the markers are, the lower the probability that they will be separated by recombination. Genes are said to be linked when the frequency of parental type progeny exceeds that of recombinant progeny.
Not occur in translocation homozygote
During meiosis in a translocation homozygote, chromosomes segregate normally according to Mendelian principles. Even though the genes have been rearranged during crossover, both haploid sets of chromosomes in the individual have the same rearrangement. As a result, all chromosomes will find a single partner with which to pair at meiosis, and there will be no deleterious consequences for the progeny.
In translocation heterozygote
In translocation heterozygote, however, certain patterns of chromosome segregation during meiosis produce genetically unbalanced gametes that at fertilization become deleterious to the zygote. In a translocation heterozygote, the two haploid sets of chromosomes do not carry the same arrangement of genetic information. As a result, during prophase of the first meiotic division, the translocated chromosomes and their normal homologs assume a crosslike configuration in which four chromosomes, rather than the normal two, pair to achieve a maximum of synapsis between similar regions. We denote the chromosomes carrying translocated material with a T and the chromosomes with a normal order of genes with an N. Chromosomes N1 and T1 have homologous centromeres found in wild type on chromosome 1; N2 and T2 have centromeres found in wild type on chromosome 2.
During anaphase of meiosis I, the mechanisms that attach the spindle to the chromosomes in this crosslike configuration still usually ens
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A "widow's peak" hairline in humans is coded by the dominant allele W. A straight hairline is coded by the recessive allele w. A man with a homozygous dominant WW produces a zygote with a woman with a heterozygous dominant Ww for the trait. Which allele combinations could occur in the zygote?
A. WW or ww
B. WW or Ww
C. WW only
D. Ww only
Answer:
|
|
sciq-8564
|
multiple_choice
|
What type of tissue consists of cells that cover inner and outer body surfaces?
|
[
"Soft Tissue",
"epithelial?",
"aberrant ?",
"mitochondrial ?"
] |
B
|
Relavent Documents:
Document 0:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 1:::
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 2:::
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
Document 3:::
This table lists the epithelia of different organs of the human body
Human anatomy
Document 4:::
In biology, the extracellular matrix (ECM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM.
The animal extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i.e., in the intercellular spaces). Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. Basement membranes are sheet-like depositions of ECM on which various epithelial cells rest. Each type of connective tissue in animals has a type of ECM: collagen fibers and bone mineral comprise the ECM of bone tissue; reticular fibers and ground substance comprise the ECM of loose connective tissue; and blood plasma is the ECM of blood.
The plant ECM includes cell wall components, like cellulose, in addition to more complex signaling molecules. Some single-celled organisms adopt multicellular biofilms in which the cells are embedded in an ECM composed primarily of extracellular polymeric substances (EPS).
Structure
Components of the ECM are produced intracellularly by resident cells and secreted into the ECM via exocytosis. Once secreted, they then aggregate with the existing matrix. The ECM is composed of an interlocking mesh of fibrous proteins and glycosaminoglycans (GAGs).
Proteoglycans
Glycosaminoglycans (GAGs) are carbohydrate polymers and mostly attached to extracellular matrix proteins to form proteoglycans (hyaluronic acid is a notable exception; see below). Proteoglycans have a net negative charge that attracts positively charged sod
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of tissue consists of cells that cover inner and outer body surfaces?
A. Soft Tissue
B. epithelial?
C. aberrant ?
D. mitochondrial ?
Answer:
|
|
sciq-1654
|
multiple_choice
|
Producing light without a high temperature is called?
|
[
"luminescence",
"plasma",
"effervescence",
"fluorescence"
] |
A
|
Relavent Documents:
Document 0:::
Nick Holonyak Jr. ( ; November 3, 1928September 18, 2022) was an American engineer and educator. He is noted particularly for his 1962 invention and first demonstration of a semiconductor laser diode that emitted visible light. This device was the forerunner of the first generation of commercial light-emitting diodes (LEDs). He was then working at a General Electric Company research laboratory near Syracuse, New York. He left General Electric in 1963 and returned to his alma mater, the University of Illinois at Urbana-Champaign, where he later became John Bardeen Endowed Chair in Electrical and Computer Engineering and Physics.
Early life and career
Nick Holonyak Jr. was born in Zeigler, Illinois, on November 3, 1928. His parents were Rusyn immigrants. His father worked in a coal mine. Holonyak was the first member of his family to receive any type of formal schooling. He once worked 30 straight hours on the Illinois Central Railroad before realizing that a life of hard labor was not what he wanted and he would prefer to go to school instead. According to a Chicago Tribune article in 2003, "The cheap and reliable semiconductor lasers critical to DVD players, bar code readers and scores of other devices owe their existence in some small way to the demanding workload thrust upon Downstate railroad crews decades ago."
Holonyak earned his bachelor's (1950), master's (1951), and doctoral (1954) degrees in electrical engineering from the University of Illinois at Urbana-Champaign. Holonyak was John Bardeen's first doctoral student there. In 1954, Holonyak went to Bell Telephone Laboratories, where he worked on silicon-based electronic devices. From 1955 to 1957 he served with the U.S. Army Signal Corps.
From 1957 to 1963 he was a scientist at the General Electric Company's Advanced Semiconductor Laboratory near Syracuse, New York. Here he invented, fabricated, and demonstrated the first visible light laser diode on October 9, 1962. He grew crystals of the alloy GaAs0.
Document 1:::
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
Document 2:::
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 3:::
Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. Thermal radiation is generated when heat from the movement of charges in the material (electrons and protons in common forms of matter) is converted to electromagnetic radiation. All matter with a temperature greater than absolute zero emits thermal radiation. At room temperature, most of the emission is in the infrared (IR) spectrum. Particle motion results in charge-acceleration or dipole oscillation which produces electromagnetic radiation.
Infrared radiation emitted by animals (detectable with an infrared camera) and cosmic microwave background radiation are examples of thermal radiation.
If a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium, the radiation is called blackbody radiation. Planck's law describes the spectrum of blackbody radiation, which depends solely on the object's temperature. Wien's displacement law determines the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the radiant intensity.
Thermal radiation is also one of the fundamental mechanisms of heat transfer.
Overview
Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. Thermal radiation reflects the conversion of thermal energy into electromagnetic energy. Thermal energy is the kinetic energy of random movements of atoms and molecules in matter. All matter with a nonzero temperature is composed of particles with kinetic energy. These atoms and molecules are composed of charged particles, i.e., protons and electrons. The kinetic interactions among matter particles result in charge acceleration and dipole oscillation. This results in the electrodynamic generation of coupled electric and magnetic fields, resulting in the emission of photons, radiating energy away from the body. Electromagnetic radiation, including visible light, will pr
Document 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.
Producing light without a high temperature is called?
A. luminescence
B. plasma
C. effervescence
D. fluorescence
Answer:
|
|
sciq-369
|
multiple_choice
|
What do hydrophilic substances have an affinity for?
|
[
"air",
"soil",
"heat",
"water"
] |
D
|
Relavent Documents:
Document 0:::
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.
In contrast, hydrophobes are not attracted to water and may seem to be repelled by it. Hygroscopics are attracted to water, but are not dissolved by water.
Molecules
A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more thermodynamically favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in other polar solvents.
Hydrophilic molecules (and portions of molecules) can be contrasted with hydrophobic molecules (and portions of molecules). In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiphilic molecules is the lipids that comprise the cell membrane. Another example is soap, which has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both water and oil.
Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively. Some hydrophilic substances do not dissolve. This type of mixture is called a colloid.
An approximate rule of thumb for hydrophilicity of organic compounds is that solubility of a molecule in water is more than 1 mass % if there is at least one neutral hydrophile group per 5 carbons, or at least one electrically charged hydrophile group per 7 carbons.
Hydrophilic substances (ex: salts) can seem to attract water out of the air. Sugar is also hydrophilic, and like salt is sometimes used to draw water out of foods. Sugar sprinkled on cut fruit will "draw out the water" through hydrophilia, making the fruit mushy and wet, as in a common strawberry compote recipe.
Chemicals
Liquid hydrophilic chemicals complexed with solid chemicals can be used to optimize solubility of hydrophobic chemical
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in an aqueous solution and exclude water molecules. The word hydrophobic literally means "water-fearing", and it describes the segregation of water and nonpolar substances, which maximizes hydrogen bonding between molecules of water and minimizes the area of contact between water and nonpolar molecules. In terms of thermodynamics, the hydrophobic effect is the free energy change of water surrounding a solute. A positive free energy change of the surrounding solvent indicates hydrophobicity, whereas a negative free energy change implies hydrophilicity.
The hydrophobic effect is responsible for the separation of a mixture of oil and water into its two components. It is also responsible for effects related to biology, including: cell membrane and vesicle formation, protein folding, insertion of membrane proteins into the nonpolar lipid environment and protein-small molecule associations. Hence the hydrophobic effect is essential to life. Substances for which this effect is observed are known as hydrophobes.
Amphiphiles
Amphiphiles are molecules that have both hydrophobic and hydrophilic domains. Detergents are composed of amphiphiles that allow hydrophobic molecules to be solubilized in water by forming micelles and bilayers (as in soap bubbles). They are also important to cell membranes composed of amphiphilic phospholipids that prevent the internal aqueous environment of a cell from mixing with external water.
Folding of macromolecules
In the case of protein folding, the hydrophobic effect is important to understanding the structure of proteins that have hydrophobic amino acids (such as glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan and methionine) clustered together within the protein. Structures of water-soluble proteins have a hydrophobic core in which side chains are buried from water, which stabilizes the folded state. Charged and polar side ch
Document 3:::
Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe (behind molecular hydrogen and carbon monoxide).
Water molecules form hydrogen bonds with each other and are strongly polar. This polarity allows it to dissociate ions in salts and bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a relatively high boiling point of 100 °C for its molar mass, and a high heat capacity.
Water is amphoteric, meaning that it can exhibit properties of an acid or a base, depending on the pH of the solution that it is in; it readily produces both and ions. Related to its amphoteric character, it undergoes self-ionization. The product of the activities, or approximately, the concentrations of and is a constant, so their respective concentrations are inversely proportional to each other.
Physical properties
Water is the chemical substance with chemical formula ; one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. Water is a tasteless, odorless liquid at ambient temperature and pressure. Liquid water has weak absorption bands at wavelengths of around 750 nm which cause it to appear to have a blue color. This can easily be observed in a water-filled bath or wash-basin whose lining is white. Large ice crystals, as in glaciers, also appear blue.
Under standard conditions, water is primarily a liquid, unlike other analogous hydrides of the oxygen family, which are generally gaseou
Document 4:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do hydrophilic substances have an affinity for?
A. air
B. soil
C. heat
D. water
Answer:
|
|
scienceQA-674
|
multiple_choice
|
What do these two changes have in common?
compost rotting
cooking a pancake
|
[
"Both are caused by heating.",
"Both are only physical changes.",
"Both are chemical changes.",
"Both are caused by cooling."
] |
C
|
Step 1: Think about each change.
Compost forms from the remains of plants and animals, such as vegetable scraps and egg shells. Compost rotting is a chemical change. As the compost rots, it breaks down and turns into a different type of matter.
Cooking a pancake is a chemical change. Pancakes are made from pancake batter. A cooked pancake is a different type of matter than pancake batter. Pancake batter is wet and slippery. Cooked pancakes are fluffy and can be good to eat!
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Cooking is caused by heating. But compost rotting is not.
Both are caused by cooling.
Neither change is caused by cooling.
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 2:::
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 3:::
Computer science and engineering (CSE) is an academic program at many universities which comprises computer science classes (e.g. data structures and algorithms) and computer engineering classes (e.g computer architecture). There is no clear division in computing between science and engineering, just like in the field of materials science and engineering. CSE is also a term often used in Europe to translate the name of engineering informatics academic programs. It is offered in both undergraduate as well postgraduate with specializations.
Academic courses
Academic programs vary between colleges, but typically include a combination of topics in computer science, computer engineering, and electrical engineering. Undergraduate courses usually include programming, algorithms and data structures, computer architecture, operating systems, computer networks, parallel computing, embedded systems, algorithms design, circuit analysis and electronics, digital logic and processor design, computer graphics, scientific computing, software engineering, database systems, digital signal processing, virtualization, computer simulations and games programming. CSE programs also include core subjects of theoretical computer science such as theory of computation, numerical methods, machine learning, programming theory and paradigms. Modern academic programs also cover emerging computing fields like image processing, data science, robotics, bio-inspired computing, computational biology, autonomic computing and artificial intelligence. Most CSE programs require introductory mathematical knowledge, hence the first year of study is dominated by mathematical courses, primarily discrete mathematics, mathematical analysis, linear algebra, probability, and statistics, as well as the basics of electrical and electronic engineering, physics, and electromagnetism.
Example universities with CSE majors and departments
APJ Abdul Kalam Technological University
American International University-B
Document 4:::
Engineering mathematics is a branch of applied mathematics concerning mathematical methods and techniques that are typically used in engineering and industry. Along with fields like engineering physics and engineering geology, both of which may belong in the wider category engineering science, engineering mathematics is an interdisciplinary subject motivated by engineers' needs both for practical, theoretical and other considerations outside their specialization, and to deal with constraints to be effective in their work.
Description
Historically, engineering mathematics consisted mostly of applied analysis, most notably: differential equations; real and complex analysis (including vector and tensor analysis); approximation theory (broadly construed, to include asymptotic, variational, and perturbative methods, representations, numerical analysis); Fourier analysis; potential theory; as well as linear algebra and applied probability, outside of analysis. These areas of mathematics were intimately tied to the development of Newtonian physics, and the mathematical physics of that period. This history also left a legacy: until the early 20th century subjects such as classical mechanics were often taught in applied mathematics departments at American universities, and fluid mechanics may still be taught in (applied) mathematics as well as engineering departments.
The success of modern numerical computer methods and software has led to the emergence of computational mathematics, computational science, and computational engineering (the last two are sometimes lumped together and abbreviated as CS&E), which occasionally use high-performance computing for the simulation of phenomena and the solution of problems in the sciences and engineering. These are often considered interdisciplinary fields, but are also of interest to engineering mathematics.
Specialized branches include engineering optimization and engineering statistics.
Engineering mathematics in tertiary educ
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
compost rotting
cooking a pancake
A. Both are caused by heating.
B. Both are only physical changes.
C. Both are chemical changes.
D. Both are caused by cooling.
Answer:
|
sciq-9711
|
multiple_choice
|
What is required between cytoskeleton and motor proteins for cell motility?
|
[
"translation",
"inhibition",
"absorption",
"interaction"
] |
D
|
Relavent Documents:
Document 0:::
Transport by molecular motor proteins (Kinesin, Dynein and unconventional Myosin) is essential for cell functioning and survival. Studies of multiple motors are inspired by the fact that multiple motors are involved in many biological processes such as intra-cellular transport and mitosis. This increasing interest in modeling multiple motor transport is particularly due to improved understanding of single motor function. Several models have been proposed in recent year to understand the transport by multiple motors.
Models developed can be broadly divided into two categories (1) mean-field/steady state model and (2) stochastic model. The mean-field model is useful for describing transport by a large group of motors. In mean-field description, fluctuation in the forces that individual motors feel while pulling the cargo is ignored. In stochastic model, fluctuation in the forces that motors feel are not ignored. Steady-state/mean-field model is useful for modeling transport by a large group of motors whereas stochastic model is useful for modeling transport by few motors.
Document 1:::
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components:microfilaments, intermediate filaments, and microtubules, and these are all capable of rapid growth or disassembly depending on the cell's requirements.
A multitude of functions can be performed by the cytoskeleton. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material (endocytosis), the segregation of chromosomes during cellular division, the cytokinesis stage of cell division, as scaffolding to organize the contents of the cell in space and in intracellular transport (for example, the movement of vesicles and organelles within the cell) and can be a template for the construction of a cell wall. Furthermore, it can form specialized structures, such as flagella, cilia, lamellipodia and podosomes. The structure, function and dynamic behavior of the cytoskeleton can be very different, depending on organism and cell type. Even within one cell, the cytoskeleton can change through association with other proteins and the previous history of the network.
A large-scale example of an action performed by the cytoskeleton is muscle contraction. This is carried out by groups of highly specialized cells working together. A main component in the cytoskeleton that helps show the true function of this muscle contraction is the microfilament. Microfilaments are composed of the most abundant cel
Document 2:::
Molecular motors are natural (biological) or artificial molecular machines that are the essential agents of movement in living organisms. In general terms, a motor is a device that consumes energy in one form and converts it into motion or mechanical work; for example, many protein-based molecular motors harness the chemical free energy released by the hydrolysis of ATP in order to perform mechanical work. In terms of energetic efficiency, this type of motor can be superior to currently available man-made motors. One important difference between molecular motors and macroscopic motors is that molecular motors operate in the thermal bath, an environment in which the fluctuations due to thermal noise are significant.
Examples
Some examples of biologically important molecular motors:
Cytoskeletal motors
Myosins are responsible for muscle contraction, intracellular cargo transport, and producing cellular tension.
Kinesin moves cargo inside cells away from the nucleus along microtubules, in anterograde transport.
Dynein produces the axonemal beating of cilia and flagella and also transports cargo along microtubules towards the cell nucleus, in retrograde transport.
Polymerisation motors
Actin polymerization generates forces and can be used for propulsion. ATP is used.
Microtubule polymerization using GTP.
Dynamin is responsible for the separation of clathrin buds from the plasma membrane. GTP is used.
Rotary motors:
FoF1-ATP synthase family of proteins convert the chemical energy in ATP to the electrochemical potential energy of a proton gradient across a membrane or the other way around. The catalysis of the chemical reaction and the movement of protons are coupled to each other via the mechanical rotation of parts of the complex. This is involved in ATP synthesis in the mitochondria and chloroplasts as well as in pumping of protons across the vacuolar membrane.
The bacterial flagellum responsible for the swimming and tumbling of E. coli and other bacteria
Document 3:::
Cell biomechanics a branch of biomechanics that involves single molecules, molecular interactions, or cells as the system of interest. Cells generate and maintain mechanical forces within their environment as a part of their physiology. Cell biomechanics deals with how mRNA, protein production, and gene expression is affected by said environment and with mechanical properties of isolated molecules or interaction of proteins that make up molecular motors.
It is known that minor alterations in mechanical properties of cells can be an indicator of an infected cell. By studying these mechanical properties, greater insight will be gained in regards to disease. Thus, the goal of understanding cell biomechanics is to combine theoretical, experimental, and computational approaches to construct a realistic description of cell mechanical behaviors to provide new insights on the role of mechanics in disease.
History
In the late seventeenth century, English polymath Robert Hooke and Dutch scientist Antonie van Leeuwenhoek looked into ciliate Vorticella with extreme fluid and cellular motion using a simple optical microscope. In 1702 on Christmas day, van Leeuwenhoek described his observations, “In structure these little animals were fashioned like a bell, and at the round opening they made such a stir, that the particles in the water thereabout were set in motion thereby…which sight I found mightily diverting” in a letter. Prior to this, Brownian motion of particles and organelles within living cells had been discovered as well as theories to measure viscosity. However, there were not enough accessible technical tools to perform these accurate experiments at the time. Thus, mechanical properties within cells were only supported qualitatively by observation.
With these new discoveries, the role of mechanical forces within biology was not always naturally accepted. In 1850, English physician William Benjamin Carpenter wrote “many of the actions taking place in the living bod
Document 4:::
The mechanome consists of the body, or ome, of data including cell and molecular processes relating to force and mechanical systems at molecular, cellular and tissue length scales - the fundamental "machine code" structures of the cell. The mechanome encompasses biological motors, like kinesin, myosin, RNAP, and Ribosome mechanical structures, like actin or the cytoskeleton and also proteomic and genomic components that are mechanosensitive and are involved in the response of cells to externally applied force.
A definition of the "Mechanome" extending to cell/organ/body given by Prof. Roger Kamm, at the 5th World Congress of Biomechanics Munich, includes understanding:
The complete state of stress existing from tissues to cells to molecules. The biological state that results from the distribution of forces. Requires knowledge of the distribution of force throughout the cell/organ/body, the functional interactions between these stresses and the fundamental biological processes.
The mechanome seeks to understand the fundamental physical-mechanical processes and events that affect biological function. An example at the molecular level includes the common structural designs used by kinesin and myosin motor proteins (such as dimer formation and mechanochemical cycles) that control their function and lead to properties such as processivity. The mechanome assembles the common features of these motors regardless of the "track" (microtubules, actin filaments, nucleotide based structures, membranes) they move on. A cytoskeletal example includes structures such as actin filament networks and bundles that can form from a variety of actin binding proteins that cross-link or bundle actin filaments leading to common mechanical changes of these structures. A cell machinery example includes common structures such as contractile ring formation formed by both actin and tubulin type structures leading to the same mechanical result of cell division.
In order to respond to loading ce
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is required between cytoskeleton and motor proteins for cell motility?
A. translation
B. inhibition
C. absorption
D. interaction
Answer:
|
|
sciq-1506
|
multiple_choice
|
Insulin is produced by what cells of the pancreas?
|
[
"alpha",
"platelet",
"gamma",
"beta"
] |
D
|
Relavent Documents:
Document 0:::
Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. Usually, the cell changes to a more specialized type. Differentiation happens multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated daughter cells during tissue repair and during normal cell turnover. Some differentiation occurs in response to antigen exposure. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression and are the study of epigenetics. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. However, metabolic composition does get altered quite dramatically where stem cells are characterized by abundant metabolites with highly unsaturated structures whose levels decrease upon differentiation. Thus, different cells can have very different physical characteristics despite having the same genome.
A specialized type of differentiation, known as terminal differentiation, is of importance in some tissues, including vertebrate nervous system, striated muscle, epidermis and gut. During terminal differentiation, a precursor cell formerly capable of cell division permanently leaves the cell cycle, dismantles the cell cycle machinery and often expresses a range of genes characteristic of the cell's final function (e.g. myosin and actin for a muscle cell). Differentiation may continue to occur after terminal differentiation if the capacity and functions of the cell undergo further changes.
Among dividing cells, there are multiple levels of cell potency, which is the cell's ability to differentiate into other cell types. A greater potency indicates a larger n
Document 1:::
Directed differentiation is a bioengineering methodology at the interface of stem cell biology, developmental biology and tissue engineering. It is essentially harnessing the potential of stem cells by constraining their differentiation in vitro toward a specific cell type or tissue of interest. Stem cells are by definition pluripotent, able to differentiate into several cell types such as neurons, cardiomyocytes, hepatocytes, etc. Efficient directed differentiation requires a detailed understanding of the lineage and cell fate decision, often provided by developmental biology.
Conceptual frame
During differentiation, pluripotent cells make a number of developmental decisions to generate first the three germ layers (ectoderm, mesoderm and endoderm) of the embryo and intermediate progenitors, followed by subsequent decisions or check points, giving rise to all the body's mature tissues. The differentiation process can be modeled as sequence of binary decisions based on probabilistic or stochastic models. Developmental biology and embryology provides the basic knowledge of the cell types' differentiation through mutation analysis, lineage tracing, embryo micro-manipulation and gene expression studies. Cell differentiation and tissue organogenesis involve a limited set of developmental signaling pathways. It is thus possible to direct cell fate by controlling cell decisions through extracellular signaling, mimicking developmental signals.
Source material
Directed differentiation is primarily applied to pluripotent stem cells (PSCs) of mammalian origin, in particular mouse and human cells for biomedical research applications. Since the discovery of embryonic stem (ES) cells (1981) and induced pluripotent stem (iPS) cells (2006), source material is potentially unlimited.
Historically, embryonic carcinoma (EC) cells have also been used. Fibroblasts or other differentiated cell types have been used for direct reprogramming strategies.
Methods
Cell differentiation invo
Document 2:::
Stem Cells is a peer-review scientific journal of cell biology. It was established as The International Journal of Cell Cloning in 1983, acquiring its current title in 1993.
The journal is published by AlphaMed Press, and is currently edited by Jan Nolta (University of California). Stem Cells currently has an impact factor of 6.277.
Abstracting and indexing
The journal is abstracted and indexed in the following bibliographic databases:
Document 3:::
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
Document 4:::
Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease (a major cause of myocardial infarction (MI)), as well as treatment for the damage that occurs to the heart after MI. After MI, the myocardium suffers from reperfusion injury which leads to death of cardiomyocytes and detrimental remodelling of the heart, consequently reducing proper cardiac function. Transfection of cardiac myocytes with human HGF reduces ischemic reperfusion injury after MI. The benefits of HGF therapy include preventing improper remodelling of the heart and ameliorating heart dysfunction post-MI.
Human hepatocyte growth factor
Human hepatocyte growth factor (HGF) is an 80kD pleiotropic protein that is endogenously produced by a variety of cell types from the mesenchymal cell lineage (such as cardiomyocytes and neurons). It is produced and proteolytically cleaved to its active state in response to cellular injury or during apoptosis. HGF binds to c-met receptors found on mesenchymal cell types to produce its many different effects such as increased cellular motility, morphogenesis, proliferation and differentiation. Research has shown that HGF has potent angiogenic, anti-fibrotic, and anti-apoptotic properties. It has also been shown to act as a chemoattractant for adult mesenchymal stem cells via c-met receptor binding.
Research and clinical trials
Animal research has demonstrated that administration of HGF cDNA plasmids into ischemic cardiac tissue can increase cardiac function (improved left ventricular ejection fraction and fractional shortening compared to control subjects) after induced MI or ischemia. Transfection with HGF plasmids in damaged cardiac tissue also promotes angiogenesis (increased capillary density compared to control subjects), as well as decreasing detrimental remodelling of the tissue at the site of injury (decreased fibrotic deposition). The increased production of HGF by transfected cardiomyocytes duri
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Insulin is produced by what cells of the pancreas?
A. alpha
B. platelet
C. gamma
D. beta
Answer:
|
|
sciq-4356
|
multiple_choice
|
The average number of individuals per unit of area or volume is referred to as a population's what?
|
[
"output",
"density",
"increase",
"diameter"
] |
B
|
Relavent Documents:
Document 0:::
Demography (), also known as Demographics, is the statistical study of populations, especially human beings.
Demographic analysis examines and measures the dimensions and dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of social actors can change across time through processes of birth, death, and migration. In the context of human biological populations, demographic analysis uses administrative records to develop an independent estimate of the population. Demographic analysis estimates are often considered a reliable standard for judging the accuracy of the census information gathered at any time. In the labor force, demographic analysis is used to estimate sizes and flows of populations of workers; in population ecology the focus is on the birth, death, migration and immigration of individuals in a population of living organisms, alternatively, in social human sciences could involve movement of firms and institutional forms. Demographic analysis is used in a wide variety of contexts. For example, it is often used in business plans, to describe the population connected to the geographic location of the business. Demographic analysis is usually abbreviated as DA. For the 2010 U.S. Census, The U.S. Census Bureau has expanded its DA categories. Also as part of the 2010 U.S. Census, DA now also includes comparative analysis between independent housing estimates, and census address lists at different key time points.
Patient demographics form the core of the data for any medical institution, such as patient and emergency contact information and patient medical record data. They allo
Document 1:::
Outline of demography contains human demography and population related important concepts and high-level aggregated lists compiled in the useful categories.
The subheadings have been grouped by the following 4 categories:
Meta (lit. "highest" level) units, such as the universal important concepts related to demographics and places.
Macro (lit. "high" level) units where the "whole world" is the smallest unit of measurement, such as the aggregated summary demographics at global level. For example, United Nations.
Meso (lit. "middle" or "intermediate" level) units where the smallest unit of measurement cover more than one nation and more than one continent but not all the nations or continents. For example, summary list at continental level, e.g. Eurasia and Latin America or Middle East which cover two or more continents. Other examples include the intercontinental organisations e.g. the Commonwealth of Nations or the organisation of Arab states.
Micro (lit. "lower" or "smaller") level units where country is the smallest unit of measurement, such as the "globally aggregated lists" by the "individual countries" .
Please do not add sections on the items that are the nano (lit. "minor" or "tiny") level units as per the context described above, e.g. list of things within a city must be kept out.
Meta or important concepts
Global human population
World population
Demographics of the world
Fertility and intelligence
Human geography
Geographic mobility
Globalization
Human migration
List of lists on linguistics
Impact of human population
Human impact on the environment
Biological dispersal
Carrying capacity
Doomsday argument
Environmental migrant
Human overpopulation
Malthusian catastrophe
List of countries by carbon dioxide emissions
List of countries by carbon dioxide emissions per capita
List of countries by greenhouse gas emissions
List of countries by greenhouse gas emissions per capita
Overconsumption
Overexploitation
Population eco
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:::
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.
Biological population densities
Population density is population divided by total land area, sometimes including seas and oceans, as appropriate.
Low densities may cause an extinction vortex and further reduce fertility. This is called the Allee effect after the scientist who identified it. Examples of the causes of reduced fertility in low population densities are:
Increased problems with locating sexual mates
Increased inbreeding
===Human densities===
Population density is the number of people per unit of area, usually transcribed as "per square kilometer" or square mile, and which may include or exclude, for example, areas of water or glaciers. Commonly this is calculated for a county, city, country, another territory or the entire world.
The world's population is around 8,000,000,000 and the Earth's total area (including land and water) is . Therefore, from this very crude type of calculation, the worldwide human population density is approximately 8,000,000,000 ÷ 510,000,000 = . However, if only the Earth's land area of is taken into account, then human population density is . This includes all continental and island land area, including Antarctica. However, if Antarctica is excluded, then population density rises to over .
The European Commission's Joint Research Centre (JRC) has developed a suite of (open and free) data and tools named the Global Human Settlement Layer (GHSL) to improve the science for policy support to the European Commission Directorate Generals and Services and as support to the United Nations system.
Several of the most densely populated territories in the world are city-states, microstates and urban dependencies. In fact, 95% of the world's population is concentrated on just 10% of the world's land.
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.
The average number of individuals per unit of area or volume is referred to as a population's what?
A. output
B. density
C. increase
D. diameter
Answer:
|
|
scienceQA-8729
|
multiple_choice
|
How long is a sofa?
|
[
"10 inches",
"10 feet",
"10 miles",
"10 yards"
] |
B
|
The best estimate for the length of a sofa is 10 feet.
10 inches is too short. 10 yards and 10 miles are too long.
|
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:::
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:::
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:::
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.
How long is a sofa?
A. 10 inches
B. 10 feet
C. 10 miles
D. 10 yards
Answer:
|
sciq-6489
|
multiple_choice
|
Nearly all earthquakes occur where?
|
[
"in Asia",
"in large cities",
"plate boundaries",
"plate centers"
] |
C
|
Relavent Documents:
Document 0:::
The Human-Induced Earthquake Database (HiQuake) is an online database that documents all reported cases of induced seismicity proposed on scientific grounds. It is the most complete compilation of its kind and is freely available to download via the associated website. The database is periodically updated to correct errors, revise existing entries, and add new entries reported in new scientific papers and reports. Suggestions for revisions and new entries can be made via the associated website.
History
In 2016, Nederlandse Aardolie Maatschappij funded a team of researchers from Durham University and Newcastle University to conduct a full review of induced seismicity. This review formed part of a scientific workshop aimed at estimating the maximum possible magnitude earthquake that might be induced by conventional gas production in the Groningen gas field.
The resulting database from the review was publicly released online on the 26 January 2017. The database was accompanied by the publication of two scientific papers, the more detailed of which is freely available online.
Document 1:::
Seismic moment is a quantity used by seismologists to measure the size of an earthquake. The scalar seismic moment is defined by the equation
, where
is the shear modulus of the rocks involved in the earthquake (in pascals (Pa), i.e. newtons per square meter)
is the area of the rupture along the geologic fault where the earthquake occurred (in square meters), and
is the average slip (displacement offset between the two sides of the fault) on (in meters).
thus has dimensions of torque, measured in newton meters. The connection between seismic moment and a torque is natural in the body-force equivalent representation of seismic sources as a double-couple (a pair of force couples with opposite torques): the seismic moment is the torque of each of the two couples. Despite having the same dimensions as energy, seismic moment is not a measure of energy. The relations between seismic moment, potential energy drop and radiated energy are indirect and approximative.
The seismic moment of an earthquake is typically estimated using whatever information is available to constrain its factors. For modern earthquakes, moment is usually estimated from ground motion recordings of earthquakes known as seismograms. For earthquakes that occurred in times before modern instruments were available, moment may be estimated from geologic estimates of the size of the fault rupture and the slip.
Seismic moment is the basis of the moment magnitude scale introduced by Hiroo Kanamori, which is often used to compare the size of different earthquakes and is especially useful for comparing the sizes of large (great) earthquakes.
The seismic moment is not restricted to earthquakes. For a more general seismic source described by a seismic moment tensor (a symmetric tensor, but not necessarily a double couple tensor), the seismic moment is
See also
Richter magnitude scale
Moment magnitude scale
Sources
.
.
.
.
Seismology measurement
Moment (physics)
Document 2:::
Temblor, Inc. is a tech company that provides information about earthquakes and enables users to both see what the seismic hazard is at their home, and learn about precautions to help lessen the risk. The company released a web app and a mobile app that can be found in the iTunes and Google Play stores. Temblor was founded in 2014 by Ross Stein and Volkan Sevilgen, both coming from the United States Geological Survey. Together they have published research on earthquakes that have struck in 30 countries. Upon release, Temblor has been mentioned in several news sources, including the New York Times, CBS News, SFGate, MSN, and the Los Angeles Times, in articles about earthquakes and earthquake preparedness.
Features
Temblor displays a map is with earthquakes and faults. Liquefaction and landslide data is also shown in several locations. Users are able to plug in an address and get the seismic hazard rank for that location along with estimates for seismic shaking and home damage. They are also shown the extent to which these risks could be mitigated by buying earthquake insurance or retrofitting the house. These features are provided for free and without ads for the general public.
Document 3:::
The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori. Similar to the local magnitude/Richter scale () defined by Charles Francis Richter in 1935, it uses a logarithmic scale; small earthquakes have approximately the same magnitudes on both scales. Despite the difference, news media often says "Richter scale" when referring to the moment magnitude scale.
Moment magnitude () is considered the authoritative magnitude scale for ranking earthquakes by size. It is more directly related to the energy of an earthquake than other scales, and does not saturatethat is, it does not underestimate magnitudes as other scales do in certain conditions. It has become the standard scale used by seismological authorities like the U.S. Geological Survey for reporting large earthquakes (typically M > 4), replacing the local magnitude () and surface wave magnitude () scales. Subtypes of the moment magnitude scale (, etc.) reflect different ways of estimating the seismic moment.
History
Richter scale: the original measure of earthquake magnitude
At the beginning of the twentieth century, very little was known about how earthquakes happen, how seismic waves are generated and propagate through the Earth's crust, and what information they carry about the earthquake rupture process; the first magnitude scales were therefore empirical. The initial step in determining earthquake magnitudes empirically came in 1931 when the Japanese seismologist Kiyoo Wadati showed that the maximum amplitude of an earthquake's seismic waves diminished with distance at a certain rate. Charles F. Richter then worked out how to adjust for epicentral distance (and some other factors) so that the logarithm of the amplitude of the seismograph trace could be used as a measure of "magnit
Document 4:::
The George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) was created by the National Science Foundation (NSF) to improve infrastructure design and construction practices to prevent or minimize damage during an earthquake or tsunami. Its headquarters were at Purdue University in West Lafayette, Indiana as part of cooperative agreement #CMMI-0927178, and it ran from 2009 till 2014. The mission of NEES is to accelerate improvements in seismic design and performance by serving as a collaboratory for discovery and innovation.
Description
The NEES network features 14 geographically distributed, shared-use laboratories that support several types of experimental work: geotechnical centrifuge research, shake table tests, large-scale structural testing, tsunami wave basin experiments, and field site research. Participating universities include: Cornell University; Lehigh University;Oregon State University; Rensselaer Polytechnic Institute; University at Buffalo, SUNY; University of California, Berkeley; University of California, Davis; University of California, Los Angeles; University of California, San Diego; University of California, Santa Barbara; University of Illinois at Urbana-Champaign; University of Minnesota; University of Nevada, Reno; and the University of Texas, Austin.
The equipment sites (labs) and a central data repository are connected to the global earthquake engineering community via the NEEShub, which is powered by the HUBzero software developed at Purdue University specifically to help the scientific community share resources and collaborate. The cyberinfrastructure, connected via Internet2, provides interactive simulation tools, a simulation tool development area, a curated central data repository, user-developed databases, animated presentations, user support, telepresence, mechanism for uploading and sharing resources and statistics about users, and usage patterns.
This allows researchers to: securely store, organize and share da
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Nearly all earthquakes occur where?
A. in Asia
B. in large cities
C. plate boundaries
D. plate centers
Answer:
|
|
sciq-1967
|
multiple_choice
|
What explains the spherical shape of ceres, once thought to be the largest asteroid?
|
[
"space debris",
"low gravity",
"orbital plane",
"high gravity"
] |
D
|
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:::
Feynman's Lost Lecture: The Motion of Planets Around the Sun is a book based on a lecture by Richard Feynman. Restoration of the lecture notes and conversion into book form was undertaken by Caltech physicist David L. Goodstein and archivist Judith R. Goodstein.
Feynman had given the lecture on the motion of bodies at Caltech on March 13, 1964, but the notes and pictures were lost for a number of years and consequently not included in The Feynman Lectures on Physics series. The lecture notes were later found, but without the photographs of his illustrative chalkboard drawings. One of the editors, David L. Goodstein, stated that at first without the photographs, it was very hard to figure out what diagrams he was referring to in the audiotapes, but a later finding of his own private lecture notes made it possible to understand completely the logical framework with which Feynman delivered the lecture.
Overview
You can explain to people who don't know much of the physics, the early history... how Newton discovered... Kepler's Laws, and equal areas, and that means it's toward the sun, and all this stuff. And then the key - they always ask then, "Well, how do you see that it's an ellipse if it's the inverse square?" Well, it's God damned hard, there's no question of that. But I tried to find the simplest one I could.
In a non-course lecture delivered to a freshman physics audience, Feynman undertakes to present an elementary, geometric demonstration of Newton's discovery of the fact that Kepler's first observation, that the planets travel in elliptical orbits, is a necessary consequence of Kepler's other two observations.
The structure of Feynman's lecture:
A historical introduction to the material
An overview of some geometric properties of an ellipse
Newton's demonstration that equal areas in equal times is equivalent to forces toward the sun
Feynman's demonstration that equal changes in velocity occur in equal angles in the orbit
Feynman's demonstration,
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:::
In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the various chunks that make them up.
The asteroids Bennu and Ryugu have a measured bulk density which suggests that their internal structure is a rubble pile. Many comets and most smaller minor planets (<10 km in diameter) are thought to be composed of coalesced rubble.
Minor planets
Most smaller asteroids are thought to be rubble piles.
Rubble piles form when an asteroid or moon (which may originally be monolithic) is smashed to pieces by an impact, and the shattered pieces subsequently fall back together, primarily due to self-gravitation. This coalescing usually takes from several hours to weeks.
When a rubble-pile asteroid passes a much more massive object, tidal forces change its shape.
Scientists first suspected that asteroids are often rubble piles when asteroid densities were first determined. Many of the calculated densities were significantly less than those of meteorites, which in some cases had been determined to be pieces of asteroids.
Many asteroids with low densities are thought to be rubble piles, for example 253 Mathilde. The mass of Mathilde, as determined by the NEAR Shoemaker mission, is far too low for the volume observed, considering the surface is rock. Even ice with a thin crust of rock would not provide a suitable density. Also, the large impact craters on Mathilde would have shattered a rigid body. However, the first unambiguous rubble pile to be photographed is 25143 Itokawa, which has no obvious impact craters and is thus almost certainly a coalescence of shattered fragments.
The asteroid 433 Eros, the primary destination of NEAR Shoemaker, was determined to be riven with cracks but otherwise solid. Other asteroids, possibly including Itokawa, have been found to be contact binaries, two majo
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What explains the spherical shape of ceres, once thought to be the largest asteroid?
A. space debris
B. low gravity
C. orbital plane
D. high gravity
Answer:
|
|
ai2_arc-841
|
multiple_choice
|
Which weather event usually includes heavy precipitation, strong winds, and surface air temperatures below 0°C?
|
[
"blizzard",
"hurricane",
"thunderstorm",
"tornado"
] |
B
|
Relavent Documents:
Document 0:::
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. (see also: List of meteorological phenomena)
A
advection
aeroacoustics
aerobiology
aerography (meteorology)
aerology
air parcel (in meteorology)
air quality index (AQI)
airshed (in meteorology)
American Geophysical Union (AGU)
American Meteorological Society (AMS)
anabatic wind
anemometer
annular hurricane
anticyclone (in meteorology)
apparent wind
Atlantic Oceanographic and Meteorological Laboratory (AOML)
Atlantic hurricane season
atmometer
atmosphere
Atmospheric Model Intercomparison Project (AMIP)
Atmospheric Radiation Measurement (ARM)
(atmospheric boundary layer [ABL]) planetary boundary layer (PBL)
atmospheric chemistry
atmospheric circulation
atmospheric convection
atmospheric dispersion modeling
atmospheric electricity
atmospheric icing
atmospheric physics
atmospheric pressure
atmospheric sciences
atmospheric stratification
atmospheric thermodynamics
atmospheric window (see under Threats)
B
ball lightning
balloon (aircraft)
baroclinity
barotropity
barometer ("to measure atmospheric pressure")
berg wind
biometeorology
blizzard
bomb (meteorology)
buoyancy
Bureau of Meteorology (in Australia)
C
Canada Weather Extremes
Canadian Hurricane Centre (CHC)
Cape Verde-type hurricane
capping inversion (in meteorology) (see "severe thunderstorms" in paragraph 5)
carbon cycle
carbon fixation
carbon flux
carbon monoxide (see under Atmospheric presence)
ceiling balloon ("to determine the height of the base of clouds above ground level")
ceilometer ("to determine the height of a cloud base")
celestial coordinate system
celestial equator
celestial horizon (rational horizon)
celestial navigation (astronavigation)
celestial pole
Celsius
Center for Analysis and Prediction of Storms (CAPS) (in Oklahoma in the US)
Center for the Study o
Document 1:::
The following outline is provided as an overview of and topical guide to the field of Meteorology.
Meteorology The interdisciplinary, scientific study of the Earth's atmosphere with the primary focus being to understand, explain, and forecast weather events. Meteorology, is applied to and employed by a wide variety of diverse fields, including the military, energy production, transport, agriculture, and construction.
Essence of meteorology
Meteorology
Climate – the average and variations of weather in a region over long periods of time.
Meteorology – the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting (in contrast with climatology).
Weather – the set of all the phenomena in a given atmosphere at a given time.
Branches of meteorology
Microscale meteorology – the study of atmospheric phenomena about 1 km or less, smaller than mesoscale, including small and generally fleeting cloud "puffs" and other small cloud features
Mesoscale meteorology – the study of weather systems about 5 kilometers to several hundred kilometers, smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems, skjjoch as sea breezes, squall lines, and mesoscale convective complexes
Synoptic scale meteorology – is a horizontal length scale of the order of 1000 kilometres (about 620 miles) or more
Methods in meteorology
Surface weather analysis – a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations
Weather forecasting
Weather forecasting – the application of science and technology to predict the state of the atmosphere for a future time and a given location
Data collection
Pilot Reports
Weather maps
Weather map
Surface weather analysis
Forecasts and reporting of
Atmospheric pressure
Dew point
High-pressure area
Ice
Black ice
Frost
Low-pressure area
Precipitation
Document 2:::
Storm spotting is a form of weather spotting in which observers watch for the approach of severe weather, monitor its development and progression, and actively relay their findings to local authorities.
History
Storm spotting developed in the United States during the early 1940s. A joint project between the military and the weather bureau saw the deployment of trained military and aviation lightning spotters in areas where ammunitions for the war were manufactured. During 1942, a serious tornado struck a key operations center in Oklahoma and another tornado on May 15, 1943 destroyed parts of the Fort Riley military base located in Kansas. After these two events and a string of other tornado outbreaks, spotter networks became commonplace, and it is estimated that there were over 200 networks by 1945. Their mandate had also changed to include reporting all types of active or severe weather; this included giving snow depth and other reports during the winter as well as fire reports in the summer, along with the more typical severe weather reports associated with thunderstorms. However, spotting was still mainly carried out by trained individuals in either the military, aviation, or law enforcement fields of service. It was not until 1947 that volunteer spotting, as it exists today, was born.
After a series of vicious tornado outbreaks hit the state of Texas in 1947, the state placed special emphasis on volunteer spotting, and the local weather offices began to offer basic training classes to the general public. Spotting required the delivery of timely information so that warnings could be issued as quickly as possible, thus civilian landline phone calls and amateur radio operators provided the most efficient and fastest means of communication. While phone lines were reliable to a degree, a common problem was the loss of service when an approaching storm damaged phone lines in its path. This eventually led to amateur radio becoming the predominant means of communicat
Document 3:::
Military meteorology is meteorology applied to military purposes, by armed forces or other agencies. It is one of the most common fields of employment for meteorologists.
World War II brought great advances in meteorology as large-scale military land, sea, and air campaigns were highly dependent on weather, particularly forecasts provided by the Royal Navy, Met Office and USAAF for the Normandy landing and strategic bombing.
University meteorology departments grew rapidly as the military services sent cadets to be trained as weather officers. Wartime technological developments such as radar also proved to be valuable meteorological observing systems. More recently, the use of satellites in space has contributed extensively to military meteorology.
Military meteorologists currently operate with a wide variety of military units, from aircraft carriers to special forces.
Military meteorology in the United States
United States Navy/Marine Corps
Chain of command
Naval Meteorology and Oceanography Command
Fleet Numerical Meteorology and Oceanography Center
Enlisted
Enlisted meteorology and oceanography forecasters are called aerographer's mates.
Officer
Naval meteorology and oceanography officers are restricted line officers in the Information Dominance Corps.
Notable military meteorologists
Capt Homer A. McCrerey, USNA Class of 1942, fleet meteorologist and oceanographer (FNMOC) (1967–1972)
Gp Capt James Martin Stagg, military meteorologist for Operation Overlord 1944
See also
U.S. Air Force 557th Weather Wing
U.S. Air Force Special Operations Weather Technician
Navy Operational Global Atmospheric Prediction System
Weather forecasting for Operation Overlord
Further reading
John F. Fuller (1974), Weather and War, Military Airlift Command, U.S. Air Force
Thomas Haldane, War History of the Australian Meteorological Service in the Royal Australian Air Force April 1941 to July 1946, accessed at Australian Science and Technology Heritage Centre, University o
Document 4:::
The Oklahoma Mesonet is a network of environmental monitoring stations designed to measure the environment at the size and duration of mesoscale weather events. The phrase "mesonet" is a portmanteau of the words mesoscale and network.
The network consists of 120 automated stations covering Oklahoma and each of Oklahoma's counties has at least one station. At each site, the environment is measured by a set of instruments located on or near a -tall tower. The measurements are packaged into “observations” and transmitted to a central facility every 5 minutes, 24 hours per day, every day of the year.
Oklahoma Mesonet is a cooperative venture between Oklahoma State University (OSU) and the University of Oklahoma (OU) and is supported by the taxpayers of Oklahoma. It is headquartered at the National Weather Center (NWC) on the OU campus.
Observations are available free of charge to the public.
Background
According to the Tulsa World, creation of the Oklahoma Mesonet resulted from the inability of emergency management officials to plan for the May 26–27, 1984 flood that killed 14 people in the Tulsa area. The 1984 flood demonstrated that emergency managers could not receive accurate and adequate data quickly enough about the progress of flooding from airport radars, updated hourly. The University of Oklahoma and Oklahoma State University collaborated with the Climatological Survey and other public and private agencies to create the Oklahoma Mesonet. This system collects weather information (e.g., wind speed, rainfall, temperature) every 5 minutes from 121 Mesonet stations throughout Oklahoma. Emergency planners can now monitor up-to-date weather information in advance of the arrival of an approaching storm. The article quoted an official of the Tulsa Area Emergency Management as saying that his staff uses the Oklahoma Mesonet every day.
Products
The Oklahoma Mesonet produces multiple weather products for public consumption and download: these include maps of all of t
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which weather event usually includes heavy precipitation, strong winds, and surface air temperatures below 0°C?
A. blizzard
B. hurricane
C. thunderstorm
D. tornado
Answer:
|
|
ai2_arc-460
|
multiple_choice
|
A road cut shows a layer of shale on top of a layer of limestone. This indicates
|
[
"the shale layer is older than the limestone layer.",
"a fault occurred during the deposition of the layers.",
"the environment changed between the times of deposition.",
"volcanic activity occurred when these layers were deposited."
] |
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:::
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:::
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 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 SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A road cut shows a layer of shale on top of a layer of limestone. This indicates
A. the shale layer is older than the limestone layer.
B. a fault occurred during the deposition of the layers.
C. the environment changed between the times of deposition.
D. volcanic activity occurred when these layers were deposited.
Answer:
|
|
ai2_arc-179
|
multiple_choice
|
Most electrical wires are covered with plastic or rubber. The wires are covered with plastic or rubber because those materials
|
[
"are conductors of electricity",
"make complete electric circuits",
"are not conductors of electricity",
"make the electricity move quickly"
] |
C
|
Relavent Documents:
Document 0:::
is a series of educational Japanese manga books. Each volume explains a particular subject in science or mathematics. The series is published in Japan by Ohmsha, in America by No Starch Press, in France by H&K, in Italy by L'Espresso, in Malaysia by Pelangi, and in Taiwan by 世茂出版社. Different volumes are written by different authors.
Volume list
The series to date of February 18, 2023 consists of 50 volumes in Japan. Fourteen of them have been published in English and six in French so far, with more planned, including one on sociology. In contrast, 49 of them have been published and translated in Chinese. One of the books has been translated into Swedish.
The Manga Guide to Electricity
This 207-page guide consists of five chapters, excluding the preface, prologue, and epilogue. It explains fundamental concepts in the study of electricity, including Ohm's law and Fleming's rules. There are written explanations after each manga chapter. An index and two pages to write notes on are provided.
The story begins with Rereko, an average high-school student who lives in Electopia (the land of electricity), failing her final electricity exam. She was forced to skip her summer vacation and go to Earth for summer school. The high school teacher Teteka sensei gave her a “transdimensional walkie-talkie and observation robot” named Yonosuke, which she will use later for going back and forth to Earth. Rereko then met her mentor Hikaru sensei, who did Electrical Engineering Research at a university in Tokyo, Japan. Hikaru sensei explained to Rereko the basic components of electricity with occasional humorous moments.
In the fifth chapter, Hikaru sensei told Rereko her studies are over. Yonosuke soon received Electopia’s call to pick Rereko up. Hikaru sensei told her that he learned a lot from teaching her, and she should keep at it, even back on Electopia. Rereko told Hikaru sensei to keep working on his research and clean his room often. Her sentence was interrupted, and she wa
Document 1:::
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 2:::
A circuit diagram (or: wiring diagram, electrical diagram, elementary diagram, electronic schematic) is a graphical representation of an electrical circuit. A pictorial circuit diagram uses simple images of components, while a schematic diagram shows the components and interconnections of the circuit using standardized symbolic representations. The presentation of the interconnections between circuit components in the schematic diagram does not necessarily correspond to the physical arrangements in the finished device.
Unlike a block diagram or layout diagram, a circuit diagram shows the actual electrical connections. A drawing meant to depict the physical arrangement of the wires and the components they connect is called artwork or layout, physical design, or wiring diagram.
Circuit diagrams are used for the design (circuit design), construction (such as PCB layout), and maintenance of electrical and electronic equipment.
In computer science, circuit diagrams are useful when visualizing expressions using Boolean algebra.
Symbols
Circuit diagrams are pictures with symbols that have differed from country to country and have changed over time, but are now to a large extent internationally standardized. Simple components often had symbols intended to represent some feature of the physical construction of the device. For example, the symbol for a resistor dates back to the time when that component was made from a long piece of wire wrapped in such a manner as to not produce inductance, which would have made it a coil. These wirewound resistors are now used only in high-power applications, smaller resistors being cast from carbon composition (a mixture of carbon and filler) or fabricated as an insulating tube or chip coated with a metal film. The internationally standardized symbol for a resistor is therefore now simplified to an oblong, sometimes with the value in ohms written inside, instead of the zig-zag symbol. A less common symbol is simply a series of peaks o
Document 3:::
This article details the history of electronics engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".
Electronics engineering as a profession sprang from technological improvements in the telegraph industry during the late 19th century and in the radio and telephone industries during the early 20th century. People gravitated to radio, attracted by the technical fascination it inspired, first in receiving and then in transmitting. Many who went into broadcasting in the 1920s had become "amateurs" in the period before World War I. The modern discipline of electronics engineering was to a large extent born out of telephone-, radio-, and television-equipment development and the large amount of electronic-systems development during World War II of radar, sonar, communication systems, and advanced munitions and weapon systems. In the interwar years, the subject was known as radio engineering. The word electronics began to be used in the 1940s In the late 1950s, the term electronics engineering started to emerge.
Electronic laboratories (Bell Labs, for instance) created and subsidized by large corporations in the industries of radio, television, and telephone equipment, began churning out a series of electronic advances. The electronics industry was revolutionized by the inventions of the first transistor in 1948, the integrated circuit chip in 1959, and the silicon MOSFET (metal–oxide–semiconductor field-effect transistor) in 1959. In the UK, the subject of electronics engineering became distinct from electrical engineering as a university-degree subject around 1960. (Before this time, students of electronics and related subjects like radio and telecommunications had to enroll in the electrical engineering department of the university as no university had departments of electronics. Electrical engineering was the nea
Document 4:::
A terminal is the point at which a conductor from a component, device or network comes to an end. Terminal may also refer to an electrical connector at this endpoint, acting as the reusable interface to a conductor and creating a point where external circuits can be connected. A terminal may simply be the end of a wire or it may be fitted with a connector or fastener.
In network analysis, terminal means a point at which connections can be made to a network in theory and does not necessarily refer to any physical object. In this context, especially in older documents, it is sometimes called a pole. On circuit diagrams, terminals for external connections are denoted by empty circles. They are distinguished from nodes or junctions which are entirely internal to the circuit, and are denoted by solid circles.
All electrochemical cells have two terminals (electrodes) which are referred to as the anode and cathode or positive (+) and negative (-). On many dry batteries, the positive terminal (cathode) is a protruding metal cap and the negative terminal (anode) is a flat metal disc . In a galvanic cell such as a common AA battery, electrons flow from the negative terminal to the positive terminal, while the conventional current is opposite to this.
Types of terminals
Connectors
Line splices
Terminal strip, also known as a tag board or tag strip
Solder cups or buckets
Wire wrap connections (wire to board)
Crimp terminals (ring, spade, fork, bullet, blade)
Turret terminals for surface-mount circuits
Crocodile clips
Screw terminals and terminal blocks
Wire nuts, a type of twist-on wire connector
Leads on electronic components
Battery terminals, often using screws or springs
Electrical polarity
See also
Electrical connector - many terminals fall under this category
Electrical termination - a method of signal conditioning
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Most electrical wires are covered with plastic or rubber. The wires are covered with plastic or rubber because those materials
A. are conductors of electricity
B. make complete electric circuits
C. are not conductors of electricity
D. make the electricity move quickly
Answer:
|
|
sciq-11394
|
multiple_choice
|
What class of organisms help decompose matter to release nutrients and make nutritious food for other organisms ?
|
[
"coral",
"bacteria",
"fungi",
"yeast"
] |
C
|
Relavent Documents:
Document 0:::
Decomposers are organisms that break down dead or decaying organisms; they carry out decomposition, a process possible by only certain kingdoms, such as fungi. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores ingest and digest dead matter internally, while decomposers directly absorb nutrients through external chemical and biological processes. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they are unable to absorb nutrients without ingesting them.
Fungi
The primary decomposer of litter in many ecosystems is fungi. Unlike bacteria, which are unicellular organisms and are decomposers as well, most saprotrophic fungi grow as a branching network of hyphae. While bacteria are restricted to growing and feeding on the exposed surfaces of organic matter, fungi can use their hyphae to penetrate larger pieces of organic matter, below the surface. Additionally, only wood-decay fungi have evolved the enzymes necessary to decompose lignin, a chemically complex substance found in wood. These two factors make fungi the primary decomposers in forests, where litter has high concentrations of lignin and often occurs in large pieces. Fungi decompose organic matter by releasing enzymes to break down the decaying material, after which they absorb the nutrients in the decaying material. Hyphae are used to break down matter and absorb nutrients and are also used in reproduction. When two compatible fungi hyphae grow close to each other, they will then fuse together for reproduction, and form another fungus.
See also
Chemotroph
Micro-animals
Microorganism
Document 1:::
Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator (see predation), host-parasite (see parasitism), plant-herbivore and victim-exploiter systems. These kinds of interactions have been studied and modeled by population ecologists for nearly a century. Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources. Species higher up in the food chain survive by consuming other species and can be classified by what they eat and how they obtain or find their food.
Classification of consumer types
The standard categorization
Various terms have arisen to define consumers by what they eat, such as meat-eating carnivores, fish-eating piscivores, insect-eating insectivores, plant-eating herbivores, seed-eating granivores, and fruit-eating frugivores and omnivores are meat eaters and plant eaters. An extensive classification of consumer categories based on a list of feeding behaviors exists.
The Getz categorization
Another way of categorizing consumers, proposed by South African American ecologist Wayne Getz, is based on a biomass transformation web (BTW) formulation that organizes resources into five components: live and dead animal, live and dead plant, and particulate (i.e. broken down plant and animal) matter. It also distinguishes between consumers that gather their resources by moving across landscapes from those that mine their resources by becoming sessile once they have located a stock of resources large enough for them to feed on during completion of a full life history stage.
In Getz's scheme, words for miners are of Greek etymology and words for gatherers are of Latin etymology. Thus a bestivore, such as a cat, preys on live animal
Document 2:::
Saprobionts are organisms that digest their food externally and then absorb the products. This process is called saprotrophic nutrition. Fungi are examples of saprobiontic organisms, which are a type of decomposer.
Saprobiontic organisms feed off dead and/or decaying biological materials. Digestion is accomplished by excretion of digestive enzymes which break down cell tissues, allowing saprobionts to extract the nutrients they need while leaving the indigestible waste. This is called extracellular digestion. This is very important in ecosystems, for the nutrient cycle.
Saprobionts should not be confused with detritivores, another class of decomposers which digest internally.
These organisms can be good sources of extracellular enzymes for industrial processes such as the production of fruit juice. For instance, the fungus Aspergillus niger is used to produce pectinase, an enzyme which is used to break down pectin in juice concentrates, making the juice appear more translucent.
Document 3:::
Microfauna (Ancient Greek mikros "small" + Neo-Latin fauna "animal") refers to microscopic animals and organisms that exhibit animal-like qualities. Microfauna are represented in the animal kingdom (e.g. nematodes, small arthropods) and the protist kingdom (i.e. protozoans).
Habitat
Microfauna are present in every habitat on Earth. They fill essential roles as decomposers and food sources for lower trophic levels, and are necessary to drive processes within larger organisms.
Role
One particular example of the role of microfauna can be seen in soil, where they are important in the cycling of nutrients in ecosystems. Soil microfauna are capable of digesting just about any organic substance, and some inorganic substances. These organisms are often essential links in the food chain between primary producers and larger species. For example, zooplankton are widespread microscopic animals and protists which feed on algae and detritus in the ocean, such as foraminifera.
Microfauna also aid in digestion and other processes in larger organisms.
Cryptozoa
The microfauna are the least understood of soil life, due to their small size and great diversity. Many microfauna are members of the so-called cryptozoa, animals that remain undescribed by science. Out of the estimated 10-20 million animal species in the world, only 1.8 million have been given scientific names, and many of the remaining millions are likely microfauna, much of it from the tropics.
Phyla
Notable phyla include:
Microscopic arthropods, including dust mites, spider mites, and some crustaceans such as copepods and certain cladocera.
Tardigrades ("water bears")
Rotifers, which are filter feeders that are usually found in fresh water.
Some nematode species
Many loricifera, including the recently discovered anaerobic species, which spend their entire lives in an anoxic environment.
See also
Fauna
Megafauna
Mesofauna
Document 4:::
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated "soil organic matter". The detritus of aquatic ecosystems is organic substances that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow".
Theory
The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which organic matter is decomposed, occurs in several phases. Micro- and macro-organisms that feed on it rapidly consume and absorb materials such as proteins, lipids, and sugars that are low in molecular weight, while other compounds such as complex carbohydrates are decomposed more slowly. The decomposing microorganisms degrade the organic materials so as to gain the resources they require for their survival and reproduction. Accordingly, simultaneous to microorganisms' decomposition of the materials of dead plants and animals is their assimilation of decomposed compounds to construct more of their biomass (i.e. to grow their own bodies). When microorganisms die, fine organic particles are produced, and if small animals that feed on microorganisms eat these particles they collect inside the intestines of the consumers, and change shape into large pellets of dung. As a result of this process, most of the materials of dead organisms disappear and are not visible and recognizable in any form, but are pres
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What class of organisms help decompose matter to release nutrients and make nutritious food for other organisms ?
A. coral
B. bacteria
C. fungi
D. yeast
Answer:
|
|
sciq-8857
|
multiple_choice
|
What stimulates the changes of pubery?
|
[
"mutation",
"parenting",
"sex education",
"sex hormones"
] |
D
|
Relavent Documents:
Document 0:::
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 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
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
The Science, Technology, Engineering and Mathematics Network or STEMNET is an educational charity in the United Kingdom that seeks to encourage participation at school and college in science and engineering-related subjects (science, technology, engineering, and mathematics) and (eventually) work.
History
It is based at Woolgate Exchange near Moorgate tube station in London and was established in 1996. The chief executive is Kirsten Bodley. The STEMNET offices are housed within the Engineering Council.
Function
Its chief aim is to interest children in science, technology, engineering and mathematics. Primary school children can start to have an interest in these subjects, leading secondary school pupils to choose science A levels, which will lead to a science career. It supports the After School Science and Engineering Clubs at schools. There are also nine regional Science Learning Centres.
STEM ambassadors
To promote STEM subjects and encourage young people to take up jobs in these areas, STEMNET have around 30,000 ambassadors across the UK. these come from a wide selection of the STEM industries and include TV personalities like Rob Bell.
Funding
STEMNET used to receive funding from the Department for Education and Skills. Since June 2007, it receives funding from the Department for Children, Schools and Families and Department for Innovation, Universities and Skills, since STEMNET sits on the chronological dividing point (age 16) of both of the new departments.
See also
The WISE Campaign
Engineering and Physical Sciences Research Council
National Centre for Excellence in Teaching Mathematics
Association for Science Education
Glossary of areas of mathematics
Glossary of astronomy
Glossary of biology
Glossary of chemistry
Glossary of engineering
Glossary of physics
Document 4:::
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 stimulates the changes of pubery?
A. mutation
B. parenting
C. sex education
D. sex hormones
Answer:
|
|
sciq-2253
|
multiple_choice
|
Deep water filling a void caused by surface winds blowing water north and south is known as?
|
[
"downwelling",
"upwelling",
"surface current",
"divergence"
] |
B
|
Relavent Documents:
Document 0:::
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a.
The increased availability of nutrients in upwelling regions results in high levels of primary production and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area. Upwellings that are driven by coastal currents or diverging open ocean have the greatest impact on nutrient-enriched waters and global fishery yields.
Mechanisms
The three main drivers that work together to cause upwelling are wind, Coriolis effect, and Ekman transport. They operate differently for different types of upwelling, but the general effects are the same. In the overall process of upwelling, winds blow across the sea surface at a particular direction, which causes a wind-water interaction. As a result of the wind, the water has transported a net of 90 degrees from the direction of the wind due to Coriolis forces and Ekman transport. Ekman transport causes the surface layer of water to move at about a 45 degree angle from the direction of the wind, and the friction between that layer and the layer beneath it causes the successive layers to move in the same direction. This results in a spiral of water moving down the water column. Then, it is the Coriolis forces that dictate which way the water will move; in the Northern hemisphere, the water is transported to the right of the direction of the wind. In the Southern Hemisphere, the water is transported
Document 1:::
Currentology is a science that studies the internal movements of water masses.
Description
In the study of fluid mechanics, researchers attempt to give a correct explanation of marine currents. Currents are caused by external driving forces such as wind, gravitational effects, coriolis forces and physical differences between various water masses, the main parameter being the difference of density that varies in function of the temperature and salinity.
The study of currents, combined with other factors such as tides and waves is relevant for understanding marine hydrodynamics and linked processes such as sediment transport and climate balance.
The measurement of maritime currents
The measurements of maritime currents can be made according to different techniques:
current meter
diversion buoys
See also
Document 2:::
The Black Sea undersea river is a current of particularly saline water flowing through the Bosphorus Strait and along the seabed of the Black Sea. The discovery of the river, announced on 1 August 2010, was made by scientists at the University of Leeds, and is the first of its kind in the world. The undersea river stems from salty water spilling through the Bosphorus Strait from the Mediterranean Sea into the Black Sea, where the water has a lower salt content.
Scientists have previously discovered channels running along ocean floors, based on sonar scanning. One of the largest of these runs from the mouth of the Amazon River into the Atlantic Ocean. Though it was suspected that these channels might function as rivers, it was only with the discovery of the Black Sea river that this suspicion was confirmed. Because of the power and unpredictability of these streams, they have been difficult to explore directly. A team of scientists headed by Jeff Peakall and Daniel Parsons of the University of Leeds collaborated with scientists from the University of Southampton, Memorial University of Newfoundland, and the Turkish Institute of Marine Sciences. The team used the Natural Environment Research Council's Autosub3 – a 7-metre torpedo-shaped autonomous underwater vehicle – to get as close to the current as possible. The river was found to be long, up to deep and wide. Though smaller than the Amazon channel, the undersea river still carried ten times more water than the Rhine. It flows at a speed of , with passing through per second. Had it been a surface river it would have ranked as the sixth largest river in the world.
The river was found to contain features typical of surface rivers, such as river banks, floodplains, waterfalls and rapids. One major difference was that the underwater river, when rounding a bend, moved in currents spinning in the opposite direction from those on land. The river works as a density current, because it carries sediments along the sea
Document 3:::
Branched flow refers to a phenomenon in wave dynamics, that produces a tree-like pattern involving successive mostly forward scattering events by smooth obstacles deflecting traveling rays or waves. Sudden and significant momentum or wavevector changes are absent, but accumulated small changes can lead to large momentum changes. The path of a single ray is less important than the environs around a ray, which rotate, compress, and stretch around in an area preserving way. Even more revealing are groups, or manifolds of neighboring rays extending over significant zones. Starting rays out from a point but varying their direction over a range, one to the next, or from different points along a line all with the same initial directions are examples of a manifold. Waves have analogous launching conditions, such as a point source spraying in many directions, or an extended plane wave heading on one direction. The ray bending or refraction leads to characteristic structure in phase space and nonuniform distributions in coordinate space that look somehow universal and resemble branches in trees or stream beds. The branches taken on non-obvious paths through the refracting landscape that are indirect and nonlocal results of terrain already traversed. For a given refracting landscape, the branches will look completely different depending on the initial manifold.
Examples
Two-dimensional electron gas
Branched flow was first identified in experiments with a two-dimensional electron gas. Electrons flowing from a quantum point contact were scanned using a scanning probe microscope. Instead of usual diffraction patterns, the electrons flowed forming branching strands that persisted for several correlation lengths of the background potential.
Ocean dynamics
Focusing of random waves in the ocean can also lead to branched flow. The fluctuation in the depth of the ocean floor can be described as a random potential. A tsunami wave propagating in such medium will form branches which
Document 4:::
Downwelling is the process of accumulation and sinking of higher density material beneath lower density material, such as cold or saline water beneath warmer or fresher water or cold air beneath warm air. It is the sinking limb of a convection cell. Upwelling is the opposite process, and together, these two forces are responsible in the oceans for the thermohaline circulation. The sinking of the cold lithosphere at subduction zones is another example of downwelling in plate tectonics.
Oceanic downwelling
Downwelling occurs in anti-cyclonic regions of the ocean where warm rings spin clockwise, causing surface convergence. When these surface waters converge, the surface water is pushed downwards. Downwelling can also occur as a result of the wind driving the sea towards the coastline. Downwelling regions have low productivity because the nutrients in the water column are used but are not continuously replenished by cold, nutrient-rich water from below the surface.
Oxygenation
Downwelling also allows for deep ocean oxygenation to occur because these waters are able to bring dissolved oxygen down from the surface to help facilitate aerobic respiration in organisms throughout the water column. Without this renewal, the dissolved oxygen in the sediment and within the water column would be quickly used up by biological processes and anaerobic bacteria would take over decomposition, leading to a build-up of hydrogen sulfide. In these toxic conditions, there are very few benthic animals that would survive. In the most extreme cases, a lack of downwelling could possibly lead to mass extinction. Paleontologists have suggested that 250 million years ago, deep ocean ventilation slowed nearly to a halt, and the ocean became stagnant. Sulfide and methane-rich waters low on oxygen filled the deep ocean and progressed onto the continental shelves, wiping out 95% of all marine species in the greatest extinction event in Earth's history, the Permian extinction.
Locations
Downwe
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Deep water filling a void caused by surface winds blowing water north and south is known as?
A. downwelling
B. upwelling
C. surface current
D. divergence
Answer:
|
|
sciq-8106
|
multiple_choice
|
Skeletal muscle cells and cardiac muscle cells share what property, which is not shared by smooth muscle cells?
|
[
"striations",
"overlap",
"surfaces",
"filaments"
] |
A
|
Relavent Documents:
Document 0:::
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix.
Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's myofilaments to slide past each other in a process called excitation-contraction coupling.
Diseases of the heart muscle known as cardiomyopathies are of major importance. These include ischemic conditions caused by a restricted blood supply to the muscle such as angina, and myocardial infarction.
Structure
Gross anatomy
Cardiac muscle tissue or myocardium forms the bulk of the heart. The heart wall is a three-layered structure with a thick layer of myocardium sandwiched between the inner endocardium and the outer epicardium (also known as the visceral pericardium). The inner endocardium lines the cardiac chambers, covers the cardiac valves, and joins with the endothelium that lines the blood vessels that connect to the heart. On the outer aspect of the myocardium is the epicardium which forms part of the pericardial sac that surrounds, protects, and lubricates the heart.
Within the myocardium, there are several sheets of cardiac muscle cells or cardiomyocytes. The sheets of muscle that wrap around the left ventricle clos
Document 1:::
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 2:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 3:::
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:::
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.
Skeletal muscle cells and cardiac muscle cells share what property, which is not shared by smooth muscle cells?
A. striations
B. overlap
C. surfaces
D. filaments
Answer:
|
|
sciq-586
|
multiple_choice
|
How do most growing plant cells expand?
|
[
"through photosynthesis",
"through germination",
"through cell respiration",
"through water uptake"
] |
D
|
Relavent Documents:
Document 0:::
Primary growth in plants is growth that takes place from the tips of roots or shoots. It leads to lengthening of roots and stems and sets the stage for organ formation. It is distinguished from secondary growth that leads to widening. Plant growth takes place in well defined plant locations. Specifically, the cell division and differentiation needed for growth occurs in specialized structures called meristems. These consist of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells continue to divide until they differentiate and then lose the ability to divide. Thus, the meristems produce all the cells used for plant growth and function.
At the tip of each stem and root, an apical meristem adds cells to their length, resulting in the elongation of both. Examples of primary growth are the rapid lengthening growth of seedlings after they emerge from the soil and the penetration of roots deep into the soil. Furthermore, all plant organs arise ultimately from cell divisions in the apical meristems, followed by cell expansion and differentiation.
In contrast, a growth process that involves thickening of stems takes place within lateral meristems that are located throughout the length of the stems. The lateral meristems of larger plants also extend into the roots. This thickening is secondary growth and is needed to give mechanical support and stability to the plant.
The functions of a plant's growing tips – its apical (or primary) meristems – include: lengthening through cell division and elongation; organising the development of leaves along the stem; creating platforms for the eventual development of branches along the stem; laying the groundwork for organ formation by providing a stock of undifferentiated or incompletely differentiated cells that later develop into fully differentiated cells, thereby ultimately allowing the "spatial deployment
Document 1:::
Plant stem cells
Plant stem cells are innately undifferentiated cells located in the meristems of plants. Plant stem cells serve as the origin of plant vitality, as they maintain themselves while providing a steady supply of precursor cells to form differentiated tissues and organs in plants. Two distinct areas of stem cells are recognised: the apical meristem and the lateral meristem.
Plant stem cells are characterized by two distinctive properties, which are: the ability to create all differentiated cell types and the ability to self-renew such that the number of stem cells is maintained. Plant stem cells never undergo aging process but immortally give rise to new specialized and unspecialized cells, and they have the potential to grow into any organ, tissue, or cell in the body. Thus they are totipotent cells equipped with regenerative powers that facilitate plant growth and production of new organs throughout lifetime.
Unlike animals, plants are immobile. As plants cannot escape from danger by taking motion, they need a special mechanism to withstand various and sometimes unforeseen environmental stress. Here, what empowers them to withstand harsh external influence and preserve life is stem cells. In fact, plants comprise the oldest and the largest living organisms on earth, including Bristlecone Pines in California, U.S. (4,842 years old), and the Giant Sequoia in mountainous regions of California, U.S. (87 meters in height and 2,000 tons in weight). This is possible because they have a modular body plan that enables them to survive substantial damage by initiating continuous and repetitive formation of new structures and organs such as leaves and flowers.
Plant stem cells are also characterized by their location in specialized structures called meristematic tissues, which are located in root apical meristem (RAM), shoot apical meristem (SAM), and vascular system ((pro)cambium or vascular meristem.)
Research and development
Traditionally, plant stem ce
Document 2:::
A plantoid is a robot or synthetic organism designed to look, act and grow like a plant. The concept was first scientifically published in 2010 (although models of comparable systems controlled by neural networks date back to 2003) and has so far remained largely theoretical. Plantoids imitate plants through appearances and mimicking behaviors and internal processes (which function to keep the plant alive or to ensure its survival). A prototype for the European Commission is now in development by сonsortium of the following scientists: Dario Floreano, Barbara Mazzolai, Josep Samitier, Stefano Mancuso.
A plantoid incorporates an inherently distributed architecture consisting of autonomous and specialized modules. Modules can be modeled on plant parts such as the root cap and communicate to form a simple swarm intelligence. This kind of system may display great robustness and resilience. It is conjectured to be capable of energy harvesting and management, collective environmental awareness and many other functions.
In science fiction, while human-like robots (androids) are fairly frequent and animal-like biomorphic robots turn up occasionally, plantoids are quite rare. Exceptions occur in the novel Hearts, Hands and Voices (1992, US: The Broken Land) by Ian McDonald and the TV series Jikuu Senshi Spielban.
Systems and Processes
Like plants, plantoids position its roots and appendages (projecting parts of the plantoid) towards beneficial conditions that stimulate growth (i.e sunlight, ideal temperatures, areas with larger water concentration) and away from factors that bar growth. This occurs through a combination of information from its sensors and the plantoid reacting accordingly.
Sensors
The use of soft tactical sensors (devices that gather information based on the surrounding physical environment) allows the plantoid to navigate its way through its environment. These sensors relay information to the plantoid and produce signals, similar to how a computer ca
Document 3:::
Transfer cells are specialized parenchyma cells that have an increased surface area, due to infoldings of the plasma membrane. They facilitate the transport of sugars from a sugar source, mainly mature leaves, to a sugar sink, often developing leaves or fruits. They are found in nectaries of flowers and some carnivorous plants.
Transfer cells are specially found in plants in the region of absorption or secretion of nutrients.
The term transfer cell was coined by Brian Gunning and John Stewart Pate. Their presence is generally correlated with the existence of extensive solute influxes across the plasma membrane.
Document 4:::
In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue. Secondary growth occurs in most seed plants, but monocots usually lack secondary growth. If they do have secondary growth, it differs from the typical pattern of other seed plants.
The formation of secondary vascular tissues from the cambium is a characteristic feature of dicotyledons and gymnosperms. In certain monocots, the vascular tissues are also increased after the primary growth is completed but the cambium of these plants is of a different nature. In the living pteridophytes this feature is extremely rare, only occurring in Isoetes.
Lateral meristems
In many vascular plants, secondary growth is the result of the activity of the two lateral meristems, the cork cambium and vascular cambium. Arising from lateral meristems, secondary growth increases the width of the plant root or stem, rather than its length. As long as the lateral meristems continue to produce new cells, the stem or root will continue to grow in diameter. In woody plants, this process produces wood, and shapes the plant into a tree with a thickened trunk.
Because this growth usually ruptures the epidermis of the stem or roots, plants with secondary growth usually also develop a cork cambium. The cork cambium gives rise to thickened cork cells to protect the surface of the plant and reduce water loss. If this is kept up over many years, this process may produce a layer of cork. In the case of the cork oak it will yield harvestable cork.
In nonwoody plants
Secondary growth also occurs in many nonwoody plants, e.g. tomato, potato tuber, carrot taproot and sweet potato tuberous root. A few long-lived leaves also have secondary growth.
Abnormal secondary growth
Abnormal seco
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
How do most growing plant cells expand?
A. through photosynthesis
B. through germination
C. through cell respiration
D. through water uptake
Answer:
|
|
sciq-3688
|
multiple_choice
|
When menstrual periods become less frequent and finally cease; this is called?
|
[
"metabolic",
"menopause",
"hormonal imbalance",
"climax"
] |
B
|
Relavent Documents:
Document 0:::
Menopause, also known as the climacteric, is the time when menstrual periods permanently cease, marking the end of reproduction. It typically occurs between the ages of 45 and 55, although the exact timing can vary. Menopause is usually a natural change. It can occur earlier in those who smoke tobacco. Other causes include surgery that removes both ovaries or some types of chemotherapy. At the physiological level, menopause happens because of a decrease in the ovaries' production of the hormones estrogen and progesterone. While typically not needed, a diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine. Menopause is the opposite of menarche, the time when a girl's periods start.
In the years before menopause, a woman's periods typically become irregular, which means that periods may be longer or shorter in duration or be lighter or heavier in the amount of flow. During this time, women often experience hot flashes; these typically last from 30 seconds to ten minutes and may be associated with shivering, night sweats, and reddening of the skin. Hot flashes can recur for four to five years. Other symptoms may include vaginal dryness, trouble sleeping, and mood changes. The severity of symptoms varies between women.
Menopause before the age of 45 years is considered to be "early menopause" and when ovarian failure/surgical removal of the ovaries occurs before the age of 40 years this is termed "premature ovarian insufficiency".
In addition to symptoms (hot flushes/flashes, night sweats, mood changes, arthralgia and vaginal dryness), the physical consequences of menopause include bone loss, increased central abdominal fat, and adverse changes in a woman's cholesterol profile and vascular function. These changes predispose postmenopausal women to increased risks of osteoporosis and bone fracture, and of cardio-metabolic disease (diabetes and cardiovascular disease).
Medical professionals often define menopause as having occurred
Document 1:::
Amenorrhea is the absence of a menstrual period in a female who has reached reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of menses during childhood and after menopause.
Amenorrhoea is a symptom with many potential causes. Primary amenorrhea is defined as an absence of secondary sexual characteristics by age 13 with no menarche or normal secondary sexual characteristics but no menarche by 15 years of age. It may be caused by developmental problems, such as the congenital absence of the uterus, failure of the ovary to receive or maintain egg cells, or delay in pubertal development. Secondary amenorrhoea, ceasing of menstrual cycles after menarche, is defined as the absence of menses for three months in a woman with previously normal menstruation, or six months for women with a history of oligomenorrhoea. It is often caused by hormonal disturbances from the hypothalamus and the pituitary gland, premature menopause, intrauterine scar formation, or eating disorders.
Pathophysiology
Although amenorrhea has multiple potential causes, ultimately, it is the result of hormonal imbalance or an anatomical abnormality.
Physiologically, menstruation is controlled by the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. GnRH acts on the pituitary to stimulate the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH). FSH and LH then act on the ovaries to stimulate the production of estrogen and progesterone which, respectively, control the proliferative and secretary phases of the menstrual cycle. Prolactin also influences the menstrual cycle as it suppresses the release of LH and FSH from the pituitary. Similarly, thyroid hormone also affects the menstrual cycle. Low levels of thyroid hormone stimulate the release of TRH from the hypothalamus, which in turn increases both TSH and prolactin release. This i
Document 2:::
Menarche ( ; ) is the first menstrual cycle, or first menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fertility.
Girls experience menarche at different ages. Having menarche occur between the ages of 9–14 in the West is considered normal. Canadian psychological researcher Niva Piran claims that menarche or the perceived average age of puberty is used in many cultures to separate girls from activity with boys, and to begin transition into womanhood.
The timing of menarche is influenced by female biology, as well as genetic and environmental factors, especially nutritional factors. The mean age of menarche has declined over the last century, but the magnitude of the decline and the factors responsible remain subjects of contention. The worldwide average age of menarche is very difficult to estimate accurately, and it varies significantly by geographical region, race, ethnicity and other characteristics, and occurs mostly during a span of ages from 8 to 16, with a small percentage of girls having menarche by age 10, and the vast majority having it by the time they were 14.
There is a later age of onset in Asian populations compared to the West, but it too is changing with time. For example a Korean study in 2011 showed an overall average age of 12.7, with around 20% before age 12, and more than 90% by age 14. A Chinese study from 2014 published in Acta Paediatrica showed similar results (overall average of age 12.8 in 2005 down to age 12.3 in 2014) and a similar trend in time, but also similar findings about ethnic, cultural, and environmental effects.
The average age of menarche was about 12.7 years in Canada in 2001, and 12.9 in the United Kingdom. A study of girls in Istanbul, Turkey, in 2011 found the median age at menarche to be 12.7 years. In the United States, an analysis of 10,590 women aged 15–44 taken from the 2013–2017 round of th
Document 3:::
Postmenopausal confusion, also commonly referred to as postmenopausal brain fog, is a group of symptoms of menopause in which women report problems with cognition at a higher frequency during postmenopause than before.
Multiple studies on cognitive performance following menopause have reported noticeable declines of greater than 60%. The common issues presented included impairments in reaction time and attention, difficulty recalling numbers or words, and forgetting reasons for involvement in certain behaviors. Association between subjective cognitive complaints and objective measures of performance show a significant impact on health-related quality of life for postmenopausal women.
Treatment primarily involves symptom management through non-pharmacological treatment strategies. This includes involvement in physical activity and following medically supervised diets, especially those that contain phytoestrogens or resveratrol. Pharmacological interventions in treating postmenopausal confusion are currently being researched. Hormone replacement therapy (HRT) is currently not indicated for the treatment of postmenopausal confusion due to inefficacy. The use of HRT for approved indications has identified no significant negative effect on postmenopausal cognition.
Although much of the literature references women, all people who undergo menopause, including those who do not self-identify as women, may experience symptoms of postmenopausal confusion.
History
Research on menopause as a whole declined with the end of the Women's Health Initiative (WHI) studies, but research on the treatment of symptoms associated with menopause—especially the treatment of cognitive decline—continues. The Study of Women's Health Across the Nation (SWAN), first started in 1996, continues to publish progress reports which include cognitive symptoms associated with menopausal transition, including those in postmenopause. , SWAN indicated, "Approximately 60% of midlife women report problems
Document 4:::
Menstruation is the shedding of the uterine lining (endometrium). It occurs on a regular basis in uninseminated sexually reproductive-age females of certain mammal species.
Although there is some disagreement in definitions between sources, menstruation is generally considered to be limited to primates. Overt menstruation (where there is bleeding from the uterus through the vagina) is found primarily in humans and close relatives such as chimpanzees. It is common in simians (Old World monkeys, New World monkeys, and apes), but completely lacking in strepsirrhine primates and possibly weakly present in tarsiers. Beyond primates, it is known only in bats, the elephant shrew, and the spiny mouse species Acomys cahirinus.
Females of other species of placental mammal undergo estrous cycles, in which the endometrium is completely reabsorbed by the animal (covert menstruation) at the end of its reproductive cycle. Many zoologists regard this as different from a "true" menstrual cycle. Female domestic animals used for breeding—for example dogs, pigs, cattle, or horses—are monitored for physical signs of an estrous cycle period, which indicates that the animal is ready for insemination.
Estrus and menstruation
Females of most mammal species advertise fertility to males with visual behavioral cues, pheromones, or both. This period of advertised fertility is known as oestrus, "estrus" or heat. In species that experience estrus, females are generally only receptive to copulation while they are in heat (dolphins are an exception). In the estrous cycles of most placental mammals, if no fertilization takes place, the uterus reabsorbs the endometrium. This breakdown of the endometrium without vaginal discharge is sometimes called covert menstruation. Overt menstruation (where there is blood flow from the vagina) occurs primarily in humans and close evolutionary relatives such as chimpanzees. Some species, such as domestic dogs, experience small amounts of vaginal bleeding
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When menstrual periods become less frequent and finally cease; this is called?
A. metabolic
B. menopause
C. hormonal imbalance
D. climax
Answer:
|
|
sciq-3745
|
multiple_choice
|
What are the two classifications for organisms living in water?
|
[
"arctan and plankton",
"scharwenka and plankton",
"arctan and nekton",
"nekton and plankton"
] |
D
|
Relavent Documents:
Document 0:::
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 1:::
Marine botany is the study of flowering vascular plant species and marine algae that live in shallow seawater of the open ocean and the littoral zone, along shorelines of the intertidal zone and coastal wetlands, even in low-salinity brackish water of estuaries.
It is a branch of marine biology and botany.
Marine Plant Classifications
There are five kingdoms that present-day classifications group organisms into: the Monera, Protist, Plantae, Fungi, and Animalia.
The Monera
Less than 2,000 species of bacteria occur in the marine environment out of the 100,000 species. Although this group of species is small, they play a tremendous role in energy transfer, mineral cycles, and organic turnover. The monera differs from the four other kingdoms as "members of the Monera have a prokaryotic cytology in which the cells lack membrane-bound organelles such as chloroplasts, mitochondria, nuclei, and complex flagella."
The bacteria can be divided into two major subkingdoms: Eubacteria and Archaebacteria.
Eubacteria
Eubacteria include the only bacteria that contain chlorophyll a. Not only that, but Eubacteria are placed in the divisions of Cyanobacteria and Prochlorophyta.
Characteristics of Eubacteria:
They do not have any membrane-bound organelles.
Most are enclosed by a cellular wall.
Archaebacteria
Archaebacteria are a type of single-cell organism and have a number of characteristics not seen in more "modern" cell types. These characteristics include:
Unique cell membrane chemistry
Unique gene transcription
Capable of methanogenesis
Differences in ribosomal RNA
Types of Archaebacteria:
Thermoproteota: Extremely heat-tolerant
"Euryarchaeota": Able to survive in very salty habitats
"Korarchaeota": The oldest lineage of archaebacteria
Archaebacteria vs. Eubacteria
While both are prokaryotic, these organisms exist in different biological domains because of how genetically different they are. Some believe archaebacteria are some of the oldest forms of lif
Document 2:::
Marine protists are defined by their habitat as protists that live in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. Life originated as marine single-celled prokaryotes (bacteria and archaea) and later evolved into more complex eukaryotes. Eukaryotes are the more developed life forms known as plants, animals, fungi and protists. Protists are the eukaryotes that cannot be classified as plants, fungi or animals. They are mostly single-celled and microscopic. The term protist came into use historically as a term of convenience for eukaryotes that cannot be strictly classified as plants, animals or fungi. They are not a part of modern cladistics because they are paraphyletic (lacking a common ancestor for all descendants).
Most protists are too small to be seen with the naked eye. They are highly diverse organisms currently organised into 18 phyla, but not easy to classify. Studies have shown high protist diversity exists in oceans, deep sea-vents and river sediments, suggesting large numbers of eukaryotic microbial communities have yet to be discovered. There has been little research on mixotrophic protists, but recent studies in marine environments found mixotrophic protists contribute a significant part of the protist biomass. Since protists are eukaryotes (and not prokaryotes) they possess within their cell at least one nucleus, as well as organelles such as mitochondria and Golgi bodies. Many protist species can switch between asexual reproduction and sexual reproduction involving meiosis and fertilization.
In contrast to the cells of prokaryotes, the cells of eukaryotes are highly organised. Plants, animals and fungi are usually multi-celled and are typically macroscopic. Most protists are single-celled and microscopic. But there are exceptions. Some single-celled marine protists are macroscopic. Some marine slime molds have unique life cycles that involve switching between unicellular, colonial, and
Document 3:::
List of eukaryotic species that belong to picoplankton, meaning one of their cell dimensions is smaller than 3 μm.
Autotrophic species
Chlorophyta
Chlorophyceae
Stichococcus cylindricus Butcher, 3 – 4.5 μm, brackish
Pedinophyceae
Marsupiomonas pelliculata Jones et al., 3 – 3 μm, brackish-marine
Resultor micron Moestrup, 1.5 – 2.5 μm, marine
Prasinophyceae
Bathycoccus prasinos Eikrem et Throndsen, 1.5 – 2.5 μm, marine
Crustomastix stigmatica Zingone, 3 – 5 μm, marine
Dolichomastix lepidota Manton, 2.5 – 2.5 μm, marine
Dolichomastix eurylepidea Manton, 3 μm, marine
Dolichomastix tenuilepis Throndsen et Zingone, 3 – 4.5 μm, marine
Mantoniella squamata Desikachary, 3 – 5 μm, marine
Micromonas pusilla Manton et Parke, 1 – 3 μm, marine
Ostreococcus tauri Courties et Chrétiennot-Dinet, 0.8 – 1.1 μm, marine
Picocystis salinarum Lewin, 2 – 3 μm, hypersaline
Prasinococcus capsulatus Miyashita et Chihara, 3 – 5.5 μm, marine
Prasinoderma coloniale Hasegawa et Chihara, 2.5 – 5.5 μm, marine
Pseudoscourfieldia marina Manton, 3 – 3.5 μm, marine
Pycnococcus provasolii Guillard, 1.5 – 4 μm, marine
Pyramimonas virginica Pennick, 2.7 – 3.5 μm, marine
Document 4:::
Marine life, sea life, or ocean life is the plants, animals, and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms, mostly microorganisms, produce oxygen and sequester carbon. Marine life in part shape and protect shorelines, and some marine organisms even help create new land (e.g. coral building reefs).
Most life forms evolved initially in marine habitats. By volume, oceans provide about 90% of the living space on the planet. The earliest vertebrates appeared in the form of fish, which live exclusively in water. Some of these evolved into amphibians, which spend portions of their lives in water and portions on land. One group of amphibians evolved into reptiles and mammals and a few subsets of each returned to the ocean as sea snakes, sea turtles, seals, manatees, and whales. Plant forms such as kelp and other algae grow in the water and are the basis for some underwater ecosystems. Plankton forms the general foundation of the ocean food chain, particularly phytoplankton which are key primary producers.
Marine invertebrates exhibit a wide range of modifications to survive in poorly oxygenated waters, including breathing tubes as in mollusc siphons. Fish have gills instead of lungs, although some species of fish, such as the lungfish, have both. Marine mammals (e.g. dolphins, whales, otters, and seals) need to surface periodically to breathe air.
, more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described.
Marine species range in size from the microscopic like phytoplankton, which can be as small as 0.02 micrometres, to huge cetaceans like the blue whale – the largest known animal, reaching in length. Marine microorganisms, including protists and bacteria and their associated viruses, have been var
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the two classifications for organisms living in water?
A. arctan and plankton
B. scharwenka and plankton
C. arctan and nekton
D. nekton and plankton
Answer:
|
|
sciq-5273
|
multiple_choice
|
What influence does the horizontal motion of a projectile have on free fall?
|
[
"increase acceleration",
"vertical",
"decrease acceleration",
"none"
] |
D
|
Relavent Documents:
Document 0:::
In physics, The Monkey and the Hunter is a hypothetical scenario often used to illustrate the effect of gravity on projectile motion. It can be presented as exercise problem or as a demonstration. No live monkeys are used in the demonstrations.
The essentials of the problem are stated in many introductory guides to physics. In essence, the problem is as follows: A hunter with a blowgun goes out in the woods to hunt for monkeys and sees one hanging in a tree. The monkey releases its grip the instant the hunter fires his blowgun. Where should the hunter aim in order to hit the monkey?
Discussion
To answer this question, recall that according to Galileo's law, all objects fall with the same constant acceleration of gravity (about 9.8 metres per second per second near the Earth's surface), regardless of the object's weight. Furthermore, horizontal motions and vertical motions are independent: gravity acts only upon an object's vertical velocity, not upon its velocity in the horizontal direction. The hunter's dart, therefore, falls with the same acceleration as the monkey.
Assume for the moment that gravity was not at work. In that case, the dart would proceed in a straight-line trajectory at a constant speed (Newton's first law). Gravity causes the dart to fall away from this straight-line path, making a trajectory that is in fact a parabola. Now, consider what happens if the hunter aims directly at the monkey, and the monkey releases his grip the instant the hunter fires. Because the force of gravity accelerates the dart and the monkey equally, they fall the same distance in the same time: the monkey falls from the tree branch, and the dart falls the same distance from the straight-line path it would have taken in the absence of gravity. Therefore, the dart will always hit the monkey, no matter the initial speed of the dart, no matter the acceleration of gravity.
Another way of looking at the problem is by a transformation of the reference frame. Earl
Document 1:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
In physics, a projectile launched with specific initial conditions will have a range. It may be more predictable assuming a flat Earth with a uniform gravity field, and no air resistance. The horizontal ranges of a projectile are equal for two complementary angles of projection with the same velocity.
The following applies for ranges which are small compared to the size of the Earth. For longer ranges see sub-orbital spaceflight. The maximum horizontal distance traveled by the projectile, neglecting air resistance, can be calculated as follows:
where
d is the total horizontal distance travelled by the projectile.
v is the velocity at which the projectile is launched
g is the gravitational acceleration—usually taken to be 9.81 m/s2 (32 f/s2) near the Earth's surface
θ is the angle at which the projectile is launched
y0 is the initial height of the projectile
If y0 is taken to be zero, meaning that the object is being launched on flat ground, the range of the projectile will simplify to:
Ideal projectile motion
Ideal projectile motion states that there is no air resistance and no change in gravitational acceleration. This assumption simplifies the mathematics greatly, and is a close approximation of actual projectile motion in cases where the distances travelled are small. Ideal projectile motion is also a good introduction to the topic before adding the complications of air resistance.
Derivations
A launch angle of 45 degrees displaces the projectile the farthest horizontally.
This is due to the nature of right triangles. Additionally, from the equation for the range :
We can see that the range will be maximum when the value of is the highest (i.e. when it is equal to 1).
Clearly, has to be 90 degrees. That is to say, is 45 degrees.
Flat ground
First we examine the case where (y0) is zero. The horizontal position of the projectile is
In the vertical direction
We are interested in the time when the projectile returns to the same height
Document 3:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 4:::
Advanced Placement (AP) Physics C: Mechanics (also known as AP Mechanics) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester calculus-based university course in mechanics. The content of Physics C: Mechanics overlaps with that of AP Physics 1, but Physics 1 is algebra-based, while Physics C is calculus-based. Physics C: Mechanics may be combined with its electricity and magnetism counterpart to form a year-long course that prepares for both exams.
Course content
Intended to be equivalent to an introductory college course in mechanics for physics or engineering majors, the course modules are:
Kinematics
Newton's laws of motion
Work, energy and power
Systems of particles and linear momentum
Circular motion and rotation
Oscillations and gravitation.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a Calculus I class.
This course is often compared to AP Physics 1: Algebra Based for its similar course material involving kinematics, work, motion, forces, rotation, and oscillations. However, AP Physics 1: Algebra Based lacks concepts found in Calculus I, like derivatives or integrals.
This course may be combined with AP Physics C: Electricity and Magnetism to make a unified Physics C course that prepares for both exams.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Mechanics is separate from the AP examination for AP Physics C: Electricity and Magnetism. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday aftern
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What influence does the horizontal motion of a projectile have on free fall?
A. increase acceleration
B. vertical
C. decrease acceleration
D. none
Answer:
|
|
sciq-3441
|
multiple_choice
|
What is liquid water falling from the sky called?
|
[
"rain",
"evaporation",
"snow",
"clouds"
] |
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:::
Evapotranspiration (ET) is the combined processes which move water from the Earth's surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in agricultural irrigation and water resource management.
Definition of evapotranspiration
Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evapotranspiration are:
Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, solar radiation and wind speed.
Transpiration: the movement of water from root systems, through a plant, and exit into the air as water vapor. This exit occurs through stomata in the plant. Rate of transpiration can be influenced by factors including plant type, soil type, weather conditions and water content, and also cultivation practices.
Evapotranspiration is typically measured in millimeters of water (i.e. volume of water moved per unit area of the Earth's surface) in a set unit of time. Globally, it is estimated that on average between three-fifths and three-quarters of land precipitation is returned to the atmosphere via evapotranspiration.
Evapotranspiration does not, in general, account for other mechanisms which are involved in returning water to the atmosphere, though some of these, such as snow and ice sublimation in regions of high elevation or high latitude, can make a large contribution to atmospheric moisture even under standard conditions.
Factors that impact evapotranspiration levels
Primary factors
Because evaporation and transpiration
Document 3:::
In fluid dynamics, a convection cell is the phenomenon that occurs when density differences exist within a body of liquid or gas. These density differences result in rising and/or falling convection currents, which are the key characteristics of a convection cell. When a volume of fluid is heated, it expands and becomes less dense and thus more buoyant than the surrounding fluid. The colder, denser part of the fluid descends to settle below the warmer, less-dense fluid, and this causes the warmer fluid to rise. Such movement is called convection, and the moving body of liquid is referred to as a convection cell. This particular type of convection, where a horizontal layer of fluid is heated from below, is known as Rayleigh–Bénard convection. Convection usually requires a gravitational field, but in microgravity experiments, thermal convection has been observed without gravitational effects.
Fluids are generalized as materials that exhibit the property of flow; however, this behavior is not unique to liquids. Fluid properties can also be observed in gases and even in particulate solids (such as sand, gravel, and larger objects during rock slides).
A convection cell is most notable in the formation of clouds with its release and transportation of energy. As air moves along the ground it absorbs heat, loses density and moves up into the atmosphere. When it is forced into the atmosphere, which has a lower air pressure, it cannot contain as much fluid as at a lower altitude, so it releases its moist air, producing rain. In this process the warm air is cooled; it gains density and falls towards the earth and the cell repeats the cycle.
Convection cells can form in any fluid, including the Earth's atmosphere (where they are called Hadley cells), boiling water, soup (where the cells can be identified by the particles they transport, such as grains of rice), the ocean, or the surface of the Sun. The size of convection cells is largely determined by the fluid's properties.
Document 4:::
At equilibrium, the relationship between water content and equilibrium relative humidity of a material can be displayed graphically by a curve, the so-called moisture sorption isotherm.
For each humidity value, a sorption isotherm indicates the corresponding water content value at a given, constant temperature. If the composition or quality of the material changes, then its sorption behaviour also changes. Because of the complexity of sorption process the isotherms cannot be determined explicitly by calculation, but must be recorded experimentally for each product.
The relationship between water content and water activity (aw) is complex. An increase in aw is usually accompanied by an increase in water content, but in a non-linear fashion. This relationship between water activity and moisture content at a given temperature is called the moisture sorption isotherm. These curves are determined experimentally and constitute the fingerprint of a food system.
BET theory (Brunauer-Emmett-Teller) provides a calculation to describe the physical adsorption of gas molecules on a solid surface. Because of the complexity of the process, these calculations are only moderately successful; however, Stephen Brunauer was able to classify sorption isotherms into five generalized shapes as shown in Figure 2. He found that Type II and Type III isotherms require highly porous materials or desiccants, with first monolayer adsorption, followed by multilayer adsorption and finally leading to capillary condensation, explaining these materials high moisture capacity at high relative humidity.
Care must be used in extracting data from isotherms, as the representation for each axis may vary in its designation. Brunauer provided the vertical axis as moles of gas adsorbed divided by the moles of the dry material, and on the horizontal axis he used the ratio of partial pressure of the gas just over the sample, divided by its partial pressure at saturation. More modern isotherms showing the
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is liquid water falling from the sky called?
A. rain
B. evaporation
C. snow
D. clouds
Answer:
|
|
sciq-5481
|
multiple_choice
|
What is the most dangerous type of radiation?
|
[
"gamma rays",
"beta rays",
"plasma rays",
"sunlight rays"
] |
A
|
Relavent Documents:
Document 0:::
absorbed dose
Electromagnetic radiation
equivalent dose
hormesis
Ionizing radiation
Louis Harold Gray (British physicist)
rad (unit)
radar
radar astronomy
radar cross section
radar detector
radar gun
radar jamming
(radar reflector) corner reflector
radar warning receiver
(Radarange) microwave oven
radiance
(radiant: see) meteor shower
radiation
Radiation absorption
Radiation acne
Radiation angle
radiant barrier
(radiation belt: see) Van Allen radiation belt
Radiation belt electron
Radiation belt model
Radiation Belt Storm Probes
radiation budget
Radiation burn
Radiation cancer
(radiation contamination) radioactive contamination
Radiation contingency
Radiation damage
Radiation damping
Radiation-dominated era
Radiation dose reconstruction
Radiation dosimeter
Radiation effect
radiant energy
Radiation enteropathy
(radiation exposure) radioactive contamination
Radiation flux
(radiation gauge: see) gauge fixing
radiation hardening
(radiant heat) thermal radiation
radiant heating
radiant intensity
radiation hormesis
radiation impedance
radiation implosion
Radiation-induced lung injury
Radiation Laboratory
radiation length
radiation mode
radiation oncologist
radiation pattern
radiation poisoning (radiation sickness)
radiation pressure
radiation protection (radiation shield) (radiation shielding)
radiation resistance
Radiation Safety Officer
radiation scattering
radiation therapist
radiation therapy (radiotherapy)
(radiation treatment) radiation therapy
(radiation units: see) :Category:Units of radiation dose
(radiation weight factor: see) equivalent dose
radiation zone
radiative cooling
radiative forcing
radiator
radio
(radio amateur: see) amateur radio
(radio antenna) antenna (radio)
radio astronomy
radio beacon
(radio broadcasting: see) broadcasting
radio clock
(radio communications) radio
radio control
radio controlled airplane
radio controlled car
radio-controlled helicopter
radio control
Document 1:::
Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation.
Cells types affected
Cells are least sensitive when in the S phase, then the G1 phase, then the G2 phase, and most sensitive in the M phase of the cell cycle. This is described by the 'law of Bergonié and Tribondeau', formulated in 1906: X-rays are more effective on cells which have a greater reproductive activity.
From their observations, they concluded that quickly dividing tumor cells are generally more sensitive than the majority of body cells. This is not always true. Tumor cells can be hypoxic and therefore less sensitive to X-rays because most of their effects are mediated by the free radicals produced by ionizing oxygen.
It has meanwhile been shown that the most sensitive cells are those that are undifferentiated, well nourished, dividing quickly and highly active metabolically. Amongst the body cells, the most sensitive are spermatogonia and erythroblasts, epidermal stem cells, gastrointestinal stem cells. The least sensitive are nerve cells and muscle fibers.
Very sensitive cells are also oocytes and lymphocytes, although they are resting cells and do not meet the criteria described above. The reasons for their sensitivity are not clear.
There also appears to be a genetic basis for the varied vulnerability of cells to ionizing radiation. This has been demonstrated across several cancer types and in normal tissues.
Cell damage classification
The damage to the cell can be lethal (the cell dies) or sublethal (the cell can repair itself). Cell damage can ultimately lead to health effects which can be classified as either Tissue Reactions or Stochastic Effects according to the International Commission on Radiological Protection.
Tissue reactions
Tissue reactions have a threshold of irradiation under which they do not appear and above which they typically appear. Fractionation of dose, dose rate, the application of antioxidan
Document 2:::
Radiation sensitivity is the susceptibility of a material to physical or chemical changes induced by radiation. Examples of radiation sensitive materials are silver chloride, photoresists and biomaterials. Pine trees are more radiation susceptible than birch due to the complexity of the pine DNA in comparison to the birch. Examples of radiation insensitive materials are metals and ionic crystals such as quartz and sapphire. The radiation effect depends on the type of the irradiating particles, their energy, and the number of incident particles per unit volume. Radiation effects can be transient or permanent. The persistence of the radiation effect depends on the stability of the induced physical and chemical change. Physical radiation effects depending on diffusion properties can be thermally annealed whereby the original structure of the material is recovered. Chemical radiation effects usually cannot be recovered.
Document 3:::
Radiation Effects and Defects in Solids is a peer-reviewed scientific journal that was established in 1969 as Radiation Effects. It obtained its current title in 1989 and
covers radiation effects and phenomena induced by the interaction of all types of radiation with condensed matter: radiation physics, radiation chemistry, radiobiology, and physical effects of medical irradiation, including research on radiative cell degeneration, optical, electrical and mechanical effects of radiation, and their secondary effects such as diffusion and particle emission from surfaces, plasma techniques, and plasma phenomena. It is published monthly by Taylor & Francis.
External links
Monthly journals
Taylor & Francis academic journals
Physics journals
Academic journals established in 1969
English-language journals
Document 4:::
Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule. Instead of producing charged ions when passing through matter, non-ionizing electromagnetic radiation has sufficient energy only for excitation (the movement of an electron to a higher energy state). Non-ionizing radiation is not a significant health risk. In contrast, ionizing radiation has a higher frequency and shorter wavelength than non-ionizing radiation, and can be a serious health hazard: exposure to it can cause burns, radiation sickness, many kinds of cancer, and genetic damage. Using ionizing radiation requires elaborate radiological protection measures, which in general are not required with non-ionizing radiation.
The region at which radiation is considered "ionizing" is not well defined, since different molecules and atoms ionize at different energies. The usual definitions have suggested that radiation with particle or photon energies less than 10 electronvolts (eV) be considered non-ionizing. Another suggested threshold is 33 electronvolts, which is the energy needed to ionize water molecules. The light from the Sun that reaches the earth is largely composed of non-ionizing radiation, since the ionizing far-ultraviolet rays have been filtered out by the gases in the atmosphere, particularly oxygen. The remaining ultraviolet radiation from the Sun causes molecular damage (for example, sunburn) by photochemical and free-radical-producing means.
Mechanisms of interaction with matter, including living tissue
Near ultraviolet, visible light, infrared, microwave, radio waves, and low-frequency radio frequency (longwave) are all examples of non-ionizing radiation. By contrast, far ultraviolet light, X-rays, gamma-rays, and all particle radiation from radioactive decay are ionizing. Visible and near ultraviolet e
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the most dangerous type of radiation?
A. gamma rays
B. beta rays
C. plasma rays
D. sunlight rays
Answer:
|
|
ai2_arc-649
|
multiple_choice
|
After a forest fire, which type of organisms will begin secondary succession?
|
[
"small shrubs",
"mature oaks",
"evergreens",
"wildflowers"
] |
D
|
Relavent Documents:
Document 0:::
Secondary succession is the secondary ecological succession of a plant's life. As opposed to the first, primary succession, secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane, etc.) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. Many factors can affect secondary succession, such as trophic interaction, initial composition, and competition-colonization trade-offs. The factors that control the increase in abundance of a species during succession may be determined mainly by seed production and dispersal, micro climate; landscape structure (habitat patch size and distance to outside seed sources); bulk density, pH, and soil texture (sand and clay).
Secondary succession is the ecological succession that occurs after the initial succession has been disrupted and some plants and animals still exist. It is usually faster than primary succession as soil is already present, and seeds, roots, and the underground vegetative organs of plants may still survive in the soil.
Examples
Imperata
Imperata grasslands are caused by human activities such as logging, forest clearing for shifting cultivation, agriculture and grazing, and also by frequent fires. The latter is a frequent result of human interference. However, when not maintained by frequent fires and human disturbances, they regenerate naturally and speedily to secondary young forest. The time of succession in Imperata grassland (for example in Samboja Lestari area), Imperata cylindrica has the highest coverage but it becomes less dominant from the fourth year onwards. While Imperata decreases, the percentage of shrubs and young trees clearly increases with time. In the burned plots, Melastoma malabathricum, Eupatorium inulaefolium, Ficus sp., and Vitex pinnata. strongly increase with
Document 1:::
Primary succession is the beginning step of ecological succession after an extreme disturbance, which usually occurs in an environment devoid of vegetation and other organisms. These environments are typically lacking in soil, as disturbances like lava flow or retreating glaciers scour the environment clear of nutrients.
In contrast, secondary succession occurs on substrates that previously supported vegetation before an ecological disturbance. This occurs when smaller disturbances like floods, hurricanes, tornadoes, and fires destroy only the local plant life and leave soil nutrients for immediate establishment by intermediate community species.
Occurrence
In primary succession pioneer species like lichen, algae and fungi as well as abiotic factors like wind and water start to "normalise" the habitat or in other words start to develop soil and other important mechanisms for greater diversity to flourish. Primary succession begins on rock formations, such as volcanoes or mountains, or in a place with no organisms or soil. Primary succession leads to conditions nearer optimum for vascular plant growth; pedogenesis or the formation of soil, and the increased amount of shade are the most important processes.
These pioneer lichen, algae, and fungi are then dominated and often replaced by plants that are better adapted to less harsh conditions, these plants include vascular plants like grasses and some shrubs that are able to live in thin soils that are often mineral-based. Water and nutrient levels increase with the amount of succession exhibited.
The early stages of primary succession are dominated by species with small propagules (seed and spores) which can be dispersed long distances. The early colonizers—often algae, fungi, and lichens—stabilize the substrate. Nitrogen supplies are limited in new soils, and nitrogen-fixing species tend to play an important role early in primary succession. Unlike in primary succession, the species that dominate secondary success
Document 2:::
The relationships between fire, vegetation, and climate create what is known as a fire regime. Within a fire regime, fire ecologists study the relationship between diverse ecosystems and fire; not only how fire affects vegetation, but also how vegetation affects the behavior of fire. The study of neighboring vegetation types that may be highly flammable and less flammable has provided insight into how these vegetation types can exist side by side, and are maintained by the presence or absence of fire events. Ecologists have studied these boundaries between different vegetation types, such as a closed canopy forest and a grassland, and hypothesized about how climate and soil fertility create these boundaries in vegetation types. Research in the field of pyrogeography shows how fire also plays an important role in the maintenance of dominant vegetation types, and how different vegetation types with distinct relationships to fire can exist side by side in the same climate conditions. These relationships can be described in conceptual models called fire–vegetation feedbacks, and alternative stable states.
Fire–vegetation feedbacks
Vegetation can be understood as highly flammable (pyrophilic) and less flammable (pyrophobic). A fire–vegetation feedback describes the relationship between fire and the dominant vegetation type. An example of a highly flammable vegetation type is a grassland. Frequent fire will maintain grassland as the dominant vegetation in a positive feedback loop. This happens because frequent fire will kill trees trying to establish in the area, yet the intervals between each fire will allow for new grasses to establish, grow into fuel, and burn again. Therefore, frequent fire on a grassland area will maintain grass as the dominant vegetation and not permit the encroachment of trees. In contrast, fire will occur less frequently and less severely in closed canopy forests because the fuels are more dense, shaded, and therefore more humid thereby not ign
Document 3:::
Fire ecology is a scientific discipline concerned with the effects of fire on natural ecosystems. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them.
Wildfire suppression campaigns in the United States have historically molded public opinion to believe that wildfires are harmful to nature. Ecological research has shown, however, that fire is an integral component in the function and biodiversity of many natural habitats, and that the organisms within these communities have adapted to withstand, and even to exploit, natural wildfire. More generally, fire is now regarded as a 'natural disturbance', similar to flooding, windstorms, and landslides, that has driven the evolution of species and controls the characteristics of ecosystems.
Fire suppression, in combination with other human-caused environmental changes, may have resulted in unforeseen consequences for natural ecosystems. Some large wildfires in the United States have been blamed on years of fire suppression and the continuing expansion of people into fire-adapted ecosystems as well as climate change. Land managers are faced with tough questions regarding how to restore a natural fire regime, but allowing wildfires to burn is likely the least expensive and most effective method in many situations.
History
Fire has played a major role in shaping the world's vegetation. The biological process of photosynthesis began to concentrate the atmospheric oxygen needed for combustion during the Devonian approximately 350 million years ago. Then, approximately 125 million years ago, fire began to influence the habitat of land plants.
In the 20th century ecologist Charles Cooper made a plea for fire as an eco
Document 4:::
A secondary forest (or second-growth forest) is a forest or woodland area which has regenerated through largely natural processes after human-caused disturbances, such as timber harvest or agriculture clearing, or equivalently disruptive natural phenomena. It is distinguished from an old-growth forest (primary or primeval forest), which has not recently undergone such disruption, and complex early seral forest, as well as third-growth forests that result from harvest in second growth forests. Secondary forest regrowing after timber harvest differs from forest regrowing after natural disturbances such as fire, insect infestation, or windthrow because the dead trees remain to provide nutrients, structure, and water retention after natural disturbances. Secondary forests are notably different from primary forests in their composition and biodiversity; however, they may still be helpful in providing habitat for native species, preserving watersheds, and restoring connectivity between ecosystems.
Development
Secondary forestation is common in areas where forests have been degraded or destroyed by agriculture or timber harvesting; this includes abandoned pastures or fields that were once forests. Additionally, secondary forestation can be seen in regions where forests have been lost by the slash-and-burn method, a component of some shifting cultivation systems of agriculture. While many definitions of secondary forests limit the cause of degradation to human activities, other definitions include forests that experienced similar degradation under natural phenomena like fires or landslides.
Secondary forests re-establish by the process of succession. Openings created in the forest canopy allow sunlight to reach the forest floor. An area that has been cleared will first be colonized by pioneer species, followed by shrubs and bushes. Over time, trees that were characteristic of the original forest begin to dominate the forest again. It typically takes a secondary forest 40
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
After a forest fire, which type of organisms will begin secondary succession?
A. small shrubs
B. mature oaks
C. evergreens
D. wildflowers
Answer:
|
|
sciq-8703
|
multiple_choice
|
What part of the sperm contains the genetic material?
|
[
"the \" body \"",
"the \" brain \"",
"the \" tail \"",
"the \"head\""
] |
D
|
Relavent Documents:
Document 0:::
The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.
Animals
In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable sexually transmitted diseases.
Most other vertebrates have similar reproductive systems consisting of gonads, ducts, and openings. However, there is a great diversity of physical adaptations as well as reproductive strategies in every group of vertebrates.
Vertebrates
Vertebrates share key elements of their reproductive systems. They all have gamete-producing organs known as gonads. In females, these gonads are then connected by oviducts to an opening to the outside of the body, typically the cloaca, but sometimes to a unique pore such as a vagina or intromittent organ.
Humans
The human reproductive system usually involves internal fertilization by sexual intercourse. During this process, the male inserts their erect penis into the female's vagina and ejaculates semen, which contains sperm. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum. Upon successful fertilization and implantation, gestation of the fetus then occurs within the female's uterus for approximately nine months, this process is known as pregnancy in humans. Gestati
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:::
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:::
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid cells.
Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion. Spermatogenesis is highly dependent upon optimal conditions for the process to occur correctly, and is essential for sexual reproduction. DNA methylation and histone modification have been implicated in the regulation of this process. It starts during puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age (see Male infertility).
Spermatogenesis starts in the bottom part of seminiferous tubes and, progressively, cells go deeper into tubes and moving along it until mature spermatozoa reaches the lumen, where mature spermatozoa are deposited. The division happens asynchronically; if the tube is cut transversally one could observe different
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What part of the sperm contains the genetic material?
A. the " body "
B. the " brain "
C. the " tail "
D. the "head"
Answer:
|
|
ai2_arc-1108
|
multiple_choice
|
Which adaptation often helps an animal attract a mate?
|
[
"hibernation",
"camouflage",
"coloration",
"migration"
] |
C
|
Relavent Documents:
Document 0:::
Communication occurs when an animal produces a signal and uses it to influences the behaviour of another animal. A signal can be any behavioural, structural or physiological trait that has evolved specifically to carry information about the sender and/or the external environment and to stimulate the sensory system of the receiver to change their behaviour. A signal is different from a cue in that cues are informational traits that have not been selected for communication purposes. For example, if an alerted bird gives a warning call to a predator and causes the predator to give up the hunt, the bird is using the sound as a signal to communicate its awareness to the predator. On the other hand, if a rat forages in the leaves and makes a sound that attracts a predator, the sound itself is a cue and the interaction is not considered a communication attempt.
Air and water have different physical properties which lead to different velocity and clarity of the signal transmission process during communication. This means that common understanding of communication mechanisms and structures of terrestrial animals cannot be applied to aquatic animals. For example, a horse can sniff the air to detect pheromones but a fish which is surrounded by water will need a different method to detect chemicals.
Aquatic animals can communicate through various signal modalities including visual, auditory, tactile, chemical and electrical signals. Communication using any of these forms requires specialised signal producing and detecting organs. Thus, the structure, distribution and mechanism of these sensory systems vary amongst different classes and species of aquatic animals and they also differ greatly to those of terrestrial animals.
The basic functions of communication in aquatic animals are similar to those of terrestrial animals. In general, communication can be used to facilitate social recognition and aggregation, to locate, attract and evaluate mating partners and to engage in te
Document 1:::
Animal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migration in ecology. It is found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The cause of migration may be local climate, local availability of food, the season of the year or for mating.
To be counted as a true migration, and not just a local dispersal or irruption, the movement of the animals should be an annual or seasonal occurrence, or a major habitat change as part of their life. An annual event could include Northern Hemisphere birds migrating south for the winter, or wildebeest migrating annually for seasonal grazing. A major habitat change could include young Atlantic salmon or sea lamprey leaving the river of their birth when they have reached a few inches in size. Some traditional forms of human migration fit this pattern.
Migrations can be studied using traditional identification tags such as bird rings, or tracked directly with electronic tracking devices.
Before animal migration was understood, folklore explanations were formulated for the appearance and disappearance of some species, such as that barnacle geese grew from goose barnacles.
Overview
Concepts
Migration can take very different forms in different species, and has a variety of causes.
As such, there is no simple accepted definition of migration. One of the most commonly used definitions, proposed by the zoologist J. S. Kennedy is
Migration encompasses four related concepts: persistent straight movement; relocation of an individual on a greater scale (in both space and time) than its normal daily activities; seasonal to-and-fro movement of a population between two areas; and movement leading to the redistribution of individuals within a population. Migration can be either obligate, meaning individuals must migrate, or facultative, meaning individuals can "choose" to migrate or not. Wi
Document 2:::
The Tinbergen Lecture is an academic prize lecture awarded by the Association for the Study of Animal Behaviour (ASAB).
Lecturers
1974 W.H. Thorpe
1975 G.P. Baerends
1976 J. Maynard Smith
1977 F. Huber
1978 R.A. Hinde
1979 J. Bowlby
1980 W.D. Hamilton
1981 S.J. Gould
1982 H. Kummer
1983 Jörg-Peter Ewert
1984 Frank A. Beach
1985 Peter Marler
1986 Jürgen Aschoff
1987 Aubrey Manning
1988 Stephen T. Emlen
1989 P.P.G. Bateson
1990 J.D. Delius
1991 John R. Krebs
1992 E. Curio
1993 Linda Partridge
1994 Fernando Nottebohm
1995 G.A. Parker
1996 Serge Daan
1997 N.B. Davies
1998 Michael Land
1999 Bert Hölldobler
2000 Richard Dawkins
2001 Felicity Huntingford
2002 Marian Dawkins
2003 Tim Clutton-Brock
2004 Tim Birkhead
2005 P.K. McGregor
2006 Pat Monaghan
2007 M. Kirkpatrick
2008 Peter Slater
2009
2010 Laurent Keller
2011 Cancelled
2012 A Cockburn
2013 Marlene Zuk
2014 Innes Cuthill
2015 Nina Wedell
2016 Alex Kacelnik
2017 Christine Nicol
2018 Bart Kempenaers
2019 Rebecca Kilner
2020 Lars Chittka
Document 3:::
Molly R. Morris is an American behavioral ecologist who has worked with treefrogs and swordtail fishes in the areas of alternative reproductive tactics and sexual selection.
Morris received a Bachelor of Arts from Earlham College and a PhD from Indiana University. As a National Science Foundation postdoctoral fellow at the University of Texas at Austin, her work with Mike Ryan demonstrated equal fitnesses between alternative reproductive tactics in a species of swordtail fish. She joined the faculty at Ohio University in 1997, where she is now a professor in the Department of Biological Sciences. She is also the Associate Editor for the journal Behavior. Her publication credits include multiple papers on Animal behavior and Ecology. Her current research relates to diabetes, as well as behavioral ecology, using the swordtail fish Xiphophorus as a model organism.
Personal life
Morris is married to Kevin de Queiroz, an evolutionary biologist at the Smithsonian Institution's National Museum of Natural History.
Selected works
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.
Which adaptation often helps an animal attract a mate?
A. hibernation
B. camouflage
C. coloration
D. migration
Answer:
|
|
sciq-5587
|
multiple_choice
|
The entropy change is positive as the solid state changes into which state?
|
[
"liquid",
"gas",
"chemical",
"mixture"
] |
A
|
Relavent Documents:
Document 0:::
In thermodynamics, the heat capacity at constant volume, , and the heat capacity at constant pressure, , are extensive properties that have the magnitude of energy divided by temperature.
Relations
The laws of thermodynamics imply the following relations between these two heat capacities (Gaskell 2003:23):
Here is the thermal expansion coefficient:
is the isothermal compressibility (the inverse of the bulk modulus):
and is the isentropic compressibility:
A corresponding expression for the difference in specific heat capacities (intensive properties) at constant volume and constant pressure is:
where ρ is the density of the substance under the applicable conditions.
The corresponding expression for the ratio of specific heat capacities remains the same since the thermodynamic system size-dependent quantities, whether on a per mass or per mole basis, cancel out in the ratio because specific heat capacities are intensive properties. Thus:
The difference relation allows one to obtain the heat capacity for solids at constant volume which is not readily measured in terms of quantities that are more easily measured. The ratio relation allows one to express the isentropic compressibility in terms of the heat capacity ratio.
Derivation
If an infinitesimally small amount of heat is supplied to a system in a reversible way then, according to the second law of thermodynamics, the entropy change of the system is given by:
Since
where C is the heat capacity, it follows that:
The heat capacity depends on how the external variables of the system are changed when the heat is supplied. If the only external variable of the system is the volume, then we can write:
From this follows:
Expressing dS in terms of dT and dP similarly as above leads to the expression:
One can find the above expression for by expressing dV in terms of dP and dT in the above expression for dS.
results in
and it follows:
Therefore,
The partial derivative can be rewritten in terms of va
Document 1:::
In thermodynamics, the entropy of mixing is the increase in the total entropy when several initially separate systems of different composition, each in a thermodynamic state of internal equilibrium, are mixed without chemical reaction by the thermodynamic operation of removal of impermeable partition(s) between them, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new unpartitioned closed system.
In general, the mixing may be constrained to occur under various prescribed conditions. In the customarily prescribed conditions, the materials are each initially at a common temperature and pressure, and the new system may change its volume, while being maintained at that same constant temperature, pressure, and chemical component masses. The volume available for each material to explore is increased, from that of its initially separate compartment, to the total common final volume. The final volume need not be the sum of the initially separate volumes, so that work can be done on or by the new closed system during the process of mixing, as well as heat being transferred to or from the surroundings, because of the maintenance of constant pressure and temperature.
The internal energy of the new closed system is equal to the sum of the internal energies of the initially separate systems. The reference values for the internal energies should be specified in a way that is constrained to make this so, maintaining also that the internal energies are respectively proportional to the masses of the systems.
For concision in this article, the term 'ideal material' is used to refer to either an ideal gas (mixture) or an ideal solution.
In the special case of mixing ideal materials, the final common volume is in fact the sum of the initial separate compartment volumes. There is no heat transfer and no work is done. The entropy of mixing is entirely accounted for by the diffusive expansion of each material into a final volume not in
Document 2:::
In chemistry, the standard molar entropy is the entropy content of one mole of pure substance at a standard state of pressure and any temperature of interest. These are often (but not necessarily) chosen to be the standard temperature and pressure.
The standard molar entropy at pressure = is usually given the symbol , and has units of joules per mole per kelvin (J⋅mol−1⋅K−1). Unlike standard enthalpies of formation, the value of is absolute. That is, an element in its standard state has a definite, nonzero value of at room temperature. The entropy of a pure crystalline structure can be 0J⋅mol−1⋅K−1 only at 0K, according to the third law of thermodynamics. However, this assumes that the material forms a 'perfect crystal' without any residual entropy. This can be due to crystallographic defects, dislocations, and/or incomplete rotational quenching within the solid, as originally pointed out by Linus Pauling. These contributions to the entropy are always present, because crystals always grow at a finite rate and at temperature. However, the residual entropy is often quite negligible and can be accounted for when it occurs using statistical mechanics.
Thermodynamics
If a mole of a solid substance is a perfectly ordered solid at 0K, then if the solid is warmed by its surroundings to 298.15K without melting, its absolute molar entropy would be the sum of a series of stepwise and reversible entropy changes. The limit of this sum as becomes an integral:
In this example, and is the molar heat capacity at a constant pressure of the substance in the reversible process . The molar heat capacity is not constant during the experiment because it changes depending on the (increasing) temperature of the substance. Therefore, a table of values for is required to find the total molar entropy. The quantity
represents the ratio of a very small exchange of heat energy to the temperature . The total molar entropy is the sum of many small changes in molar entropy, where each sm
Document 3:::
In the thermodynamics of equilibrium, a state function, function of state, or point function for a thermodynamic system is a mathematical function relating several state variables or state quantities (that describe equilibrium states of a system) that depend only on the current equilibrium thermodynamic state of the system (e.g. gas, liquid, solid, crystal, or emulsion), not the path which the system has taken to reach that state. A state function describes equilibrium states of a system, thus also describing the type of system. A state variable is typically a state function so the determination of other state variable values at an equilibrium state also determines the value of the state variable as the state function at that state. The ideal gas law is a good example. In this law, one state variable (e.g., pressure, volume, temperature, or the amount of substance in a gaseous equilibrium system) is a function of other state variables so is regarded as a state function. A state function could also describe the number of a certain type of atoms or molecules in a gaseous, liquid, or solid form in a heterogeneous or homogeneous mixture, or the amount of energy required to create such a system or change the system into a different equilibrium state.
Internal energy, enthalpy, and entropy are examples of state quantities or state functions because they quantitatively describe an equilibrium state of a thermodynamic system, regardless of how the system has arrived in that state. In contrast, mechanical work and heat are process quantities or path functions because their values depend on a specific "transition" (or "path") between two equilibrium states that a system has taken to reach the final equilibrium state. Heat (in certain discrete amounts) can describe a state function such as enthalpy, but in general, does not truly describe the system unless it is defined as the state function of a certain system, and thus enthalpy is described by an amount of heat. This can al
Document 4:::
In classical thermodynamics, entropy () is a property of a thermodynamic system that expresses the direction or outcome of spontaneous changes in the system. The term was introduced by Rudolf Clausius in the mid-19th century to explain the relationship of the internal energy that is available or unavailable for transformations in form of heat and work. Entropy predicts that certain processes are irreversible or impossible, despite not violating the conservation of energy. The definition of entropy is central to the establishment of the second law of thermodynamics, which states that the entropy of isolated systems cannot decrease with time, as they always tend to arrive at a state of thermodynamic equilibrium, where the entropy is highest. Entropy is therefore also considered to be a measure of disorder in the system.
Ludwig Boltzmann explained the entropy as a measure of the number of possible microscopic configurations of the individual atoms and molecules of the system (microstates) which correspond to the macroscopic state (macrostate) of the system. He showed that the thermodynamic entropy is , where the factor has since been known as the Boltzmann constant.
Concept
Differences in pressure, density, and temperature of a thermodynamic system tend to equalize over time. For example, in a room containing a glass of melting ice, the difference in temperature between the warm room and the cold glass of ice and water is equalized by energy flowing as heat from the room to the cooler ice and water mixture. Over time, the temperature of the glass and its contents and the temperature of the room achieve a balance. The entropy of the room has decreased. However, the entropy of the glass of ice and water has increased more than the entropy of the room has decreased. In an isolated system, such as the room and ice water taken together, the dispersal of energy from warmer to cooler regions always results in a net increase in entropy. Thus, when the system of the room
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The entropy change is positive as the solid state changes into which state?
A. liquid
B. gas
C. chemical
D. mixture
Answer:
|
|
sciq-2488
|
multiple_choice
|
Where does cellular respiration occur?
|
[
"Golgi apparatus",
"nucleus",
"chloroplasts",
"mitochondria"
] |
D
|
Relavent Documents:
Document 0:::
Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term physiology refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show similarities in their functions even though they vary in structure.
General characteristics
There are two types of cells: prokaryotes and eukaryotes.
Prokaryotes were the first of the two to develop and do not have a self-contained nucleus. Their mechanisms are simpler than later-evolved eukaryotes, which contain a nucleus that envelops the cell's DNA and some organelles.
Prokaryotes
Prokaryotes have DNA located in an area called the nucleoid, which is not separated from other parts of the cell by a membrane. There are two domains of prokaryotes: bacteria and archaea. Prokaryotes have fewer organelles than eukaryotes. Both have plasma membranes and ribosomes (structures that synthesize proteins and float free in cytoplasm). Two unique characteristics of prokaryotes are fimbriae (finger-like projections on the surface of a cell) and flagella (threadlike structures that aid movement).
Eukaryotes
Eukaryotes have a nucleus where DNA is contained. They are usually larger than prokaryotes and contain many more organelles. The nucleus, the feature of a eukaryote that distinguishes it from a prokaryote, contains a nuclear envelope, nucleolus and chromatin. In cytoplasm, endoplasmic reticulum (ER) synthesizes membranes and performs other metabolic activities. There are two types, rough ER (containing ribosomes) and smooth ER (lacking ribosomes). The Golgi apparatus consists of multiple membranous sacs, responsible for manufacturing and shipping out materials such as proteins. Lysosomes are structures that use enzymes to break down substances through phagocytosis, a process that comprises endocytosis and exocytosis. In the mitochondria, metabolic processes such as cellular respiration occur. The cytoskeleton is made of fibers that support the str
Document 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
Document 2:::
Cellular compartments in cell biology comprise all of the closed parts within the cytosol of a eukaryotic cell, usually surrounded by a single or double lipid layer membrane. These compartments are often, but not always, defined as membrane-bound organelles. The formation of cellular compartments is called compartmentalization.
Both organelles, the mitochondria and chloroplasts (in photosynthetic organisms), are compartments that are believed to be of endosymbiotic origin. Other compartments such as peroxisomes, lysosomes, the endoplasmic reticulum, the cell nucleus or the Golgi apparatus are not of endosymbiotic origin. Smaller elements like vesicles, and sometimes even microtubules can also be counted as compartments.
It was thought that compartmentalization is not found in prokaryotic cells., but the discovery of carboxysomes and many other metabolosomes revealed that prokaryotic cells are capable of making compartmentalized structures, albeit these are in most cases not surrounded by a lipid bilayer, but of pure proteinaceous built.
Types
In general there are 4 main cellular compartments, they are:
The nuclear compartment comprising the nucleus
The intercisternal space which comprises the space between the membranes of the endoplasmic reticulum (which is continuous with the nuclear envelope)
Organelles (the mitochondrion in all eukaryotes and the plastid in phototrophic eukaryotes)
The cytosol
Function
Compartments have three main roles. One is to establish physical boundaries for biological processes that enables the cell to carry out different metabolic activities at the same time. This may include keeping certain biomolecules within a region, or keeping other molecules outside. Within the membrane-bound compartments, different intracellular pH, different enzyme systems, and other differences are isolated from other organelles and cytosol. With mitochondria, the cytosol has an oxidizing environment which converts NADH to NAD+. With these cases, the
Document 3:::
Cellular respiration is the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into ATP, and then release waste products.
Cellular respiration is a vital process that happens in the cells of living organisms, including humans, plants, and animals. It's how cells produce energy to power all the activities necessary for life.
The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, producing large amounts of energy (ATP). Respiration is one of the key ways a cell releases chemical energy to fuel cellular activity. The overall reaction occurs in a series of biochemical steps, some of which are redox reactions. Although cellular respiration is technically a combustion reaction, it is an unusual one because of the slow, controlled release of energy from the series of reactions.
Nutrients that are commonly used by animal and plant cells in respiration include sugar, amino acids and fatty acids, and the most common oxidizing agent is molecular oxygen (O2). The chemical energy stored in ATP (the bond of its third phosphate group to the rest of the molecule can be broken allowing more stable products to form, thereby releasing energy for use by the cell) can then be used to drive processes requiring energy, including biosynthesis, locomotion or transportation of molecules across cell membranes.
Aerobic respiration
Aerobic respiration requires oxygen (O2) in order to create ATP. Although carbohydrates, fats and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate to the mitochondria in order to be fully oxidized by the c
Document 4:::
The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane, and contains many macromolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites. The term comes from the Latin word meaning 'small room'.
Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell.
Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms.
The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology.
Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
Discovery
With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as i
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Where does cellular respiration occur?
A. Golgi apparatus
B. nucleus
C. chloroplasts
D. mitochondria
Answer:
|
|
ai2_arc-614
|
multiple_choice
|
Animals may fight, make threatening sounds, and act aggressively toward members of the same species. These behaviors usually occur as the result of
|
[
"competition",
"conservation",
"decomposition",
"pollution"
] |
B
|
Relavent Documents:
Document 0:::
Agonism is a broad term which encompasses many behaviours that result from, or are triggered by biological conflict between competing organisms. Approximately 23 shark species are capable of producing such displays when threatened by intraspecific or interspecific competitors, as an evolutionary strategy to avoid unnecessary combat. The behavioural, postural, social and kinetic elements which comprise this complex, ritualized display can be easily distinguished from normal, or non-display behaviour, considered typical of that species' life history. The display itself confers pertinent information to the foe regarding the displayer's physical fitness, body size, inborn biological weaponry, confidence and determination to fight. This behaviour is advantageous because it is much less biologically taxing for an individual to display its intention to fight than the injuries it would sustain during conflict, which is why agonistic displays have been reinforced through evolutionary time, as an adaptation to personal fitness. Agonistic displays are essential to the social dynamics of many biological taxa, extending far beyond sharks.
Characteristics
Definition
Agonistic displays are ritualized sequences of actions, produced by animals belonging to almost all biological taxa, in response to conflict with other organisms. If challenged or threatened, animals may employ a suite of adaptive behaviours, which are used to reinforce the chances of their own survival. Behaviours which arise from agonistic conflict include:
fight or flight response
threat display to warn competitors and signal honest intentions
defence behaviour
simulated paralysis
avoidance behaviour
withdrawal
settling behaviour.
Each of these listed strategies constitute some manifestation of agonistic behaviour, and have been observed in numerous shark species, among many higher taxa in Kingdom Animalia. Displays of this nature are influenced and reinforced by natural selection, as an optimal strategy for
Document 1:::
Horse behavior is best understood from the view that horses are prey animals with a well-developed fight-or-flight response. Their first reaction to a threat is often to flee, although sometimes they stand their ground and defend themselves or their offspring in cases where flight is untenable, such as when a foal would be threatened.
Nonetheless, because of their physiology horses are also suited to a number of work and entertainment-related tasks. Humans domesticated horses thousands of years ago, and they have been used by humans ever since. Through selective breeding, some breeds of horses have been bred to be quite docile, particularly certain large draft horses. On the other hand, most light horse riding breeds were developed for speed, agility, alertness, and endurance; building on natural qualities that extended from their wild ancestors.
Horses' instincts can be used to human advantage to create a bond between human and horse. These techniques vary, but are part of the art of horse training.
The "fight-or-flight" response
Horses evolved from small mammals whose survival depended on their ability to flee from predators (for example: wolves, big cats, bears). This survival mechanism still exists in the modern domestic horse. Humans have removed many predators from the life of the domestic horse; however, its first instinct when frightened is to escape. If running is not possible, the horse resorts to biting, kicking, striking or rearing to protect itself. Many of the horse's natural behavior patterns, such as herd-formation and social facilitation of activities, are directly related to their being a prey species.
The fight-or-flight response involves nervous impulses which result in hormone secretions into the bloodstream. When a horse reacts to a threat, it may initially "freeze" in preparation to take flight. The fight-or-flight reaction begins in the amygdala, which triggers a neural response in the hypothalamus. The initial reaction is followed b
Document 2:::
Cats and dogs have a range of interactions. The natural instincts of each species lead towards antagonistic interactions, though individual animals can have non-aggressive relationships with each other, particularly under conditions where humans have socialized non-aggressive behaviors.
The generally aggressive interactions between the species have been noted in cultural expressions. In domestic homes where dog and cat are reared and trained properly, they tend to relate well with each other, especially when their owner is taking good care of them.
Range of relationships
The signals and behaviors that cats and dogs use to communicate are different and can lead to signals of aggression, fear, dominance, friendship or territoriality being misinterpreted by the other species. Dogs have a natural instinct to chase smaller animals that flee, an instinct common among cats. Most cats flee from a dog, while others take actions such as hissing, arching their backs and swiping at the dog. After being scratched by a cat, most dogs will become fearful of cats.
If appropriately socialized, cats and dogs may have relationships that are not antagonistic, and dogs raised with cats may prefer the presence of cats to other dogs. Even cats and dogs in the same household that have historically had positive interactions may revert to aggressive reactions due to external stimuli, illness, or play that escalates and could eventually be harmful.
Cultural impact
The phrase "fight like cats and dogs" reflects a natural tendency for the relationship between the two species to be antagonistic. Other phrases and proverbs include "The cat is mighty dignified until the dog comes by" and "The cat and dog may kiss, but are none the better friends."
Eugene Field's children's poem, "The Duel," projects and amplifies the real-life antipathy between cats and dogs onto a stuffed gingham dog and a stuffed calico cat who had an all-night fight during which they "ate each other up."
In Fam Ekman's
Document 3:::
Animals have many different tactics for defending themselves, depending on the severity of the threat they are encountering. Stages of threat vary along a spectrum referred to as the "predatory imminence continuum", spanning from low-risk (pre-encounter) to high-risk (interaction) threats. The main assumption of the predatory imminence continuum is that as threat levels increase, defensive response strategies change. During the pre-encounter period, an animal may engage in activities like exploration or foraging. But if the animal senses that a predator is nearby, the animal may begin to express species specific defense reactions such as freezing in an attempt to avoid detection by the predator. However, in situations where a threat is imminent, once the animal is detected by its predator, freezing may no longer be the optimal behaviour for survival. At this point, the animal enters the circa-strike phase, where its behaviour will transition from passive freezing to active flight, or even attack if escape is not possible.
Development
The development of the predatory imminence continuum began with the description of species-specific defence reactions. Species-specific defence reactions are innate responses demonstrated by an animal when they experience a threat. Since survival behaviours are so vital for an animal to acquire and demonstrate rapidly, it has been theorized that these defence reactions would not have time to be learned and therefore, must be innate. While these behaviours are species-specific, there are three general categories of defence reactions - fleeing, freezing, and threatening. Species-specific defence reactions are now recognized as being organized in a hierarchical system where different behaviours are exhibited, depending on the level of threat experienced. However, when this concept was first proposed, the dominant species-specific defence reaction in a certain context was thought to be controlled by operant conditioning. That is, if a spe
Document 4:::
Cat behavior is a cat's behavior and responses to events and other stimuli. Cat behavior includes body language, elimination habits, aggression, play, communication, hunting, grooming, urine marking, and face rubbing. It varies among individuals, colonies, and breeds.
Communication and sociability can vary greatly among individual cats. In a family with many cats, the interactions can change depending on which individuals are present and how restricted the territory and resources are. One or more individuals may become aggressive: fighting may occur with the attack, resulting in scratches and deep bite wounds.
Communication
Kittens vocalize early in development. Some examples of different vocalizations are described below.
Purring - means that the cat is either content or is self-soothing due to fear
Meowing - a frequently used greeting. A mother meows when interacting with her young. Meows can also be used when a cat wishes for attention.
Hissing or spitting - indicates an angry or defensive cat.
Yowling - means that the cat is in distress or feeling aggressive.
Chattering - occurs when hunting or tracking potential prey. This consists of quick chirps made while the mouth vibrates. The gaze is fixed and staring. This behavior may be in response to a surge of adrenaline or may be caused by the anticipation of a pending hunt.
Body language
Cats rely strongly on body language to communicate. A cat may rub against an object or lick a person. Much of a cat's body language is through its tail, ears, head position, and back posture.
The tail
Observing how a cat holds its tail can give a good sense of the cat’s current temperament.
Held high, may have a slight curl forward - a sign of friendliness. The cat is happy, content, and comfortable. The tail may quiver or vibrate if the cat is excited.
Held low and tucked under - a sign of fear or unease. The cat is attempting to make itself a smaller target to potential threats.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Animals may fight, make threatening sounds, and act aggressively toward members of the same species. These behaviors usually occur as the result of
A. competition
B. conservation
C. decomposition
D. pollution
Answer:
|
|
sciq-1925
|
multiple_choice
|
What type of cell does the sperm cell fertilize?
|
[
"bacteria",
"fat",
"protein",
"egg"
] |
D
|
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:::
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 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:::
In vitro spermatogenesis is the process of creating male gametes (spermatozoa) outside of the body in a culture system. The process could be useful for fertility preservation, infertility treatment and may further develop the understanding of spermatogenesis at the cellular and molecular level.
Spermatogenesis is a highly complex process and artificially rebuilding it in vitro is challenging. These include creating a similar microenvironment to that of the testis as well as supporting endocrine and paracrine signalling, and ensuring survival of the somatic and germ cells from spermatogonial stem cells (SSCs) to mature spermatozoa.
Different methods of culturing can be used in the process such as isolated cell cultures, fragment cultures and 3D cultures
Culture techniques
Isolated cell cultures
Cell cultures can include either monocultures, where one cell population is cultured, or co-culturing systems, where several cell lines (must be at least two) can be cultured together. Cells are initially isolated for culture by enzymatically digesting the testis tissue to separate out the different cell types for culture The process of isolating cells can lead to cell damage.
The main advantage of monoculture is that the effect of different influences on one specific cell population of cells can be investigated. Co-culture allows for the interactions between cell populations to be observed and experimented on, which is seen as an advantage over the monoculture model.
Isolated cell culture, specifically co-culture of testis tissue, has been a useful technique for examining the influences of specific factors such as hormones or different feeder cells on the progression of spermatogenesis in vitro. For example, factors such as temperature, feeder cell influence and the role of testosterone and follicle-stimulating hormone (FSH) have all been investigated using isolated cell culture techniques.
Studies have concluded that different factors can influence the culture of g
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of cell does the sperm cell fertilize?
A. bacteria
B. fat
C. protein
D. egg
Answer:
|
|
sciq-289
|
multiple_choice
|
A turbine that spins a generator will produce?
|
[
"solar energy",
"magnetic fields",
"electricity",
"light"
] |
C
|
Relavent Documents:
Document 0:::
In electricity generation, a generator is a device that converts motion-based power (potential and kinetic energy) or fuel-based power (chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.
In addition to electricity- and motion-based designs, photovoltaic and fuel cell powered generators use solar power and hydrogen-based fuels, respectively, to generate electrical output.
The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators are very similar. Many motors can generate electricity from mechanical energy.
Terminology
Electromagnetic generators fall into one of two broad categories, dynamos and alternators.
Dynamos generate pulsing direct current through the use of a commutator.
Alternators generate alternating current.
Mechanically, a generator consists of a rotating part and a stationary part which together form a magnetic circuit:
Rotor: The rotating part of an electrical machine.
Stator: The stationary part of an electrical machine, which surrounds the rotor.
One of these parts generates a magnetic field, the other has a wire winding in which the changing field induces an electric current:
Field winding or field (permanent) magnets: The magnetic field-producing component of an electrical machine. The magnetic field of the dynamo or alternator can be provided by either wire windings called field coils or permanent magnets. Electrically-excited generators include an excitation system to produce the field flux. A generator using permanent magnets (PMs) is sometimes called a magneto, or a permanent magnet synchronous generator (PMSG).
Armature: The power-p
Document 1:::
Micropower describes the use of very small electric generators and prime movers or devices to convert heat or motion to electricity, for use close to the generator. The generator is typically integrated with microelectronic devices and produces "several watts of power or less." These devices offer the promise of a power source for portable electronic devices which is lighter weight and has a longer operating time than batteries.
Microturbine technology
The components of any turbine engine — the gas compressor, the combustion chamber, and the turbine rotor — are fabricated from etched silicon, much like integrated circuits. The technology holds the promise of ten times the operating time of a battery of the same weight as the micropower unit, and similar efficiency to large utility gas turbines. Researchers at Massachusetts Institute of Technology have thus far succeeded in fabricating the parts for such a micro turbine out of six etched and stacked silicon wafers, and are working toward combining them into a functioning engine about the size of a U.S. quarter coin.
Researchers at Georgia Tech have built a micro generator 10 mm wide, which spins a magnet above an array of coils fabricated on a silicon chip. The device spins at 100,000 revolutions per minute, and produces 1.1 watts of electrical power, sufficient to operate a cell phone. Their goal is to produce 20 to 50 watts, sufficient to power a laptop computer.
Scientists at Lehigh University are developing a hydrogen generator on a silicon chip that can convert methanol, diesel, or gasoline into fuel for a microengine or a miniature fuel cell.
Professor Sanjeev Mukerjee of Northeastern University's chemistry department is developing fuel cells for the military that will burn hydrogen to power portable electronic equipment, such as night vision goggles, computers, and communication equipment. In his system, a cartridge of methanol would be used to produce hydrogen to run a small fuel cell for up to 5,000 ho
Document 2:::
In electrical engineering, electric machine is a general term for machines using electromagnetic forces, such as electric motors, electric generators, and others. They are electromechanical energy converters: an electric motor converts electricity to mechanical power while an electric generator converts mechanical power to electricity. The moving parts in a machine can be rotating (rotating machines) or linear (linear machines). Besides motors and generators, a third category often included is transformers, which although they do not have any moving parts are also energy converters, changing the voltage level of an alternating current.
Electric machines, in the form of synchronous and induction generators, produce about 95% of all electric power on Earth (as of early 2020s), and in the form of electric motors consume approximately 60% of all electric power produced. Electric machines were developed beginning in the mid 19th century and since that time have been a ubiquitous component of the infrastructure. Developing more efficient electric machine technology is crucial to any global conservation, green energy, or alternative energy strategy.
Generator
An electric generator is a device that converts mechanical energy to electrical energy. A generator forces electrons to flow through an external electrical circuit. It is somewhat analogous to a water pump, which creates a flow of water but does not create the water inside. The source of mechanical energy, the prime mover, may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.
The two main parts of an electrical machine can be described in either mechanical or electrical terms. In mechanical terms, the rotor is the rotating part, and the stator is the stationary part of an electrical machine. In electrical terms, the armature is the power-producing compo
Document 3:::
This page lists examples of the power in watts produced by various sources of energy. They are grouped by orders of magnitude from small to large.
Below 1 W
1 to 102 W
103 to 108 W
The productive capacity of electrical generators operated by utility companies is often measured in MW. Few things can sustain the transfer or consumption of energy on this scale; some of these events or entities include: lightning strikes, naval craft (such as aircraft carriers and submarines), engineering hardware, and some scientific research equipment (such as supercolliders and large lasers).
For reference, about 10,000 100-watt lightbulbs or 5,000 computer systems would be needed to draw 1 MW. Also, 1 MW is approximately 1360 horsepower. Modern high-power diesel-electric locomotives typically have a peak power of 3–5 MW, while a typical modern nuclear power plant produces on the order of 500–2000 MW peak output.
109 to 1014 W
1015 to 1026 W
Over 1027 W
See also
Orders of magnitude (energy)
Orders of magnitude (voltage)
World energy resources and consumption
International System of Units (SI)
SI prefix
Notes
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
A turbine that spins a generator will produce?
A. solar energy
B. magnetic fields
C. electricity
D. light
Answer:
|
|
sciq-11008
|
multiple_choice
|
When this forms underground, volcanoes rise?
|
[
"CO2",
"soil",
"pumice",
"magma"
] |
D
|
Relavent Documents:
Document 0:::
Maui Nui is a modern geologists' name given to a prehistoric Hawaiian island and the corresponding modern biogeographic region. Maui Nui is composed of four modern islands: Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe. Administratively, the four modern islands comprise Maui County (and a tiny part of Molokaʻi called Kalawao County). Long after the breakup of Maui Nui, the four modern islands retained plant and animal life similar to each other. Thus, Maui Nui is not only a prehistoric island but also a modern biogeographic region.
Geology
Maui Nui formed and broke up during the Pleistocene Epoch, which lasted from about 2.58 million to 11,700 years ago.
Maui Nui is built from seven shield volcanoes. The three oldest are Penguin Bank, West Molokaʻi, and East Molokaʻi, which probably range from slightly over to slightly less than 2 million years old. The four younger volcanoes are Lāna‘i, West Maui, Kaho‘olawe, and Haleakalā, which probably formed between 1.5 and 2 million years ago.
At its prime 1.2 million years ago, Maui Nui was , 50% larger than today's Hawaiʻi Island. The island of Maui Nui included four modern islands (Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe) and landmass west of Molokaʻi called Penguin Bank, which is now completely submerged.
Maui Nui broke up as rising sea levels flooded the connections between the volcanoes. The breakup was complex because global sea levels rose and fell intermittently during the Quaternary glaciation. About 600,000 years ago, the connection between Molokaʻi and the island of Lāna‘i/Maui/Kahoʻolawe became intermittent. About 400,000 years ago, the connection between Lāna‘i and Maui/Kahoʻolawe also became intermittent. The connection between Maui and Kahoʻolawe was permanently broken between 200,000 and 150,000 years ago. Maui, Lāna‘i, and Molokaʻi were connected intermittently thereafter, most recently about 18,000 years ago during the Last Glacial Maximum.
Today, the sea floor between these four islands is relatively shallow
Document 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:::
The rock cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneous rock such as basalt may break down and dissolve when exposed to the atmosphere, or melt as it is subducted under a continent. Due to the driving forces of the rock cycle, plate tectonics and the water cycle, rocks do not remain in equilibrium and change as they encounter new environments. The rock cycle explains how the three rock types are related to each other, and how processes change from one type to another over time. This cyclical aspect makes rock change a geologic cycle and, on planets containing life, a biogeochemical cycle.
Transition to igneous rock
When rocks are pushed deep under the Earth's surface, they may melt into magma. If the conditions no longer exist for the magma to stay in its liquid state, it cools and solidifies into an igneous rock. A rock that cools within the Earth is called intrusive or plutonic and cools very slowly, producing a coarse-grained texture such as the rock granite. As a result of volcanic activity, magma (which is called lava when it reaches Earth's surface) may cool very rapidly on the Earth's surface exposed to the atmosphere and are called extrusive or volcanic rocks. These rocks are fine-grained and sometimes cool so rapidly that no crystals can form and result in a natural glass, such as obsidian, however the most common fine-grained rock would be known as basalt. Any of the three main types of rocks (igneous, sedimentary, and metamorphic rocks) can melt into magma and cool into igneous rocks.
Secondary changes
Epigenetic change (secondary processes occurring at low temperatures and low pressures) may be arranged under a number of headings, each of which is typical of a group of rocks or rock-forming minerals, though usually more than one of these alt
Document 3:::
A kīpuka is an area of land surrounded by one or more younger lava flows. A kīpuka forms when lava flows on either side of a hill, ridge, or older lava dome as it moves downslope or spreads from its source. Older and more weathered than their surroundings, kīpukas often appear to be like islands within a sea of lava flows. They are often covered with soil and late ecological successional vegetation that provide visual contrast as well as habitat for animals in an otherwise inhospitable environment. In volcanic landscapes, kīpukas play an important role as biological reservoirs or refugia for plants and animals, from which the covered land can be recolonized.
Etymology
Kīpuka, along with aā and pāhoehoe, are Hawaiian words related to volcanology that have entered the lexicon of geology. Descriptive proverbs and poetical sayings in Hawaiian oral tradition also use the word, in an allusive sense, to mean a place where life or culture endures, regardless of any encroachment or interference. By extension, from the appearance of island "patches" within a highly contrasted background, any similarly noticeable variation or change of form, such as an opening in a forest, or a clear place in a congested setting, may be colloquially called kīpuka.
Significance to research
Kīpuka provides useful study sites for ecological research because they facilitate replication; multiple kīpuka in a system (isolated by the same lava flow) will tend to have uniform substrate age and successional characteristics, but are often isolated-enough from their neighbors to provide meaningful, comparable differences in size, invasion, etc. They are also receptive to experimental treatments. Kīpuka along Saddle Road on Hawaii have served as the natural laboratory for a variety of studies, examining ecological principles like island biogeography, food web control, and biotic resistance to invasiveness. In addition, Drosophila silvestris populations inhabit kīpukas, making kīpukas useful for unders
Document 4:::
The plate theory is a model of volcanism that attributes all volcanic activity on Earth, even that which appears superficially to be anomalous, to the operation of plate tectonics. According to the plate theory, the principal cause of volcanism is extension of the lithosphere. Extension of the lithosphere is a function of the lithospheric stress field. The global distribution of volcanic activity at a given time reflects the contemporaneous lithospheric stress field, and changes in the spatial and temporal distribution of volcanoes reflect changes in the stress field. The main factors governing the evolution of the stress field are:
Changes in the configuration of plate boundaries.
Vertical motions.
Thermal contraction.
Lithospheric extension enables pre-existing melt in the crust and mantle to escape to the surface. If extension is severe and thins the lithosphere to the extent that the asthenosphere rises, then additional melt is produced by decompression upwelling.
Origins of the plate theory
Developed during the late 1960s and 1970s, plate tectonics provided an elegant explanation for most of the Earth's volcanic activity. At spreading boundaries where plates move apart, the asthenosphere decompresses and melts to form new oceanic crust. At subduction zones, slabs of oceanic crust sink into the mantle, dehydrate, and release volatiles which lower the melting temperature and give rise to volcanic arcs and back-arc extensions. Several volcanic provinces, however, do not fit this simple picture and have traditionally been considered exceptional cases which require a non-plate-tectonic explanation.
Just prior to the development of plate tectonics in the early 1960s, the Canadian Geophysicist John Tuzo Wilson suggested that chains of volcanic islands form from movement of the seafloor over relatively stationary hotspots in stable centres of mantle convection cells. In the early 1970s, Wilson's idea was revived by the American geophysicist W. Jason Morgan. In
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
When this forms underground, volcanoes rise?
A. CO2
B. soil
C. pumice
D. magma
Answer:
|
|
sciq-1285
|
multiple_choice
|
Name the law that determines as to which rock layers are younger or older than others.
|
[
"law of gravity",
"geologic theory",
"law of superposition",
"law of apposition"
] |
C
|
Relavent Documents:
Document 0:::
The geologic record in stratigraphy, paleontology and other natural sciences refers to the entirety of the layers of rock strata. That is, deposits laid down by volcanism or by deposition of sediment derived from weathering detritus (clays, sands etc.). This includes all its fossil content and the information it yields about the history of the Earth: its past climate, geography, geology and the evolution of life on its surface. According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other. They harden over time to become a solidified (competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events.
Correlating the rock record
At a certain locality on the Earth's surface, the rock column provides a cross section of the natural history in the area during the time covered by the age of the rocks. This is sometimes called the rock history and gives a window into the natural history of the location that spans many geological time units such as ages, epochs, or in some cases even multiple major geologic periods—for the particular geographic region or regions. The geologic record is in no one place entirely complete for where geologic forces one age provide a low-lying region accumulating deposits much like a layer cake, in the next may have uplifted the region, and the same area is instead one that is weathering and being torn down by chemistry, wind, temperature, and water. This is to say that in a given location, the geologic record can be and is quite often interrupted as the ancient local environment was converted by geological forces into new landforms and features. Sediment core data at the mouths of large riverine drainage basins, some of which go deep thoroughly support the law of superposition.
However using broadly occurring deposited layers trapped within differently located rock columns, geologists have pieced together a system of units covering most of the geologic time scale
Document 1:::
Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term law has diverse usage in many cases (approximate, accurate, broad, or narrow) across all fields of natural science (physics, chemistry, astronomy, geoscience, biology). Laws are developed from data and can be further developed through mathematics; in all cases they are directly or indirectly based on empirical evidence. It is generally understood that they implicitly reflect, though they do not explicitly assert, causal relationships fundamental to reality, and are discovered rather than invented.
Scientific laws summarize the results of experiments or observations, usually within a certain range of application. In general, the accuracy of a law does not change when a new theory of the relevant phenomenon is worked out, but rather the scope of the law's application, since the mathematics or statement representing the law does not change. As with other kinds of scientific knowledge, scientific laws do not express absolute certainty, as mathematical theorems or identities do. A scientific law may be contradicted, restricted, or extended by future observations.
A law can often be formulated as one or several statements or equations, so that it can predict the outcome of an experiment. Laws differ from hypotheses and postulates, which are proposed during the scientific process before and during validation by experiment and observation. Hypotheses and postulates are not laws, since they have not been verified to the same degree, although they may lead to the formulation of laws. Laws are narrower in scope than scientific theories, which may entail one or several laws. Science distinguishes a law or theory from facts. Calling a law a fact is ambiguous, an overstatement, or an equivocation. The nature of scientific laws has been much discussed in philosophy, but in essence scientific laws are simply empirical
Document 2:::
Rock mechanics is a theoretical and applied science of the mechanical behavior of rocks and rock masses.
Compared to geology, it is the branch of mechanics concerned with the response of rock and rock masses to the force fields of their physical environment.
Background
Rock mechanics is part of a much broader subject of geomechanics, which is concerned with the mechanical responses of all geological materials, including soils.
Rock mechanics is concerned with the application of the principles of engineering mechanics to the design of structures built in or on rock. The structure could include many objects such as a drilling well, a mine shaft, a tunnel, a reservoir dam, a repository component, or a building. Rock mechanics is used in many engineering disciplines, but is primarily used in Mining, Civil, Geotechnical, Transportation, and Petroleum Engineering.
Rock mechanics answers questions such as, "is reinforcement necessary for a rock, or will it be able to handle whatever load it is faced with?" It also includes the design of reinforcement systems, such as rock bolting patterns.
Assessing the Project Site
Before any work begins, the construction site must be investigated properly to inform of the geological conditions of the site. Field observations, deep drilling, and geophysical surveys, can all give necessary information to develop a safe construction plan and create a site geological model. The level of investigation conducted at this site depends on factors such as budget, time frame, and expected geological conditions.
The first step of the investigation is the collection of maps and aerial photos to analyze. This can provide information about potential sinkholes, landslides, erosion, etc. Maps can provide information on the rock type of the site, geological structure, and boundaries between bedrock units.
Boreholes
Creating a borehole is a technique that consists of drilling through the ground in various areas at various depths, to get a bett
Document 3:::
Margaret Armstrong is an Australian geostatistician, mathematical geoscientist, and textbook author. She works as an associate professor in the School of Applied Mathematics at the Fundação Getúlio Vargas in Brazil, and as a research associate in the Centre for Industrial Economics of Mines ParisTech in France.
Education
Armstrong graduated from the University of Queensland in 1972, with a bachelor's degree in mathematics and a diploma of education. After working as a mathematics teacher she returned to graduate study, first with a master's degree in mathematics from Queensland in 1977, and then with Georges Matheron at the École des Mines de Paris. She completed her doctorate there in 1980.
Books
Armstrong is the author of the textbook Basic Linear Geostatistics (Springer, 1998), and co-author of the book Plurigaussian Simulations in Geosciences (Springer, 2003; 2nd ed., 2011). With Matheron, she edited Geostatistical Case Studies (Springer, 1987).
Recognition
In 1998, Armstrong was the winner of the John Cedric Griffiths Teaching Award of the International Association for Mathematical Geosciences. The award statement noted "her aptitude at the blackboard", the international demand for her short courses, and the "great clarity" of her book Basic Linear Geostatistics.
Document 4:::
The following outline is provided as an overview of and topical guide to geophysics:
Geophysics – the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations have a broader definition that includes the hydrological cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets.
Nature of geophysics
Geophysics can be described as all of the following:
An academic discipline – branch of knowledge that is taught and researched at the college or university level. Disciplines are defined (in part), and recognized by the academic journals in which research is published, and the learned societies and academic departments or faculties to which their practitioners belong.
A scientific field (a branch of science) – widely recognized category of specialized expertise within science, and typically embodies its own terminology and nomenclature. Such a field will usually be represented by one or more scientific journals, where peer-reviewed research is published. There are several geophysics-related scientific journals.
A natural science – one that seeks to elucidate the rules that govern the natural world using empirical and scientific methods.
A physical science – one that studies non-living systems.
An earth science – one that studies the planet Earth and its surroundings.
A biological science – one that studies the effect of organisms on their physical environment.
An interdisciplinary field – one that overlap
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Name the law that determines as to which rock layers are younger or older than others.
A. law of gravity
B. geologic theory
C. law of superposition
D. law of apposition
Answer:
|
|
sciq-2635
|
multiple_choice
|
Viruses lack metabolic enzymes and equipment for making what?
|
[
"dna",
"cells",
"acids",
"proteins"
] |
D
|
Relavent Documents:
Document 0:::
MicrobeLibrary is a permanent collection of over 1400 original peer-reviewed resources for teaching undergraduate microbiology. It is provided by the American Society for Microbiology, Washington DC, United States.
Contents include curriculum activities; images and animations; reviews of books, websites and other resources; and articles from Focus on Microbiology Education, Microbiology Education and Microbe. Around 40% of the materials are free to educators and students, the remainder require a subscription. the service is suspended with the message to:
"Please check back with us in 2017".
External links
MicrobeLibrary
Microbiology
Document 1:::
A microbiologist (from Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of microscopic organisms such as bacteria, algae, fungi, and some types of parasites and their vectors. Most microbiologists work in offices and/or research facilities, both in private biotechnology companies and in academia. Most microbiologists specialize in a given topic within microbiology such as bacteriology, parasitology, virology, or immunology.
Duties
Microbiologists generally work in some way to increase scientific knowledge or to utilise that knowledge in a way that improves outcomes in medicine or some industry. For many microbiologists, this work includes planning and conducting experimental research projects in some kind of laboratory setting. Others may have a more administrative role, supervising scientists and evaluating their results. Microbiologists working in the medical field, such as clinical microbiologists, may see patients or patient samples and do various tests to detect disease-causing organisms.
For microbiologists working in academia, duties include performing research in an academic laboratory, writing grant proposals to fund research, as well as some amount of teaching and designing courses. Microbiologists in industry roles may have similar duties except research is performed in industrial labs in order to develop or improve commercial products and processes. Industry jobs may also not include some degree of sales and marketing work, as well as regulatory compliance duties. Microbiologists working in government may have a variety of duties, including laboratory research, writing and advising, developing and reviewing regulatory processes, and overseeing grants offered to outside institutions. Some microbiologists work in the field of patent law, either with national patent offices or private law practices. Her duties include research and navigation of intellectual proper
Document 2:::
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 11,000 of the millions of virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology.
When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or virions, consisting of (i) genetic material, i.e., long molecules of DNA or RNA that encode the structure of the proteins by which the virus acts; (ii) a protein coat, the capsid, which surrounds and protects the genetic material; and in some cases (iii) an outside envelope of lipids. The shapes of these virus particles range from simple helical and icosahedral forms to more complex structures. Most virus species have virions too small to be seen with an optical microscope and are one-hundredth the size of most bacteria.
The origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids—pieces of DNA that can move between cells—while others may have evolved from bacteria. In evolution, viruses are an important means of horizontal gene transfer, which increases genetic diversity in a way analogous to sexual reproduction. Viruses are considered by some biologists to be a life form, because they carry genetic material, reproduce, and evolve through natural selection, although they lack the key characteristics, such as cell structure, that are generally
Document 3:::
The Investigative Biology Teaching Laboratories are located at Cornell University on the first floor Comstock Hall. They are well-equipped biology teaching laboratories used to provide hands-on laboratory experience to Cornell undergraduate students. Currently, they are the home of the Investigative Biology Laboratory Course, (BioG1500), and frequently being used by the Cornell Institute for Biology Teachers, the Disturbance Ecology course and Insectapalooza. In the past the Investigative Biology Teaching Laboratories hosted the laboratory portion of the Introductory Biology Course with the course number of Bio103-104 (renumbered to BioG1103-1104).
The Investigative Biology Teaching Laboratories house the Science Communication and Public Engagement Undergraduate Minor.
History
Bio103-104
BioG1103-1104 Biological Sciences Laboratory course was a two-semester, two-credit course. BioG1103 was offered in the spring, while 1104 was offered in the fall.
BioG1500
This course was first offered in Fall 2010. It is a one semester course, offered in the Fall, Spring and Summer for 2 credits. One credit is being awarded for the letter and one credit for the three-hour-long lab, following the SUNY system.
Document 4:::
This is a list of topics in molecular biology. See also index of biochemistry articles.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Viruses lack metabolic enzymes and equipment for making what?
A. dna
B. cells
C. acids
D. proteins
Answer:
|
|
sciq-5374
|
multiple_choice
|
Which type of cell can carry out more functions, eukaryotic cells or prokaryotic cells?
|
[
"both",
"Prokaryotic Cells",
"chromosomal cells",
"eukaryotic cells"
] |
D
|
Relavent Documents:
Document 0:::
Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term physiology refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show similarities in their functions even though they vary in structure.
General characteristics
There are two types of cells: prokaryotes and eukaryotes.
Prokaryotes were the first of the two to develop and do not have a self-contained nucleus. Their mechanisms are simpler than later-evolved eukaryotes, which contain a nucleus that envelops the cell's DNA and some organelles.
Prokaryotes
Prokaryotes have DNA located in an area called the nucleoid, which is not separated from other parts of the cell by a membrane. There are two domains of prokaryotes: bacteria and archaea. Prokaryotes have fewer organelles than eukaryotes. Both have plasma membranes and ribosomes (structures that synthesize proteins and float free in cytoplasm). Two unique characteristics of prokaryotes are fimbriae (finger-like projections on the surface of a cell) and flagella (threadlike structures that aid movement).
Eukaryotes
Eukaryotes have a nucleus where DNA is contained. They are usually larger than prokaryotes and contain many more organelles. The nucleus, the feature of a eukaryote that distinguishes it from a prokaryote, contains a nuclear envelope, nucleolus and chromatin. In cytoplasm, endoplasmic reticulum (ER) synthesizes membranes and performs other metabolic activities. There are two types, rough ER (containing ribosomes) and smooth ER (lacking ribosomes). The Golgi apparatus consists of multiple membranous sacs, responsible for manufacturing and shipping out materials such as proteins. Lysosomes are structures that use enzymes to break down substances through phagocytosis, a process that comprises endocytosis and exocytosis. In the mitochondria, metabolic processes such as cellular respiration occur. The cytoskeleton is made of fibers that support the str
Document 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
Document 2:::
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 3:::
The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane, and contains many macromolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites. The term comes from the Latin word meaning 'small room'.
Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell.
Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms.
The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology.
Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
Discovery
With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as i
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which type of cell can carry out more functions, eukaryotic cells or prokaryotic cells?
A. both
B. Prokaryotic Cells
C. chromosomal cells
D. eukaryotic cells
Answer:
|
|
ai2_arc-244
|
multiple_choice
|
Many houses are built on the sides of hills. Which of these actions would best prevent houses from sliding down hills after heavy rainfalls?
|
[
"increasing the slope of the hill",
"spraying herbicides on the hill",
"adding plants to the hill",
"removing grass from the hill"
] |
C
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
A 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:::
Vegetation and slope stability are interrelated by the ability of the plant life growing on slopes to both promote and hinder the stability of the slope. The relationship is a complex combination of the type of soil, the rainfall regime, the plant species present, the slope aspect, and the steepness of the slope. Knowledge of the underlying slope stability as a function of the soil type, its age, horizon development, compaction, and other impacts is a major underlying aspect of understanding how vegetation can alter the stability of the slope. There are four major ways in which vegetation influences slope stability: wind throwing, the removal of water, mass of vegetation (surcharge), and mechanical reinforcement of roots.
Wind throwing
Wind throw is the toppling of a tree due to the force of the wind, this exposes the root plate and adjacent soil beneath the tree and influences slope stability. Wind throw is factor when considering one tree on a slope, however it is of lesser importance when considering general slope stability for a body of trees as the wind forces involved represent a smaller percentage of the potential disturbing forces and the trees which are in the centre of the group will be sheltered by those on the outside.
Removal of water
Vegetation influences slope stability by removing water through transpiration. Transpiration is the vaporisation of liquid water contained in plant tissue and the vapour removal to the air. Water is drawn up from the roots and transported through the plant up to the leaves.
The major effect of transpiration is the reduction of soil pore water pressures which counteracts the loss of strength which occurs through wetting, this is most readily seen as a loss of moisture around trees. However it is not easy to rely on tree and shrub roots to remove water from slopes and consequently help ensure slope stability. The ability to transpire in wet conditions is severely reduced and therefore any increase in soil strength
Document 3:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 4:::
The Q-slope method for rock slope engineering and rock mass classification is developed by Barton and Bar. It expresses the quality of the rock mass for slope stability using the Q-slope value, from which long-term stable, reinforcement-free slope angles can be derived.
The Q-slope value can be determined with:
Q-slope utilizes similar parameters to the Q-system which has been used for over 40 years in the design of ground support for tunnels and underground excavations. The first four parameters, RQD (rock quality designation), Jn (joint set number), Jr (joint roughness number) and Ja (joint alteration number) are the same as in the Q-system. However, the frictional resistance pair Jr and Ja can apply, when needed, to individual sides of a potentially unstable wedges. Simply applied orientation factors (0), like (Jr/Ja)1x0.7 for set J1 and (Jr/Ja)2x0.9 for set J2, provide estimates of overall whole-wedge frictional resistance reduction, if appropriate. The Q-system term Jw is replaced with Jwice, and takes into account a wider range of environmental conditions appropriate to rock slopes, which are exposed to the environment indefinitely. The conditions include the extremes of erosive intense rainfall, ice wedging, as may seasonally occur at opposite ends of the rock-type and regional spectrum. There are also slope-relevant SRF (strength reduction factor) categories.
Multiplication of these terms results in the Q-slope value, which can range between 0.001 (exceptionally poor) to 1000 (exceptionally good) for different rock masses.
A simple formula for the steepest slope angle (β), in degrees, not requiring reinforcement or support is given by:
Q-slope is intended for use in reinforcement-free site access road cuts, roads or railway cuttings, or individual benches in open cast mines. It is based on over 500 case studies in slopes ranging from 35 to 90 degrees in fresh hard rock slopes as well as weak, weathered and saprolitic rock slopes. Q-slope has also been a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Many houses are built on the sides of hills. Which of these actions would best prevent houses from sliding down hills after heavy rainfalls?
A. increasing the slope of the hill
B. spraying herbicides on the hill
C. adding plants to the hill
D. removing grass from the hill
Answer:
|
|
sciq-10035
|
multiple_choice
|
Along with climate, this also influences the type of vegetation that can grow in the region?
|
[
"population density",
"soil type",
"fertilizer use",
"gravity"
] |
B
|
Relavent Documents:
Document 0:::
In viticulture, there are several levels of regional climates that are used to describe the terroir or immutable characteristics of an area. These levels can be as broad as a macroclimate which includes entire wine regions or as small as a microclimate which includes the unique environment around an individual grapevine. In the middle is the mesoclimate which usually describes the characteristics of a particular vineyard site.
Levels
Macroclimate, in viticulture, refers to the regional climate of a broad area such as an American Viticultural Area (AVA) or a French Appellation d'origine contrôlée (AOC). It can include an area on the scale of tens to hundreds of kilometers. On smaller scales are the related designations of mesoclimate and microclimate.
Mesoclimate refers to the climate of a particular vineyard site and is generally restricted to a space of tens or hundreds of meters.
Microclimate refers to the specific environment in a small restricted spaces-such as a row of vines. The more delineated term canopy microclimate refers to the environment around an individual grapevine. although many viticulturists use the term "microclimate" when talking about an individual vine and the effects of canopy management.
See also
Climate categorizations in viticulture
Document 1:::
Plant functional types (PFTs) refers to a grouping or classification system often used by ecologists and climatologists to classify plant species based on their similar functions and performances in an ecosystem. It is a way to simplify the complexity of plant diversity and behaviour in ecological models by grouping plants into categories that share common functional characteristics. This simplification helps researchers model vegetation dynmaics which can be used in land use studies and climate models.
PFTs provide a finer level of modeling than biomes, which represent gross areas such as desert, savannah, deciduous forest. In creating models with PFTs, areas as small as 1 km2 are modeled by defining the predominant plant type for that area, interpreted from satellite data or other means. For each plant functional type, a number of key parameters are defined, such as fecundity, competitiveness, resorption (rate at which plant decays and returns nutrients to the soil after death), etc. The value of each parameter is determined or inferred from observable characteristics such as plant height, leaf area, etc.
Plant Functional Type (PFT) models have some limitations and problems. For example, it is difficult for climatologists and ecologists to determine which minimal set of plant characteristics best model the actual responses of the biosphere in response to climate changes. Furthermore, by oversimplifying species to a few key traits, researchers may not capture the full diversity and variability of plant species within a given ecosystem or represent rare or unique species. As such, researchers are developing more sophisticated models, such as trait-based models, to address these problems.
See also
Ecotone
Document 2:::
Ecological classification or ecological typology is the classification of land or water into geographical units that represent variation in one or more ecological features. Traditional approaches focus on geology, topography, biogeography, soils, vegetation, climate conditions, living species, habitats, water resources, and sometimes also anthropic factors. Most approaches pursue the cartographical delineation or regionalisation of distinct areas for mapping and planning.
Approaches to classifications
Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines. Traditionally these approaches have focused on biotic components (vegetation classification), abiotic components (environmental approaches) or implied ecological and evolutionary processes (biogeographical approaches). Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems: a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy (ecotope).
Vegetation classification
Vegetation is often used to classify terrestrial ecological units. Vegetation classification can be based on vegetation structure and floristic composition. Classifications based entirely on vegetation structure overlap with land cover mapping categories.
Many schemes of vegetation classification are in use by the land, resource and environmental management agencies of different national and state jurisdictions. The International Vegetation Classification (IVC or EcoVeg) has been recently proposed but has not been yet widely adopted.
Vegetation classifications have limited use in aquatic systems, since only a handful of freshwater or marine habitats are dominated by plants (e.g. kelp forests or seagrass meadows). Also, some extreme terrestrial environments, like subterranean or cryogenic ecosystems, are not properly described in vegetation c
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.
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Along with climate, this also influences the type of vegetation that can grow in the region?
A. population density
B. soil type
C. fertilizer use
D. gravity
Answer:
|
|
scienceQA-9278
|
multiple_choice
|
Select the amphibian.
|
[
"snowy owl",
"helmeted iguana",
"brown pelican",
"arroyo toad"
] |
D
|
An arroyo toad is an amphibian. It has moist skin and begins its life in water.
Toads do not have teeth! They swallow their food whole.
A snowy owl is a bird. It has feathers, two wings, and a beak.
Snowy owls live in cold places. Even their feet have feathers to keep warm!
A brown pelican is a bird. It has feathers, two wings, and a beak.
Brown pelicans live near water. They can dive underwater to catch fish.
A helmeted iguana is a reptile. It has scaly, waterproof skin.
Iguanas are a type of lizard. Iguanas eat plants and fruit.
|
Relavent Documents:
Document 0:::
AmphibiaWeb is an American non-profit website that provides information about amphibians. It is run by a group of universities working with the California Academy of Sciences: San Francisco State University, the University of California at Berkeley, University of Florida at Gainesville, and University of Texas at Austin.
AmphibiaWeb's goal is to provide a single page for every species of amphibian in the world so research scientists, citizen scientists and conservationists can collaborate. It added its 7000th animal in 2012, a glass frog from Peru. As of 2022, it hosted more than 8,400 species located worldwide.
Beginning
Scientist David Wake founded AmphibiaWeb in 2000. Wake had been inspired by the decline of amphibian populations across the world. He founded it at the Digital Library Project at the University of California at Berkeley in 2000. Wake came to consider AmphibiaWeb part of his legacy.
Uses
AmphibiaWeb provides information to the IUCN, CalPhotos, Encyclopedia of Life and iNaturalist, and the database is cited in scientific publications.
Document 1:::
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 2:::
The Reptile Database is a scientific database that collects taxonomic information on all living reptile species (i.e. no fossil species such as dinosaurs). The database focuses on species (as opposed to higher ranks such as families) and has entries for all currently recognized ~13,000 species and their subspecies, although there is usually a lag time of up to a few months before newly described species become available online. The database collects scientific and common names, synonyms, literature references, distribution information, type information, etymology, and other taxonomically relevant information.
History
The database was founded in 1995 as EMBL Reptile Database when the founder, Peter Uetz, was a graduate student at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany. Thure Etzold had developed the first web interface for the EMBL DNA sequence database which was also used as interface for the Reptile Database. In 2006 the database moved to The Institute of Genomic Research (TIGR) and briefly operated as TIGR Reptile Database until TIGR was merged into the J Craig Venter Institute (JCVI) where Uetz was an associate professor until 2010. Since 2010 the database has been maintained on servers in the Czech Republic under the supervision of Peter Uetz and Jirí Hošek, a Czech programmer. The database celebrated its 25th anniversary together with AmphibiaWeb which had its 20th anniversary in 2021.
Content
As of September 2020, the Reptile Database lists about 11,300 species (including another ~2,200 subspecies) in about 1200 genera (see figure), and has more than 50,000 literature references and about 15,000 photos. The database has constantly grown since its inception with an average of 100 to 200 new species described per year over the preceding decade. Recently, the database also added a more or less complete list of primary type specimens.
Relationship to other databases
The Reptile Database has been a member of the Species 2000 pro
Document 3:::
Batrachology is the branch of zoology concerned with the study of amphibians including frogs and toads, salamanders, newts, and caecilians. It is a sub-discipline of herpetology, which also includes non-avian reptiles (snakes, lizards, amphisbaenids, turtles, terrapins, tortoises, crocodilians, and the tuatara). Batrachologists may study the evolution, ecology, ethology, or anatomy of amphibians.
Amphibians are cold blooded vertebrates largely found in damp habitats although many species have special behavioural adaptations that allow them to live in deserts, trees, underground and in regions with wide seasonal variations in temperature. There are over 7250 species of amphibians.
Notable batrachologists
Jean Marius René Guibé
Gabriel Bibron
Oskar Boettger
George Albert Boulenger
Edward Drinker Cope
François Marie Daudin
Franz Werner
Leszek Berger
Document 4:::
Vertebrate zoology is the biological discipline that consists of the study of Vertebrate animals, i.e., animals with a backbone, such as fish, amphibians, reptiles, birds and mammals. Many natural history museums have departments named Vertebrate Zoology. In some cases whole museums bear this name, e.g. the Museum of Vertebrate Zoology at the University of California, Berkeley.
Subdivisions
This subdivision of zoology has many further subdivisions, including:
Ichthyology - the study of fishes.
Mammalogy - the study of mammals.
Chiropterology - the study of bats.
Primatology - the study of primates.
Ornithology - the study of birds.
Herpetology - the study of reptiles.
Batrachology - the study of amphibians.
These divisions are sometimes further divided into more specific specialties.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Select the amphibian.
A. snowy owl
B. helmeted iguana
C. brown pelican
D. arroyo toad
Answer:
|
sciq-7818
|
multiple_choice
|
Different forms of the same element are called what?
|
[
"amines",
"allotropes",
"subclasses",
"polymorphs"
] |
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:::
Advanced Level (A-Level) Mathematics is a qualification of further education taken in the United Kingdom (and occasionally other countries as well). In the UK, A-Level exams are traditionally taken by 17-18 year-olds after a two-year course at a sixth form or college. Advanced Level Further Mathematics is often taken by students who wish to study a mathematics-based degree at university, or related degree courses such as physics or computer science.
Like other A-level subjects, mathematics has been assessed in a modular system since the introduction of Curriculum 2000, whereby each candidate must take six modules, with the best achieved score in each of these modules (after any retake) contributing to the final grade. Most students will complete three modules in one year, which will create an AS-level qualification in their own right and will complete the A-level course the following year—with three more modules.
The system in which mathematics is assessed is changing for students starting courses in 2017 (as part of the A-level reforms first introduced in 2015), where the reformed specifications have reverted to a linear structure with exams taken only at the end of the course in a single sitting.
In addition, while schools could choose freely between taking Statistics, Mechanics or Discrete Mathematics (also known as Decision Mathematics) modules with the ability to specialise in one branch of applied Mathematics in the older modular specification, in the new specifications, both Mechanics and Statistics were made compulsory, with Discrete Mathematics being made exclusive as an option to students pursuing a Further Mathematics course. The first assessment opportunity for the new specification is 2018 and 2019 for A-levels in Mathematics and Further Mathematics, respectively.
2000s specification
Prior to the 2017 reform, the basic A-Level course consisted of six modules, four pure modules (C1, C2, C3, and C4) and two applied modules in Statistics, Mechanics
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 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:::
Further Mathematics is the title given to a number of advanced secondary mathematics courses. The term "Higher and Further Mathematics", and the term "Advanced Level Mathematics", may also refer to any of several advanced mathematics courses at many institutions.
In the United Kingdom, Further Mathematics describes a course studied in addition to the standard mathematics AS-Level and A-Level courses. In the state of Victoria in Australia, it describes a course delivered as part of the Victorian Certificate of Education (see § Australia (Victoria) for a more detailed explanation). Globally, it describes a course studied in addition to GCE AS-Level and A-Level Mathematics, or one which is delivered as part of the International Baccalaureate Diploma.
In other words, more mathematics can also be referred to as part of advanced mathematics, or advanced level math.
United Kingdom
Background
A qualification in Further Mathematics involves studying both pure and applied modules. Whilst the pure modules (formerly known as Pure 4–6 or Core 4–6, now known as Further Pure 1–3, where 4 exists for the AQA board) build on knowledge from the core mathematics modules, the applied modules may start from first principles.
The structure of the qualification varies between exam boards.
With regard to Mathematics degrees, most universities do not require Further Mathematics, and may incorporate foundation math modules or offer "catch-up" classes covering any additional content. Exceptions are the University of Warwick, the University of Cambridge which requires Further Mathematics to at least AS level; University College London requires or recommends an A2 in Further Maths for its maths courses; Imperial College requires an A in A level Further Maths, while other universities may recommend it or may promise lower offers in return. Some schools and colleges may not offer Further mathematics, but online resources are available
Although the subject has about 60% of its cohort obtainin
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Different forms of the same element are called what?
A. amines
B. allotropes
C. subclasses
D. polymorphs
Answer:
|
|
sciq-3407
|
multiple_choice
|
In what kind of bond does one atom contribute both of the electrons in the shared pair?
|
[
"a covalent bond",
"a valence bond",
"an ionic bond",
"a metallic bond"
] |
A
|
Relavent Documents:
Document 0:::
A bonding electron is an electron involved in chemical bonding. This can refer to:
Chemical bond, a lasting attraction between atoms, ions or molecules
Covalent bond or molecular bond, a sharing of electron pairs between atoms
Bonding molecular orbital, an attraction between the atomic orbitals of atoms in a molecule
Chemical bonding
Document 1:::
An intramolecular force (or primary forces) is any force that binds together the atoms making up a molecule or compound, not to be confused with intermolecular forces, which are the forces present between molecules. The subtle difference in the name comes from the Latin roots of English with inter meaning between or among and intra meaning inside. Chemical bonds are considered to be intramolecular forces which are often stronger than intermolecular forces present between non-bonding atoms or molecules.
Types
The classical model identifies three main types of chemical bonds — ionic, covalent, and metallic — distinguished by the degree of charge separation between participating atoms. The characteristics of the bond formed can be predicted by the properties of constituent atoms, namely electronegativity. They differ in the magnitude of their bond enthalpies, a measure of bond strength, and thus affect the physical and chemical properties of compounds in different ways. % of ionic character is directly proportional difference in electronegitivity of bonded atom.
Ionic bond
An ionic bond can be approximated as complete transfer of one or more valence electrons of atoms participating in bond formation, resulting in a positive ion and a negative ion bound together by electrostatic forces. Electrons in an ionic bond tend to be mostly found around one of the two constituent atoms due to the large electronegativity difference between the two atoms, generally more than 1.9, (greater difference in electronegativity results in a stronger bond); this is often described as one atom giving electrons to the other. This type of bond is generally formed between a metal and nonmetal, such as sodium and chlorine in NaCl. Sodium would give an electron to chlorine, forming a positively charged sodium ion and a negatively charged chloride ion.
Covalent bond
In a true covalent bond, the electrons are shared evenly between the two atoms of the bond; there is little or no charge separa
Document 2:::
In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond. When shared, each of the two electrons involved is no longer in the sole possession of the orbital in which it originated. Rather, both of the two electrons spend time in either of the orbitals which overlap in the bonding process. As a Lewis structure, a single bond is denoted as AːA or A-A, for which A represents an element. In the first rendition, each dot represents a shared electron, and in the second rendition, the bar represents both of the electrons shared in the single bond.
A covalent bond can also be a double bond or a triple bond. A single bond is weaker than either a double bond or a triple bond. This difference in strength can be explained by examining the component bonds of which each of these types of covalent bonds consists (Moore, Stanitski, and Jurs 393).
Usually, a single bond is a sigma bond. An exception is the bond in diboron, which is a pi bond. In contrast, the double bond consists of one sigma bond and one pi bond, and a triple bond consists of one sigma bond and two pi bonds (Moore, Stanitski, and Jurs 396). The number of component bonds is what determines the strength disparity. It stands to reason that the single bond is the weakest of the three because it consists of only a sigma bond, and the double bond or triple bond consist not only of this type of component bond but also at least one additional bond.
The single bond has the capacity for rotation, a property not possessed by the double bond or the triple bond. The structure of pi bonds does not allow for rotation (at least not at 298 K), so the double bond and the triple bond which contain pi bonds are held due to this property. The sigma bond is not so restrictive, and the single bond is able to rotate using the sigma bond as the axis of rotation (Moore, Stanits
Document 3:::
A chemical bonding model is a theoretical model used to explain atomic bonding structure, molecular geometry, properties, and reactivity of physical matter. This can refer to:
VSEPR theory, a model of molecular geometry.
Valence bond theory, which describes molecular electronic structure with localized bonds and lone pairs.
Molecular orbital theory, which describes molecular electronic structure with delocalized molecular orbitals.
Crystal field theory, an electrostatic model for transition metal complexes.
Ligand field theory, the application of molecular orbital theory to transition metal complexes.
Chemical bonding
Document 4:::
In chemistry, an electron pair or Lewis pair consists of two electrons that occupy the same molecular orbital but have opposite spins. Gilbert N. Lewis introduced the concepts of both the electron pair and the covalent bond in a landmark paper he published in 1916.
Because electrons are fermions, the Pauli exclusion principle forbids these particles from having the same quantum numbers. Therefore, for two electrons to occupy the same orbital, and thereby have the same orbital quantum number, they must have different spin quantum number. This also limits the number of electrons in the same orbital to two.
The pairing of spins is often energetically favorable, and electron pairs therefore play a large role in chemistry. They can form a chemical bond between two atoms, or they can occur as a lone pair of valence electrons. They also fill the core levels of an atom.
Because the spins are paired, the magnetic moment of the electrons cancel one another, and the pair's contribution to magnetic properties is generally diamagnetic.
Although a strong tendency to pair off electrons can be observed in chemistry, it is also possible that electrons occur as unpaired electrons.
In the case of metallic bonding the magnetic moments also compensate to a large extent, but the bonding is more communal so that individual pairs of electrons cannot be distinguished and it is better to consider the electrons as a collective 'sea'.
A very special case of electron pair formation occurs in superconductivity: the formation of Cooper pairs. In unconventional superconductors, whose crystal structure contains copper anions, the electron pair bond is due to antiferromagnetic spin fluctuations.
See also
Electron pair production
Frustrated Lewis pair
Jemmis mno rules
Lewis acids and bases
Nucleophile
Polyhedral skeletal electron pair theory
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In what kind of bond does one atom contribute both of the electrons in the shared pair?
A. a covalent bond
B. a valence bond
C. an ionic bond
D. a metallic bond
Answer:
|
|
sciq-6650
|
multiple_choice
|
Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). it is most common along with the onset of puberty due to association with these?
|
[
"hormonal changes",
"digestive changes",
"thermal changes",
"mental changes"
] |
A
|
Relavent Documents:
Document 0:::
Single Best Answer (SBA or One Best Answer) is a written examination form of multiple choice questions used extensively in medical education.
Structure
A single question is posed with typically five alternate answers, from which the candidate must choose the best answer. This method avoids the problems of past examinations of a similar form described as Single Correct Answer. The older form can produce confusion where more than one of the possible answers has some validity. The newer form makes it explicit that more than one answer may have elements that are correct, but that one answer will be superior.
Prior to the widespread introduction of SBAs into medical education, the typical form of examination was true-false multiple choice questions. But during the 2000s, educators found that SBAs would be superior.
Document 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:::
Advanced Placement (AP) Physics C: Electricity and Magnetism (also known as AP Physics C: E&M or AP E&M) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a second-semester calculus-based university course in electricity and magnetism. The content of Physics C: E&M overlaps with that of AP Physics 2, but Physics 2 is algebra-based and covers other topics outside of electromagnetism, while Physics C is calculus-based and only covers electromagnetism. Physics C: E&M may be combined with its mechanics counterpart to form a year-long course that prepares for both exams.
Course content
E&M is equivalent to an introductory college course in electricity and magnetism for physics or engineering majors. The course modules are:
Electrostatics
Conductors, capacitors, and dielectrics
Electric circuits
Magnetic fields
Electromagnetism.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a calculus class.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Electricity and Magnetism is separate from the AP examination for AP Physics C: Mechanics. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday afternoon in May. The exam is configured in two categories: a 35-question multiple choice section and a 3-question free response section. Test takers are allowed to use an approved calculator during the entire exam. The test is weighted such that each section is worth half of the final score. This and AP Physics C: Mechanics are the shortest AP exams, with
Document 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:::
Emma Guttman-Yassky is the System Chair of the Department of Dermatology and Waldman professor of dermatology and immunology at the Icahn School of Medicine at Mount Sinai in New York. She is also director of its center for excellence in eczema, its occupational dermatitis clinic, and its inflammatory skin disease laboratory.
According to Scopus she has an h-index of 80.
Education
Research
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). it is most common along with the onset of puberty due to association with these?
A. hormonal changes
B. digestive changes
C. thermal changes
D. mental changes
Answer:
|
|
sciq-9062
|
multiple_choice
|
What type of mammals are characterized by detailed development of the hands and feet, a shortened snout, and a large brain?
|
[
"primates",
"mammles",
"apes",
"amphibians"
] |
A
|
Relavent Documents:
Document 0:::
This is a list of large extant primate species (excluding humans) that can be ordered by average weight or height range. There is no fixed definition of a large primate, it is typically assessed empirically. Primates exhibit the highest levels of sexual dimorphism amongst mammals, therefore the maximum body dimensions included in this list generally refer to male specimens.
Mandrills and baboons are monkeys; the rest of the species on this list are apes. Typically, Old World monkeys (paleotropical) are larger than New World monkeys (neotropical); the reasons for this are not entirely understood but several hypotheses have been generated. As a rule, primate brains are "significantly larger" than those of other mammals with similar body sizes. Until well into the 19th century, juvenile orangutans were taken from the wild and died within short order, eventually leading naturalists to mistakenly assume that the living specimens they briefly encountered and skeletons of adult orangutans were entirely different species.
Largest non-human primates
See also
Largest wild canids
List of largest land carnivorans
Monkey
Great apes
List of heaviest land mammals
Largest mammals
Sexual dimorphism in non-human primates
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:::
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 3:::
Miacis ("small point") is an extinct genus of placental mammals from clade Carnivoraformes, that lived in North America from early to middle Eocene.
Description
Miacis was five-clawed, about the size of a weasel (~30 cm), and lived on the North American continent. It retained some primitive characteristics such as low skulls, long slender bodies, long tails, and short legs. Miacis retained 44 teeth, although some reductions in this number were apparently in progress and some of the teeth were reduced in size.
The hind limbs were longer than the forelimbs, the pelvis was dog-like in form and structure, and some specialized traits were present in the vertebrae. It had retractable claws, agile joints for climbing, and binocular vision. Miacis and related forms had brains that were relatively larger than those of the creodonts, and the larger brain size as compared with body size probably reflects an increase in intelligence.
Like many other early carnivoramorphans, it was well suited for an arboreal climbing lifestyle with needle-sharp claws, limbs, and joints resembling modern carnivorans. Miacis was probably a very agile forest dweller that preyed upon smaller animals, such as small mammals, reptiles, and birds, and might also have eaten eggs and fruits.
Classification and phylogeny
Classification
History of taxonomy
Since Edward Drinker Cope first described the genus Miacis in 1872, at least twenty other species have been assigned to Miacis. However, these species share few synapomorphies other than plesiomorphic characteristics of miacids in general. This reflects the fact that Miacis has been treated as a wastebasket taxon and contains a diverse collection of species that belong to the stemgroup within the Carnivoraformes. Many of the species originally assigned to Miacis have since been assigned to other genera and, apart from the type species, Miacis parvivorus, the remaining species are often referred to with Miacis in quotations (e.g. "Miacis" latidens)
Document 4:::
Bats are the only mammal capable of true flight. Bats use flight for capturing prey, breeding, avoiding predators, and long-distance migration. Bat wing morphology is often highly specialized to the needs of the species.
Evolution
Charles Darwin foresaw an issue with his theory of evolution by natural selection in the evolution of complex traits such as eyes or "the structure and habits of a bat." Indeed, the oldest bat fossils are very similar in wing morphology to the bats of today, despite living and dying 52.5 million years ago. Onychonycteris finneyi, the earliest known bat, already possessed powered flight. O. finneyi likely had an undulating flight style that alternated periods of fluttering with gliding. Evidence for this lies in the broad and short nature of O. finneyi wing morphology, which would have made it difficult to efficiently maneuver in the air or sustain flight. Additionally claws were seen on the ends of their forelimb digits (which have since disappeared in modern-day bats) giving evidence that O. finneyi was a skilled climber. The common ancestor of all bats is hypothesized to have been an arboreal quadruped of the northern hemisphere. This ancestor is predicted to have lived 64 million years ago at the border of the Cretaceous and Paleogene, based on molecular and paleontological data. There is a gap in the fossil record, and no transitional fossils exist from this quadrupedal ancestor to the appearance of the modern bat. It is unclear how long the transition from quadrupedalism to powered flight took. Based on a phylogenetic analysis of wing aerodynamics, the ancestral Chiropteran had wings with a low aspect ratio and rounded wingtips; this indicates it had slow but maneuverable and agile flight. After evolving powered flight, bats underwent massive adaptive radiation, becoming the second-most speciose mammal order, after rodents.
A 2011 study hypothesized that, rather than having evolved from gliders, the ancestors of bats were flutter
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What type of mammals are characterized by detailed development of the hands and feet, a shortened snout, and a large brain?
A. primates
B. mammles
C. apes
D. amphibians
Answer:
|
|
sciq-4547
|
multiple_choice
|
What delivers power to the chemical factory chloroplasts?
|
[
"the sun",
"water",
"chlorophyll",
"oxygen"
] |
A
|
Relavent Documents:
Document 0:::
The Bionic Leaf is a biomimetic system that gathers solar energy via photovoltaic cells that can be stored or used in a number of different functions. Bionic leaves can be composed of both synthetic (metals, ceramics, polymers, etc.) and organic materials (bacteria), or solely made of synthetic materials. The Bionic Leaf has the potential to be implemented in communities, such as urbanized areas to provide clean air as well as providing needed clean energy.
History
In 2009 at MIT, Daniel Nocera's lab first developed the "artificial leaf", a device made from silicon and an anode electrocatalyst for the oxidation of water, capable of splitting water into hydrogen and oxygen gases. In 2012, Nocera came to Harvard and The Silver Lab of Harvard Medical School joined Nocera’s team. Together the teams expanded the existing technology to create the Bionic Leaf. It merged the concept of the artificial leaf with genetically engineered bacteria that feed on the hydrogen and convert CO2 in the air into alcohol fuels or chemicals.
The first version of the teams Bionic Leaf was created in 2015 but the catalyst used was harmful to the bacteria. In 2016, a new catalyst was designed to solve this issue, named the "Bionic Leaf 2.0". Other versions of artificial leaves have been developed by the California Institute of Technology and the Joint Center for Artificial Photosynthesis, the University of Waterloo, and the University of Cambridge.
Mechanics
Photosynthesis
In natural photosynthesis, photosynthetic organisms produce energy-rich organic molecules from water and carbon dioxide by using solar radiation. Therefore, the process of photosynthesis removes carbon dioxide, a greenhouse gas, from the air. Artificial photosynthesis, as performed by the Bionic Leaf, is approximately 10 times more efficient than natural photosynthesis. Using a catalyst, the Bionic Leaf can remove excess carbon dioxide in the air and convert that to useful alcohol fuels, like isopropanol and isobutan
Document 1:::
Bioproducts engineering or bioprocess engineering refers to engineering of bio-products from renewable bioresources. This pertains to the design and development of processes and technologies for the sustainable manufacture of bioproducts (materials, chemicals and energy) from renewable biological resources.
Bioproducts engineers harness the molecular building blocks of renewable resources to design, develop and manufacture environmentally friendly industrial and consumer products. From biofuels, renewable energy, and bioplastics to paper products and "green" building materials such as bio-based composites, Bioproducts engineers are developing sustainable solutions to meet the world's growing materials and energy demand. Conventional bioproducts and emerging bioproducts are two broad categories used to categorize bioproducts. Examples of conventional bio-based products include building materials, pulp and paper, and forest products. Examples of emerging bioproducts or biobased products include biofuels, bioenergy, starch-based and cellulose-based ethanol, bio-based adhesives, biochemicals, biodegradable plastics, etc. Bioproducts Engineers play a major role in the design and development of "green" products including biofuels, bioenergy, biodegradable plastics, biocomposites, building materials, paper and chemicals. Bioproducts engineers also develop energy efficient, environmentally friendly manufacturing processes for these products as well as effective end-use applications. Bioproducts engineers play a critical role in a sustainable 21st century bio-economy by using renewable resources to design, develop, and manufacture the products we use every day. The career outlook for bioproducts engineers is very bright with employment opportunities in a broad range of industries, including pulp and paper, alternative energy, renewable plastics, and other fiber, forest products, building materials and chemical-based industries.
Commonly referred to as bioprocess engineerin
Document 2:::
The European Algae Biomass Association (EABA), established on 2 June 2009, is the European association representing both research and industry in the field of algae technologies.
EABA was founded during its inaugural conference on 1–2 June 2009 at Villa La Pietra in Florence. The association is headquartered in Florence, Italy.
History
The first EABA's President, Prof. Dr. Mario Tredici, served a 2-year term since his election on 2 June 2009. The EABA Vice-presidents were Mr. Claudio Rochietta, (Oxem, Italy), Prof. Patrick Sorgeloos (University of Ghent, Belgium) and Mr. Marc Van Aken (SBAE Industries, Belgium). The EABA Executive Director was Mr. Raffaello Garofalo.
EABA had 58 founding members and the EABA reached 79 members in 2011.
The last election occurred on 3 December 2018 in Amsterdam. The EABA's President is Mr. Jean-Paul Cadoret (Algama / France). The EABA Vice-presidents are Prof. Dr. Sammy Boussiba (Ben-Gurion University of the Negev / Israel), Prof. Dr. Gabriel Acien (University of Almeria / Spain) and Dr. Alexandra Mosch (Germany). The EABA General Manager is Dr. Vítor Verdelho (A4F AlgaFuel, S.A. / Portugal) and Prof. Dr. Mario Tredici (University of Florence / Italy) is elected as Honorary President.
Cooperation with other organisations
ART Fuels Forum
European Society of Biochemical Engineering Sciences
Algae Biomass Organization
Document 3:::
The MSU-DOE Plant Research Laboratory (PRL), commonly referred to as Plant Research Lab,
is a research institute funded to a large extent by the U.S. Department of Energy Office of Science and located at Michigan State University (MSU)
in East Lansing, Michigan. The Plant Research Lab was founded in 1965, and it currently includes twelve laboratories that conduct collaborative basic research
into the biology of diverse photosynthetic organisms, including plants, bacteria, and algae, in addition to developing new technologies towards
addressing energy and food challenges.
History
1964-1978
The contract for the establishment of the MSU-DOE Plant Research Laboratory was signed on March 6, 1964, between the U.S. Atomic Energy Commission (AEC) and Michigan State University. The institute was initially funded by the AEC's Division of Biology and Medicine, which saw a need for improving the state of plant sciences in the United States. The Division aimed to create a new program at one or more universities where student interest in plant research could be fostered.
The contract signed between AEC and Michigan State University provided for a comprehensive research program in plant biology and related education and training at the graduate and postgraduate levels. The program was to draw strongly on related disciplines such as biochemistry, biophysics, genetics, microbiology, and others.
In 1966, personnel of the new program - called MSU-AEC Plant Research Laboratory at that time - moved into their new quarters in the Plant Biology Laboratories building at Michigan State University. The first research projects generally focused on problems specific to plants, such as cell growth and its regulation by plant hormones, cell wall structure and composition, and the physiology of flower formation; other research projects addressed general biological problems, such as the regulation of enzyme formation during development and cellular and genetic aspects of hormone action.
I
Document 4:::
Chloroplast DNA (cpDNA) is the DNA located in chloroplasts, which are photosynthetic organelles located within the cells of some eukaryotic organisms. Chloroplasts, like other types of plastid, contain a genome separate from that in the cell nucleus. The existence of chloroplast DNA was identified biochemically in 1959, and confirmed by electron microscopy in 1962. The discoveries that the chloroplast contains ribosomes and performs protein synthesis revealed that the chloroplast is genetically semi-autonomous. The first complete chloroplast genome sequences were published in 1986, Nicotiana tabacum (tobacco) by Sugiura and colleagues and Marchantia polymorpha (liverwort) by Ozeki et al. Since then, a great number of chloroplast DNAs from various species have been sequenced.
Molecular structure
Chloroplast DNAs are circular, and are typically 120,000–170,000 base pairs long. They can have a contour length of around 30–60 micrometers, and have a mass of about 80–130 million daltons.
Most chloroplasts have their entire chloroplast genome combined into a single large ring, though those of dinophyte algae are a notable exception—their genome is broken up into about forty small plasmids, each 2,000–10,000 base pairs long. Each minicircle contains one to three genes, but blank plasmids, with no coding DNA, have also been found.
Chloroplast DNA has long been thought to have a circular structure, but some evidence suggests that chloroplast DNA more commonly takes a linear shape. Over 95% of the chloroplast DNA in corn chloroplasts has been observed to be in branched linear form rather than individual circles.
Inverted repeats
Many chloroplast DNAs contain two inverted repeats, which separate a long single copy section (LSC) from a short single copy section (SSC).
The inverted repeats vary wildly in length, ranging from 4,000 to 25,000 base pairs long each. Inverted repeats in plants tend to be at the upper end of this range, each being 20,000–25,000 base pairs long.
T
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What delivers power to the chemical factory chloroplasts?
A. the sun
B. water
C. chlorophyll
D. oxygen
Answer:
|
|
sciq-11298
|
multiple_choice
|
Birds are thought to have evolved around 150 million years ago from what?
|
[
"raptor dinosaurs",
"theropod dinosaurs",
"teradactils",
"parrot dinosaurs"
] |
B
|
Relavent Documents:
Document 0:::
History of Animals (, Ton peri ta zoia historion, "Inquiries on Animals"; , "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. It was written in the fourth century BC; Aristotle died in 322 BC.
Generally seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the what (the existing facts about animals) prior to establishing the why (the causes of these characteristics). The book is thus an attempt to apply philosophy to part of the natural world. Throughout the work, Aristotle seeks to identify differences, both between individuals and between groups. A group is established when it is seen that all members have the same set of distinguishing features; for example, that all birds have feathers, wings, and beaks. This relationship between the birds and their features is recognized as a universal.
The History of Animals contains many accurate eye-witness observations, in particular of the marine biology around the island of Lesbos, such as that the octopus had colour-changing abilities and a sperm-transferring tentacle, that the young of a dogfish grow inside their mother's body, or that the male of a river catfish guards the eggs after the female has left. Some of these were long considered fanciful before being rediscovered in the nineteenth century. Aristotle has been accused of making errors, but some are due to misinterpretation of his text, and others may have been based on genuine observation. He did however make somewhat uncritical use of evidence from other people, such as travellers and beekeepers.
The History of Animals had a powerful influence on zoology for some two thousand years. It continued to be a primary source of knowledge until zoologists in the sixteenth century, such as Conrad Gessner, all influenced by Aristotle, wrote their own studies of the subject.
Context
Aristotle (384–322 BC) studied at Plat
Document 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:::
Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds. It has also been an area with a large contribution made by amateurs in terms of time, resources, and financial support. Studies on birds have helped develop key concepts in biology including evolution, behaviour and ecology such as the definition of species, the process of speciation, instinct, learning, ecological niches, guilds, island biogeography, phylogeography, and conservation.
While early ornithology was principally concerned with descriptions and distributions of species, ornithologists today seek answers to very specific questions, often using birds as models to test hypotheses or predictions based on theories. Most modern biological theories apply across life forms, and the number of scientists who identify themselves as "ornithologists" has therefore declined. A wide range of tools and techniques are used in ornithology, both inside the laboratory and out in the field, and innovations are constantly made. Most biologists who recognise themselves as "ornithologists" study specific categories, such as anatomy, taxonomy, or ecology lifestyles and behaviours, just as with all biological practises.
Definition and etymology
The word "ornithology" comes from the late 16th-century Latin ornithologia meaning "bird science" from the Greek ὄρνις ornis ("bird") and λόγος logos ("theory, science, thought").
History
The history of ornithology largely reflects the trends in the history of biology, as well as many other scientific disciplines, including ecology, anatomy, physiology, paleontology, and more recently, molecular biology. Trends include the move from mere descriptions to the identification of patterns, thus towards elucidating the processes that produce these patterns.
Early knowledge and study
Humans have had an observational relationship with birds sin
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:::
The following is a timeline of ornithology events:
Until 1700
1500–800 BC – The Vedas mention the habit of brood parasitism in the Asian koel (Eudynamys scolopacea).
4th century BC – Aristotle mentions over 170 sorts of birds in his work on animals. He recognises eight principal groups.
3rd century BC – The Erya, a Chinese encyclopedia comprising glosses on passages in ancient texts, notably the Book of Songs, features 79 entries in its chapter "Describing Birds"
1st century AD – Pliny the Elder's Historia Naturalis Book X is devoted to birds. Three groups based on characteristics of feet
2nd century AD – Aelian mentions a number of birds in his work on animals. Birds are listed alphabetically
1037 – Death of Abu ‘Ali al-Husayn ibn Abd Allah ibn Sina (known as Avicenna in Latin) author of Abbreviatio de animalibus, a homage to Aristotle
c 1100 Hugh of Fouilloy authors De avibus, a moral treatise on birds later incorporated into many versions of the popular medieval bestiary.
1220 – Books on birds and other animals by Aristotle and Avicenna translated into Latin for the first time by Michael Scot
1250 – Death of Frederick II von Hohenstaufen, Holy Roman Emperor, and author of De arte venandi cum avibus ("concerning the art of hunting with birds") that describes the first manipulative experiments in ornithology and the methods of falconry
1478 – De Avibus by Albertus Magnus is printed, which mentions many bird names for the first time
1485 – First dated copy of Ortus sanitatis by Johannes de Cuba
1544 – William Turner prints a commentary on the birds mentioned by Aristotle and Pliny
1555 – Conrad Gessner's Historic Animalium qui est de Auium natura and Pierre Belon's (Bellonius) Histoire de la nature des Oyseaux. Belon lists birds according to a definite system
1573 – Volcher Coiter publishes his first treatise on bird anatomy
1591 – Joris Hoefnagel starts to work for Rudolf II, Holy Roman Emperor and produces for him 90 oil-base paintings, of which one is of the d
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Birds are thought to have evolved around 150 million years ago from what?
A. raptor dinosaurs
B. theropod dinosaurs
C. teradactils
D. parrot dinosaurs
Answer:
|
|
sciq-6676
|
multiple_choice
|
What is the term for a substance that causes the speed of a reaction to increase?
|
[
"indicate",
"component",
"monite",
"catalyst"
] |
D
|
Relavent Documents:
Document 0:::
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms reactant and reagent are often used interchangeably, but reactant specifies a substance consumed in the course of a chemical reaction. Solvents, though involved in the reaction mechanism, are usually not called reactants. Similarly, catalysts are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates.
Definitions
Organic chemistry
In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents.
Analytical chemistry
In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by colorimetry. Examples include Fehling's reagent, Millon's reagent, and Tollens' reagent.
Commercial or laboratory preparations
In commercial or laboratory preparations, reagent-grade designates chemical substances meeting standards of purity that ensure the scientific precision and reliability of chemical analysis, chemical reactions or physical testing. Purity standards for reagents are set by organizations such as ASTM International or the American Chemical Society. For instance, reagent-quality water must have very low levels of impurities such as sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity. Laboratory products which are less pure, but still useful and economical for undemanding work, may be designated as technical, practical, or crude grade to distinguish them from reagent versions.
Biology
In t
Document 1:::
The Hatta number (Ha) was developed by Shirôji Hatta, who taught at Tohoku University. It is a dimensionless parameter that compares the rate of reaction in a liquid film to the rate of diffusion through the film. For a second order reaction (), the maximum rate of reaction assumes that the liquid film is saturated with gas at the interfacial concentration ; thus, the maximum rate of reaction is .
For a reaction order in and order in :
It is an important parameter used in Chemical Reaction Engineering.
Document 2:::
In chemistry, yield, also referred to as reaction yield, is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. Yield is one of the primary factors that scientists must consider in organic and inorganic chemical synthesis processes. In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms used to describe ratios of how much of a reactant was consumed (conversion), how much desired product was formed (yield) in relation to the undesired product (selectivity), represented as X, Y, and S.
Definitions
In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms used to describe ratios of how much of a reactant has reacted—conversion, how much of a desired product was formed—yield, and how much desired product was formed in ratio to the undesired product—selectivity, represented as X,S, and Y.
According to the Elements of Chemical Reaction Engineering manual, yield refers to the amount of a specific product formed per mole of reactant consumed. In chemistry, mole is used to describe quantities of reactants and products in chemical reactions.
The Compendium of Chemical Terminology defined yield as the "ratio expressing the efficiency of a mass conversion process. The yield coefficient is defined as the amount of cell mass (kg) or product formed (kg,mol) related to the consumed substrate (carbon or nitrogen source or oxygen in kg or moles) or to the intracellular ATP production (moles)."
In the section "Calculations of yields in the monitoring of reactions" in the 1996 4th edition of Vogel's Textbook of Practical Organic Chemistry (1978), the authors write that, "theoretical yield in an organic reaction is the weight of product which would be obtained if the reaction has proceeded to completion according to the chemical equation. The yield is the weight of the pure product which is isolated from the react
Document 3:::
Enzyme assays are laboratory methods for measuring enzymatic activity. They are vital for the study of enzyme kinetics and enzyme inhibition.
Enzyme units
The quantity or concentration of an enzyme can be expressed in molar amounts, as with any other chemical, or in terms of activity in enzyme units.
Enzyme activity
Enzyme activity is a measure of the quantity of active enzyme present and is thus dependent on various physical conditions, which should be specified.
It is calculated using the following formula:
where
Enzyme activity
Moles of substrate converted per unit time
Rate of the reaction
Reaction volume
The SI unit is the katal, 1 katal = 1 mol s−1 (mole per second), but this is an excessively large unit. A more practical and commonly used value is enzyme unit (U) = 1 μmol min−1 (micromole per minute). 1 U corresponds to 16.67 nanokatals.
Enzyme activity as given in katal generally refers to that of the assumed natural target substrate of the enzyme. Enzyme activity can also be given as that of certain standardized substrates, such as gelatin, then measured in gelatin digesting units (GDU), or milk proteins, then measured in milk clotting units (MCU). The units GDU and MCU are based on how fast one gram of the enzyme will digest gelatin or milk proteins, respectively. 1 GDU approximately equals 1.5 MCU.
An increased amount of substrate will increase the rate of reaction with enzymes, however once past a certain point, the rate of reaction will level out because the amount of active sites available has stayed constant.
Specific activity
The specific activity of an enzyme is another common unit. This is the activity of an enzyme per milligram of total protein (expressed in μmol min−1 mg−1). Specific activity gives a measurement of enzyme purity in the mixture. It is the micro moles of product formed by an enzyme in a given amount of time (minutes) under given conditions per milligram of total proteins. Specific activity is equal to the rate of reacti
Document 4:::
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas. The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction. The chemical formulas may be symbolic, structural (pictorial diagrams), or intermixed. The coefficients next to the symbols and formulas of entities are the absolute values of the stoichiometric numbers. The first chemical equation was diagrammed by Jean Beguin in 1615.
Structure
A chemical equation (see an example below) consists of a list of reactants (the starting substances) on the left-hand side, an arrow symbol, and a list of products (substances formed in the chemical reaction) on the right-hand side. Each substance is specified by its chemical formula, optionally preceded by a number called stoichiometric coefficient. The coefficient specifies how many entities (e.g. molecules) of that substance are involved in the reaction on a molecular basis. If not written explicitly, the coefficient is equal to 1. Multiple substances on any side of the equation are separated from each other by a plus sign.
As an example, the equation for the reaction of hydrochloric acid with sodium can be denoted:
Given the formulas are fairly simple, this equation could be read as "two H-C-L plus two N-A yields two N-A-C-L and H two." Alternately, and in general for equations involving complex chemicals, the chemical formulas are read using IUPAC nomenclature, which could verbalise this equation as "two hydrochloric acid molecules and two sodium atoms react to form two formula units of sodium chloride and a hydrogen gas molecule."
Reaction types
Different variants of the arrow symbol are used to denote the type of a reaction:
{|
| style="text-align: center; padding-right: 0.5em;" | -> || net forwa
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the term for a substance that causes the speed of a reaction to increase?
A. indicate
B. component
C. monite
D. catalyst
Answer:
|
|
sciq-2130
|
multiple_choice
|
Within organs, arteries branch into what small vessels that convey blood to the capillaries?
|
[
"aeortic vessels",
"Metarterioles",
"arterioles",
"blood valves"
] |
C
|
Relavent Documents:
Document 0:::
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.
There are three sizes of veins, large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries.
Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of capacitance vessels. At any time, nearly 70% of the total volume of blood in the human body is in the veins. In medium and large sized veins the flow of blood is maintained by one-way (unidirectional) venous valves to prevent backflow. In the lower limbs this is also aided by muscle pumps, also known as venous pumps that exert pressure on intramuscular veins when they contract and drive blood back to the heart.
Structure
There are three sizes of vein, large, medium, and small. Smaller veins are called venules. The smallest veins are the post-capillary venules. Veins have a similar three-layered structure to arteries. The layers known as tunicae have a concentric arrangement that forms the wall of the vessel. The outer layer, is a thick layer of connective tissue called the tunica externa or adventitia; this layer is absent in the post-capillary venules. The middle layer, consists of bands of smooth muscle and is known as the tunica media. The inner layer, is a thin lining of endothelium known as the tunica intima. The tunica media in the veins is mu
Document 1:::
Great vessels are the large vessels that bring blood to and from the heart. These are:
Superior vena cava
Inferior vena cava
Pulmonary arteries
Pulmonary veins
Aorta
Transposition of the great vessels is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels.
Document 2:::
The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body.
The coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called epicardial (above the epicardium, or the outermost tissue of the heart) and microvascular (close to the endocardium, or the innermost tissue of the heart).
Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coronary arteries can have a serious impact on health, possibly leading to angina, a heart attack, and even death.
Structure
The coronary arteries are mainly composed of the left and right coronary arteries, both of which give off several branches, as shown in the 'coronary artery flow' figure.
Aorta
Left coronary artery
Left anterior descending artery
Left circumflex artery
Posterior descending artery
Ramus or intermediate artery
Right coronary artery
Right marginal artery
Posterior descending artery
The left coronary artery arises from the aorta within the left cusp of the aortic valve and feeds blood to the left side of the heart. It branches into two arteries, the left anterior descending and the left circumflex. The left anterior descending artery perfuses the interventricular septum and anterior wall of the left ventricle. The left circumflex artery perfuses the left ventricular free wall. In approximately 33% of individuals, the left coronary artery gives rise to the posterior descending artery wh
Document 3:::
The deep palmar arch, an arterial network is accompanied by a pair of venae comitantes which constitute the deep venous palmar arch. It receives the veins corresponding to the branches of the arterial arch: the palmar metacarpal veins.
Document 4:::
In human anatomy, the pancreatic veins consist of several small blood vessels which drain the body and tail of the pancreas, and open into the trunk of the great pancreatic vein.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Within organs, arteries branch into what small vessels that convey blood to the capillaries?
A. aeortic vessels
B. Metarterioles
C. arterioles
D. blood valves
Answer:
|
|
scienceQA-31
|
multiple_choice
|
Which organ controls the function of other body organs?
|
[
"skeleton",
"lungs",
"heart",
"brain"
] |
D
|
Relavent Documents:
Document 0:::
This article contains a list of organs of the human body. A general consensus is widely believed to be 79 organs (this number goes up if you count each bone and muscle as an organ on their own, which is becoming more common practice to do); however, there is no universal standard definition of what constitutes an organ, and some tissue groups' status as one is debated. Since there is no single standard definition of what an organ is, the number of organs varies depending on how one defines an organ. For example, this list contains more than 79 organs (about ~103).
It is still not clear which definition of an organ is used for all the organs in this list, it seemed that it may have been compiled based on what wikipedia articles were available on organs.
Musculoskeletal system
Skeleton
Joints
Ligaments
Muscular system
Tendons
Digestive system
Mouth
Teeth
Tongue
Lips
Salivary glands
Parotid glands
Submandibular glands
Sublingual glands
Pharynx
Esophagus
Stomach
Small intestine
Duodenum
Jejunum
Ileum
Large intestine
Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Liver
Gallbladder
Mesentery
Pancreas
Anal canal
Appendix
Respiratory system
Nasal cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchioles and smaller air passages
Lungs
Muscles of breathing
Urinary system
Kidneys
Ureter
Bladder
Urethra
Reproductive systems
Female reproductive system
Internal reproductive organs
Ovaries
Fallopian tubes
Uterus
Cervix
Vagina
External reproductive organs
Vulva
Clitoris
Male reproductive system
Internal reproductive organs
Testicles
Epididymis
Vas deferens
Prostate
External reproductive organs
Penis
Scrotum
Endocrine system
Pituitary gland
Pineal gland
Thyroid gland
Parathyroid glands
Adrenal glands
Pancreas
Circulatory system
Circulatory system
Heart
Arteries
Veins
Capillaries
Lymphatic system
Lymphatic vessel
Lymph node
Bone marrow
Thymus
Spleen
Gut-associated lymphoid tissue
Tonsils
Interstitium
Nervous system
Central nervous system
Document 1:::
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs.
The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
Animals
Except for placozoans, multicellular animals including humans have a variety of organ systems. These specific systems are widely studied in human anatomy. The functions of these organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The sam
Document 2:::
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.
Document 3:::
Instruments used in Anatomy dissections are as follows:
Instrument list
Image gallery
Document 4:::
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.
Which organ controls the function of other body organs?
A. skeleton
B. lungs
C. heart
D. brain
Answer:
|
|
sciq-5233
|
multiple_choice
|
What is never lost and just changes forms?
|
[
"life",
"fuel",
"energy",
"food"
] |
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:::
The STEM (Science, Technology, Engineering, and Mathematics) pipeline is a critical infrastructure for fostering the development of future scientists, engineers, and problem solvers. It's the educational and career pathway that guides individuals from early childhood through to advanced research and innovation in STEM-related fields.
Description
The "pipeline" metaphor is based on the idea that having sufficient graduates requires both having sufficient input of students at the beginning of their studies, and retaining these students through completion of their academic program. The STEM pipeline is a key component of workplace diversity and of workforce development that ensures sufficient qualified candidates are available to fill scientific and technical positions.
The STEM pipeline was promoted in the United States from the 1970s onwards, as “the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness.”
Today, this metaphor is commonly used to describe retention problems in STEM fields, called “leaks” in the pipeline. For example, the White House reported in 2012 that 80% of minority groups and women who enroll in a STEM field switch to a non-STEM field or drop out during their undergraduate education. These leaks often vary by field, gender, ethnic and racial identity, socioeconomic background, and other factors, drawing attention to structural inequities involved in STEM education and careers.
Current efforts
The STEM pipeline concept is a useful tool for programs aiming at increasing the total number of graduates, and is especially important in efforts to increase the number of underrepresented minorities and women in STEM fields. Using STEM methodology, educational policymakers can examine the quantity and retention of students at all stages of the K–12 educational process and beyo
Document 2:::
The Science, Technology, Engineering and Mathematics Network or STEMNET is an educational charity in the United Kingdom that seeks to encourage participation at school and college in science and engineering-related subjects (science, technology, engineering, and mathematics) and (eventually) work.
History
It is based at Woolgate Exchange near Moorgate tube station in London and was established in 1996. The chief executive is Kirsten Bodley. The STEMNET offices are housed within the Engineering Council.
Function
Its chief aim is to interest children in science, technology, engineering and mathematics. Primary school children can start to have an interest in these subjects, leading secondary school pupils to choose science A levels, which will lead to a science career. It supports the After School Science and Engineering Clubs at schools. There are also nine regional Science Learning Centres.
STEM ambassadors
To promote STEM subjects and encourage young people to take up jobs in these areas, STEMNET have around 30,000 ambassadors across the UK. these come from a wide selection of the STEM industries and include TV personalities like Rob Bell.
Funding
STEMNET used to receive funding from the Department for Education and Skills. Since June 2007, it receives funding from the Department for Children, Schools and Families and Department for Innovation, Universities and Skills, since STEMNET sits on the chronological dividing point (age 16) of both of the new departments.
See also
The WISE Campaign
Engineering and Physical Sciences Research Council
National Centre for Excellence in Teaching Mathematics
Association for Science Education
Glossary of areas of mathematics
Glossary of astronomy
Glossary of biology
Glossary of chemistry
Glossary of engineering
Glossary of physics
Document 3:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 4:::
Female education in STEM refers to child and adult female representation in the educational fields of science, technology, engineering, and mathematics (STEM). In 2017, 33% of students in STEM fields were women.
The organization UNESCO has stated that this gender disparity is due to discrimination, biases, social norms and expectations that influence the quality of education women receive and the subjects they study. UNESCO also believes that having more women in STEM fields is desirable because it would help bring about sustainable development.
Current status of girls and women in STEM education
Overall trends in STEM education
Gender differences in STEM education participation are already visible in early childhood care and education in science- and math-related play, and become more pronounced at higher levels of education. Girls appear to lose interest in STEM subjects with age, particularly between early and late adolescence. This decreased interest affects participation in advanced studies at the secondary level and in higher education. Female students represent 35% of all students enrolled in STEM-related fields of study at this level globally. Differences are also observed by disciplines, with female enrollment lowest in engineering, manufacturing and construction, natural science, mathematics and statistics and ICT fields. Significant regional and country differences in female representation in STEM studies can be observed, though, suggesting the presence of contextual factors affecting girls’ and women's engagement in these fields. Women leave STEM disciplines in disproportionate numbers during their higher education studies, in their transition to the world of work and even in their career cycle.
Learning achievement in STEM education
Data on gender differences in learning achievement present a complex picture, depending on what is measured (subject, knowledge acquisition against knowledge application), the level of education/age of students, and
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is never lost and just changes forms?
A. life
B. fuel
C. energy
D. food
Answer:
|
|
sciq-8751
|
multiple_choice
|
What are organisms that depend on other living things for food?
|
[
"customers",
"products",
"buyers",
"consumers"
] |
D
|
Relavent Documents:
Document 0:::
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 1:::
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 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:::
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products (ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.
Different types of organisms have different essential nutrients. Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts, to humans and some other animal species, but some animals and plants are able to synthesize it. Nutrients may be organic or inorganic: organic compounds include most compounds containing carbon, while all other chemicals are inorganic. Inorganic nutrients include nutrients such as iron, selenium, and zinc, while organic nutrients include, among many others, energy-providing compounds and vitamins.
A classification used primarily to describe nutrient needs of animals divides nutrients into macronutrients and micronutrients. Consumed in relatively large amounts (grams or ounces), macronutrients (carbohydrates, fats, proteins, water) are primarily used to generate energy or to incorporate into tissues for growth and repair. Micronutrients are needed in smaller amounts (milligrams or micrograms); they have subtle biochemical and physiologi
Document 4:::
Heterotrophic nutrition is a mode of nutrition in which organisms depend upon other organisms for food to survive. They can't make their own food like Green plants. Heterotrophic organisms have to take in all the organic substances they need to survive.
All animals, certain types of fungi, and non-photosynthesizing plants are heterotrophic. In contrast, green plants, red algae, brown algae, and cyanobacteria are all autotrophs, which use photosynthesis to produce their own food from sunlight. Some fungi may be saprotrophic, meaning they will extracellularly secrete enzymes onto their food to be broken down into smaller, soluble molecules which can diffuse back into the fungus.
Description
All eukaryotes except for green plants and algae are unable to manufacture their own food: They obtain food from other organisms. This mode of nutrition is also known as heterotrophic nutrition.
All heterotrophs (except blood and gut parasites) have to convert solid food into soluble compounds which are capable of being absorbed (digestion). Then the soluble products of digestion for the organism are being broken down for the release of energy (respiration). All heterotrophs depend on autotrophs for their nutrition. Heterotrophic organisms have only four types of nutrition.
Footnotes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are organisms that depend on other living things for food?
A. customers
B. products
C. buyers
D. consumers
Answer:
|
|
sciq-5013
|
multiple_choice
|
What are responsible for removing excess h+ ions from the blood?
|
[
"intestinal walls",
"stomach chambers",
"liver nodes",
"kidneys"
] |
D
|
Relavent Documents:
Document 0:::
In pharmacology the elimination or excretion of a drug is understood to be any one of a number of processes by which a drug is eliminated (that is, cleared and excreted) from an organism either in an unaltered form (unbound molecules) or modified as a metabolite. The kidney is the main excretory organ although others exist such as the liver, the skin, the lungs or glandular structures, such as the salivary glands and the lacrimal glands. These organs or structures use specific routes to expel a drug from the body, these are termed elimination pathways:
Urine
Tears
Perspiration
Saliva
Respiration
Milk
Faeces
Bile
Drugs are excreted from the kidney by glomerular filtration and by active tubular secretion following the same steps and mechanisms as the products of intermediate metabolism. Therefore, drugs that are filtered by the glomerulus are also subject to the process of passive tubular reabsorption. Glomerular filtration will only remove those drugs or metabolites that are not bound to proteins present in blood plasma (free fraction) and many other types of drugs (such as the organic acids) are actively secreted. In the proximal and distal convoluted tubules non-ionised acids and weak bases are reabsorbed both actively and passively. Weak acids are excreted when the tubular fluid becomes too alkaline and this reduces passive reabsorption. The opposite occurs with weak bases. Poisoning treatments use this effect to increase elimination, by alkalizing the urine causing forced diuresis which promotes excretion of a weak acid, rather than it getting reabsorbed. As the acid is ionised, it cannot pass through the plasma membrane back into the blood stream and instead gets excreted with the urine. Acidifying the urine has the same effect for weakly basic drugs.
On other occasions drugs combine with bile juices and enter the intestines. In the intestines the drug will join with the unabsorbed fraction of the administered dose and be eliminated with the faeces
Document 1:::
An Ussing chamber is an apparatus for measuring epithelial membrane properties. It can detect and quantify transport and barrier functions of living tissue. The Ussing chamber was invented by the Danish zoologist and physiologist Hans Henriksen Ussing in 1946.
The technique is used to measure the short-circuit current as an indicator of net ion transport taking place across an epithelium. Ussing chambers are used to measure ion transport in native tissue, such as gut mucosa, and in a monolayer of cells grown on permeable supports.
Function
The Ussing chamber provides a system to measure the transport of ions, nutrients, and drugs across various epithelial tissues, (although can generate false-negative results for lipophilic substances). It consists of two halves separated by the epithelia (sheet of mucosa or monolayer of epithelial cells grown on permeable supports). Epithelia are polar in nature, i.e., they have an apical or mucosal side and a basolateral or serosal side. An Ussing chamber can isolate the apical side from the basolateral side. The two half chambers are filled with equal amounts of symmetrical Ringer solution to remove chemical, mechanical or electrical driving forces. Ion transport takes place across any epithelium. Transport may be in either direction. Ion transport produces a potential difference (voltage difference) across the epithelium. The voltage is measured using two voltage electrodes placed near the tissue/epithelium. This voltage is cancelled out by injecting current, using two other current electrodes placed away from the epithelium. This short-circuit current (Isc) is the measure of net ion transport.
Measuring epithelial ion transport is helped by Ussing chambers. The voltage result from this ion transport is easy to accurately measure. The epithelium pumps ions from one side to the other and the ions leak back through so-called tight junctions that are situated between the epithelial cells. To measure ion transport, an external
Document 2:::
Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52–55%). The exact percentage of fluid relative to body weight is inversely proportional to the percentage of body fat. A lean man, for example, has about 42 (42–47) liters of water in his body.
The total body of water is divided into fluid compartments, between the intracellular fluid compartment (also called space, or volume) and the extracellular fluid (ECF) compartment (space, volume) in a two-to-one ratio: 28 (28–32) liters are inside cells and 14 (14–15) liters are outside cells.
The ECF compartment is divided into the interstitial fluid volume – the fluid outside both the cells and the blood vessels – and the intravascular volume (also called the vascular volume and blood plasma volume) – the fluid inside the blood vessels – in a three-to-one ratio: the interstitial fluid volume is about 12 liters; the vascular volume is about 4 liters.
The interstitial fluid compartment is divided into the lymphatic fluid compartment – about 2/3, or 8 (6–10) liters, and the transcellular fluid compartment (the remaining 1/3, or about 4 liters).
The vascular volume is divided into the venous volume and the arterial volume; and the arterial volume has a conceptually useful but unmeasurable subcompartment called the effective arterial blood volume.
Compartments by location
intracellular fluid (ICF), which consist of cytosol and fluids in the cell nucleus
Extracellular fluid
Intravascular fluid (blood plasma)
Interstitial fluid
Lymphatic fluid (sometimes included in interstitial fluid)
Transcellular fluid
Health
Body fluid is the term most often used in medical and health contexts. Modern medical, public health, and personal hygiene practices treat body fluids as potentially unclean. This is because they can be vectors for infectious
Document 3:::
The human body and even its individual body fluids may be conceptually divided into various fluid compartments, which, although not literally anatomic compartments, do represent a real division in terms of how portions of the body's water, solutes, and suspended elements are segregated. The two main fluid compartments are the intracellular and extracellular compartments. The intracellular compartment is the space within the organism's cells; it is separated from the extracellular compartment by cell membranes.
About two-thirds of the total body water of humans is held in the cells, mostly in the cytosol, and the remainder is found in the extracellular compartment. The extracellular fluids may be divided into three types: interstitial fluid in the "interstitial compartment" (surrounding tissue cells and bathing them in a solution of nutrients and other chemicals), blood plasma and lymph in the "intravascular compartment" (inside the blood vessels and lymphatic vessels), and small amounts of transcellular fluid such as ocular and cerebrospinal fluids in the "transcellular compartment".
The normal processes by which life self-regulates its biochemistry (homeostasis) produce fluid balance across the fluid compartments. Water and electrolytes are continuously moving across barriers (eg, cell membranes, vessel walls), albeit often in small amounts, to maintain this healthy balance. The movement of these molecules is controlled and restricted by various mechanisms. When illnesses upset the balance, electrolyte imbalances can result.
The interstitial and intravascular compartments readily exchange water and solutes, but the third extracellular compartment, the transcellular, is thought of as separate from the other two and not in dynamic equilibrium with them.
The science of fluid balance across fluid compartments has practical application in intravenous therapy, where doctors and nurses must predict fluid shifts and decide which IV fluids to give (for example, isot
Document 4:::
The Starling principle holds that extracellular fluid movements between blood and tissues are determined by differences in hydrostatic pressure and colloid osmotic (oncotic) pressure between plasma inside microvessels and interstitial fluid outside them. The Starling Equation, proposed many years after the death of Starling, describes that relationship in mathematical form and can be applied to many biological and non-biological semipermeable membranes. The classic Starling principle and the equation that describes it have in recent years been revised and extended.
Every day around 8 litres of water (solvent) containing a variety of small molecules (solutes) leaves the blood stream of an adult human and perfuses the cells of the various body tissues. Interstitial fluid drains by afferent lymph vessels to one of the regional lymph node groups, where around 4 litres per day is reabsorbed to the blood stream. The remainder of the lymphatic fluid is rich in proteins and other large molecules and rejoins the blood stream via the thoracic duct which empties into the great veins close to the heart. Filtration from plasma to interstitial (or tissue) fluid occurs in microvascular capillaries and post-capillary venules. In most tissues the micro vessels are invested with a continuous internal surface layer that includes a fibre matrix now known as the endothelial glycocalyx whose interpolymer spaces function as a system of small pores, radius circa 5 nm. Where the endothelial glycocalyx overlies a gap in the junction molecules that bind endothelial cells together (inter endothelial cell cleft), the plasma ultrafiltrate may pass to the interstitial space, leaving larger molecules reflected back into the plasma.
A small number of continuous capillaries are specialised to absorb solvent and solutes from interstitial fluid back into the blood stream through fenestrations in endothelial cells, but the volume of solvent absorbed every day is small.
Discontinuous capillaries as
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are responsible for removing excess h+ ions from the blood?
A. intestinal walls
B. stomach chambers
C. liver nodes
D. kidneys
Answer:
|
|
sciq-1512
|
multiple_choice
|
In what do substances combine chemically to form a new substance?
|
[
"element",
"component",
"compound",
"suspension"
] |
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 chemistry, a mixture is a material made up of two or more different chemical substances which are not chemically bonded. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.
Mixtures are one product of mechanically blending or mixing chemical substances such as elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup. Despite the fact that there are no chemical changes to its constituents, the physical properties of a mixture, such as its melting point, may differ from those of the components. Some mixtures can be separated into their components by using physical (mechanical or thermal) means. Azeotropes are one kind of mixture that usually poses considerable difficulties regarding the separation processes required to obtain their constituents (physical or chemical processes or, even a blend of them).
Characteristics of mixtures
All mixtures can be characterized as being separable by mechanical means (e.g. purification, distillation, electrolysis, chromatography, heat, filtration, gravitational sorting, centrifugation). Mixtures differ from chemical compounds in the following ways:
the substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.
there is little or no energy change when a mixture forms (see Enthalpy of mixing).
The substances in a mixture keep its separate properties.
In the example of sand and water, neither one of the two substances changed in any way when they are mixed. Although the sand is in the water it still keeps the same properties that it had when it was outside the water.
mixtures have variable compositions, while compounds have a fixed, definite formula.
when mixed, individual substances keep their properties in a mixture, while if they form a compound their properties
Document 2:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
Document 3:::
A 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
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In what do substances combine chemically to form a new substance?
A. element
B. component
C. compound
D. suspension
Answer:
|
|
sciq-6931
|
multiple_choice
|
Pure nonpolar covalent bonds exist only between what?
|
[
"two altered atoms",
"three altered atoms",
"two identical atoms",
"two producing atoms"
] |
C
|
Relavent Documents:
Document 0:::
A non-bonding electron is an electron not involved in chemical bonding. This can refer to:
Lone pair, with the electron localized on one atom.
Non-bonding orbital, with the electron delocalized throughout the molecule.
Chemical bonding
Document 1:::
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 2:::
Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons. It often, but not always, involves some chemical bonding.
In some cases, the associations can be quite strong—for example, the protein streptavidin and the vitamin biotin have a dissociation constant (reflecting the ratio between bound and free biotin) on the order of 10−14—and so the reactions are effectively irreversible. The result of molecular binding is sometimes the formation of a molecular complex in which the attractive forces holding the components together are generally non-covalent, and thus are normally energetically weaker than covalent bonds.
Molecular binding occurs in biological complexes (e.g., between pairs or sets of proteins, or between a protein and a small molecule ligand it binds) and also in abiologic chemical systems, e.g. as in cases of coordination polymers and coordination networks such as metal-organic frameworks.
Types
Molecular binding can be classified into the following types:
Non-covalent – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
Reversible covalent – a chemical bond is formed, however the free energy difference separating the noncovalently-bonded reactants from bonded product is near equilibrium and the activation barrier is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
Irreversible covalent – a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such that the reverse reaction does not take place.
Bound molecules are sometimes called a "molecular complex"—the term generally refers to non-covalent associations. Non-covalent interactions can effectively become irreversible; for example, tight binding inhibitors of enzymes
Document 3:::
An intramolecular force (or primary forces) is any force that binds together the atoms making up a molecule or compound, not to be confused with intermolecular forces, which are the forces present between molecules. The subtle difference in the name comes from the Latin roots of English with inter meaning between or among and intra meaning inside. Chemical bonds are considered to be intramolecular forces which are often stronger than intermolecular forces present between non-bonding atoms or molecules.
Types
The classical model identifies three main types of chemical bonds — ionic, covalent, and metallic — distinguished by the degree of charge separation between participating atoms. The characteristics of the bond formed can be predicted by the properties of constituent atoms, namely electronegativity. They differ in the magnitude of their bond enthalpies, a measure of bond strength, and thus affect the physical and chemical properties of compounds in different ways. % of ionic character is directly proportional difference in electronegitivity of bonded atom.
Ionic bond
An ionic bond can be approximated as complete transfer of one or more valence electrons of atoms participating in bond formation, resulting in a positive ion and a negative ion bound together by electrostatic forces. Electrons in an ionic bond tend to be mostly found around one of the two constituent atoms due to the large electronegativity difference between the two atoms, generally more than 1.9, (greater difference in electronegativity results in a stronger bond); this is often described as one atom giving electrons to the other. This type of bond is generally formed between a metal and nonmetal, such as sodium and chlorine in NaCl. Sodium would give an electron to chlorine, forming a positively charged sodium ion and a negatively charged chloride ion.
Covalent bond
In a true covalent bond, the electrons are shared evenly between the two atoms of the bond; there is little or no charge separa
Document 4:::
In molecular biology, a scissile bond is a covalent chemical bond that can be broken by an enzyme. Examples would be the cleaved bond in the self-cleaving hammerhead ribozyme or the peptide bond of a substrate cleaved by a peptidase.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Pure nonpolar covalent bonds exist only between what?
A. two altered atoms
B. three altered atoms
C. two identical atoms
D. two producing atoms
Answer:
|
|
sciq-8585
|
multiple_choice
|
What are the 3 types of tissues that modern plants have?
|
[
"cambrium, epidermis, and ground",
"dermal, ground, and vascular",
"sturdy , ground , and vascular",
"sinuous , ground , and vascular"
] |
B
|
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
Document 1:::
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones.
Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the term is generally considered to be unscientific.
Characteristics
Botanists define vascular plants by three primary characteristics:
Vascular plants have vascular tissues which distribute resources through the plant. Two kinds of vascular tissue occur in plants: xylem and phloem. Phloem and xylem are closely associated with one another and are typically located immediately adjacent to each other in the plant. The combination of one xylem and one phloem strand adjacent to each other is known as a vascular bundle. The evolution of vascular tissue in plants allowed them to evolve to larger sizes than non-vascular plants, which lack these specialized conducting tissues and are thereby restricted to relatively small sizes.
In vascular plants, the principal generation or phase is the sporophyte, which produces spores and is diploid (having two sets of chromosomes per cell). (By contrast, the principal generation phase in non-vascular plants is the gametophyte, which produces gametes and is haploid - with
Document 2:::
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
Document 3:::
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.
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the 3 types of tissues that modern plants have?
A. cambrium, epidermis, and ground
B. dermal, ground, and vascular
C. sturdy , ground , and vascular
D. sinuous , ground , and vascular
Answer:
|
|
sciq-186
|
multiple_choice
|
Many hydrocarbons are cyclic and adopt specific three-dimensional structures that influence their physical and what properties?
|
[
"radiation",
"chemical",
"electrical",
"liquid"
] |
B
|
Relavent Documents:
Document 0:::
In organic chemistry, a Platonic hydrocarbon is a hydrocarbon (molecule) whose structure matches one of the five Platonic solids, with carbon atoms replacing its vertices, carbon–carbon bonds replacing its edges, and hydrogen atoms as needed.
Not all Platonic solids have molecular hydrocarbon counterparts; those that do are the tetrahedron (tetrahedrane), the cube (cubane), and the dodecahedron (dodecahedrane).
Tetrahedrane
Tetrahedrane (C4H4) is a hypothetical compound. It has not yet been synthesized without substituents, but it is predicted to be kinetically stable in spite of its angle strain. Some stable derivatives, including tetra(tert-butyl)tetrahedrane (a hydrocarbon) and tetra(trimethylsilyl)tetrahedrane, have been produced.
Cubane
Cubane (C8H8) has been synthesized. Although it has high angle strain, cubane is kinetically stable, due to a lack of readily available decomposition paths.
Octahedrane
Angle strain would make an octahedron highly unstable due to inverted tetrahedral geometry at each vertex. There would also be no hydrogen atoms because four edges meet at each corner; thus, the hypothetical octahedrane molecule would be an allotrope of elemental carbon, C6, and not a hydrocarbon. The existence of octahedrane cannot be ruled out completely, although calculations have shown that it is unlikely.
Dodecahedrane
Dodecahedrane (C20H20) was first synthesized in 1982, and has minimal angle strain; the tetrahedral angle is 109.5° and the dodecahedral angle is 108°, only a slight discrepancy.
Icosahedrane
The tetravalency (4-connectedness) of carbon excludes an icosahedron because 5 edges meet at each vertex. True pentavalent carbon is unlikely; methanium, nominally , usually exists as . The hypothetical icosahedral lacks hydrogen so it is not a hydrocarbon; it is also an ion.
Both icosahedral and octahedral structures have been observed in boron compounds such as the dodecaborate ion and some of the carbon-containing carboranes.
Other polyhedr
Document 1:::
The prismanes are a class of hydrocarbon compounds consisting of prism-like polyhedra of various numbers of sides on the polygonal base. Chemically, it is a series of fused cyclobutane rings (a ladderane, with all-cis/all-syn geometry) that wraps around to join its ends and form a band, with cycloalkane edges. Their chemical formula is (C2H2)n, where n is the number of cyclobutane sides (the size of the cycloalkane base), and that number also forms the basis for a system of nomenclature within this class. The first few chemicals in this class are:
Triprismane, tetraprismane, and pentaprismane have been synthesized and studied experimentally, and many higher members of the series have been studied using computer models. The first several members do indeed have the geometry of a regular prism, with flat n-gon bases. As n becomes increasingly large, however, modeling experiments find that highly symmetric geometry is no longer stable, and the molecule distorts into less-symmetric forms. One series of modelling experiments found that starting with [11]prismane, the regular-prism form is not a stable geometry. For example, the structure of [12]prismane would have the cyclobutane chain twisted, with the dodecagonal bases non-planar and non-parallel.
Nonconvex prismanes
For large base-sizes, some of the cyclobutanes can be fused anti to each other, giving a non-convex polygon base. These are geometric isomers of the prismanes. Two isomers of [12]prismane that have been studied computationally are named helvetane and israelane, based on the star-like shapes of the rings that form their bases. This was explored computationally after originally being proposed as an April fools joke. Their names refer to the shapes found on the flags of Switzerland and Israel, respectively.
Polyprismanes
The polyprismanes consist of multiple prismanes stacked base-to-base. The carbons at each intermediate level—the n-gon bases where the prismanes fuse to each other—have no hydrogen atom
Document 2:::
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry (informally called the Blue Book). Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
To avoid long and tedious names in normal communication, the official IUPAC naming recommendations are not always followed in practice, except when it is necessary to give an unambiguous and absolute definition to a compound. IUPAC names can sometimes be simpler than older names, as with ethanol, instead of ethyl alcohol. For relatively simple molecules they can be more easily understood than non-systematic names, which must be learnt or looked over. However, the common or trivial name is often substantially shorter and clearer, and so preferred. These non-systematic names are often derived from an original source of the compound. Also, very long names may be less clear than structural formulas.
Basic principles
In chemistry, a number of prefixes, suffixes and infixes are used to describe the type and position of the functional groups in the compound.
The steps for naming an organic compound are:
Identification of the parent hydride parent hydrocarbon chain. This chain must obey the following rules, in order of precedence:
It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, unlike halogen substituents. If more than one functional group is present, the one with highest group precedence should be used.
It should have the maximum number of multiple bonds.
It should have the maximum length.
It should have the maximum number of substituents or branches cited as prefixes
It should have the ma
Document 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:::
A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and is formed between one hybridized orbital from each of the carbon atoms. In ethane, the orbitals are sp3-hybridized orbitals, but single bonds formed between carbon atoms with other hybridizations do occur (e.g. sp2 to sp2). In fact, the carbon atoms in the single bond need not be of the same hybridization. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond.
Chains and branching
Carbon is one of the few elements that can form long chains of its own atoms, a property called catenation. This coupled with the strength of the carbon–carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements of life, so carbon compounds have their own field of study: organic chemistry.
Branching is also common in C−C skeletons. Carbon atoms in a molecule are categorized by the number of carbon neighbors they have:
A primary carbon has one carbon neighbor.
A secondary carbon has two carbon neighbors.
A tertiary carbon has three carbon neighbors.
A quaternary carbon has four carbon neighbors.
In "structurally complex organic molecules", it is the three-dimensional orientation of the carbon–carbon bonds at quaternary loci which dictates the shape of the molecule. Further, quaternary loci are found in many biologically active small molecules, such as cortisone and morphine.
Synthesis
Carbon–carbon bond-forming reactions are organic reactions in which a new carbon–carbon bond is formed. They are important in th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Many hydrocarbons are cyclic and adopt specific three-dimensional structures that influence their physical and what properties?
A. radiation
B. chemical
C. electrical
D. liquid
Answer:
|
|
sciq-11488
|
multiple_choice
|
New land can be created when what happens to a volcano?
|
[
"it stays dormant",
"it evolves",
"it dies",
"it erupts"
] |
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:::
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 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:::
Tech City College (Formerly STEM Academy) is a free school sixth form located in the Islington area of the London Borough of Islington, England.
It originally opened in September 2013, as STEM Academy Tech City and specialised in Science, Technology, Engineering and Maths (STEM) and the Creative Application of Maths and Science. In September 2015, STEM Academy joined the Aspirations Academy Trust was renamed Tech City College. Tech City College offers A-levels and BTECs as programmes of study for students.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
New land can be created when what happens to a volcano?
A. it stays dormant
B. it evolves
C. it dies
D. it erupts
Answer:
|
|
ai2_arc-847
|
multiple_choice
|
Rat snakes, Elaphe obsoleta, are a species made of many distinct populations in different areas. Each of the populations has different markings and colorings. Where would rat snakes most likely be gray?
|
[
"in a forest",
"in a swamp",
"in a gravel pit",
"in a corn field"
] |
C
|
Relavent Documents:
Document 0:::
The Haitian border threadsnake (Mitophis leptepileptus) is a possibly extinct species of snake in the family Leptotyphlopidae endemic to Haiti.
Description
Last seen in 1984, the species was thought to be already rare, but intensive surveys in the area have not recorded it. If it is extinct, causes are certainly due to deforestation of its habitat and agricultural activities, which have intensified since its last collection.
Document 1:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
Joy Tivy FRSE FRSGS FIB (1924–1995) was a 20th century Irish physical geographer at the University of Glasgow. She specialised in biogeography and has been credited for having helped raise the profile of biogeography as a distinct sub-discipline of geography. She published over 40 papers, books and reports and she was often asked to advise government agencies and other organisations. She was a strong advocate of the importance of field studies for providing essential skills for geography graduates. Her capacity as a teacher was as highly regarded as her research — she was known to be enthusiastic and engaging to a wide range of audiences - a medal has been created by the Royal Scottish Geographical Society in honour of her commitment to Geographical Education and Teaching.
Life
Joy Tivy was born in Carlow, Ireland on 24 August 1924.
She commenced studies at the University College Dublin in 1942 where she studied geography as her primary subject with botany and geology as her secondary areas. She excelled as an undergraduate most notably scoring highest in highly competitive exams in 1944, which granted her status as a Scholar. She graduated with first class honours in 1946 and after a brief period of teaching at the University of Leeds she accepted a position at the University of Edinburgh where she completed her doctorate. Her PhD thesis was entitled, A study of the effect of physical factors on the vegetation of hill grazings in selected areas of southern Scotland, p. 55. In 1956 she moved to the University of Glasgow where she stayed for the rest of her career (she retired in 1989). She was the second female to be awarded at professorship at the University of Glasgow in 1976 and was head of the Department of Geography and Topographic Science.
In 1984 she was elected a Fellow of the Royal Society of Edinburgh. Her proposers were John Lenihan, William Whigham Fletcher, Donald Michie, S. G. Checkland, Lord Cameron, and Wreford Watson. She was also elected a Fell
Document 4:::
Advanced Placement (AP) Calculus (also known as AP Calc, Calc AB / Calc BC or simply AB / BC) is a set of two distinct Advanced Placement calculus courses and exams offered by the American nonprofit organization College Board. AP Calculus AB covers basic introductions to limits, derivatives, and integrals. AP Calculus BC covers all AP Calculus AB topics plus additional topics (including integration by parts, Taylor series, parametric equations, vector calculus, and polar coordinate functions).
AP Calculus AB
AP Calculus AB is an Advanced Placement calculus course. It is traditionally taken after precalculus and is the first calculus course offered at most schools except for possibly a regular calculus class. The Pre-Advanced Placement pathway for math helps prepare students for further Advanced Placement classes and exams.
Purpose
According to the College Board:
Topic outline
The material includes the study and application of differentiation and integration, and graphical analysis including limits, asymptotes, and continuity. An AP Calculus AB course is typically equivalent to one semester of college calculus.
Analysis of graphs (predicting and explaining behavior)
Limits of functions (one and two sided)
Asymptotic and unbounded behavior
Continuity
Derivatives
Concept
At a point
As a function
Applications
Higher order derivatives
Techniques
Integrals
Interpretations
Properties
Applications
Techniques
Numerical approximations
Fundamental theorem of calculus
Antidifferentiation
L'Hôpital's rule
Separable differential equations
AP Calculus BC
AP Calculus BC is equivalent to a full year regular college course, covering both Calculus I and II. After passing the exam, students may move on to Calculus III (Multivariable Calculus).
Purpose
According to the College Board,
Topic outline
AP Calculus BC includes all of the topics covered in AP Calculus AB, as well as the following:
Convergence tests for series
Taylor series
Parametric equations
Polar functions (inclu
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Rat snakes, Elaphe obsoleta, are a species made of many distinct populations in different areas. Each of the populations has different markings and colorings. Where would rat snakes most likely be gray?
A. in a forest
B. in a swamp
C. in a gravel pit
D. in a corn field
Answer:
|
|
sciq-2035
|
multiple_choice
|
Like people with type 1 diabetes, people with type 2 diabetes must frequently check what level?
|
[
"glucose",
"blood sugar",
"pulse",
"heartbeat"
] |
B
|
Relavent Documents:
Document 0:::
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 1:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 2:::
Single Best Answer (SBA or One Best Answer) is a written examination form of multiple choice questions used extensively in medical education.
Structure
A single question is posed with typically five alternate answers, from which the candidate must choose the best answer. This method avoids the problems of past examinations of a similar form described as Single Correct Answer. The older form can produce confusion where more than one of the possible answers has some validity. The newer form makes it explicit that more than one answer may have elements that are correct, but that one answer will be superior.
Prior to the widespread introduction of SBAs into medical education, the typical form of examination was true-false multiple choice questions. But during the 2000s, educators found that SBAs would be superior.
Document 3:::
Progress tests are longitudinal, feedback oriented educational assessment tools for the evaluation of development and sustainability of cognitive knowledge during a learning process. A progress test is a written knowledge exam (usually involving multiple choice questions) that is usually administered to all students in the "A" program at the same time and at regular intervals (usually twice to four times yearly) throughout the entire academic program. The test samples the complete knowledge domain expected of new graduates upon completion of their courses, regardless of the year level of the student). The differences between students’ knowledge levels show in the test scores; the further a student has progressed in the curriculum the higher the scores. As a result, these resultant scores provide a longitudinal, repeated measures, curriculum-independent assessment of the objectives (in knowledge) of the entire programme.
History
Since its inception in the late 1970s at both Maastricht University and the University of Missouri–Kansas City independently, the progress test of applied knowledge has been increasingly used in medical and health sciences programs across the globe. They are well established and increasingly used in medical education in both undergraduate and postgraduate medical education. They are used formatively and summatively.
Use in academic programs
The progress test is currently used by national progress test consortia in the United Kingdom, Italy, The Netherlands, in Germany (including Austria), and in individual schools in Africa, Saudi Arabia, South East Asia, the Caribbean, Australia, New Zealand, Sweden, Finland, UK, and the USA. The National Board of Medical Examiners in the USA also provides progress testing in various countries The feasibility of an international approach to progress testing has been recently acknowledged and was first demonstrated by Albano et al. in 1996, who compared test scores across German, Dutch and Italian medi
Document 4:::
The SAT Subject Test in Biology was the name of a one-hour multiple choice test given on biology by the College Board. A student chose whether to take the test depending upon college entrance requirements for the schools in which the student is planning to apply. Until 1994, the SAT Subject Tests were known as Achievement Tests; and from 1995 until January 2005, they were known as SAT IIs. Of all SAT subject tests, the Biology E/M test was the only SAT II that allowed the test taker a choice between the ecological or molecular tests. A set of 60 questions was taken by all test takers for Biology and a choice of 20 questions was allowed between either the E or M tests. This test was graded on a scale between 200 and 800. The average for Molecular is 630 while Ecological is 591.
On January 19 2021, the College Board discontinued all SAT Subject tests, including the SAT Subject Test in Biology E/M. This was effective immediately in the United States, and the tests were to be phased out by the following summer for international students. This was done as a response to changes in college admissions due to the impact of the COVID-19 pandemic on education.
Format
This test had 80 multiple-choice questions that were to be answered in one hour. All questions had five answer choices. Students received one point for each correct answer, lost ¼ of a point for each incorrect answer, and received 0 points for questions left blank. The student's score was based entirely on his or her performance in answering the multiple-choice questions.
The questions covered a broad range of topics in general biology. There were more specific questions related respectively on ecological concepts (such as population studies and general Ecology) on the E test and molecular concepts such as DNA structure, translation, and biochemistry on the M test.
Preparation
The College Board suggested a year-long course in biology at the college preparatory level, as well as a one-year course in algebra, a
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Like people with type 1 diabetes, people with type 2 diabetes must frequently check what level?
A. glucose
B. blood sugar
C. pulse
D. heartbeat
Answer:
|
|
sciq-3374
|
multiple_choice
|
What three parameters do seismographs measure?
|
[
"trouble , length and distance",
"strength, length and distance",
"height, width and distance",
"aging , length and distance"
] |
B
|
Relavent Documents:
Document 0:::
In geophysics, admittance is a term for a transfer function, that measures the response (can be amplitude, force) to the applied change (force, pressure) in function of variable of interest (frequency, wave number) applied to the physical body, such as the atmosphere or the Earth's crust. In seismology or geodesy it describes the effects of the body to applied forcing (tidal admittance ).
The admittance Q(k) can be also defined as the transfer function between the spectral representation of gravity G(k) and topography H(k):
N(k) is the uncorrelated noise in the data (assumed to be small) and k is the two-dimensional wave number ()where l is the wavelength.
Another application of admittance in geophysics takes atmospheric pressure as the input and measures changes in the gravitational field as the output. In such case admittance is measured in μGal/mbar. These units convert according to 1 Gal = 0.01 m/s2 and 1 bar = 100 kPa, so in SI units the measurement would be in units of;
or or or, in primary units
However, the relationship is not a straightforward one of proportionality. Rather, an admittance function is described which is time and frequency dependent in a complex way.
Document 1:::
Seismic moment is a quantity used by seismologists to measure the size of an earthquake. The scalar seismic moment is defined by the equation
, where
is the shear modulus of the rocks involved in the earthquake (in pascals (Pa), i.e. newtons per square meter)
is the area of the rupture along the geologic fault where the earthquake occurred (in square meters), and
is the average slip (displacement offset between the two sides of the fault) on (in meters).
thus has dimensions of torque, measured in newton meters. The connection between seismic moment and a torque is natural in the body-force equivalent representation of seismic sources as a double-couple (a pair of force couples with opposite torques): the seismic moment is the torque of each of the two couples. Despite having the same dimensions as energy, seismic moment is not a measure of energy. The relations between seismic moment, potential energy drop and radiated energy are indirect and approximative.
The seismic moment of an earthquake is typically estimated using whatever information is available to constrain its factors. For modern earthquakes, moment is usually estimated from ground motion recordings of earthquakes known as seismograms. For earthquakes that occurred in times before modern instruments were available, moment may be estimated from geologic estimates of the size of the fault rupture and the slip.
Seismic moment is the basis of the moment magnitude scale introduced by Hiroo Kanamori, which is often used to compare the size of different earthquakes and is especially useful for comparing the sizes of large (great) earthquakes.
The seismic moment is not restricted to earthquakes. For a more general seismic source described by a seismic moment tensor (a symmetric tensor, but not necessarily a double couple tensor), the seismic moment is
See also
Richter magnitude scale
Moment magnitude scale
Sources
.
.
.
.
Seismology measurement
Moment (physics)
Document 2:::
Seismic Handler (SH) is an interactive analysis program for preferably continuous waveform data. It was developed at the Seismological Observatory Gräfenberg and is in use there for daily routine analysis of local and global seismic events. In original form Seismic Handler was command line based, but now an interactive version is available.
Main features
Reading traces from continuous data streams in Steim-compressed MiniSEED files. Additionally supported formats are event data from GSE, AH and Q (private format of SH) files.
Zoom in and out traces in time and amplitude.
Application of a set of standard filters (simulation filters and Butterworth filters) on broadband input traces.
Reading phases on original or preprocessed traces.
Determination of signal/noise ratio
Computation of teleseismic beam traces using array-beamforming or FK-algorithm, determination of slowness and back-azimuth of an incoming wavefront.
Location of teleseismic events using global travel time tables based on array methods or relative travel times, determination of focal depth using depth phases
Location of regional and local events using LocSAT program, flexible interface provided for integration of own location programs.
Integration of an own external programs (e.g.: map display, phase diagrams).
Displaying theoretical travel times.
Determination of amplitudes and magnitudes (ml or mb and Ms).
Saving analysis results into an output text file for further processing.
Supported operating systems: Solaris and Linux
Additional features
Rotation of 3-component seismograms
Particle motion diagrams
Vespagram-like trace summation
Trace spectrum display
External links
Seismic Handler official home page (SHM)
Seismic Handler development site
Seismological Observatory Gräfenberg (SZGRF)
Science software
Seismology measurement
Document 3:::
The Richter scale (), also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale, is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 paper, where he called it the "magnitude scale". This was later revised and renamed the local magnitude scale, denoted as ML or .
Because of various shortcomings of the original scale, most seismological authorities now use other similar scales such as the moment magnitude scale () to report earthquake magnitudes, but much of the news media still erroneously refers to these as "Richter" magnitudes. All magnitude scales retain the logarithmic character of the original and are scaled to have roughly comparable numeric values (typically in the middle of the scale). Due to the variance in earthquakes, it is essential to understand the Richter scale uses logarithms simply to make the measurements manageable (i.e., a magnitude 3 quake factors 10³ while a magnitude 5 quake is 100 times stronger than that).
Richter magnitudes
The Richter magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs (adjustments are included to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquake). The original formula is:
where is the maximum excursion of the Wood-Anderson seismograph, the empirical function depends only on the epicentral distance of the station, . In practice, readings from all observing stations are averaged after adjustment with station-specific corrections to obtain the value.
Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; in terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released, and each increase of 0.2 corresponds to approximately a doubling of the energy rel
Document 4:::
The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates.
Determination
The primary purpose of a seismometer is to locate the initiating points of earthquake epicenters. The secondary purpose, of determining the 'size' or magnitude must be calculated after the precise location is known.
The earliest seismographs were designed to give a sense of the direction of the first motions from an earthquake. The Chinese frog seismograph would have dropped its ball in the general compass direction of the earthquake, assuming a strong positive pulse. We now know that first motions can be in almost any direction depending on the type of initiating rupture (focal mechanism).
The first refinement that allowed a more precise determination of the location was the use of a time scale. Instead of merely noting, or recording, the absolute motions of a pendulum, the displacements were plotted on a moving graph, driven by a clock mechanism. This was the first seismogram, which allowed precise timing of the first ground motion, and an accurate plot of subsequent motions.
From the first seismograms, as seen in the figure, it was noticed that the trace was divided into two major portions. The first seismic wave to arrive was the P-wave, followed closely by the S-wave. Knowing the relative 'velocities of propagation', it was a simple matter to calculate the distance of the earthquake.
One seismograph would give the distance, but that could be plotted as a circle, with an infinite number of possibilities. Two seismographs would give two intersecting circles, with two possible locations. Only with a third seismograph would there be a precise location.
Modern earthquake location still requires a minimum of three seismometers. Most likely, there are many, forming a seismic array. The emphasis is on precision since much can be learned about the fau
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What three parameters do seismographs measure?
A. trouble , length and distance
B. strength, length and distance
C. height, width and distance
D. aging , length and distance
Answer:
|
|
sciq-1614
|
multiple_choice
|
Along with dna, what is the other main type of nucleic acid?
|
[
"cytoplasm",
"protein",
"rna",
"nucleotides"
] |
C
|
Relavent Documents:
Document 0:::
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 1:::
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 2:::
Experimental approaches of determining the structure of nucleic acids, such as RNA and DNA, can be largely classified into biophysical and biochemical methods. Biophysical methods use the fundamental physical properties of molecules for structure determination, including X-ray crystallography, NMR and cryo-EM. Biochemical methods exploit the chemical properties of nucleic acids using specific reagents and conditions to assay the structure of nucleic acids. Such methods may involve chemical probing with specific reagents, or rely on native or analogue chemistry. Different experimental approaches have unique merits and are suitable for different experimental purposes.
Biophysical methods
X-ray crystallography
X-ray crystallography is not common for nucleic acids alone, since neither DNA nor RNA readily form crystals. This is due to the greater degree of intrinsic disorder and dynamism in nucleic acid structures and the negatively charged (deoxy)ribose-phosphate backbones, which repel each other in close proximity. Therefore, crystallized nucleic acids tend to be complexed with a protein of interest to provide structural order and neutralize the negative charge.
Nuclear magnetic resonance spectroscopy (NMR)
Nucleic acid NMR is the use of NMR spectroscopy to obtain information about the structure and dynamics of nucleic acid molecules, such as DNA or RNA. As of 2003, nearly half of all known RNA structures had been determined by NMR spectroscopy.
Nucleic acid NMR uses similar techniques as protein NMR, but has several differences. Nucleic acids have a smaller percentage of hydrogen atoms, which are the atoms usually observed in NMR, and because nucleic acid double helices are stiff and roughly linear, they do not fold back on themselves to give "long-range" correlations. The types of NMR usually done with nucleic acids are 1H or proton NMR, 13C NMR, 15N NMR, and 31P NMR. Two-dimensional NMR methods are almost always used, such as correlation spectroscopy (COSY
Document 3:::
Nucleic acid analogues are compounds which are analogous (structurally similar) to naturally occurring RNA and DNA, used in medicine and in molecular biology research.
Nucleic acids are chains of nucleotides, which are composed of three parts: a phosphate backbone, a pentose sugar, either ribose or deoxyribose, and one of four nucleobases.
An analogue may have any of these altered. Typically the analogue nucleobases confer, among other things, different base pairing and base stacking properties. Examples include universal bases, which can pair with all four canonical bases, and phosphate-sugar backbone analogues such as PNA, which affect the properties of the chain (PNA can even form a triple helix).
Nucleic acid analogues are also called Xeno Nucleic Acid and represent one of the main pillars of xenobiology, the design of new-to-nature forms of life based on alternative biochemistries.
Artificial nucleic acids include peptide nucleic acid (PNA), Morpholino and locked nucleic acid (LNA), as well as glycol nucleic acid (GNA), threose nucleic acid (TNA) and hexitol nucleic acids (HNA). Each of these is distinguished from naturally occurring DNA or RNA by changes to the backbone of the molecule.
In May 2014, researchers announced that they had successfully introduced two new artificial nucleotides into bacterial DNA, and by including individual artificial nucleotides in the culture media, were able to passage the bacteria 24 times; they did not create mRNA or proteins able to use the artificial nucleotides. The artificial nucleotides featured 2 fused aromatic rings.
Medicine
Several nucleoside analogues are used as antiviral or anticancer agents. The viral polymerase incorporates these compounds with non-canonical bases. These compounds are activated in the cells by being converted into nucleotides, they are administered as nucleosides since charged nucleotides cannot easily cross cell membranes.
Molecular biology
Nucleic acid analogues are used in molecular b
Document 4:::
In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated). DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria (a Bacterial Artificial Chromosome or BAC library) or yeast such that each organism contains on average one construct (vector + insert). As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated (thus, "cloned").
Terminology
The term "library" can refer to a population of organisms, each of which carries a DNA molecule inserted into a cloning vector, or alternatively to the collection of all of the cloned vector molecules.
cDNA libraries
A cDNA library represents a sample of the mRNA purified from a particular source (either a collection of cells, a particular tissue, or an entire organism), which has been converted back to a DNA template by the use of the enzyme reverse transcriptase. It thus represents the genes that were being actively transcribed in that particular source under the physiological, developmental, or environmental conditions that existed when the mRNA was purified. cDNA libraries can be generated using techniques that promote "full-length" clones or under conditions that generate shorter f
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Along with dna, what is the other main type of nucleic acid?
A. cytoplasm
B. protein
C. rna
D. nucleotides
Answer:
|
|
sciq-5739
|
multiple_choice
|
What system carries nerve impulses to internal organs, controlling activities that are not under your control, such as sweating and digesting food?
|
[
"circulatory nervous system",
"autonomic nervous system",
"hormonal nervous system",
"limbic nervous system"
] |
B
|
Relavent Documents:
Document 0:::
Body reactivity is usually understood as the body's ability to react in a proper way to influence the environment. Resistance of an organism is its stability under the influence of pathogenic factors. The body reactivity can range from homeostasis to a fight or flight response. Ultimately, they are all governed by the nervous system.
Nervous system divisions
The central nervous system (CNS) consists of parts that are encased by the bones of the skull and spinal column: the brain and spinal cord. The peripheral nervous system (PNS) is found outside those bones and consists of the nerves and most of the sensory organs.
Central nervous system
The CNS can be divided into the brain and spinal cord. The CNS processes many different kinds of incoming sensory information. It is also the source of thoughts, emotions, and memories. Most signals that stimulate muscles to contract and glands to secrete originate in the CNS. The spinal cord and spinal nerves contribute to homeostasis by providing quick reflexive responses to many stimuli. The spinal cord is the pathway for sensory input to the brain and motor output from the brain. The brain is responsible for integrating most sensory information and coordinating body function, both consciously and unconsciously.
Peripheral nervous system
The PNS can be divided into the autonomic and somatic nervous system. The autonomic nervous system can be divided into the parasympathetic, sympathetic, and enteric nervous system. The sympathetic nervous system regulates the “fight or flight” responses. The parasympathetic nervous system regulates the “rest and digest” responses. The enteric nervous system innervates the viscera (gastrointestinal tract, pancreas, and gall bladder). The somatic nervous system consists of peripheral nerve fibers that send sensory information to the central nervous system and motor nerve fibers that project to skeletal muscle. The somatic nervous system engages in voluntary reactions, and the autonomic nervous
Document 1:::
The following diagram is provided as an overview of and topical guide to the human nervous system:
Human nervous system – the part of the human body that coordinates a person's voluntary and involuntary actions and transmits signals between different parts of the body. The human nervous system consists of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are long fibers that connect the CNS to every other part of the body. The PNS includes motor neurons, mediating voluntary movement; the autonomic nervous system, comprising the sympathetic nervous system and the parasympathetic nervous system and regulating involuntary functions; and the enteric nervous system, a semi-independent part of the nervous system whose function is to control the gastrointestinal system.
Evolution of the human nervous system
Evolution of nervous systems
Evolution of human intelligence
Evolution of the human brain
Paleoneurology
Some branches of science that study the human nervous system
Neuroscience
Neurology
Paleoneurology
Central nervous system
The central nervous system (CNS) is the largest part of the nervous system and includes the brain and spinal cord.
Spinal cord
Brain
Brain – center of the nervous system.
Outline of the human brain
List of regions of the human brain
Principal regions of the vertebrate brain:
Peripheral nervous system
Peripheral nervous system (PNS) – nervous system structures that do not lie within the CNS.
Sensory system
A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception.
List of sensory systems
Sensory neuron
Perception
Visual system
Auditory system
Somatosensory system
Vestibular system
Olfactory system
Taste
Pain
Components of the nervous system
Neuron
I
Document 2:::
Cutaneous innervation refers to an area of the skin which is supplied by a specific cutaneous nerve.
Dermatomes are similar; however, a dermatome only specifies the area served by a spinal nerve. In some cases, the dermatome is less specific (when a spinal nerve is the source for more than one cutaneous nerve), and in other cases it is more specific (when a cutaneous nerve is derived from multiple spinal nerves.)
Modern texts are in agreement about which areas of the skin are served by which nerves, but there are minor variations in some of the details. The borders designated by the diagrams in the 1918 edition of Gray's Anatomy are similar, but not identical, to those generally accepted today.
Importance of the peripheral nervous system
The peripheral nervous system (PNS) is divided into the somatic nervous system, the autonomic nervous system, and the enteric nervous system. However, it is the somatic nervous system, responsible for body movement and the reception of external stimuli, which allows one to understand how cutaneous innervation is made possible by the action of specific sensory fibers located on the skin, as well as the distinct pathways they take to the central nervous system. The skin, which is part of the integumentary system, plays an important role in the somatic nervous system because it contains a range of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury.
Importance of the central nervous system
The central nervous system (CNS) works with the peripheral nervous system in cutaneous innervation. The CNS is responsible for processing the information it receives from the cutaneous nerves that detect a given stimulus, and then identifying the kind of sensory inputs which project to a specific region of the primary somatosensory cortex.
The role of nerve endings on the surface of the skin
Groups of nerve terminals located in the different layers of the skin are categorized depending on whether the skin
Document 3:::
The enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract. It is capable of acting independently of the sympathetic and parasympathetic nervous systems, although it may be influenced by them. The ENS is nicknamed the "second brain". It is derived from neural crest cells.
The enteric nervous system is capable of operating independently of the brain and spinal cord, but does rely on innervation from the vagus nerve and prevertebral ganglia in healthy subjects. However, studies have shown that the system is operable with a severed vagus nerve. The neurons of the enteric nervous system control the motor functions of the system, in addition to the secretion of gastrointestinal enzymes. These neurons communicate through many neurotransmitters similar to the CNS, including acetylcholine, dopamine, and serotonin. The large presence of serotonin and dopamine in the gut are key areas of research for neurogastroenterologists.
Structure
The enteric nervous system in humans consists of some 500 million neurons (including the various types of Dogiel cells), 0.5% of the number of neurons in the brain, five times as many as the one hundred million neurons in the human spinal cord, and about as many as in the whole nervous system of a cat. The enteric nervous system is embedded in the lining of the gastrointestinal system, beginning in the esophagus and extending down to the anus.
The neurons of the ENS are collected into two types of ganglia: myenteric (Auerbach's) and submucosal (Meissner's) plexuses. Myenteric plexuses are located between the inner and outer layers of the muscularis externa, while submucosal plexuses are located in the submucosa.
Auerbach's plexus
Auerbach's plexus, also known as the myenteric plexus, is a collection of fibers and postganglionic autonomic cell bodies that lie betwe
Document 4:::
The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways, and parts of the brain involved in sensory perception and interoception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, balance and visceral sensation. Sense organs are transducers that convert data from the outer physical world to the realm of the mind where people interpret the information, creating their perception of the world around them.
The receptive field is the area of the body or environment to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field. Receptive fields have been identified for the visual system, auditory system and somatosensory system.
Stimulus
Organisms need information to solve at least three kinds of problems: (a) to maintain an appropriate environment, i.e., homeostasis; (b) to time activities (e.g., seasonal changes in behavior) or synchronize activities with those of conspecifics; and (c) to locate and respond to resources or threats (e.g., by moving towards resources or evading or attacking threats). Organisms also need to transmit information in order to influence another's behavior: to identify themselves, warn conspecifics of danger, coordinate activities, or deceive.
Sensory systems code for four aspects of a stimulus; type (modality), intensity, location, and duration. Arrival time of a sound pulse and phase differences of continuous sound are used for sound localization. Certain receptors are sensitive to certain types of stimuli (for example, different mechanoreceptors respond best to different kinds of touch stimuli, like sharp or blunt objects). Receptors send impulses in certain patterns to send information about the intensity of a stimul
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What system carries nerve impulses to internal organs, controlling activities that are not under your control, such as sweating and digesting food?
A. circulatory nervous system
B. autonomic nervous system
C. hormonal nervous system
D. limbic nervous system
Answer:
|
|
sciq-1333
|
multiple_choice
|
Fossil records show that what process may occur in "fits and starts"?
|
[
"variation",
"generation",
"evolution",
"isolation"
] |
C
|
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:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
The 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 3:::
In evolutionary biology, megatrajectories are the major evolutionary milestones and directions in the evolution of life.
Posited by A. H. Knoll and Richard K. Bambach in their 2000 collaboration, "Directionality in the History of Life," Knoll and Bamback argue that, in consideration of the problem of progress in evolutionary history, a middle road that encompasses both contingent and convergent features of biological evolution may be attainable through the idea of the megatrajectory:
We believe that six broad megatrajectories capture the essence of vectoral change in the history of life. The megatrajectories for a logical sequence dictated by the necessity for complexity level N to exist before N+1 can evolve...In the view offered here, each megatrajectory adds new and qualitatively distinct dimensions to the way life utilizes ecospace.
According to Knoll and Bambach, the six megatrajectories outlined by biological evolution thus far are:
the origin of life to the "Last Common Ancestor"
prokaryote diversification
unicellular eukaryote diversification
multicellular organisms
land organisms
appearance of intelligence and technology
Milan M. Ćirković and Robert Bradbury, have taken the megatrajectory concept one step further by theorizing that a seventh megatrajectory exists: postbiological evolution triggered by the emergence of artificial intelligence at least equivalent to the biologically-evolved one, as well as the invention of several key technologies of the similar level of complexity and environmental impact, such as molecular nanoassembling or stellar uplifting.
See also
Intelligence principle
Document 4:::
In biology, evolution is the process of change in all forms of life over generations, and evolutionary biology is the study of how evolution occurs. Biological populations evolve through genetic changes that correspond to changes in the organisms' observable traits. Genetic changes include mutations, which are caused by damage or replication errors in organisms' DNA. As the genetic variation of a population drifts randomly over generations, natural selection gradually leads traits to become more or less common based on the relative reproductive success of organisms with those traits.
The age of the Earth is about 4.5 billion years. The earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago. Evolution does not attempt to explain the origin of life (covered instead by abiogenesis), but it does explain how early lifeforms evolved into the complex ecosystem that we see today. Based on the similarities between all present-day organisms, all life on Earth is assumed to have originated through common descent from a last universal ancestor from which all known species have diverged through the process of evolution.
All individuals have hereditary material in the form of genes received from their parents, which they pass on to any offspring. Among offspring there are variations of genes due to the introduction of new genes via random changes called mutations or via reshuffling of existing genes during sexual reproduction. The offspring differs from the parent in minor random ways. If those differences are helpful, the offspring is more likely to survive and reproduce. This means that more offspring in the next generation will have that helpful difference and individuals will not have equal chances of reproductive success. In this way, traits that result in organisms being better adapted to their living conditions become more common in descendant populations. These differences accumulate resulting in changes within the population. This proce
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Fossil records show that what process may occur in "fits and starts"?
A. variation
B. generation
C. evolution
D. isolation
Answer:
|
|
ai2_arc-367
|
multiple_choice
|
Visible light passes through glass. Other types of electromagnetic radiation are able to pass through other materials in a similar way. Which of the following are used in medical technology because they can pass through some parts of the human body?
|
[
"x-rays",
"infrared waves",
"microwaves",
"ultraviolet rays"
] |
A
|
Relavent Documents:
Document 0:::
Medical applications of radio frequency (RF) energy, in the form of electromagnetic waves (radio waves) or electrical currents, have existed for over 125 years, and now include diathermy, hyperthermy treatment of cancer, electrosurgery scalpels used to cut and cauterize in operations, and radiofrequency ablation. Magnetic resonance imaging (MRI) uses radio frequency waves to generate images of the human body.
Radio frequencies at non-ablation energy levels are commonly used as a part of aesthetic treatments that can tighten skin, reduce fat by lipolysis and also apoptosis, or promote healing.
RF diathermy is a medical treatment that uses RF induced heat as a form of physical therapy and in surgical procedures. It is commonly used for muscle relaxation. It is also a method of heating tissue electromagnetically for therapeutic purposes in medicine. Diathermy is used in physical therapy to deliver moderate heat directly to pathologic lesions in the deeper tissues of the body. Surgically, the extreme heat that can be produced by diathermy may be used to destroy neoplasms, warts, and infected tissues, and to cauterize blood vessels to prevent excessive bleeding. The technique is particularly valuable in neurosurgery and surgery of the eye. Diathermy equipment typically operates in the short-wave radio frequency (range 1–100 MHz) or microwave energy (range 434–915 MHz).
Pulsed electromagnetic field therapy (PEMF) is a medical treatment that purportedly helps to heal bone tissue reported in a recent NASA study. This method usually employs electromagnetic radiation of different frequencies – ranging from static magnetic fields, through extremely low frequencies (ELF) to higher radio frequencies (RF) administered in pulses.
History
The idea that high-frequency electromagnetic currents could have therapeutic effects was explored independently around the same time (1890–91) by French physician and biophysicist Jacques Arsene d'Arsonval and Serbian American engineer Nikol
Document 1:::
Clinical biophysics is that branch of medical science that studies the action process and the effects of non-ionising physical energies utilised for therapeutic purposes.
Physical energy can be applied for diagnostic or therapeutic aims.
The principle on which clinical biophysics is based are represented by the recognizability and the specificity of the physical signal applied:
recognizability: the capacity of the biological target to recognise the presence of the physical energy: this aspect becomes more important with the lowering of the energy applied.
specificity: the capacity of the physical agent applied to the biological target to obtain a response depending on its physical characteristics: frequency, length, energy, etc. The effects do not necessarily depend on the quantity of energy applied to the biological target.
Definition
Several papers show that the response of a biological system when exposed to non-ionizing physical stimuli is not necessarily dependent on the amount of energy applied.
Specific combinations of amplitude, frequency and waveform may trigger the most intense response. For example, cell proliferation or activation of metabolic pathways.
This has been demonstrated for:
a) mechanical strains directly applied to the cells or tissue;
b) mechanical energy applied by ultrasound;
c) electromagnetic field exposure;
d) electric field exposure.
Several pre-clinical experiences have laid the foundation to identify exposure conditions that may be used in humans to treat diseases or to promote tissue healing.
The identification of the best parameters to apply in any particular circumstance is the current goal of research activities in the field.
Medical applications
Orthopaedics
PEMF
LIPUS
CCEF
Direct current
Neurology
Plastic surgery
Oncology
Document 2:::
Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities. Although imaging of removed organs and tissues can be performed for medical reasons, such procedures are usually considered part of pathology instead of medical imaging.
Measurement and recording techniques that are not primarily designed to produce images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (ECG), and others, represent other technologies that produce data susceptible to representation as a parameter graph versus time or maps that contain data about the measurement locations. In a limited comparison, these technologies can be considered forms of medical imaging in another discipline of medical instrumentation.
As of 2010, 5 billion medical imaging studies had been conducted worldwide. Radiation exposure from medical imaging in 2006 made up about 50% of total ionizing radiation exposure in the United States. Medical imaging equipment is manufactured using technology from the semiconductor industry, including CMOS integrated circuit chips, power semiconductor devices, sensors such as image sensors (particularly CMOS sensors) and biosensors, and processors such as microcontrollers, microprocessors, digital signal processors, media processors and system-on-chip devices. , annual shipments of medical imaging chips amount to 46million units and .
Medical imaging is often perceived to designate the set of techniques that noninvasively produce images of the internal aspect of the body. In this restricted sense, medical imaging can be seen as the solution to mathem
Document 3:::
Medical physics deals with the application of the concepts and methods of physics to the prevention, diagnosis and treatment of human diseases with a specific goal of improving human health and well-being. Since 2008, medical physics has been included as a health profession according to International Standard Classification of Occupation of the International Labour Organization.
Although medical physics may sometimes also be referred to as biomedical physics, medical biophysics, applied physics in medicine, physics applications in medical science, radiological physics or hospital radio-physics, a "medical physicist" is specifically a health professional with specialist education and training in the concepts and techniques of applying physics in medicine and competent to practice independently in one or more of the subfields of medical physics. Traditionally, medical physicists are found in the following healthcare specialties: radiation oncology (also known as radiotherapy or radiation therapy), diagnostic and interventional radiology (also known as medical imaging), nuclear medicine, and radiation protection. Medical physics of radiation therapy can involve work such as dosimetry, linac quality assurance, and brachytherapy. Medical physics of diagnostic and interventional radiology involves medical imaging techniques such as magnetic resonance imaging, ultrasound, computed tomography and x-ray. Nuclear medicine will include positron emission tomography and radionuclide therapy. However one can find Medical Physicists in many other areas such as physiological monitoring, audiology, neurology, neurophysiology, cardiology and others.
Medical physics departments may be found in institutions such as universities, hospitals, and laboratories. University departments are of two types. The first type are mainly concerned with preparing students for a career as a hospital Medical Physicist and research focuses on improving the practice of the profession. A second type (in
Document 4:::
Biological imaging may refer to any imaging technique used in biology.
Typical examples include:
Bioluminescence imaging, a technique for studying laboratory animals using luminescent protein
Calcium imaging, determining the calcium status of a tissue using fluorescent light
Diffuse optical imaging, using near-infrared light to generate images of the body
Diffusion-weighted imaging, a type of MRI that uses water diffusion
Fluorescence lifetime imaging, using the decay rate of a fluorescent sample
Gallium imaging, a nuclear medicine method for the detection of infections and cancers
Imaging agent, a chemical designed to allow clinicians to determine whether a mass is benign or malignant
Imaging studies, which includes many medical imaging techniques
Magnetic resonance imaging (MRI), a non-invasive method to render images of living tissues
Magneto-acousto-electrical tomography (MAET), is an imaging modality to image the electrical conductivity of biological tissues
Medical imaging, creating images of the human body or parts of it, to diagnose or examine disease
Microscopy, creating images of objects or features too small to be detectable by the naked human eye
Molecular imaging, used to study molecular pathways inside organisms
Non-contact thermography, is the field of thermography that derives diagnostic indications from infrared images of the human body.
Nuclear medicine, uses administered radioactive substances to create images of internal organs and their function.
Optical imaging, using light as an investigational tool for biological research and medical diagnosis
Optoacoustic imaging, using the photothermal effect, for the accuracy of spectroscopy with the depth resolution of ultrasound
Photoacoustic Imaging, a technique to detect vascular disease and cancer using non-ionizing laser pulses
Ultrasound imaging, using very high frequency sound to visualize muscles and internal organs
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Visible light passes through glass. Other types of electromagnetic radiation are able to pass through other materials in a similar way. Which of the following are used in medical technology because they can pass through some parts of the human body?
A. x-rays
B. infrared waves
C. microwaves
D. ultraviolet rays
Answer:
|
|
sciq-9956
|
multiple_choice
|
The voltage of a voltaic cell can be determined by the reduction potentials of what?
|
[
"old reactions",
"full reactions",
"half reactions",
"thermal reactions"
] |
C
|
Relavent Documents:
Document 0:::
The values below are standard apparent reduction potentials for electro-biochemical half-reactions measured at 25 °C, 1 atmosphere and a pH of 7 in aqueous solution.
The actual physiological potential depends on the ratio of the reduced () and oxidized () forms according to the Nernst equation and the thermal voltage.
When an oxidizer () accepts a number z of electrons () to be converted in its reduced form (), the half-reaction is expressed as:
+ z →
The reaction quotient (r) is the ratio of the chemical activity (ai) of the reduced form (the reductant, aRed) to the activity of the oxidized form (the oxidant, aox). It is equal to the ratio of their concentrations (Ci) only if the system is sufficiently diluted and the activity coefficients (γi) are close to unity (ai = γi Ci):
The Nernst equation is a function of and can be written as follows:
At chemical equilibrium, the reaction quotient of the product activity (aRed) by the reagent activity (aOx) is equal to the equilibrium constant () of the half-reaction and in the absence of driving force () the potential () also becomes nul.
The numerically simplified form of the Nernst equation is expressed as:
Where is the standard reduction potential of the half-reaction expressed versus the standard reduction potential of hydrogen. For standard conditions in electrochemistry (T = 25 °C, P = 1 atm and all concentrations being fixed at 1 mol/L, or 1 M) the standard reduction potential of hydrogen is fixed at zero by convention as it serves of reference. The standard hydrogen electrode (SHE), with [] = 1 M works thus at a pH = 0.
At pH = 7, when [] = 10−7 M, the reduction potential of differs from zero because it depends on pH.
Solving the Nernst equation for the half-reaction of reduction of two protons into hydrogen gas gives:
In biochemistry and in biological fluids, at pH = 7, it is thus important to note that the reduction potential of the protons () into hydrogen gas is no longer zero
Document 1:::
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 2:::
In electrochemistry, protein film voltammetry (or protein film electrochemistry, or direct electrochemistry of proteins) is a technique for examining the behavior of proteins immobilized (either adsorbed or covalently attached) on an electrode. The technique is applicable to proteins and enzymes that engage in electron transfer reactions and it is part of the methods available to study enzyme kinetics.
Provided that it makes suitable contact with the electrode surface (electron transfer between the electrode and the protein is direct) and provided that it is not denatured, the protein can be fruitfully interrogated by monitoring current as a function of electrode potential and other experimental parameters.
Various electrode materials can be used. Special electrode designs are required to address membrane-bound proteins.
Experiments with redox proteins
Small redox proteins such as cytochromes and ferredoxins can be investigated on condition that their electroactive coverage (the amount of protein undergoing direct electron transfer) is large enough (in practice, greater than a fraction of pmol/cm2).
Electrochemical data obtained with small proteins can be used to measure the redox potentials of the protein's redox sites, the rate of electron transfer between the protein and the electrode, or the rates of chemical reactions (such as protonations) that are coupled to electron transfer.
Interpretation of the peak current and peak area
In a cyclic voltammetry experiment carried out with an adsorbed redox protein, the oxidation and reduction of each redox site shows as a pair of positive and negative peaks. Since all the sample is oxidised or reduced during the potential sweep, the peak current and peak area should be proportional to scan rate (observing that the peak current is proportional to scan rate proves that the redox species that gives the peak is actually immobilised). The same is true for experiments performed with non-biological redox molecules adsorb
Document 3:::
In analytical chemistry, a rotating disk electrode (RDE) is a working electrode used in three-electrode systems for hydrodynamic voltammetry. The electrode rotates during experiments, inducing a flux of analyte to the electrode. These working electrodes are used in electrochemical studies when investigating reaction mechanisms related to redox chemistry, among other chemical phenomena. The more complex rotating ring-disk electrode can be used as a rotating disk electrode if the ring is left inactive during the experiment.
Structure
The electrode includes a conductive disk embedded in an inert non-conductive polymer or resin that can be attached to an electric motor that has very fine control of the electrode's rotation rate. The disk, like any working electrode, is generally made of a noble metal or glassy carbon, however any conductive material can be used based on specific needs.
Function
The disk's rotation is usually described in terms of angular velocity. As the disk turns, some of the solution described as the hydrodynamic boundary layer is dragged by the spinning disk and the resulting centrifugal force flings the solution away from the center of the electrode. Solution flows up, perpendicular to the electrode, from the bulk to replace the boundary layer. The sum result is a laminar flow of solution towards and across the electrode. The rate of the solution flow can be controlled by the electrode's angular velocity and modeled mathematically. This flow can quickly achieve conditions in which the steady-state current is controlled by the solution flow rather than diffusion. This is a contrast to still and unstirred experiments such as cyclic voltammetry where the steady-state current is limited by the diffusion of species in solution.
By running linear sweep voltammetry and other experiments at various rotation rates, different electrochemical phenomena can be investigated, including multi-electron transfer, the kinetics of a slow electron t
Document 4:::
A potentiostat is the electronic hardware required to control a three electrode cell and run most electroanalytical experiments. A Bipotentiostat and polypotentiostat are potentiostats capable of controlling two working electrodes and more than two working electrodes, respectively.
The system functions by maintaining the potential of the working electrode at a constant level with respect to the reference electrode by adjusting the current at an auxiliary electrode. The heart of the different potentiostatic electronic circuits is an operational amplifier (op amp). It consists of an electric circuit which is usually described in terms of simple op amps.
Primary use
This equipment is fundamental to modern electrochemical studies using three electrode systems for investigations of reaction mechanisms related to redox chemistry and other chemical phenomena. The dimensions of the resulting data depend on the experiment. In voltammetry, electric current in amps is plotted against electric potential in voltage. In a bulk electrolysis total coulombs passed (total electric charge) is plotted against time in seconds even though the experiment measures electric current (amperes) over time. This is done to show that the experiment is approaching an expected number of coulombs.
Most early potentiostats could function independently, providing data output through a physical data trace. Modern potentiostats are designed to interface with a personal computer and operate through a dedicated software package. The automated software allows the user rapidly to shift between experiments and experimental conditions. The computer allows data to be stored and analyzed more effectively, rapidly, and accurately than the earlier standalone devices.
Basic relationships
A potentiostat is a control and measuring device. It comprises an electric circuit which controls the potential across the cell by sensing changes in its resistance, varying accordingly the current supplied
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The voltage of a voltaic cell can be determined by the reduction potentials of what?
A. old reactions
B. full reactions
C. half reactions
D. thermal reactions
Answer:
|
|
sciq-10703
|
multiple_choice
|
What bodily structures consist of the endothelium and its basal lamina?
|
[
"veins",
"muscles",
"capillaries",
"fibers"
] |
C
|
Relavent Documents:
Document 0:::
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue.
Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries.
These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues throughout the body.
Structure
The endothelium is a thin layer of single flat (squamous) cells that line the interior surface of blood vessels and lymphatic vessels.
Endothelium is of mesodermal origin. Both blood and lymphatic capillaries are composed of a single layer of endothelial cells called a monolayer. In straight sections of a blood vessel, vascular endothelial cells typically align and elongate in the direction of fluid flow.
Terminology
The foundational model of anatomy, an index of terms used to describe anatomical structures, makes a distinction between endothelial cells and epithelial cells on the basis of which tissues they develop from, and states that the presence of vimentin rather than keratin filaments separates these from epithelial cells. Many considered the endothelium a specialized epithelial tissue.
Function
The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. This forms a barrier between v
Document 1:::
H2.00.04.4.01001: Lymphoid tissue
H2.00.05.0.00001: Muscle tissue
H2.00.05.1.00001: Smooth muscle tissue
H2.00.05.2.00001: Striated muscle tissue
H2.00.06.0.00001: Nerve tissue
H2.00.06.1.00001: Neuron
H2.00.06.2.00001: Synapse
H2.00.06.2.00001: Neuroglia
h3.01: Bones
h3.02: Joints
h3.03: Muscles
h3.04: Alimentary system
h3.05: Respiratory system
h3.06: Urinary system
h3.07: Genital system
h3.08:
Document 2:::
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
Document 3:::
This table lists the epithelia of different organs of the human body
Human anatomy
Document 4:::
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.
What bodily structures consist of the endothelium and its basal lamina?
A. veins
B. muscles
C. capillaries
D. fibers
Answer:
|
|
sciq-5612
|
multiple_choice
|
Smaller sized galaxies are known as what?
|
[
"black holes",
"nebula",
"constellations",
"dwarf galaxies"
] |
D
|
Relavent Documents:
Document 0:::
Types
Quasar
Supermassive black hole
Hypercompact stellar system (hypothetical object organized around a supermassive black hole)
Intermediate-mass black holes and candidates
Cigar Galaxy (Messier 82, NGC 3034)
GCIRS 13E
HLX-1
M82 X-1
Messier 15 (NGC 7078)
Messier 110 (NGC 205)
Sculptor Galaxy (NGC 253)
Triangulum Galaxy (Messier 33, NGC 598
Document 1:::
A brightest cluster galaxy (BCG) is defined as the brightest galaxy in a cluster of galaxies. BCGs include the most massive galaxies in the universe. They are generally elliptical galaxies which lie close to the geometric and kinematical center of their host galaxy cluster, hence at the bottom of the cluster potential well. They are also generally coincident with the peak of the cluster X-ray emission.
Formation scenarios for BCGs include:
Cooling flow—Star formation from the central cooling flow in high density cooling centers of X-ray cluster halos.
The study of accretion populations in BCGs has cast doubt over this theory and astronomers have seen no evidence of cooling flows in radiative cooling clusters. The two remaining theories exhibit healthier prospects.
Galactic cannibalism—Galaxies sink to the center of the cluster due to dynamical friction and tidal stripping.
Galactic merger—Rapid galactic mergers between several galaxies take place during cluster collapse.
It is possible to differentiate the cannibalism model from the merging model by considering the formation period of the BCGs. In the cannibalism model, there are numerous small galaxies present in the evolved cluster, whereas in the merging model, a hierarchical cosmological model is expected due to the collapse of clusters. It has been shown that the orbit decay of cluster galaxies is not effective enough to account for the growth of BCGs.
The merging model is now generally accepted as the most likely one, but recent observations are at odds with some of its predictions. For example, it has been found that the stellar mass of BCGs was assembled much earlier than the merging model predicts.
BCGs are divided into various classes of galaxies: giant ellipticals (gE), D galaxies and cD galaxies. cD and D galaxies both exhibit an extended diffuse envelope surrounding an elliptical-like nucleus akin to regular elliptical galaxies. The light profiles of BCGs are often described by a Sersic surface
Document 2:::
Eris is a computer simulation of the Milky Way galaxy's physics. It was done by astrophysicists from the Institute for Theoretical Physics at the University of Zurich, Switzerland and University of California, Santa Cruz. The simulation project was undertaken at the NASA Advanced Supercomputer Division's Pleiades and the Swiss National Supercomputing Centre for nearly eight months, which would have otherwise taken 570 years in a personal computer. The Eris simulation is the first successful detailed simulation of a Milky Way like galaxy. The results of the simulation were announced in August 2011.
Background
Simulation projects intending to simulate spiral galaxies have been undertaken for the past 20 years. All of these projects had failed as the simulation results showed central bulges which are huge compared to the disk size.
Simulation
The simulation was undertaken using supercomputers which include the Pleiades supercomputer, the Swiss National Supercomputing Centre and the supercomputers at the University of California, Santa Cruz. The simulation used 1.4 million processor-hours of the Pleiades supercomputer.
It is based on the theory that in the early universe, cold and slow moving dark matter particles clumped together. These dark matter clumps then formed the "scaffolding" around galaxies and galactic clusters. The motions of more than 60 million particles which represented dark matter and galactic gas were simulated for a period of 13 billion years. The software platform Gasoline was used for the simulation.
Simulation results
The Eris simulation is the first successful simulation to have resolved the high-density gas clouds where stars formed. The simulation result consisted of a galaxy which is very similar to the Milky Way galaxy. Some of the parameters which were similar to Milky Way are stellar content, gas content, kinematic decomposition, brightness profile and the bulge-to-disk ratio.
Document 3:::
Gems of the Galaxy Zoos (Zoogems) was a gap-filler project which used the Hubble Space Telescope to take images of unusual objects found by volunteers classifying data from both Galaxy Zoo (GZ) and Radio Galaxy Zoo (RGZ). Between the HSTs' main observations, there is a short time that objects within that field of view can be imaged using gaps which last approximately 12 - 25 mins. The Zoogems project sought to use those small observation gaps to image 300 candidates taken from the two Zoos in order to better study and comprehend them. Starting observations in May 2018, HST Proposal 15445 had by the end of September 2023 imaged 193 of the 300 candidates with many of them having near 11 minute exposures.
Background
GZ is a crowdsourced astronomy project which invites people to assist in the morphological classification of a large number of galaxies. Initially, many of the objects now being imaged were posted on the GZ forum and Talk pages from Summer 2007 through various versions until 2017.
The project Radio Galaxy Zoo started in December 2013, seeking to locate supermassive black holes. The science team wanted to identify black hole/jet pairs and associate them with their host galaxies. As a result of citizens' classifications, many unusual candidates visible in radio frequencies were flagged for further studies.
Through public analysis of more than 900,000 objects, volunteers collected a "menagerie of weird and wonderful galaxies" which few had seen before. The original proposal estimated that there were 1100 targets available, yet only 300 observation slots, so the public were asked to vote for which targets should be in the final list. Voting took place in February 2018 in order to meet the proposal's deadline of 28 February.
Project lead Dr. William Keel said in an interview on the University of Alabama site that Zoogems addressed a range of studies and that this happens rarely with galaxies. He explained that after volunteers had sifted through the images
Document 4:::
The Morphs collaboration was a coordinated study to determine the morphologies of galaxies in distant clusters and to investigate the evolution of galaxies as a function of environment and epoch. Eleven clusters were examined and a detailed ground-based and space-based study was carried out.
The project was begun in 1997 based upon the earlier observations by two groups using data from images derived from the pre-refurbished Hubble Space Telescope. It was a collaboration of Alan Dressler and Augustus Oemler, Jr., at Observatory of the Carnegie Institute of Washington, Warrick J. Couch at the University of New South Wales, Richard Ellis at Caltech, Bianca Poggianti at the University of Padua, Amy Barger at the University of Hawaii's Institute for Astronomy, Harvey Butcher at ASTRON, and Ray M. Sharples and Ian Smail at Durham University. Results were published through 2000.
The collaboration sought answers to the differences in the origins of the various galaxy types — elliptical, lenticular, and spiral. The studies found that elliptical galaxies were the oldest and formed from the violent merger of other galaxies about two to three billion years after the Big Bang. Star formation in elliptical galaxies ceased about that time. On the other hand, new stars are still forming in the spiral arms of spiral galaxies. Lenticular galaxies (SO) are intermediate between the first two. They contain structures similar to spiral arms, but devoid of the gas and new stars of the spiral galaxies. Lenticular galaxies are the prevalent form in rich galaxy clusters, which suggests that spirals may be transformed into lenticular galaxies as time progresses. The exact process may be related to high galactic density, or to the total mass in a rich cluster's central core. The Morphs collaboration found that one of the principal mechanisms of this transformation involves the interaction among spiral galaxies, as they fall toward the core of the cluster.
The Inamori Magellan Areal Camer
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Smaller sized galaxies are known as what?
A. black holes
B. nebula
C. constellations
D. dwarf galaxies
Answer:
|
|
sciq-113
|
multiple_choice
|
In some species, what has led to the evolution of alternative male mating behavior and morphology?
|
[
"similar selection",
"sexual process",
"sexual selection",
"distributive selection"
] |
C
|
Relavent Documents:
Document 0:::
Human reproductive ecology is a subfield in evolutionary biology that is concerned with human reproductive processes and responses to ecological variables. It is based in the natural and social sciences, and is based on theory and models deriving from human and animal biology, evolutionary theory, and ecology. It is associated with fields such as evolutionary anthropology and seeks to explain human reproductive variation and adaptations. The theoretical orientation of reproductive ecology applies the theory of natural selection to reproductive behaviors, and has also been referred to as the evolutionary ecology of human reproduction.
Theoretical foundations
Multiple theoretical foundations from evolutionary biology and evolutionary anthropology are important to human reproductive ecology. Notably, reproductive ecology relies heavily on Life History Theory, energetics, fitness theories, kin selection, and theories based on the study of animal evolution.
Life history theory
Life history theory is a prominent analytical framework used in evolutionary anthropology, biology, and reproductive ecology that seeks to explain growth and development of an organism through various life history stages of the entire lifespan. The life history stages include early growth and development, puberty, sexual development, reproductive career, and post-reproductive stage. Life history theory is based in evolutionary theory and suggests that natural selection operates on the allocation of different types of resources (material and metabolic) to meet the competing demands of growth, maintenance, and reproduction at the various life stages. Life history theory is applied to reproductive ecology in the theoretical understandings of puberty, sexual growth and maturation, fertility, parenting, and senescence because at every life stage organisms are bound to encounter and cope with unconscious and conscious decisions that hold trade-offs. Reproductive ecologists have specifically impacte
Document 1:::
Molly R. Morris is an American behavioral ecologist who has worked with treefrogs and swordtail fishes in the areas of alternative reproductive tactics and sexual selection.
Morris received a Bachelor of Arts from Earlham College and a PhD from Indiana University. As a National Science Foundation postdoctoral fellow at the University of Texas at Austin, her work with Mike Ryan demonstrated equal fitnesses between alternative reproductive tactics in a species of swordtail fish. She joined the faculty at Ohio University in 1997, where she is now a professor in the Department of Biological Sciences. She is also the Associate Editor for the journal Behavior. Her publication credits include multiple papers on Animal behavior and Ecology. Her current research relates to diabetes, as well as behavioral ecology, using the swordtail fish Xiphophorus as a model organism.
Personal life
Morris is married to Kevin de Queiroz, an evolutionary biologist at the Smithsonian Institution's National Museum of Natural History.
Selected works
Document 2:::
Social selection is a term used with varying meanings in biology.
Joan Roughgarden proposed a hypothesis called social selection as an alternative to sexual selection. Social selection is argued to be a mode of natural selection based on reproductive transactions and a two-tiered approach to evolution and the development of social behavior. Reproductive transactions refer to a situation where one organism offers assistance to another in exchange for access to reproductive opportunity. The two tiers of the theory are behavioral and population genetic. The genetic aspect states that anisogamy arose to maximize contact rate between gametes. The behavioral aspect is concerned with cooperative game theory and the formation of social groups to maximize the production of offspring. In her critique against the neo-Darwinian defense of sexual selection, Roughgarden outlines exceptions to many of the assumptions that come with sexual selection. These exceptions include sexually monomorphic species, species which reverse standard sex roles, species with template multiplicity, species with transgender presentation, frequencies of homosexual mating, and the lack of correlation between sexually selected traits and deleterious mutation.
An article published by Roughgarden's lab on her ideas received criticism in the journal Science. Forty scientists produced ten critical letters. The critics stated that the article was misleading, that it contained misunderstandings and misrepresentations, that sexual selection accounted for all the data presented and subsumed Roughgarden's theoretical analysis, and that sexual selection explained data that her theory could not.
Other researchers, such as biologist Mary Jane West-Eberhard and evolutionary medicine researcher Randolph M. Nesse, instead view sexual selection as a subcategory of social selection, with Nesse and anthropologist Christopher Boehm arguing further that altruism in humans held fitness advantages that enabled evolutionar
Document 3:::
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior. In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort.
These mechanisms are a part of evolutionary change because they operate in a way that causes the qualities that are desired in a mate to be more frequently passed on to each generation over time. For example, if female peacocks desire mates who have a colourful plumage, then this trait will increase in frequency over time as male peacocks with a colourful plumage will have more reproductive success. Further investigation of this concept, has found that it is in fact the specific trait of blue and green colour near the eyespot that seems to increase the females likelihood of mating with a specific peacock.
Mate choice is a major component of sexual selection, another being intrasexual selection. Ideas on sexual selection were first introduced in 1871, by Charles Darwin, then expanded on by Ronald Fisher in 1915. At present, there are five sub mechanisms that explain how mate choice has evolved over time. These are direct phenotypic benefits, sensory bias, the Fisherian runaway hypothesis, indicator traits and genetic compatibility.
In the majority of systems where mate choice exists, one sex tends to be competitive with their same-sex members and the other sex is choosy (meaning they are selective when it comes to picking individuals to mate with). There are direct and indirect benefits of being the selective individual. In most species, females are the choosy sex which discriminates among competitive males, but there are several examples of reverse
Document 4:::
Although the subject of sexual dimorphism is not in itself controversial, the measures by which it is assessed differ widely. Most of the measures are used on the assumption that a random variable is considered so that probability distributions should be taken into account. In this review, a series of sexual dimorphism measures are discussed concerning both their definition and the probability law on which they are based. Most of them are sample functions, or statistics, which account for only partial characteristics, for example the mean or expected value, of the distribution involved. Further, the most widely used measure fails to incorporate an inferential support.
Introduction
It is widely known that sexual dimorphism is an important component of the morphological variation in biological populations (see, e.g., Klein and Cruz-Uribe, 1984; Oxnard, 1987; Kelley, 1993). In higher Primates, sexual dimorphism is also related to some aspects of the social organization and behavior (Alexander et al., 1979; Clutton-Brock, 1985). Thus, it has been observed that the most dimorphic species tend to polygyny and a social organization based on male dominance, whereas in the less dimorphic species, monogamy and family groups are more common. Fleagle et al. (1980) and Kay (1982), on the other hand, have suggested that the behavior of extinct species can be inferred on the basis of sexual dimorphism and, e.g. Plavcan and van Schaick (1992) think that sex differences in size among primate species reflect processes of an ecological and social nature. Some references on sexual dimorphism regarding human populations can be seen in Lovejoy (1981), Borgognini Tarli and Repetto (1986) and Kappelman (1996).
These biological facts do not appear to be controversial. However, they are based on a series of different sexual dimorphism measures, or indices. Sexual dimorphism, in most works, is measured on the assumption that a random variable is being taken into account. This means that th
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In some species, what has led to the evolution of alternative male mating behavior and morphology?
A. similar selection
B. sexual process
C. sexual selection
D. distributive selection
Answer:
|
|
sciq-8288
|
multiple_choice
|
Basidiomycetes do what to wood and other plant material?
|
[
"revive",
"evolve",
"decompose",
"evaporate"
] |
C
|
Relavent Documents:
Document 0:::
Wood science, commonly referred to as wood sciences, is a scientific discipline that predominantly investigates elements associated with the formation, composition and macro- and microstructure of wood. It additionally delves into the biological, chemical, physical, and mechanical properties and characteristics of wood, as a natural lignocellulosic material.
A deep understanding of wood plays a pivotal role in various endeavors, such as the processing of wood, the production of wood-based materials like particleboard, fiberboard, OSB, plywood and other materials, as well as the utilization of wood and wood-based materials in construction and a wide array of products, including pulpwood, furniture, engineered wood products such as glued laminated timber, CLT, LVL, PSL, as well as pellets, briquettes, and numerous other products.
History
Initial comprehensive investigations in the field of wood science emerged at the start of the 20th century. The advent of contemporary wood research commenced in 1910, when the Forest Products Laboratory (FPL) was established in Madison, Wisconsin, USA. The Forest Products Laboratory played a fundamental role in wood science providing scientific research on wood and wood products in partnership with academia, industry, local and other institutions in North and South America and worldwide.
In the following years, many wood research institutes came into existence across almost all industrialized nations. A general overview of these institutes and laboratories is shown below:
1913: Institute of Wood and Pulp Chemistry Eberswalde (today's Eberswalde University for Sustainable Development), Germany
1913: Forest Products Laboratory Montreal, Canada
1918: Forest Products Laboratory Vancouver, Canada
1919: Forest Products Laboratory Melbourne, Australia
1923: Forest Products Research Laboratory, Princes Risborough, Great Britain
1929: Institute for Wood Science and Technology, Leningrant, St. Petersburg, USSR
1933: Centre Technique
Document 1:::
Bast fibre (also called phloem fibre or skin fibre) is plant fibre collected from the phloem (the "inner bark", sometimes called "skin") or bast surrounding the stem of certain dicotyledonous plants. It supports the conductive cells of the phloem and provides strength to the stem. Some of the economically important bast fibres are obtained from herbs cultivated in agriculture, as for instance flax, hemp, or ramie, but bast fibres from wild plants, as stinging nettle, and trees such as lime or linden, willow, oak, wisteria, and mulberry have also been used in the past. Bast fibres are classified as soft fibres, and are flexible. Fibres from monocotyledonous plants, called "leaf fiber", are classified as hard fibres and are stiff.
Since the valuable fibres are located in the phloem, they must often be separated from the xylem material ("woody core"), and sometimes also from the epidermis. The process for this is called retting, and can be performed by micro-organisms either on land (nowadays the most important) or in water, or by chemicals (for instance high pH and chelating agents) or by pectinolytic enzymes. In the phloem, bast fibres occur in bundles that are glued together by pectin and calcium ions. More intense retting separates the fibre bundles into elementary fibres, that can be several centimetres long. Often bast fibres have higher tensile strength than other kinds, and are used in high-quality textiles (sometimes in blends with cotton or synthetic fibres), ropes, yarn, paper, composite materials and burlap. An important property of bast fibres is that they contain a special structure, the fibre node, that represents a weak point, and gives flexibility. Seed hairs, such as cotton, do not have nodes.
Etymology
The term "bast" derives from Old English bæst ("inner bark of trees from which ropes were made"), from Proto-Germanic *bastaz ("bast, rope"). It may have the same root as Latin ("bundle") and Middle Irish basc ("necklace").
Use of bast fibre
Plants
Document 2:::
BY1 is a taxonomically unidentified basidiomycete fungus. ITS sequencing has placed it in the Russulales and is referred to as a stereaceous basidiomycete. Chemotaxonomically supporting its placement in this group, it produces fomannoxins and vibralactones. The fungus' mycelia were isolated from dead aspen in Minnesota, USA. It is presumed to decompose wood by white rot.
The mycelium can be grown on YMG agar at room temperature (4 g/L d-glucose, 4 g/L yeast extract, 10 g/L malt extract, 18 g/L agar). The culture can be obtained at the Jena Microbial Resource Collection registration number SF:011241.
Document 3:::
Mycelium, the fungal equivalent of roots in plants, has been identified as an ecologically friendly substitute to a litany of materials throughout different industries, including but not limited to packaging, fashion and building materials. Such substitutes present a biodegradable alternative (also known as a "Living Building Material") to conventional materials.
Mycelium was most notably first examined as an ecologically friendly material alternative in 2007. It was widely popularized by Eben Bayer and Gavin McIntyre, through their work developing mycelium packaging and founding their company, Ecovative. during their time at Rensselaer Polytechnic Institute. Since its inception, the material function has diversified into many niches.
Species and biological structures
Mycelium-based composites require a fungus and substrate. “Mycelium” is a term referring to the network of branching fibers, called hyphae, that are created by a fungus to grow and feed. When introduced to a substrate, the fungi will penetrate using their mycelium network, which then breaks down the substrate into basic nutrients for the fungi. By this method, the fungi can grow. For mycelium-based composites, the substrate is not fully broken down during this process and is instead kept intertwined with the mycelium.
The main components of fungi are chitin, polysaccharides, lipids, and proteins. Different compositional amounts of these molecules change the properties of the composites. This is also true for different substrates. Substrates that have higher amounts of chitin and are harder for the mycelium to break down and lead to a stiffer composite formation.
Commonly used species of fungi to grow mycelium are aerobic basidiomycetes, which include Ganoderma sp., Pleurotus sp., and Trametes sp. Basidiomycetes have favorable properties as fungi for creating mycelium based composites because they grow at a relatively steady and quick pace, and can use many different types of organic waste as subs
Document 4:::
Mold control and prevention is a conservation activity that is performed in libraries and archives to protect books, documents and other materials from deterioration caused by mold growth. Mold prevention consists of different methods, such as chemical treatments, careful environmental control, and manual
cleaning. Preservationists use one or a combination of these methods to combat mold spores in library and archival collections.
Due to the resilient nature of mold and its potential for damage to library collections, mold prevention has become an important activity among preservation librarians. Although mold is naturally present in both indoor and outdoor environments, under the right circumstances it can become active after being in a dormant state. Mold growth responds to increased moisture, high humidity, and warm temperatures. Library collections are particularly vulnerable to mold since mold thrives off of organic, cellulose-based materials such as paper, wood, and textiles made of natural fibers. Changes in the moisture in the atmosphere can lead to mold growth and irreparable damage to library collections.
Mold
Mold is a generic term for a specific type of fungi. Mildew may also refer to types of mold. Since there are so many species of mold, their appearance varies in color and growth habit. In general, active mold has a musty odor and appears fuzzy, slimy, or damp. Inactive mold looks dry and powdery.
Mold propagates via spores, which are always present in the environment. Mold spores can be transferred to an object by mechanical instruments or air circulation. When spores attach to another organism, and the environment is favorable, they begin to germinate. Mold produce mycelium which growth pattern resembles cobwebs. Mycelium allows the mold to obtain food and nutrients through the host. Inevitably, the mycelium produces spore sacs and release new spores into the air. Eventually the spores land on new material, and the reproductive cycle begins aga
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Basidiomycetes do what to wood and other plant material?
A. revive
B. evolve
C. decompose
D. evaporate
Answer:
|
|
sciq-6665
|
multiple_choice
|
What term is used to describe an illusion that light from faraway objects is reflected by a pool of water that is not really there?
|
[
"mirage",
"prototype",
"Mirror",
"version"
] |
A
|
Relavent Documents:
Document 0:::
Snell's window (also called Snell's circle or optical man-hole) is a phenomenon by which an underwater viewer sees everything above the surface through a cone of light of width of about 96 degrees. This phenomenon is caused by refraction of light entering water, and is governed by Snell's Law. The area outside Snell's window will either be completely dark or show a reflection of underwater objects by total internal reflection.
Underwater photographers sometimes compose photographs from below such that their subjects fall inside Snell's window, which backlights and focuses attention on the subjects.
Image formation
Under ideal conditions, an observer looking up at the water surface from underneath sees a perfectly circular image of the entire above-water hemisphere—from horizon to horizon. Due to refraction at the air/water boundary, Snell's window compresses a 180° angle of view above water to a 97° angle of view below water, similar to the effect of a fisheye lens. The brightness of this image falls off to nothing at the circumference/horizon because more of the incident light at low grazing angles is reflected rather than refracted (see Fresnel equations). Refraction is very sensitive to any irregularities in the flatness of the surface (such as ripples or waves), which will cause local distortions or complete disintegration of the image. Turbidity in the water will veil the image behind a cloud of scattered light.
Document 1:::
This is a list of visual illusions.
See also
Adaptation (eye)
Alice in Wonderland syndrome
Auditory illusion
Camouflage
Contingent perceptual aftereffect
Contour rivalry
Depth perception
Emmert's law
Entoptic phenomenon
Gestalt psychology
Infinity pool
Kinetic depth effect
Mirage
Multistable perception
Op Art
Notes
External links
Optical Illusion Examples by Great Optical Illusions
Optical Illusions & Visual Phenomena by Michael Bach
Optical Illusions Database by Mighty Optical Illusions
Optical illusions and perception paradoxes by Archimedes Lab
https://web.archive.org/web/20100419004856/http://ilusaodeotica.com/ hundreds of optical illusions
Project LITE Atlas of Visual Phenomena
Akiyoshi's illusion pages Professor Akiyoshi KITAOKA's anomalous motion illusions
Spiral Or Not? by Enrique Zeleny, Wolfram Demonstrations Project
Magical Optical Illusions by Rangki
Hunch Optical Illusions by Hunch
Optical Illusions by Ooh, My Brain!
Optical phenomena
Articles containing video clips
Document 2:::
Underwater vision is the ability to see objects underwater, and this is significantly affected by several factors. Underwater, objects are less visible because of lower levels of natural illumination caused by rapid attenuation of light with distance passed through the water. They are also blurred by scattering of light between the object and the viewer, also resulting in lower contrast. These effects vary with wavelength of the light, and color and turbidity of the water. The vertebrate eye is usually either optimised for underwater vision or air vision, as is the case in the human eye. The visual acuity of the air-optimised eye is severely adversely affected by the difference in refractive index between air and water when immersed in direct contact. Provision of an airspace between the cornea and the water can compensate, but has the side effect of scale and distance distortion. The diver learns to compensate for these distortions. Artificial illumination is effective to improve illumination at short range.
Stereoscopic acuity, the ability to judge relative distances of different objects, is considerably reduced underwater, and this is affected by the field of vision. A narrow field of vision caused by a small viewport in a helmet results in greatly reduced stereoacuity, and associated loss of hand-eye coordination. At very short range in clear water distance is underestimated, in accordance with magnification due to refraction through the flat lens of the mask, but at greater distances - greater than arm's reach, the distance tends to be overestimated to a degree influenced by turbidity. Both relative and absolute depth perception are reduced underwater. Loss of contrast results in overestimation, and magnification effects account for underestimation at short range. Divers can to a large extent adapt to these effects over time and with practice.
Light rays bend when they travel from one medium to another; the amount of bending is determined by the refractive in
Document 3:::
Invisibility is the state of an object that cannot be seen. An object in this state is said to be invisible (literally, "not visible"). The phenomenon is studied by physics and perceptual psychology.
Since objects can be seen by light in the visible spectrum from a source reflecting off their surfaces and hitting the viewer's eye, the most natural form of invisibility (whether real or fictional) is an object that neither reflects nor absorbs light (that is, it allows light to pass through it). This is known as
transparency, and is seen in many naturally occurring materials (although no naturally occurring material is 100% transparent).
Invisibility perception depends on several optical and visual factors. For example, invisibility depends on the eyes of the observer and/or the instruments used. Thus an object can be classified as "invisible to" a person, animal, instrument, etc. In research on sensorial perception it has been shown that invisibility is perceived in cycles.
Invisibility is often considered to be the supreme form of camouflage, as it does not reveal to the viewer any kind of vital signs, visual effects, or any frequencies of the electromagnetic spectrum detectable to the human eye, instead making use of radio, infrared or ultraviolet wavelengths.
In illusion optics, invisibility is a special case of illusion effects: the illusion of free space.
The term is often used in fantasy and science fiction, where objects cannot be seen by means of magic or hypothetical technology.
Practical efforts
Technology can be used theoretically or practically to render real-world objects invisible.
Making use of a real-time image displayed on a wearable display, it is possible to create a see-through effect. This is known as active camouflage. Though stealth technology is declared to be invisible to radar, all officially disclosed applications of the technology can only reduce the size and/or clarity of the signature detected by radar.
In 2003 the Chilean s
Document 4:::
Entoptic phenomena () are visual effects whose source is within the human eye itself. (Occasionally, these are called entopic phenomena, which is probably a typographical mistake.)
In Helmholtz's words: "Under suitable conditions light falling on the eye may render visible certain objects within the eye itself. These perceptions are called entoptical."
Overview
Entoptic images have a physical basis in the image cast upon the retina. Hence, they are different from optical illusions, which are caused by the visual system and characterized by a visual percept that (loosely said) appears to differ from reality. Because entoptic images are caused by phenomena within the observer's own eye, they share one feature with optical illusions and hallucinations: the observer cannot share a direct and specific view of the phenomenon with others.
Helmholtz commented on entoptic phenomena which could be seen easily by some observers, but could not be seen at all by others. This variance is not surprising because the specific aspects of the eye that produce these images are unique to each individual. Because of the variation between individuals, and the inability for two observers to share a nearly identical stimulus, these phenomena are unlike most visual sensations. They are also unlike most optical illusions which are produced by viewing a common stimulus. Yet, there is enough commonality between the main entoptic phenomena that their physical origin is now well understood.
Examples
Some examples of entoptical effects include:
Floaters or muscae volitantes are slowly drifting blobs of varying size, shape, and transparency, which are particularly noticeable when viewing a bright, featureless background (such as the sky) or a point source of diffuse light very close to the eye. They are shadow images of objects floating in liquid between the retina and the gel inside the eye (vitreous humor). They are visible because they move; if they were pinned to retina by the vitreous o
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What term is used to describe an illusion that light from faraway objects is reflected by a pool of water that is not really there?
A. mirage
B. prototype
C. Mirror
D. version
Answer:
|
|
sciq-3143
|
multiple_choice
|
What is an object that orbits a larger object called?
|
[
"comet",
"satellite",
"asteroid",
"meteorite"
] |
B
|
Relavent Documents:
Document 0:::
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 1:::
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
Document 2:::
In astrodynamics, an orbiting body is any physical body that orbits a more massive one, called the primary body. The orbiting body is properly referred to as the secondary body (), which is less massive than the primary body ().
Thus, or .
Under standard assumptions in astrodynamics, the barycenter of the two bodies is a focus of both orbits.
An orbiting body may be a spacecraft (i.e. an artificial satellite) or a natural satellite, such as a planet, dwarf planet, moon, moonlet, asteroid, or comet.
A system of two orbiting bodies is modeled by the Two-Body Problem and a system of three orbiting bodies is modeled by the Three-Body Problem. These problems can be generalized to an N-body problem. While there are a few analytical solutions to the n-body problem, it can be reduced to a 2-body system if the secondary body stays out of other bodies' Sphere of Influence and remains in the primary body's sphere of influence.
See also
Barycenter
Double planet
Primary (astronomy)
Satellite
Two-body problem
Three-body problem
N-body problem
Document 3:::
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 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is an object that orbits a larger object called?
A. comet
B. satellite
C. asteroid
D. meteorite
Answer:
|
|
sciq-385
|
multiple_choice
|
What is the force of attraction between things that have mass
|
[
"gravity",
"motion",
"friction",
"momentum"
] |
A
|
Relavent Documents:
Document 0:::
<noinclude>
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
Document 1:::
In common usage, the mass of an object is often referred to as its weight, though these are in fact different concepts and quantities. Nevertheless, one object will always weigh more than another with less mass if both are subject to the same gravity (i.e. the same gravitational field strength).
In scientific contexts, mass is the amount of "matter" in an object (though "matter" may be difficult to define), but weight is the force exerted on an object's matter by gravity. At the Earth's surface, an object whose mass is exactly one kilogram weighs approximately 9.81 newtons, the product of its mass and the gravitational field strength there. The object's weight is less on Mars, where gravity is weaker; more on Saturn, where gravity is stronger; and very small in space, far from significant sources of gravity, but it always has the same mass.
Material objects at the surface of the Earth have weight despite such sometimes being difficult to measure. An object floating freely on water, for example, does not appear to have weight since it is buoyed by the water. But its weight can be measured if it is added to water in a container which is entirely supported by and weighed on a scale. Thus, the "weightless object" floating in water actually transfers its weight to the bottom of the container (where the pressure increases). Similarly, a balloon has mass but may appear to have no weight or even negative weight, due to buoyancy in air. However the weight of the balloon and the gas inside it has merely been transferred to a large area of the Earth's surface, making the weight difficult to measure. The weight of a flying airplane is similarly distributed to the ground, but does not disappear. If the airplane is in level flight, the same weight-force is distributed to the surface of the Earth as when the plane was on the runway, but spread over a larger area.
A better scientific definition of mass is its description as being a measure of inertia, which is the tendency of an
Document 2:::
As described by the third of Newton's laws of motion of classical mechanics, all forces occur in pairs such that if one object exerts a force on another object, then the second object exerts an equal and opposite reaction force on the first. The third law is also more generally stated as: "To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts." The attribution of which of the two forces is the action and which is the reaction is arbitrary. Either of the two can be considered the action, while the other is its associated reaction.
Examples
Interaction with ground
When something is exerting force on the ground, the ground will push back with equal force in the opposite direction. In certain fields of applied physics, such as biomechanics, this force by the ground is called 'ground reaction force'; the force by the object on the ground is viewed as the 'action'.
When someone wants to jump, he or she exerts additional downward force on the ground ('action'). Simultaneously, the ground exerts upward force on the person ('reaction'). If this upward force is greater than the person's weight, this will result in upward acceleration. When these forces are perpendicular to the ground, they are also called a normal force.
Likewise, the spinning wheels of a vehicle attempt to slide backward across the ground. If the ground is not too slippery, this results in a pair of friction forces: the 'action' by the wheel on the ground in backward direction, and the 'reaction' by the ground on the wheel in forward direction. This forward force propels the vehicle.
Gravitational forces
The Earth, among other planets, orbits the Sun because the Sun exerts a gravitational pull that acts as a centripetal force, holding the Earth to it, which would otherwise go shooting off into space. If the Sun's pull is considered an action, then Earth simultaneously exerts a reaction as a gravi
Document 3:::
This is a list of topics that are included in high school physics curricula or textbooks.
Mathematical Background
SI Units
Scalar (physics)
Euclidean vector
Motion graphs and derivatives
Pythagorean theorem
Trigonometry
Motion and forces
Motion
Force
Linear motion
Linear motion
Displacement
Speed
Velocity
Acceleration
Center of mass
Mass
Momentum
Newton's laws of motion
Work (physics)
Free body diagram
Rotational motion
Angular momentum (Introduction)
Angular velocity
Centrifugal force
Centripetal force
Circular motion
Tangential velocity
Torque
Conservation of energy and momentum
Energy
Conservation of energy
Elastic collision
Inelastic collision
Inertia
Moment of inertia
Momentum
Kinetic energy
Potential energy
Rotational energy
Electricity and magnetism
Ampère's circuital law
Capacitor
Coulomb's law
Diode
Direct current
Electric charge
Electric current
Alternating current
Electric field
Electric potential energy
Electron
Faraday's law of induction
Ion
Inductor
Joule heating
Lenz's law
Magnetic field
Ohm's law
Resistor
Transistor
Transformer
Voltage
Heat
Entropy
First law of thermodynamics
Heat
Heat transfer
Second law of thermodynamics
Temperature
Thermal energy
Thermodynamic cycle
Volume (thermodynamics)
Work (thermodynamics)
Waves
Wave
Longitudinal wave
Transverse waves
Transverse wave
Standing Waves
Wavelength
Frequency
Light
Light ray
Speed of light
Sound
Speed of sound
Radio waves
Harmonic oscillator
Hooke's law
Reflection
Refraction
Snell's law
Refractive index
Total internal reflection
Diffraction
Interference (wave propagation)
Polarization (waves)
Vibrating string
Doppler effect
Gravity
Gravitational potential
Newton's law of universal gravitation
Newtonian constant of gravitation
See also
Outline of physics
Physics education
Document 4:::
The gravity of Earth, denoted by , is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation).
It is a vector quantity, whose direction coincides with a plumb bob and strength or magnitude is given by the norm .
In SI units this acceleration is expressed in metres per second squared (in symbols, m/s2 or m·s−2) or equivalently in newtons per kilogram (N/kg or N·kg−1). Near Earth's surface, the acceleration due to gravity, accurate to 2 significant figures, is . This means that, ignoring the effects of air resistance, the speed of an object falling freely will increase by about per second every second. This quantity is sometimes referred to informally as little (in contrast, the gravitational constant is referred to as big ).
The precise strength of Earth's gravity varies with location. The agreed upon value for is by definition. This quantity is denoted variously as , (though this sometimes means the normal gravity at the equator, ), , or simply (which is also used for the variable local value).
The weight of an object on Earth's surface is the downwards force on that object, given by Newton's second law of motion, or (). Gravitational acceleration contributes to the total gravity acceleration, but other factors, such as the rotation of Earth, also contribute, and, therefore, affect the weight of the object. Gravity does not normally include the gravitational pull of the Moon and Sun, which are accounted for in terms of tidal effects.
Variation in magnitude
A non-rotating perfect sphere of uniform mass density, or whose density varies solely with distance from the centre (spherical symmetry), would produce a gravitational field of uniform magnitude at all points on its surface. The Earth is rotating and is also not spherically symmetric; rather, it is slightly flatter at the poles while bulging at the Equator: an oblate spheroid.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the force of attraction between things that have mass
A. gravity
B. motion
C. friction
D. momentum
Answer:
|
|
sciq-7256
|
multiple_choice
|
What is an example of a biochemical lipid that contributes to weight gain?
|
[
"acids",
"proteins",
"sugars",
"fats"
] |
D
|
Relavent Documents:
Document 0:::
Fat globules (also known as mature lipid droplets) are individual pieces of intracellular fat in human cell biology. The lipid droplet's function is to store energy for the organism's body and is found in every type of adipocytes. They can consist of a vacuole, droplet of triglyceride, or any other blood lipid, as opposed to fat cells in between other cells in an organ. They contain a hydrophobic core and are encased in a phospholipid monolayer membrane. Due to their hydrophobic nature, lipids and lipid digestive derivatives must be transported in the globular form within the cell, blood, and tissue spaces.
The formation of a fat globule starts within the membrane bilayer of the endoplasmic reticulum. It starts as a bud and detaches from the ER membrane to join other droplets. After the droplets fuse, a mature droplet (full-fledged globule) is formed and can then partake in neutral lipid synthesis or lipolysis.
Globules of fat are emulsified in the duodenum into smaller droplets by bile salts during food digestion, speeding up the rate of digestion by the enzyme lipase at a later point in digestion. Bile salts possess detergent properties that allow them to emulsify fat globules into smaller emulsion droplets, and then into even smaller micelles. This increases the surface area for lipid-hydrolyzing enzymes to act on the fats.
Micelles are roughly 200 times smaller than fat emulsion droplets, allowing them to facilitate the transport of monoglycerides and fatty acids across the surface of the enterocyte, where absorption occurs.
Milk fat globules (MFGs) are another form of intracellular fat found in the mammary glands of female mammals. Their function is to provide enriching glycoproteins from the female to their offspring. They are formed in the endoplasmic reticulum found in the mammary epithelial lactating cell. The globules are made up of triacylglycerols encased in cellular membranes and proteins like adipophilin and TIP 47. The proteins are spread througho
Document 1:::
The lipidome refers to the totality of lipids in cells. Lipids are one of the four major molecular components of biological organisms, along with proteins, sugars and nucleic acids. Lipidome is a term coined in the context of omics in modern biology, within the field of lipidomics. It can be studied using mass spectrometry and bioinformatics as well as traditional lab-based methods. The lipidome of a cell can be subdivided into the membrane-lipidome and mediator-lipidome.
The first cell lipidome to be published was that of a mouse macrophage in 2010. The lipidome of the yeast Saccharomyces cerevisiae has been characterised with an estimated 95% coverage; studies of the human lipidome are ongoing. For example, the human plasma lipidome consist of almost 600 distinct molecular species. Research suggests that the lipidome of an individual may be able to indicate cancer risks associated with dietary fats, particularly breast cancer.
See also
Genome
Proteome
Glycome
Document 2:::
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond.
A saturated fat has no carbon to carbon double bonds, so the maximum possible number of hydrogens bonded to the carbons, and is "saturated" with hydrogen atoms. To form carbon to carbon double bonds, hydrogen atoms are removed from the carbon chain. In cellular metabolism, unsaturated fat molecules contain less energy (i.e., fewer calories) than an equivalent amount of saturated fat. The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds in the fatty acid) the more vulnerable it is to lipid peroxidation (rancidity). Antioxidants can protect unsaturated fat from lipid peroxidation.
Composition of common fats
In chemical analysis, fats are broken down to their constituent fatty acids, which can be analyzed in various ways. In one approach, fats undergo transesterification to give fatty acid methyl esters (FAMEs), which are amenable to separation and quantitation using by gas chromatography. Classically, unsaturated isomers were separated and identified by argentation thin-layer chromatography.
The saturated fatty acid components are almost exclusively stearic (C18) and palmitic acids (C16). Monounsaturated fats are almost exclusively oleic acid. Linolenic acid comprises most of the triunsaturated fatty acid component.
Chemistry and nutrition
Although polyunsaturated fats are protective against cardiac arrhythmias, a study of post-menopausal women with a relatively low fat intake showed that polyunsaturated fat is positively associated with progression of coronary atherosclerosis, whereas monounsaturated fat is not. This probably is an indication of the greater vulnerability of polyunsaturated fats to lipid peroxidation, against which vitamin E has been shown to be protective.
Examples
Document 3:::
Fatty acid metabolism consists of various metabolic processes involving or closely related to fatty acids, a family of molecules classified within the lipid macronutrient category. These processes can mainly be divided into (1) catabolic processes that generate energy and (2) anabolic processes where they serve as building blocks for other compounds.
In catabolism, fatty acids are metabolized to produce energy, mainly in the form of adenosine triphosphate (ATP). When compared to other macronutrient classes (carbohydrates and protein), fatty acids yield the most ATP on an energy per gram basis, when they are completely oxidized to CO2 and water by beta oxidation and the citric acid cycle. Fatty acids (mainly in the form of triglycerides) are therefore the foremost storage form of fuel in most animals, and to a lesser extent in plants.
In anabolism, intact fatty acids are important precursors to triglycerides, phospholipids, second messengers, hormones and ketone bodies. For example, phospholipids form the phospholipid bilayers out of which all the membranes of the cell are constructed from fatty acids. Phospholipids comprise the plasma membrane and other membranes that enclose all the organelles within the cells, such as the nucleus, the mitochondria, endoplasmic reticulum, and the Golgi apparatus. In another type of anabolism, fatty acids are modified to form other compounds such as second messengers and local hormones. The prostaglandins made from arachidonic acid stored in the cell membrane are probably the best-known of these local hormones.
Fatty acid catabolism
Fatty acids are stored as triglycerides in the fat depots of adipose tissue. Between meals they are released as follows:
Lipolysis, the removal of the fatty acid chains from the glycerol to which they are bound in their storage form as triglycerides (or fats), is carried out by lipases. These lipases are activated by high epinephrine and glucagon levels in the blood (or norepinephrine secreted by s
Document 4:::
Lipolysis is the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and free fatty acids. It is used to mobilize stored energy during fasting or exercise, and usually occurs in fat adipocytes. The most important regulatory hormone in lipolysis is insulin; lipolysis can only occur when insulin action falls to low levels, as occurs during fasting. Other hormones that affect lipolysis include glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol.
Mechanisms
In the body, stores of fat are referred to as adipose tissue. In these areas, intracellular triglycerides are stored in cytoplasmic lipid droplets. When lipase enzymes are phosphorylated, they can access lipid droplets and through multiple steps of hydrolysis, breakdown triglycerides into fatty acids and glycerol. Each step of hydrolysis leads to the removal of one fatty acid. The first step and the rate-limiting step of lipolysis is carried out by adipose triglyceride lipase (ATGL). This enzyme catalyzes the hydrolysis of triacylglycerol to diacylglycerol. Subsequently, hormone-sensitive lipase (HSL) catalyzes the hydrolysis of diacylglycerol to monoacylglycerol and monoacylglycerol lipase (MGL) catalyzes the hydrolysis of monoacylglycerol to glycerol.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is an example of a biochemical lipid that contributes to weight gain?
A. acids
B. proteins
C. sugars
D. fats
Answer:
|
|
sciq-6815
|
multiple_choice
|
What is used to describe gas concentrations of a solution?
|
[
"mole fractions",
"atom fractions",
"fixation fractions",
"mesh fractions"
] |
A
|
Relavent Documents:
Document 0:::
The Gas composition of any gas can be characterised by listing the pure substances it contains, and stating for each substance its proportion of the gas mixture's molecule count.Nitrogen 78.084
Oxygen 20.9476
Argon Ar 0.934
Carbon Dioxide 0.0314
Gas composition of air
To give a familiar example, air has a composition of:
Standard Dry Air is the agreed-upon gas composition for air from which all water vapour has been removed. There are various standards bodies which publish documents that define a dry air gas composition. Each standard provides a list of constituent concentrations, a gas density at standard conditions and a molar mass.
It is extremely unlikely that the actual composition of any specific sample of air will completely agree with any definition for standard dry air. While the various definitions for standard dry air all attempt to provide realistic information about the constituents of air, the definitions are important in and of themselves because they establish a standard which can be cited in legal contracts and publications documenting measurement calculation methodologies or equations of state.
The standards below are two examples of commonly used and cited publications that provide a composition for standard dry air:
ISO TR 29922-2017 provides a definition for standard dry air which specifies an air molar mass of 28,965 46 ± 0,000 17 kg·kmol-1.
GPA 2145:2009 is published by the Gas Processors Association. It provides a molar mass for air of 28.9625 g/mol, and provides a composition for standard dry air as a footnote.
Document 1:::
Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular, of a solute in a solution, in terms of amount of substance per unit volume of solution. In chemistry, the most commonly used unit for molarity is the number of moles per liter, having the unit symbol mol/L or mol/dm3 in SI units. A solution with a concentration of 1 mol/L is said to be 1 molar, commonly designated as 1 M or 1 M. Molarity is often depicted with square brackets around the substance of interest; for example, the molarity of the hydrogen ion is depicted as [H+].
Definition
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase :
Here, is the amount of the solute in moles, is the number of constituent particles present in volume (in litres) of the solution, and is the Avogadro constant, since 2019 defined as exactly . The ratio is the number density .
In thermodynamics the use of molar concentration is often not convenient because the volume of most solutions slightly depends on temperature due to thermal expansion. This problem is usually resolved by introducing temperature correction factors, or by using a temperature-independent measure of concentration such as molality.
The reciprocal quantity represents the dilution (volume) which can appear in Ostwald's law of dilution.
Formality or analytical concentration
If a molecular entity dissociates in solution, the concentration refers to the original chemical formula in solution, the molar concentration is sometimes called formal concentration or formality (FA) or analytical concentration (cA). For example, if a sodium carbonate solution () has a formal concentration of c() = 1 mol/L, the molar concentra
Document 2:::
In chemistry and fluid mechanics, the volume fraction φi is defined as the volume of a constituent Vi divided by the volume of all constituents of the mixture V prior to mixing:
Being dimensionless, its unit is 1; it is expressed as a number, e.g., 0.18. It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e.g., 18%.
The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients).
The sum of all volume fractions of a mixture is equal to 1:
The volume fraction (percentage by volume, vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
Volume concentration and volume percent
Volume percent is the concentration of a certain solute, measured by volume, in a solution. It has as a denominator the volume of the mixture itself, as usual for expressions of concentration, rather than the total of all the individual components’ volumes prior to mixing:
Volume percent is usually used when the solution is made by mixing two fluids, such as liquids or gases. However, percentages are only additive for ideal gases.
The percentage by volume (vol%) is one way of expressing the composition of a mixture with a dimensionless quantity; mass fraction (percentage by weight, wt%) and mole fraction (percentage by moles, mol%) are others.
In the case of a mixture of ethanol and water, which are miscible in all proportions, the designation of solvent and solute is arbitrary. The volume of such a mixture is slightly less than the sum of the volumes of the components. Thus, by the above definition, the term "40% alcohol by volume" refers to a mixture of 40 volume units of ethanol with enough water to make a final volume of 100 units, rather than a
Document 3:::
In physical chemistry, there are numerous quantities associated with chemical compounds and reactions; notably in terms of amounts of substance, activity or concentration of a substance, and the rate of reaction. This article uses SI units.
Introduction
Theoretical chemistry requires quantities from core physics, such as time, volume, temperature, and pressure. But the highly quantitative nature of physical chemistry, in a more specialized way than core physics, uses molar amounts of substance rather than simply counting numbers; this leads to the specialized definitions in this article. Core physics itself rarely uses the mole, except in areas overlapping thermodynamics and chemistry.
Notes on nomenclature
Entity refers to the type of particle/s in question, such as atoms, molecules, complexes, radicals, ions, electrons etc.
Conventionally for concentrations and activities, square brackets [ ] are used around the chemical molecular formula. For an arbitrary atom, generic letters in upright non-bold typeface such as A, B, R, X or Y etc. are often used.
No standard symbols are used for the following quantities, as specifically applied to a substance:
the mass of a substance m,
the number of moles of the substance n,
partial pressure of a gas in a gaseous mixture p (or P),
some form of energy of a substance (for chemistry enthalpy H is common),
entropy of a substance S
the electronegativity of an atom or chemical bond χ.
Usually the symbol for the quantity with a subscript of some reference to the quantity is used, or the quantity is written with the reference to the chemical in round brackets. For example, the mass of water might be written in subscripts as mH2O, mwater, maq, mw (if clear from context) etc., or simply as m(H2O). Another example could be the electronegativity of the fluorine-fluorine covalent bond, which might be written with subscripts χF-F, χFF or χF-F etc., or brackets χ(F-F), χ(FF) etc.
Neither is standard. For the purpose of this a
Document 4:::
In chemistry, the mole map is a graphical representation of an algorithm that compares molar mass, number of particles per mole, and factors from balanced equations or other formulae.
Stoichiometry
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is used to describe gas concentrations of a solution?
A. mole fractions
B. atom fractions
C. fixation fractions
D. mesh fractions
Answer:
|
|
sciq-6248
|
multiple_choice
|
Force times distance is the equation for what?
|
[
"gravity",
"speed",
"work",
"power"
] |
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:::
Advanced Placement (AP) Physics C: Mechanics (also known as AP Mechanics) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to proxy a one-semester calculus-based university course in mechanics. The content of Physics C: Mechanics overlaps with that of AP Physics 1, but Physics 1 is algebra-based, while Physics C is calculus-based. Physics C: Mechanics may be combined with its electricity and magnetism counterpart to form a year-long course that prepares for both exams.
Course content
Intended to be equivalent to an introductory college course in mechanics for physics or engineering majors, the course modules are:
Kinematics
Newton's laws of motion
Work, energy and power
Systems of particles and linear momentum
Circular motion and rotation
Oscillations and gravitation.
Methods of calculus are used wherever appropriate in formulating physical principles and in applying them to physical problems. Therefore, students should have completed or be concurrently enrolled in a Calculus I class.
This course is often compared to AP Physics 1: Algebra Based for its similar course material involving kinematics, work, motion, forces, rotation, and oscillations. However, AP Physics 1: Algebra Based lacks concepts found in Calculus I, like derivatives or integrals.
This course may be combined with AP Physics C: Electricity and Magnetism to make a unified Physics C course that prepares for both exams.
AP test
The course culminates in an optional exam for which high-performing students may receive some credit towards their college coursework, depending on the institution.
Registration
The AP examination for AP Physics C: Mechanics is separate from the AP examination for AP Physics C: Electricity and Magnetism. Before 2006, test-takers paid only once and were given the choice of taking either one or two parts of the Physics C test.
Format
The exam is typically administered on a Monday aftern
Document 2:::
The Force Concept Inventory is a test measuring mastery of concepts commonly taught in a first semester of physics developed by Hestenes, Halloun, Wells, and Swackhamer (1985). It was the first such "concept inventory" and several others have been developed since for a variety of topics. The FCI was designed to assess student understanding of the Newtonian concepts of force. Hestenes (1998) found that while "nearly 80% of the [students completing introductory college physics courses] could state Newton's Third Law at the beginning of the course, FCI data showed that less than 15% of them fully understood it at the end". These results have been replicated in a number of studies involving students at a range of institutions (see sources section below), and have led to greater recognition in the physics education research community of the importance of students' "active engagement" with the materials to be mastered.
The 1995 version has 30 five-way multiple choice questions.
Example question (question 4):
Gender differences
The FCI shows a gender difference in favor of males that has been the subject of some research in regard to gender equity in education. Men score on average about 10% higher.
Document 3:::
There are four Advanced Placement (AP) Physics courses administered by the College Board as part of its Advanced Placement program: the algebra-based Physics 1 and Physics 2 and the calculus-based Physics C: Mechanics and Physics C: Electricity and Magnetism. All are intended to be at the college level. Each AP Physics course has an exam for which high-performing students may receive credit toward their college coursework.
AP Physics 1 and 2
AP Physics 1 and AP Physics 2 were introduced in 2015, replacing AP Physics B. The courses were designed to emphasize critical thinking and reasoning as well as learning through inquiry. They are algebra-based and do not require any calculus knowledge.
AP Physics 1
AP Physics 1 covers Newtonian mechanics, including:
Unit 1: Kinematics
Unit 2: Dynamics
Unit 3: Circular Motion and Gravitation
Unit 4: Energy
Unit 5: Momentum
Unit 6: Simple Harmonic Motion
Unit 7: Torque and Rotational Motion
Until 2020, the course also covered topics in electricity (including Coulomb's Law and resistive DC circuits), mechanical waves, and sound. These units were removed because they are included in AP Physics 2.
AP Physics 2
AP Physics 2 covers the following topics:
Unit 1: Fluids
Unit 2: Thermodynamics
Unit 3: Electric Force, Field, and Potential
Unit 4: Electric Circuits
Unit 5: Magnetism and Electromagnetic Induction
Unit 6: Geometric and Physical Optics
Unit 7: Quantum, Atomic, and Nuclear Physics
AP Physics C
From 1969 to 1972, AP Physics C was a single course with a single exam that covered all standard introductory university physics topics, including mechanics, fluids, electricity and magnetism, optics, and modern physics. In 1973, the College Board split the course into AP Physics C: Mechanics and AP Physics C: Electricity and Magnetism. The exam was also split into two separate 90-minute tests, each equivalent to a semester-length calculus-based college course. Until 2006, both exams could be taken for a single
Document 4:::
Engineering mathematics is a branch of applied mathematics concerning mathematical methods and techniques that are typically used in engineering and industry. Along with fields like engineering physics and engineering geology, both of which may belong in the wider category engineering science, engineering mathematics is an interdisciplinary subject motivated by engineers' needs both for practical, theoretical and other considerations outside their specialization, and to deal with constraints to be effective in their work.
Description
Historically, engineering mathematics consisted mostly of applied analysis, most notably: differential equations; real and complex analysis (including vector and tensor analysis); approximation theory (broadly construed, to include asymptotic, variational, and perturbative methods, representations, numerical analysis); Fourier analysis; potential theory; as well as linear algebra and applied probability, outside of analysis. These areas of mathematics were intimately tied to the development of Newtonian physics, and the mathematical physics of that period. This history also left a legacy: until the early 20th century subjects such as classical mechanics were often taught in applied mathematics departments at American universities, and fluid mechanics may still be taught in (applied) mathematics as well as engineering departments.
The success of modern numerical computer methods and software has led to the emergence of computational mathematics, computational science, and computational engineering (the last two are sometimes lumped together and abbreviated as CS&E), which occasionally use high-performance computing for the simulation of phenomena and the solution of problems in the sciences and engineering. These are often considered interdisciplinary fields, but are also of interest to engineering mathematics.
Specialized branches include engineering optimization and engineering statistics.
Engineering mathematics in tertiary educ
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Force times distance is the equation for what?
A. gravity
B. speed
C. work
D. power
Answer:
|
|
sciq-7071
|
multiple_choice
|
After an adaptive defense is produced against a pathogen, typically plasma cells first secrete immunoglobin, which constitutes about ten percent of all what?
|
[
"parasites",
"antibodies",
"allergies",
"hormones"
] |
B
|
Relavent Documents:
Document 0:::
The adaptive immune system, also known as the acquired immune system, or specific immune system is a subsystem of the immune system that is composed of specialized, systemic cells and processes that eliminate pathogens or prevent their growth. The acquired immune system is one of the two main immunity strategies found in vertebrates (the other being the innate immune system).
Like the innate system, the adaptive immune system includes both humoral immunity components and cell-mediated immunity components and destroys invading pathogens. Unlike the innate immune system, which is pre-programmed to react to common broad categories of pathogen, the adaptive immune system is highly specific to each particular pathogen the body has encountered.
Adaptive immunity creates immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to future encounters with that pathogen. Antibodies are a critical part of the adaptive immune system. Adaptive immunity can provide long-lasting protection, sometimes for the person's entire lifetime. For example, someone who recovers from measles is now protected against measles for their lifetime; in other cases it does not provide lifetime protection, as with chickenpox. This process of adaptive immunity is the basis of vaccination.
The cells that carry out the adaptive immune response are white blood cells known as lymphocytes. B cells and T cells, two different types of lymphocytes, carry out the main activities: antibody responses, and cell-mediated immune response. In antibody responses, B cells are activated to secrete antibodies, which are proteins also known as immunoglobulins. Antibodies travel through the bloodstream and bind to the foreign antigen causing it to inactivate, which does not allow the antigen to bind to the host. Antigens are any substances that elicit the adaptive immune response. Sometimes the adaptive system is unable to distinguish harmful from harmless foreign molecule
Document 1:::
Immunopathology is a branch of medicine that deals with immune responses associated with disease. It includes the study of the pathology of an organism, organ system, or disease with respect to the immune system, immunity, and immune responses. In biology, it refers to damage caused to an organism by its own immune response, as a result of an infection. It could be due to mismatch between pathogen and host species, and often occurs when an animal pathogen infects a human (e.g. avian flu leads to a cytokine storm which contributes to the increased mortality rate).
Types of Immunity
In all vertebrates, there are two different kinds of immunities: Innate and Adaptive immunity. Innate immunity is used to fight off non-changing antigens and is therefore considered nonspecific. It is usually a more immediate response than the adaptive immune system, usually responding within minutes to hours. It is composed of physical blockades such as the skin, but also contains nonspecific immune cells such as dendritic cells, macrophages, and basophils. The second form of immunity is Adaptive immunity. This form of immunity requires recognition of the foreign antigen before a response is produced. Once the antigen is recognized, a specific response is produced in order to destroy the specific antigen. Because of its tailored response characteristic, adaptive immunity is considered to be specific immunity. A key part of adaptive immunity that separates it from innate is the use of memory to combat the antigen in the future. When the antigen is originally introduced, the organism does not have any receptors for the antigen so it must generate them from the first time the antigen is present. The immune system then builds a memory of that antigen, which enables it to recognize the antigen quicker in the future and be able to combat it quicker and more efficiently. The more the system is exposed to the antigen, the quicker it will build up its responsiveness. Nested within Adaptive immu
Document 2:::
This is a list of Immune cells, also known as white blood cells, white cells, leukocytes, or leucocytes. They are cells involved in protecting the body against both infectious disease and foreign invaders.
Document 3:::
An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellular bacteria, protozoa, helminths, and fungi which could cause serious problems to the health of the host organism if not cleared from the body.
In addition, there are other forms of immune response. For example, harmless exogenous factors (such as pollen and food components) can trigger allergy; latex and metals are also known allergens.
A transplanted tissue (for example, blood) or organ can cause graft-versus-host disease. A type of immune reactivity known as Rh disease can be observed in pregnant women. These special forms of immune response are classified as hypersensitivity. Another special form of immune response is antitumor immunity.
In general, there are two branches of the immune response, the innate and the adaptive, which work together to protect against pathogens. Both branches engage humoral and cellular components.
The innate branch—the body's first reaction to an invader—is known to be a non-specific and quick response to any sort of pathogen. Components of the innate immune response include physical barriers like the skin and mucous membranes, immune cells such as neutrophils, macrophages, and monocytes, and soluble factors including cytokines and complement. On the other hand, the adaptive branch is the body's immune response which is catered against specific antigens and thus, it takes longer to activate the components involved. The adaptive branch include cells such as dendritic cells, T cell, and B cells as well as antibodies—also known as immunoglobulins—which directly interact with antigen and are a very important component for a strong response against an invader.
The first contact that an organism has with a particular antigen will result in the production of effector T and B cells which are act
Document 4:::
The pluripotency of biological compounds describes the ability of certain substances to produce several distinct biological responses. Pluripotent is also described as something that has no fixed developmental potential, as in being able to differentiate into different cell types in the case of pluripotent stem cells.
One type of pluripotent cell, called a hematopoietic stem cell, can differentiate into a large variety of cells with different functions. This stem cell can produce red blood cells, platelets, mast cells, dendritic cells, macrophages, lymphocytes, neutrophils, basophils, and eosinophils. Each of these cells have a different function, but they all work together as part of the immune system.
Monocytes can differentiate into either dendritic cells or macrophages. Macrophages are covered with chemical receptors and phagocytose foreign particles, but are specific about what immune responses to be involved in. Dendritic cells phagocytose invaders; then they present the antigen on their surface to stimulate the acquired immune system (lymphocytes) as backup.
Another example are lymphocytes called naïve T-helper cells. These cells can differentiate into many subtypes once activated by antigen presenting cells (APCs) like dendrites. They divide into memory cells, TH1, TH17, and TH2 cells, to name a few. Memory cells are made solely for the purpose of having a template to use in the case of reinfection so the body has a jump start instead of starting over as if never infected. TH17 cells do a variety of tasks including recruiting neutrophils, creating defensins, and mediating inflammation in the intestinal epithelium and skin. TH2 cells produce cytokines that will trigger certain B cells. B cells can differentiate into memory cells or plasma cells. The B plasma cells produce the antibodies that are used to tag invading cells so they can be attacked, among other functions. TH1 cells are created to make cytokines, like interferon gamma, that activate macrophage
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
After an adaptive defense is produced against a pathogen, typically plasma cells first secrete immunoglobin, which constitutes about ten percent of all what?
A. parasites
B. antibodies
C. allergies
D. hormones
Answer:
|
|
sciq-8393
|
multiple_choice
|
What can all living things sense and respond to in their environment?
|
[
"wind",
"sunlight",
"stimuli",
"warmth"
] |
C
|
Relavent Documents:
Document 0:::
Sensory ecology is a relatively new field focusing on the information organisms obtain about their environment. It includes questions of what information is obtained, how it is obtained (the mechanism), and why the information is useful to the organism (the function).
Sensory ecology is the study of how organisms acquire, process, and respond to information from their environment. All individual organisms interact with their environment (consisting of both animate and inanimate components), and exchange materials, energy, and sensory information. Ecology has generally focused on the exchanges of matter and energy, while sensory interactions have generally been studied as influences on behavior and functions of certain physiological systems (sense organs). The relatively new area of sensory ecology has emerged as more researchers focus on questions concerning information in the environment. This field covers topics ranging from the neurobiological mechanisms of sensory systems to the behavioral patterns employed in the acquisition of sensory information to the role of sensory ecology in larger evolutionary processes such as speciation and reproductive isolation. While human perception is largely visual, other species may rely more heavily on different senses. In fact, how organisms perceive and filter information from their environment varies widely. Organisms experience different perceptual worlds, also known as “umwelten”, as a result of their sensory filters. These senses range from smell (olfaction), taste (gustation), hearing (mechanoreception), and sight (vision) to pheromone detection, pain detection (nociception), electroreception and magnetoreception. Because different species rely on different senses, sensory ecologists seek to understand which environmental and sensory cues are more important in determining the behavioral patterns of certain species. In recent years, this information has been widely applied in conservation and management fields.
Reactio
Document 1:::
The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways, and parts of the brain involved in sensory perception and interoception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, balance and visceral sensation. Sense organs are transducers that convert data from the outer physical world to the realm of the mind where people interpret the information, creating their perception of the world around them.
The receptive field is the area of the body or environment to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field. Receptive fields have been identified for the visual system, auditory system and somatosensory system.
Stimulus
Organisms need information to solve at least three kinds of problems: (a) to maintain an appropriate environment, i.e., homeostasis; (b) to time activities (e.g., seasonal changes in behavior) or synchronize activities with those of conspecifics; and (c) to locate and respond to resources or threats (e.g., by moving towards resources or evading or attacking threats). Organisms also need to transmit information in order to influence another's behavior: to identify themselves, warn conspecifics of danger, coordinate activities, or deceive.
Sensory systems code for four aspects of a stimulus; type (modality), intensity, location, and duration. Arrival time of a sound pulse and phase differences of continuous sound are used for sound localization. Certain receptors are sensitive to certain types of stimuli (for example, different mechanoreceptors respond best to different kinds of touch stimuli, like sharp or blunt objects). Receptors send impulses in certain patterns to send information about the intensity of a stimul
Document 2:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 3:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What can all living things sense and respond to in their environment?
A. wind
B. sunlight
C. stimuli
D. warmth
Answer:
|
|
sciq-10830
|
multiple_choice
|
In a scientific investigation, what do you call a direct, physical observation of something or a process?
|
[
"evidence",
"reason",
"sighting",
"declaration"
] |
A
|
Relavent Documents:
Document 0:::
Discovery is the act of detecting something new, or something previously unrecognized as meaningful. Concerning sciences and academic disciplines, discovery is the observation of new phenomena, new actions, or new events and providing new reasoning to explain the knowledge gathered through such observations with previously acquired knowledge from abstract thought and everyday experiences. A discovery may sometimes be based on earlier discoveries, collaborations, or ideas. Some discoveries represent a radical breakthrough in knowledge or technology.
New discoveries are acquired through various senses and are usually assimilated, merging with pre-existing knowledge and actions. Questioning is a major form of human thought and interpersonal communication, and plays a key role in discovery. Discoveries are often made due to questions. Some discoveries lead to the invention of objects, processes, or techniques. A discovery may sometimes be based on earlier discoveries, collaborations or ideas, and the process of discovery requires at least the awareness that an existing concept or method can be modified or transformed. However, some discoveries also represent a radical breakthrough in knowledge.
Science
Within scientific disciplines, discovery is the observation of new phenomena, actions, or events which help explain the knowledge gathered through previously acquired scientific evidence. In science, exploration is one of three purposes of research, the other two being description and explanation. Discovery is made by providing observational evidence and attempts to develop an initial, rough understanding of some phenomenon.
Discovery within the field of particle physics has an accepted definition for what constitutes a discovery: a five-sigma level of certainty. Such a level defines statistically how unlikely it is that an experimental result is due to chance. The combination of a five-sigma level of certainty, and independent confirmation by other experiments, turn f
Document 1:::
A glossary of terms used in experimental research.
Concerned fields
Statistics
Experimental design
Estimation theory
Glossary
Alias: When the estimate of an effect also includes the influence of one or more other effects (usually high order interactions) the effects are said to be aliased (see confounding). For example, if the estimate of effect D in a four factor experiment actually estimates (D + ABC), then the main effect D is aliased with the 3-way interaction ABC. Note: This causes no difficulty when the higher order interaction is either non-existent or insignificant.
Analysis of variance (ANOVA): A mathematical process for separating the variability of a group of observations into assignable causes and setting up various significance tests.
Balanced design: An experimental design where all cells (i.e. treatment combinations) have the same number of observations.
Blocking: A schedule for conducting treatment combinations in an experimental study such that any effects on the experimental results due to a known change in raw materials, operators, machines, etc., become concentrated in the levels of the blocking variable. Note: the reason for blocking is to isolate a systematic effect and prevent it from obscuring the main effects. Blocking is achieved by restricting randomization.
Center Points: Points at the center value of all factor ranges.
Coding Factor Levels: Transforming the scale of measurement for a factor so that the high value becomes +1 and the low value becomes -1 (see scaling). After coding all factors in a 2-level full factorial experiment, the design matrix has all orthogonal columns. Coding is a simple linear transformation of the original measurement scale. If the "high" value is Xh and the "low" value is XL (in the original scale), then the scaling transformation takes any original X value and converts it to (X − a)/b, where a = (Xh + XL)/2 and b = (Xh−XL)/2. To go back to the original measurement scale, just take the coded value a
Document 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:::
In mathematics and empirical science, quantification (or quantitation) is the act of counting and measuring that maps human sense observations and experiences into quantities. Quantification in this sense is fundamental to the scientific method.
Natural science
Some measure of the undisputed general importance of quantification in the natural sciences can be gleaned from the following comments:
"these are mere facts, but they are quantitative facts and the basis of science."
It seems to be held as universally true that "the foundation of quantification is measurement."
There is little doubt that "quantification provided a basis for the objectivity of science."
In ancient times, "musicians and artists ... rejected quantification, but merchants, by definition, quantified their affairs, in order to survive, made them visible on parchment and paper."
Any reasonable "comparison between Aristotle and Galileo shows clearly that there can be no unique lawfulness discovered without detailed quantification."
Even today, "universities use imperfect instruments called 'exams' to indirectly quantify something they call knowledge."
This meaning of quantification comes under the heading of pragmatics.
In some instances in the natural sciences a seemingly intangible concept may be quantified by creating a scale—for example, a pain scale in medical research, or a discomfort scale at the intersection of meteorology and human physiology such as the heat index measuring the combined perceived effect of heat and humidity, or the wind chill factor measuring the combined perceived effects of cold and wind.
Social sciences
In the social sciences, quantification is an integral part of economics and psychology. Both disciplines gather data – economics by empirical observation and psychology by experimentation – and both use statistical techniques such as regression analysis to draw conclusions from it.
In some instances a seemingly intangible property may be quantified by asking
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.
In a scientific investigation, what do you call a direct, physical observation of something or a process?
A. evidence
B. reason
C. sighting
D. declaration
Answer:
|
|
sciq-2919
|
multiple_choice
|
In biology, what is required for ecosystems to survive?
|
[
"helium",
"space",
"energy",
"minerals"
] |
C
|
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:::
Controlled (or closed) ecological life-support systems (acronym CELSS) are a self-supporting life support system for space stations and colonies typically through controlled closed ecological systems, such as the BioHome, BIOS-3, Biosphere 2, Mars Desert Research Station, and Yuegong-1.
Original concept
CELSS was first pioneered by the Soviet Union during the famed "Space Race" in the 1950s–60s. Originated by Konstantin Tsiolkovsky and furthered by V.I. Vernadsky, the first forays into this science were the use of closed, unmanned ecosystems, expanding into the research facility known as the BIOS-3.
Then in 1965, manned experiments began in the BIOS-3.
Rationale
Human presence in space, thus far, has been limited to our own Earth–Moon system. Also, everything that astronauts would need in the way of life support (air, water, and food) has been brought with them. This may be economical for short missions of spacecraft, but it is not the most viable solution when dealing with the life support systems of a long-term craft (such as a generation ship) or a settlement.
The aim of CELSS is to create a regenerative environment that can support and maintain human life via agricultural means.
Components of CELSS
Air revitalization
In non-CELSS environments, air replenishment and processing typically consists of stored air tanks and scrubbers. The drawback to this method lies in the fact that upon depletion the tanks would have to be refilled; the scrubbers would also require replacement after they become ineffective.
There is also the issue of processing toxic fumes, which come from the synthetic materials used in the construction of habitats. Therefore, the issue of how air quality is maintained requires attention; in experiments, it was found that the plants also removed volatile organic compounds offgassed by synthetic materials used thus far to build and maintain all man-made habitats.
In CELSS, air is initially supplied by external supply, but is maintained by
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
GRE Subject Biochemistry, Cell and Molecular Biology was a standardized exam provided by ETS (Educational Testing Service) that was discontinued in December 2016. It is a paper-based exam and there are no computer-based versions of it. ETS places this exam three times per year: once in April, once in October and once in November. Some graduate programs in the United States recommend taking this exam, while others require this exam score as a part of the application to their graduate programs. ETS sends a bulletin with a sample practice test to each candidate after registration for the exam. There are 180 questions within the biochemistry subject test.
Scores are scaled and then reported as a number between 200 and 990; however, in recent versions of the test, the maximum and minimum reported scores have been 760 (corresponding to the 99 percentile) and 320 (1 percentile) respectively. The mean score for all test takers from July, 2009, to July, 2012, was 526 with a standard deviation of 95.
After learning that test content from editions of the GRE® Biochemistry, Cell and Molecular Biology (BCM) Test has been compromised in Israel, ETS made the decision not to administer this test worldwide in 2016–17.
Content specification
Since many students who apply to graduate programs in biochemistry do so during the first half of their fourth year, the scope of most questions is largely that of the first three years of a standard American undergraduate biochemistry curriculum. A sampling of test item content is given below:
Biochemistry (36%)
A Chemical and Physical Foundations
Thermodynamics and kinetics
Redox states
Water, pH, acid-base reactions and buffers
Solutions and equilibria
Solute-solvent interactions
Chemical interactions and bonding
Chemical reaction mechanisms
B Structural Biology: Structure, Assembly, Organization and Dynamics
Small molecules
Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
Supramolecular complexes (e.g.
Document 4:::
The Science, Technology, Engineering and Mathematics Network or STEMNET is an educational charity in the United Kingdom that seeks to encourage participation at school and college in science and engineering-related subjects (science, technology, engineering, and mathematics) and (eventually) work.
History
It is based at Woolgate Exchange near Moorgate tube station in London and was established in 1996. The chief executive is Kirsten Bodley. The STEMNET offices are housed within the Engineering Council.
Function
Its chief aim is to interest children in science, technology, engineering and mathematics. Primary school children can start to have an interest in these subjects, leading secondary school pupils to choose science A levels, which will lead to a science career. It supports the After School Science and Engineering Clubs at schools. There are also nine regional Science Learning Centres.
STEM ambassadors
To promote STEM subjects and encourage young people to take up jobs in these areas, STEMNET have around 30,000 ambassadors across the UK. these come from a wide selection of the STEM industries and include TV personalities like Rob Bell.
Funding
STEMNET used to receive funding from the Department for Education and Skills. Since June 2007, it receives funding from the Department for Children, Schools and Families and Department for Innovation, Universities and Skills, since STEMNET sits on the chronological dividing point (age 16) of both of the new departments.
See also
The WISE Campaign
Engineering and Physical Sciences Research Council
National Centre for Excellence in Teaching Mathematics
Association for Science Education
Glossary of areas of mathematics
Glossary of astronomy
Glossary of biology
Glossary of chemistry
Glossary of engineering
Glossary of physics
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In biology, what is required for ecosystems to survive?
A. helium
B. space
C. energy
D. minerals
Answer:
|
|
sciq-9978
|
multiple_choice
|
What do solar cells convert the energy in sunlight into?
|
[
"experimental energy",
"electrical energy",
"subsequent energy",
"free energy"
] |
B
|
Relavent Documents:
Document 0:::
A solar panel is a device that converts sunlight into electricity by using photovoltaic (PV) cells. PV cells are made of materials that generate electrons when exposed to light. The electrons flow through a circuit and produce direct current (DC) electricity, which can be used to power various devices or be stored in batteries. Solar panels are also known as solar cell panels, solar electric panels, or PV modules.
Solar panels are usually arranged in groups called arrays or systems. A photovoltaic system consists of one or more solar panels, an inverter that converts DC electricity to alternating current (AC) electricity, and sometimes other components such as controllers, meters, and trackers. A photovoltaic system can be used to provide electricity for off-grid applications, such as remote homes or cabins, or to feed electricity into the grid and earn credits or payments from the utility company. This is called a grid-connected photovoltaic system.
Some advantages of solar panels are that they use a renewable and clean source of energy, reduce greenhouse gas emissions, and lower electricity bills. Some disadvantages are that they depend on the availability and intensity of sunlight, require cleaning, and have high initial costs. Solar panels are widely used for residential, commercial, and industrial purposes, as well as for space and transportation applications.
History
In 1839, the ability of some materials to create an electrical charge from light exposure was first observed by the French physicist Edmond Becquerel. Though these initial solar panels were too inefficient for even simple electric devices, they were used as an instrument to measure light.
The observation by Becquerel was not replicated again until 1873, when the English electrical engineer Willoughby Smith discovered that the charge could be caused by light hitting selenium. After this discovery, William Grylls Adams and Richard Evans Day published "The action of light on selenium" in 1876,
Document 1:::
For description and history, see Solar cell
A solar cell (also called photovoltaic cell or photoelectric cell) is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage or resistance, vary when exposed to light.
The following are the different types of solar cells.
Amorphous Silicon solar cell (a-Si)
Biohybrid solar cell
Cadmium telluride solar cell (CdTe)
Concentrated PV cell (CVP and HCVP)
Copper indium gallium selenide solar cells (CI(G)S)
Crystalline silicon solar cell (c-Si)
Float-zone silicon
Dye-sensitized solar cell (DSSC)
Gallium arsenide germanium solar cell (GaAs)
Hybrid solar cell
Luminescent solar concentrator cell (LSC)
Micromorph (tandem-cell using a-Si/μc-Si)
Monocrystalline solar cell (mono-Si)
Multi-junction solar cell (MJ)
Nanocrystal solar cell
Organic solar cell (OPV)
Perovskite solar cell
Photoelectrochemical cell (PEC)
Plasmonic solar cell
Polycrystalline solar cell (multi-Si)
Quantum dot solar cell
Solid-state solar cell
Thin-film solar cell (TFSC)
Wafer solar cell, or wafer-based solar cell crystalline
Non concentrated hetrogeneos PV cell
Solar cells
Silicon solar cells
Thin-film cells
Infrared solar cells
Silicon forms
Semiconductor materials
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
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
Document 4:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do solar cells convert the energy in sunlight into?
A. experimental energy
B. electrical energy
C. subsequent energy
D. free energy
Answer:
|
|
sciq-8854
|
multiple_choice
|
Oxygen is essentially just a waste product of the light reactions of what?
|
[
"electrolysis",
"photosynthesis",
"Fibrinolysis",
"glycolysis"
] |
B
|
Relavent Documents:
Document 0:::
Oxygen evolution is the process of generating molecular oxygen (O2) by a chemical reaction, usually from water. Oxygen evolution from water is effected by oxygenic photosynthesis, electrolysis of water, and thermal decomposition of various oxides. The biological process supports aerobic life. When relatively pure oxygen is required industrially, it is isolated by distilling liquefied air.
Oxygen evolution in nature
Photosynthetic oxygen evolution is the fundamental process by which oxygen is generated in the earth's biosphere. The reaction is part of the light-dependent reactions of photosynthesis in cyanobacteria and the chloroplasts of green algae and plants. It utilizes the energy of light to split a water molecule into its protons and electrons for photosynthesis. Free oxygen, generated as a by-product of this reaction, is released into the atmosphere.
Water oxidation is catalyzed by a manganese-containing cofactor contained in photosystem II, known as the oxygen-evolving complex (OEC) or the water-splitting complex. Manganese is an important cofactor, and calcium and chloride are also required for the reaction to occur. The stoichiometry of this reaction is as follows:
2H2O ⟶ 4e− + 4H+ + O2
The protons are released into the thylakoid lumen, thus contributing to the generation of a proton gradient across the thylakoid membrane. This proton gradient is the driving force for adenosine triphosphate (ATP) synthesis via photophosphorylation and the coupling of the absorption of light energy and the oxidation of water for the creation of chemical energy during photosynthesis.
History of discovery
It was not until the end of the 18th century that Joseph Priestley accidentally discovered the ability of plants to "restore" air that had been "injured" by the burning of a candle. He followed up on the experiment by showing that air "restored" by vegetation was "not at all inconvenient to a mouse." He was later awarded a medal for his discoveries that "...no vegetabl
Document 1:::
Classification
Oxidoreductases are classified as EC 1 in the EC number classification of enzymes. Oxidoreductases can be further classified into 21 subclasses:
EC 1.1 includes oxidoreductases that act on the CH-OH group of donors (alcohol oxidoreductases such as methanol dehydrogenase)
EC 1.2 includes oxidoreductases that act on the aldehyde or oxo group of donors
EC 1.3 includes oxidoreductases that act on the CH-CH group of donors (CH-CH oxidore
Document 2:::
Cellular waste products are formed as a by-product of cellular respiration, a series of processes and reactions that generate energy for the cell, in the form of ATP. One example of cellular respiration creating cellular waste products are aerobic respiration and anaerobic respiration.
Each pathway generates different waste products.
Aerobic respiration
When in the presence of oxygen, cells use aerobic respiration to obtain energy from glucose molecules.
Simplified Theoretical Reaction: C6H12O6 (aq) + 6O2 (g) → 6CO2 (g) + 6H2O (l) + ~ 30ATP
Cells undergoing aerobic respiration produce 6 molecules of carbon dioxide, 6 molecules of water, and up to 30 molecules of ATP (adenosine triphosphate), which is directly used to produce energy, from each molecule of glucose in the presence of surplus oxygen.
In aerobic respiration, oxygen serves as the recipient of electrons from the electron transport chain. Aerobic respiration is thus very efficient because oxygen is a strong oxidant.
Aerobic respiration proceeds in a series of steps, which also increases efficiency - since glucose is broken down gradually and ATP is produced as needed, less energy is wasted as heat. This strategy results in the waste products H2O and CO2 being formed in different amounts at different phases of respiration. CO2 is formed in Pyruvate decarboxylation, H2O is formed in oxidative phosphorylation, and both are formed in the citric acid cycle.
The simple nature of the final products also indicates the efficiency of this method of respiration. All of the energy stored in the carbon-carbon bonds of glucose is released, leaving CO2 and H2O. Although there is energy stored in the bonds of these molecules, this energy is not easily accessible by the cell. All usable energy is efficiently extracted.
Anaerobic respiration
Anaerobic respiration is done by aerobic organisms when there is not sufficient oxygen in a cell to undergo aerobic respiration as well as by cells called anaerobes that
Document 3:::
Cellular respiration is the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into ATP, and then release waste products.
Cellular respiration is a vital process that happens in the cells of living organisms, including humans, plants, and animals. It's how cells produce energy to power all the activities necessary for life.
The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, producing large amounts of energy (ATP). Respiration is one of the key ways a cell releases chemical energy to fuel cellular activity. The overall reaction occurs in a series of biochemical steps, some of which are redox reactions. Although cellular respiration is technically a combustion reaction, it is an unusual one because of the slow, controlled release of energy from the series of reactions.
Nutrients that are commonly used by animal and plant cells in respiration include sugar, amino acids and fatty acids, and the most common oxidizing agent is molecular oxygen (O2). The chemical energy stored in ATP (the bond of its third phosphate group to the rest of the molecule can be broken allowing more stable products to form, thereby releasing energy for use by the cell) can then be used to drive processes requiring energy, including biosynthesis, locomotion or transportation of molecules across cell membranes.
Aerobic respiration
Aerobic respiration requires oxygen (O2) in order to create ATP. Although carbohydrates, fats and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate to the mitochondria in order to be fully oxidized by the c
Document 4:::
Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by photons. It is defined as the interaction of one or more photons with one target molecule.
Photodissociation is not limited to visible light. Any photon with sufficient energy can affect the chemical bonds of a chemical compound. Since a photon's energy is inversely proportional to its wavelength, electromagnetic radiations with the energy of visible light or higher, such as ultraviolet light, X-rays, and gamma rays can induce such reactions.
Photolysis in photosynthesis
Photolysis is part of the light-dependent reaction or light phase or photochemical phase or Hill reaction of photosynthesis. The general reaction of photosynthetic photolysis can be given in terms of photons as:
The chemical nature of "A" depends on the type of organism. Purple sulfur bacteria oxidize hydrogen sulfide () to sulfur (S). In oxygenic photosynthesis, water () serves as a substrate for photolysis resulting in the generation of diatomic oxygen (). This is the process which returns oxygen to Earth's atmosphere. Photolysis of water occurs in the thylakoids of cyanobacteria and the chloroplasts of green algae and plants.
Energy transfer models
The conventional semi-classical model describes the photosynthetic energy transfer process as one in which excitation energy hops from light-capturing pigment molecules to reaction center molecules step-by-step down the molecular energy ladder.
The effectiveness of photons of different wavelengths depends on the absorption spectra of the photosynthetic pigments in the organism. Chlorophylls absorb light in the violet-blue and red parts of the spectrum, while accessory pigments capture other wavelengths as well. The phycobilins of red algae absorb blue-green light which penetrates deeper into water than red light, enabling them to photosynthesize in deep waters. Each absorbed photon causes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Oxygen is essentially just a waste product of the light reactions of what?
A. electrolysis
B. photosynthesis
C. Fibrinolysis
D. glycolysis
Answer:
|
|
sciq-3677
|
multiple_choice
|
What are the smallest particles of elements that maintain their unique properties?
|
[
"molecules",
"protons",
"electrons",
"atoms"
] |
D
|
Relavent Documents:
Document 0:::
The subatomic scale is the domain of physical size that encompasses objects smaller than an atom. It is the scale at which the atomic constituents, such as the nucleus containing protons and neutrons, and the electrons in their orbitals, become apparent.
The subatomic scale includes the many thousands of times smaller subnuclear scale, which is the scale of physical size at which constituents of the protons and neutrons - particularly quarks - become apparent.
See also
Astronomical scale the opposite end of the spectrum
Subatomic particles
Document 1:::
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:::
Electron scattering occurs when electrons are displaced from their original trajectory. This is due to the electrostatic forces within matter interaction or, if an external magnetic field is present, the electron may be deflected by the Lorentz force. This scattering typically happens with solids such as metals, semiconductors and insulators; and is a limiting factor in integrated circuits and transistors.
The application of electron scattering is such that it can be used as a high resolution microscope for hadronic systems, that allows the measurement of the distribution of charges for nucleons and nuclear structure. The scattering of electrons has allowed us to understand that protons and neutrons are made up of the smaller elementary subatomic particles called quarks.
Electrons may be scattered through a solid in several ways:
Not at all: no electron scattering occurs at all and the beam passes straight through.
Single scattering: when an electron is scattered just once.
Plural scattering: when electron(s) scatter several times.
Multiple scattering: when electron(s) scatter many times over.
The likelihood of an electron scattering and the degree of the scattering is a probability function of the specimen thickness to the mean free path.
History
The principle of the electron was first theorised in the period of 1838-1851 by a natural philosopher by the name of Richard Laming who speculated the existence of sub-atomic, unit charged particles; he also pictured the atom as being an 'electrosphere' of concentric shells of electrical particles surrounding a material core.
It is generally accepted that J. J. Thomson first discovered the electron in 1897, although other notable members in the development in charged particle theory are George Johnstone Stoney (who coined the term "electron"), Emil Wiechert (who was first to publish his independent discovery of the electron), Walter Kaufmann, Pieter Zeeman and Hendrik Lorentz.
Compton scattering was first observed at
Document 3:::
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The debye (D) is another unit of measurement used in atomic physics and chemistry.
Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.
Elementary definition
Often in physics the dimensions of a massive object can be ignored and can be treated as a pointlike object, i.e. a point particle. Point particles with electric charge are referred to as point charges. Two point charges, one with charge and the other one with charge separated by a distance , constitute an electric dipole (a simple case of an electric multipole). For this case, the electric dipole moment has a magnitude and is directed from the negative charge to the positive one. Some authors may split in half and use since this quantity is the distance between either charge and the center of the dipole, leading to a factor of two in the definition.
A stronger mathematical definition is to use vector algebra, since a quantity with magnitude and direction, like the dipole moment of two point charges, can be expressed in vector form where is the displacement vector pointing from the negative charge to the positive charge. The electric dipole moment vector also points from the negative charge to the positive charge. With this definition the dipole direction tends to align itself with an external electric field (and note that the electric flux lines produced by the charges of the dipole itself, which point from positive charge to negative charge then tend to oppose the flux lines of the external field). Note that this sign convention is used in physics, while the opposite sign convention for th
Document 4:::
The elementary charge, usually denoted by , is a fundamental physical constant, defined as the electric charge carried by a single proton or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 .
In the SI system of units, the value of the elementary charge is exactly defined as = coulombs, or 160.2176634 zeptocoulombs (zC). Since the 2019 redefinition of SI base units, the seven SI base units are defined by seven fundamental physical constants, of which the elementary charge is one.
In the centimetre–gram–second system of units (CGS), the corresponding quantity is .
Robert A. Millikan and Harvey Fletcher's oil drop experiment first directly measured the magnitude of the elementary charge in 1909, differing from the modern accepted value by just 0.6%. Under assumptions of the then-disputed atomic theory, the elementary charge had also been indirectly inferred to ~3% accuracy from blackbody spectra by Max Planck in 1901 and (through the Faraday constant) at order-of-magnitude accuracy by Johann Loschmidt's measurement of the Avogadro number in 1865.
As a unit
In some natural unit systems, such as the system of atomic units, e functions as the unit of electric charge. The use of elementary charge as a unit was promoted by George Johnstone Stoney in 1874 for the first system of natural units, called Stoney units. Later, he proposed the name electron for this unit. At the time, the particle we now call the electron was not yet discovered and the difference between the particle electron and the unit of charge electron was still blurred. Later, the name electron was assigned to the particle and the unit of charge e lost its name. However, the unit of energy electronvolt (eV) is a remnant of the fact that the elementary charge was once called electron.
In other natural unit systems, the unit of charge is defined as with the result that
where is the fine-structure constant, is the speed of light, is
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are the smallest particles of elements that maintain their unique properties?
A. molecules
B. protons
C. electrons
D. atoms
Answer:
|
|
sciq-6684
|
multiple_choice
|
What mineral that occurs in bones helps combat osteoporosis?
|
[
"potassium",
"calcium",
"iron",
"magnesium"
] |
B
|
Relavent Documents:
Document 0:::
Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood.
The osteoclasts are multi-nucleated cells that contain numerous mitochondria and lysosomes. These are the cells responsible for the resorption of bone. Osteoblasts are generally present on the outer layer of bone, just beneath the periosteum. Attachment of the osteoclast to the osteon begins the process. The osteoclast then induces an infolding of its cell membrane and secretes collagenase and other enzymes important in the resorption process. High levels of calcium, magnesium, phosphate and products of collagen will be released into the extracellular fluid as the osteoclasts tunnel into the mineralized bone. Osteoclasts are prominent in the tissue destruction found in psoriatic arthritis and rheumatological disorders.
The human body is in a constant state of bone remodeling. Bone remodeling is a process which maintains bone strength and ion homeostasis by replacing discrete parts of old bone with newly synthesized packets of proteinaceous matrix. Bone is resorbed by osteoclasts, and is deposited by osteoblasts in a process called ossification. Osteocyte activity plays a key role in this process. Conditions that result in a decrease in bone mass can either be caused by an increase in resorption or by a decrease in ossification. During childhood, bone formation exceeds resorption. As the aging process occurs, resorption exceeds formation.
Bone resorption rates are much higher in post-menopausal older women due to estrogen deficiency related with menopause. Common treatments include drugs that increase bone mineral density. Bisphosphonates, RANKL inhibitors, SERMs—selective oestrogen receptor modulators, hormone replacement therapy and calcitonin are some of the common treatments. Light weight bearing exercise tends to eliminate the negative effects of bon
Document 1:::
In osteology, bone remodeling or bone metabolism is a lifelong process where mature bone tissue is removed from the skeleton (a process called bone resorption) and new bone tissue is formed (a process called ossification or new bone formation). These processes also control the reshaping or replacement of bone following injuries like fractures but also micro-damage, which occurs during normal activity. Remodeling responds also to functional demands of the mechanical loading.
In the first year of life, almost 100% of the skeleton is replaced. In adults, remodeling proceeds at about 10% per year.
An imbalance in the regulation of bone remodeling's two sub-processes, bone resorption and bone formation, results in many metabolic bone diseases, such as osteoporosis.
Physiology
Bone homeostasis involves multiple but coordinated cellular and molecular events. Two main types of cells are responsible for bone metabolism: osteoblasts (which secrete new bone), and osteoclasts (which break bone down). The structure of bones as well as adequate supply of calcium requires close cooperation between these two cell types and other cell populations present at the bone remodeling sites (e.g. immune cells). Bone metabolism relies on complex signaling pathways and control mechanisms to achieve proper rates of growth and differentiation. These controls include the action of several hormones, including parathyroid hormone (PTH), vitamin D, growth hormone, steroids, and calcitonin, as well as several bone marrow-derived membrane and soluble cytokines and growth factors (e.g. M-CSF, RANKL, VEGF and IL-6 family). It is in this way that the body is able to maintain proper levels of calcium required for physiological processes. Thus bone remodeling is not just occasional "repair of bone damage" but rather an active, continual process that is always happening in a healthy body.
Subsequent to appropriate signaling, osteoclasts move to resorb the surface of the bone, followed by deposition o
Document 2:::
Bone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture.
Generally, bone fracture treatment consists of a doctor reducing (pushing) displaced bones back into place via relocation with or without anaesthetic, stabilizing their position to aid union, and then waiting for the bone's natural healing process to occur.
Adequate nutrient intake has been found to significantly affect the integrity of the fracture repair. Age, bone type, drug therapy and pre-existing bone pathology are factors that affect healing. The role of bone healing is to produce new bone without a scar as seen in other tissues which would be a structural weakness or deformity.
The process of the entire regeneration of the bone can depend on the angle of dislocation or fracture. While the bone formation usually spans the entire duration of the healing process, in some instances, bone marrow within the fracture has healed two or fewer weeks before the final remodelling phase.
While immobilization and surgery may facilitate healing, a fracture ultimately heals through physiological processes. The healing process is mainly determined by the periosteum (the connective tissue membrane covering the bone). The periosteum is one source of precursor cells that develop into chondroblasts and osteoblasts that are essential to the healing of bone. Other sources of precursor cells are the bone marrow (when present), endosteum, small blood vessels, and fibroblasts.
Primary healing
Primary healing (also known as direct healing) requires a correct anatomical reduction which is stable, without any gap formation. Such healing requires only the remodeling of lamellar bone, the Haversian canals and the blood vessels without callus formation. This process may take a few months to a few years.
Contact healing
When the gap between the bone ends is less than 0.01 mm, and interfragmentary strain is less than 2%, contact healing can occur. In
Document 3:::
See also
List of minerals
Document 4:::
Minor salts (micronutrients) per litre
Boric acid (H3BO3) 6. 2 mg/l
Cobalt chloride (CoCl2 · 6H2O) 0.025 mg/l
Ferrous sulfate (FeSO4 · 7H2O) 27.8 mg/l
Manganese(II) sulfate (MnSO4 · 4H2O) 22.3 mg/l
Potassium iodide (KI) 0.83 mg/l
Sodium molybdate (Na2MoO4 · 2H2O) 0.25 mg/l
Zinc sulfate (ZnSO4·7H2O) 8.6 mg/l
Ethylenediaminetetraacetic acid ferric sodium (FeNaEDTA) 36.70 mg/L
Copper sulfate (CuSO4 · 5H2O) 0.025 mg/l
Vitamins and organic compounds per litre
Myo-Inositol 100 mg/l
Nicotini
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What mineral that occurs in bones helps combat osteoporosis?
A. potassium
B. calcium
C. iron
D. magnesium
Answer:
|
|
sciq-9587
|
multiple_choice
|
Do placental mammals give birth to relatively small or large fetuses?
|
[
"small",
"large",
"they don't give birth",
"neither"
] |
B
|
Relavent Documents:
Document 0:::
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the fetus at a developmental stage when it is ready to feed and breathe.
In some species the offspring is precocial and can move around almost immediately after birth but in others it is altricial and completely dependent on parenting.
In marsupials, the fetus is born at a very immature stage after a short gestation and develops further in its mother's womb pouch.
It is not only mammals that give birth. Some reptiles, amphibians, fish and invertebrates carry their developing young inside them. Some of these are ovoviviparous, with the eggs being hatched inside the mother's body, and others are viviparous, with the embryo developing inside their body, as in the case of mammals.
Mammals
Large mammals, such as primates, cattle, horses, some antelopes, giraffes, hippopotamuses, rhinoceroses, elephants, seals, whales, dolphins, and porpoises, generally are pregnant with one offspring at a time, although they may have twin or multiple births on occasion.
In these large animals, the birth process is similar to that of a human, though in most the offspring is precocial. This means that it is born in a more advanced state than a human baby and is able to stand, walk and run (or swim in the case of an aquatic mammal) shortly after birth.
In the case of whales, dolphins and porpoises, the single calf is normally born tail first which minimizes the risk of drowning. The mother encourages the newborn calf to rise to the surface of the water to breathe.
Most smaller mammals have multiple births, producing litters of young which may number twelve or more. In these animals, each fetus is surrounded by its own amniotic sac and has a separate placenta. This separates from the wall of the uterus during labor and the fetus works its way towar
Document 1:::
Fetal pigs are unborn pigs used in elementary as well as advanced biology classes as objects for dissection. Pigs, as a mammalian species, provide a good specimen for the study of physiological systems and processes due to the similarities between many pig and human organs.
Use in biology labs
Along with frogs and earthworms, fetal pigs are among the most common animals used in classroom dissection. There are several reasons for this, the main reason being that pigs, like humans, are mammals. Shared traits include common hair, mammary glands, live birth, similar organ systems, metabolic levels, and basic body form. They also allow for the study of fetal circulation, which differs from that of an adult. Secondly, fetal pigs are easy to obtain because they are by-products of the pork industry. Fetal pigs are the unborn piglets of sows that were killed by the meat-packing industry. These pigs are not bred and killed for this purpose, but are extracted from the deceased sow’s uterus. Fetal pigs not used in classroom dissections are often used in fertilizer or simply discarded. Thirdly, fetal pigs are cheap, which is an essential component for dissection use by schools. They can be ordered for about $30 at biological product companies. Fourthly, fetal pigs are easy to dissect because of their soft tissue and incompletely developed bones that are still made of cartilage. In addition, they are relatively large with well-developed organs that are easily visible. As long as the pork industry exists, fetal pigs will be relatively abundant, making them the prime choice for classroom dissections.
Alternatives
Several peer-reviewed comparative studies have concluded that the educational outcomes of students who are taught basic and advanced biomedical concepts and skills using non-animal methods are equivalent or superior to those of their peers who use animal-based laboratories such as animal dissection.
A systematic review concluded that students taught using non-animal m
Document 2:::
Fetus in fetu (or foetus in foetu) is a rare developmental abnormality in which a mass of tissue resembling a fetus forms inside the body of its twin. An early example of the phenomenon was described in 1808 by George William Young.
There are two hypotheses for the origin of a "fetus in fetu". One hypothesis is that the mass begins as a normal fetus but becomes enveloped inside its twin. The other hypothesis is that the mass is a highly developed teratoma. "Fetus in fetu" is estimated to occur in 1 in 500,000 live births.
Classification as life
A fetus in fetu can be considered alive, but only in the sense that its component tissues have not yet died or been eliminated. Thus, the life of a fetus in fetu is akin to that of a tumor in that its cells remain viable by way of normal metabolic activity. However, without the gestational conditions in utero with the amnion and placenta, a fetus in fetu can develop into, at best, an especially well differentiated teratoma; or, at worst, a high-grade metastatic teratocarcinoma. In terms of physical maturation, its organs have a working blood supply from the host, but all cases of fetus in fetu present critical defects, such as no functional brain, heart, lungs, gastrointestinal tract, or urinary tract. Accordingly, while a fetus in fetu can share select morphological features with a normal fetus, it has no prospect of any life outside of the host twin. Moreover, it poses clear threats to the life of the host twin on whom its own life depends.
Hypotheses of development
There are two main hypotheses about the development of fetus in fetu.
Teratoma hypothesis
Fetus in fetu may be a very highly differentiated form of dermoid cyst, itself a highly differentiated form of mature teratoma.
Parasitic twin hypothesis
Fetus in fetu may be a parasitic twin fetus growing within its host twin. Very early in a monozygotic twin pregnancy, in which both fetuses share a common placenta, one fetus wraps around and envelops the other.
Document 3:::
The human reproductive system includes the male reproductive system which functions to produce and deposit sperm; and the female reproductive system which functions to produce egg cells, and to protect and nourish the fetus until birth. Humans have a high level of sexual differentiation. In addition to differences in nearly every reproductive organ, there are numerous differences in typical secondary sex characteristics.
Human reproduction usually involves internal fertilization by sexual intercourse. In this process, the male inserts his penis into the female's vagina and ejaculates semen, which contains sperm. A small proportion of the sperm pass through the cervix into the uterus, and then into the fallopian tubes for fertilization of the ovum. Only one sperm is required to fertilize the ovum. Upon successful fertilization, the fertilized ovum, or zygote, travels out of the fallopian tube and into the uterus, where it implants in the uterine wall. This marks the beginning of gestation, better known as pregnancy, which continues for around nine months as the fetus develops. When the fetus has developed to a certain point, pregnancy is concluded with childbirth, involving labor. During labor, the muscles of the uterus contract and the cervix dilates over the course of hours, and the baby passes out of the vagina. Human infants are completely dependent on their caregivers, and require high levels of parental care. Infants rely on their caregivers for comfort, cleanliness, and food. Food may be provided by breastfeeding or formula feeding.
Structure
Female
The human female reproductive system is a series of organs primarily located inside the body and around the pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vulva, which leads to the vagina, the vaginal opening, to the uterus; the uterus, which holds the developing fetus; and the ovaries, which produce the female's o
Document 4:::
The obstetrical dilemma is a hypothesis to explain why humans often require assistance from other humans during childbirth to avoid complications, whereas most non-human primates give birth unassisted with relatively little difficulty. This occurs due to the tight fit of the fetal head to the maternal birth canal, which is additionally convoluted, meaning the head and therefore body of the infant must rotate during childbirth in order to fit, unlike in other, non-upright walking mammals. Consequently, there is a usually high incidence of cephalopelvic disproportion and obstructed labor in humans.
The obstetrical dilemma claims that this difference is due to the biological trade-off imposed by two opposing evolutionary pressures in the development of the human pelvis: smaller birth canals in the mothers, and larger brains, and therefore skulls in the babies. Proponents believe bipedal locomotion (the ability to walk upright) decreased the size of the bony parts of the birth canal. They also believe that as hominids' and humans' skull and brain sizes increased over the millennia, that women needed wider hips to give birth, that these wider hips made women inherently less able to walk or run than men, and that babies had to be born earlier to fit through the birth canal, resulting in the so-called fourth trimester period for newborns (being born when the baby seems less developed than in other animals). Recent evidence has suggested bipedal locomotion is only a part of the strong evolutionary pressure constraining the expansion of the maternal birth canal. In addition to bipedal locomotion, the reduced strength of the pelvic floor due to a wider maternal pelvis also leads to fitness detriments in the mother pressuring the birth canal to remain relatively narrow.
This idea was widely accepted when first published in 1960, but has since been criticized by other scientists.
History
The term, obstetrical dilemma, was coined in 1960, by Sherwood Larned Washburn, a pr
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Do placental mammals give birth to relatively small or large fetuses?
A. small
B. large
C. they don't give birth
D. neither
Answer:
|
|
sciq-4227
|
multiple_choice
|
Give an example of a ball-and-socket joint, which has the greatest range of motion, allowing movement in several directions.
|
[
"pulley",
"monkey wrench",
"lever",
"shoulder"
] |
D
|
Relavent Documents:
Document 0:::
In anatomy, a biaxial joint is a freely mobile joint that allows movement in two anatomical planes. An example of a biaxial joint is a metacarpophalangeal joint of the hand. The joint allows for movement along one axis to produce bending or straightening of the finger, and movement along a second axis, which allows for spreading of the fingers away from each other and bringing them together.
Document 1:::
Range of motion (or ROM) is the linear or angular distance that a moving object may normally travel while properly attached to another.
In biomechanics and strength training, ROM refers to the angular distance and direction a joint can move between the flexed position and the extended position. The act of attempting to increase this distance through therapeutic exercises (range of motion therapy—stretching from flexion to extension for physiological gain) is also sometimes called range of motion.
In mechanical engineering, it is (also called range of travel or ROT) used particularly when talking about mechanical devices, such as a sound volume control knob.
In biomechanics
Measuring range of motion
Each specific joint has a normal range of motion that is expressed in degrees. The reference values for the normal ROM in individuals differ slightly depending on age and gender. For example, as an individual ages, they typically lose a small amount of ROM.
Analog and traditional devices to measure range of motion in the joints of the body include the goniometer and inclinometer which use a stationary arm, protractor, fulcrum, and movement arm to measure angle from axis of the joint. As measurement results will vary by the degree of resistance, two levels of range of motion results are recorded in most cases.
Recent technological advances in 3D motion capture technology allow for the measurement of joints concurrently, which can be used to measure a patient's active range of motion.
Limited range of motion
Limited range of motion refers to a joint that has a reduction in its ability to move. The reduced motion may be a problem with the specific joint or it may be caused by injury or diseases such as osteoarthritis, rheumatoid arthritis, or other types of arthritis. Pain, swelling, and stiffness associated with arthritis can limit the range of motion of a particular joint and impair function and the ability to perform usual daily activities.
Limited range of moti
Document 2:::
A mechanical joint is a section of a machine which is used to connect one or more mechanical part to another. Mechanical joints may be temporary or permanent; most types are designed to be disassembled. Most mechanical joints are designed to allow relative movement of these mechanical parts of the machine in one degree of freedom, and restrict movement in one or more others.
Pin
A pin joint, also called a revolute joint, is a one-degree-of-freedom kinematic pair. It constrains the motion of two bodies to pure rotation along a common axis. The joint doesn't allow translation, or sliding linear motion. This is usually done through a rotary bearing. It enforces a cylindrical contact area, which makes it a lower kinematic pair, also called a full joint.
Prismatic
A prismatic joint provides a linear sliding movement between two bodies, and is often called a slider, as in the slider-crank linkage. A prismatic pair is also called as sliding pair. A prismatic joint can be formed with a polygonal cross-section to resist rotation.
The relative position of two bodies connected by a prismatic joint is defined by the amount of linear slide of one relative to the other one. This one parameter movement identifies this joint as a one degree of freedom kinematic pair.
Prismatic joints provide single-axis sliding often found in hydraulic and pneumatic cylinders.
Ball
In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles. They are used on virtually every automobile made and work similarly to the ball-and-socket design of the human hip joint.
A ball joint consists of a bearing stud and socket enclosed in a casing; all these parts are made of steel. The bearing stud is tapered and threaded, and fits into a tapered hole in the steering knuckle. A protective encasing prevents dirt from getting into the joint assembly. Usually, this is a rubber-like boot that allows movement and expansion of lubricant. Motion-control ball
Document 3:::
Joint constraints are rotational constraints on the joints of an artificial system. They are used in an inverse kinematics chain, in fields including 3D animation or robotics. Joint constraints can be implemented in a number of ways, but the most common method is to limit rotation about the X, Y and Z axis independently. An elbow, for instance, could be represented by limiting rotation on X and Z axis to 0 degrees, and constraining the Y-axis rotation to 130 degrees.
To simulate joint constraints more accurately, dot-products can be used with an independent axis to repulse the child bones orientation from the unreachable axis. Limiting the orientation of the child bone to a border of vectors tangent to the surface of the joint, repulsing the child bone away from the border, can also be useful in the precise restriction of shoulder movement.
Document 4:::
In mechanical engineering, a kinematic diagram or kinematic scheme (also called a joint map or skeleton diagram) illustrates the connectivity of links and joints of a mechanism or machine rather than the dimensions or shape of the parts. Often links are presented as geometric objects, such as lines, triangles or squares, that support schematic versions of the joints of the mechanism or machine.
For example, the figures show the kinematic diagrams (i) of the slider-crank that forms a piston and crank-shaft in an engine, and (ii) of the first three joints for a PUMA manipulator.
|- style="text-align:center;"
| ||
|- style="text-align:center;"
| PUMA robot || and its kinematic diagram
Linkage graph
A kinematic diagram can be formulated as a graph by representing the joints of the mechanism as vertices and the links as edges of the graph. This version of the kinematic diagram has proven effective in enumerating kinematic structures in the process of machine design.
An important consideration in this design process is the degree of freedom of the system of links and joints, which is determined using the Chebychev–Grübler–Kutzbach criterion.
Elements of machines
Elements of kinematics diagrams include the frame, which is the frame of reference for all the moving components, as well as links (kinematic pairs), and joints. Primary Joints include pins, sliders and other elements that allow pure rotation or pure linear motion. Higher order joints also exist that allow a combination of rotation or linear motion. Kinematic diagrams also include points of interest, and other important components.
See also
Free body diagram
Kinematic synthesis
Left-hand–right-hand activity chart
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Give an example of a ball-and-socket joint, which has the greatest range of motion, allowing movement in several directions.
A. pulley
B. monkey wrench
C. lever
D. shoulder
Answer:
|
|
sciq-5468
|
multiple_choice
|
The group of plants that can make their own food from inorganic raw materials in the presence of sunlight are referred to as what?
|
[
"autosynonomys",
"heterotrophic",
"symbiotic",
"autotrophic"
] |
D
|
Relavent Documents:
Document 0:::
Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi.
Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude the fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts, mosses, lycophytes, ferns, conifers and other gymnosperms, and flowering plants). A definition based on genomes includes the Viridiplantae, along with the red algae and the glaucophytes, in the clade Archaeplastida.
There are about 380,000 known species of plants, of which the majority, some 260,000, produce seeds. They range in size from single cells to the tallest trees. Green plants provide a substantial proportion of the world's molecular oxygen; the sugars they create supply the energy for most of Earth's ecosystems; other organisms, including animals, either consume plants directly or rely on organisms which do so.
Grain, fruit, and vegetables are basic human foods and have been domesticated for millennia. People use plants for many purposes, such as building materials, ornaments, writing materials, and, in great variety, for medicines. The scientific study of plants is known as botany, a branch of biology.
Definition
Taxonomic history
All living things were traditionally placed into one of two groups, plants and animals. This classification dates from Aristotle (384–322 BC), who distinguished d
Document 1:::
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 2:::
Heterotrophic nutrition is a mode of nutrition in which organisms depend upon other organisms for food to survive. They can't make their own food like Green plants. Heterotrophic organisms have to take in all the organic substances they need to survive.
All animals, certain types of fungi, and non-photosynthesizing plants are heterotrophic. In contrast, green plants, red algae, brown algae, and cyanobacteria are all autotrophs, which use photosynthesis to produce their own food from sunlight. Some fungi may be saprotrophic, meaning they will extracellularly secrete enzymes onto their food to be broken down into smaller, soluble molecules which can diffuse back into the fungus.
Description
All eukaryotes except for green plants and algae are unable to manufacture their own food: They obtain food from other organisms. This mode of nutrition is also known as heterotrophic nutrition.
All heterotrophs (except blood and gut parasites) have to convert solid food into soluble compounds which are capable of being absorbed (digestion). Then the soluble products of digestion for the organism are being broken down for the release of energy (respiration). All heterotrophs depend on autotrophs for their nutrition. Heterotrophic organisms have only four types of nutrition.
Footnotes
Document 3:::
Macroflora is a term used for all the plants occurring in a particular area that are large enough to be seen with the naked eye. It is usually synonymous with the Flora and can be contrasted with the microflora, a term used for all the bacteria and other microorganisms in an ecosystem.
Macroflora is also an informal term used by many palaeobotanists to refer to an assemblage of plant fossils as preserved in the rock. This is in contrast to the flora, which in this context refers to the assemblage of living plants that were growing in a particular area, whose fragmentary remains became entrapped within the sediment from which the rock was formed and thus became the macroflora.
Document 4:::
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
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The group of plants that can make their own food from inorganic raw materials in the presence of sunlight are referred to as what?
A. autosynonomys
B. heterotrophic
C. symbiotic
D. autotrophic
Answer:
|
|
scienceQA-49
|
multiple_choice
|
How long is a walk across Central Park in New York City?
|
[
"3 centimeters",
"3 millimeters",
"3 kilometers",
"3 meters"
] |
C
|
The best estimate for the length of a walk across Central Park in New York City is 3 kilometers.
3 millimeters, 3 centimeters, and 3 meters are all too short.
|
Relavent Documents:
Document 0:::
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This course is designed for students who wish to pursue an interest in the life sciences. The College Board recommends successful completion of high school biology and high school chemistry before commencing AP Biology, although the actual prerequisites vary from school to school and from state to state. This course, nevertheless, is considered very challenging and one of the most difficult AP classes, as shown with AP Finals grade distributions.
Topic outline
The exam covers the following 8 units. The percentage indicates the portion of the multiple-choice section of the exam focused on each content area:
The course is based on and tests six skills, called scientific practices which include:
In addition to the topics above, students are required to be familiar with general lab procedure. Students should know how to collect data, analyze data to form conclusions, and apply those conclusions.
Exam
Students are allowed to use a four-function, scientific, or graphing calculator.
The exam has two sections: a 90 minute multiple choice section and a 90 minute free response section. There are 60 multiple choice questions and six free responses, two long and four short. Both sections are worth 50% of the score.
Score distribution
Commonly used textbooks
Biology, AP Edition by Sylvia Mader (2012, hardcover )
Life: The Science of Biology (Sadava, Heller, Orians, Purves, and Hillis, )
Campbell Biology AP Ninth Edition (Reece, Urry, Cain, Wasserman, Minorsky, and Andrew Jackson )
See also
Glossary of biology
A.P Bio (TV Show)
Document 1:::
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:::
Tech City College (Formerly STEM Academy) is a free school sixth form located in the Islington area of the London Borough of Islington, England.
It originally opened in September 2013, as STEM Academy Tech City and specialised in Science, Technology, Engineering and Maths (STEM) and the Creative Application of Maths and Science. In September 2015, STEM Academy joined the Aspirations Academy Trust was renamed Tech City College. Tech City College offers A-levels and BTECs as programmes of study for students.
Document 3:::
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
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 long is a walk across Central Park in New York City?
A. 3 centimeters
B. 3 millimeters
C. 3 kilometers
D. 3 meters
Answer:
|
sciq-913
|
multiple_choice
|
Under appropriate conditions, the attractions between all molecules in what state will cause them to form liquids or solids?
|
[
"soild",
"plasma",
"liquid",
"gas"
] |
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:::
In physics, ultradivided matter is a family of states of matter characterised by a heterogeneous mixture of two or more different materials, where the interaction energy between the suspended phase is larger than kT. The term 'ultradivided matter' encapsulates several types of substance including: soap micelles, emulsions, and suspensions of solids such as colloids.).
An ultradivided state differs from a solution. In a steady-state solution, all interactions between a solution's constituent molecules are on the order of the thermal energy kT. Thus any otherwise aggregative force between similar molecules in a solution is subordinate to thermal fluctuations, and the solution does allow flocculation of one of the constituent components. Ultradivided matter, however, is characterised by large interfacial energies where the intermolecular interactions of one or more constituents of the substance are stronger than kT. This leads to different behaviour. An intuitive example of this can be seen in the tendency of a biphasic mixture of water (a polar liquid) and oil (a non-polar liquid) to spontaneously separate into two phases. This may seem to imply a change from a state with higher disorder or higher entropy (a suspension of oil droplets in water) to a lower-entropy arrangement (a neat separation into two regions of different material). Such a transition would seem to violate the second law of thermodynamics, which is impossible. The resolution to this apparent paradox is that the interface between oil and water necessitates an ordered alignment of oil and water molecules at the interface. Minimisation of the surface area between the two phases thus correlates with an increase of the entropy of the system. The highest entropy state thus has a minimum interfacial surface area between the two phases and thus a neat separation is created, into two regions of different material.
See also
Colloid
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:::
States of matter are distinguished by changes in the properties of matter associated with external factors like pressure and temperature. States are usually distinguished by a discontinuity in one of those properties: for example, raising the temperature of ice produces a discontinuity at 0°C, as energy goes into a phase transition, rather than temperature increase. The three classical states of matter are solid, liquid and gas. In the 20th century, however, increased understanding of the more exotic properties of matter resulted in the identification of many additional states of matter, none of which are observed in normal conditions.
Low-energy states of matter
Classical states
Solid: A solid holds a definite shape and volume without a container. The particles are held very close to each other.
Amorphous solid: A solid in which there is no far-range order of the positions of the atoms.
Crystalline solid: A solid in which atoms, molecules, or ions are packed in regular order.
Plastic crystal: A molecular solid with long-range positional order but with constituent molecules retaining rotational freedom.
Quasicrystal: A solid in which the positions of the atoms have long-range order, but this is not in a repeating pattern.
Liquid: A mostly non-compressible fluid. Able to conform to the shape of its container but retains a (nearly) constant volume independent of pressure.
Liquid crystal: Properties intermediate between liquids and crystals. Generally, able to flow like a liquid but exhibiting long-range order.
Gas: A compressible fluid. Not only will a gas take the shape of its container but it will also expand to fill the container.
Modern states
Plasma: Free charged particles, usually in equal numbers, such as ions and electrons. Unlike gases, plasma may self-generate magnetic fields and electric currents and respond strongly and collectively to electromagnetic forces. Plasma is very uncommon on Earth (except for the ionosphere), although it is the mo
Document 4:::
A two-dimensional liquid (2D liquid) is a collection of objects constrained to move in a planar or other two-dimensional space in a liquid state.
Relations with 3D liquids
The movement of the particles in a 2D liquid is similar to 3D, but with limited degrees of freedom. E.g. rotational motion can be limited to rotation about only one axis, in contrast to a 3D liquid, where rotation of molecules about two or three axis would be possible.
The same is true for the translational motion. The particles in 2D liquids can move in a 2D plane, whereas the particles is a 3D liquid can move in three directions inside the 3D volume.
Vibrational motion is in most cases not constrained in comparison to 3D.
The relations with other states of aggregation (see below) are also analogously in 2D and 3D.
Relation to other states of aggregation
2D liquids are related to 2D gases. If the density of a 2D liquid is decreased, a 2D gas is formed. This was observed by scanning tunnelling microscopy under ultra-high vacuum (UHV) conditions for molecular adsorbates.
2D liquids are related to 2D solids. If the density of a 2D liquid is increased, the rotational degree of freedom is frozen and a 2D solid is created.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Under appropriate conditions, the attractions between all molecules in what state will cause them to form liquids or solids?
A. soild
B. plasma
C. liquid
D. gas
Answer:
|
|
sciq-3981
|
multiple_choice
|
The layers of the atmosphere correspond with what changes with altitude?
|
[
"nitrogen",
"oxygen",
"friction",
"temperature"
] |
D
|
Relavent Documents:
Document 0:::
Atmospheric temperature is a measure of temperature at different levels of the Earth's atmosphere. It is governed by many factors, including incoming solar radiation, humidity and altitude. When discussing surface air temperature, the annual atmospheric temperature range at any geographical location depends largely upon the type of biome, as measured by the Köppen climate classification
Temperature versus altitude
Temperature varies greatly at different heights relative to Earth's surface and this variation in temperature characterizes the four layers that exist in the atmosphere. These layers include the troposphere, stratosphere, mesosphere, and thermosphere.
The troposphere is the lowest of the four layers, extending from the surface of the Earth to about into the atmosphere where the tropopause (the boundary between the troposphere stratosphere) is located. The width of the troposphere can vary depending on latitude, for example, the troposphere is thicker in the tropics (about ) because the tropics are generally warmer, and thinner at the poles (about ) because the poles are colder. Temperatures in the atmosphere decrease with height at an average rate of 6.5°C (11.7°F) per kilometer. Because the troposphere experiences its warmest temperatures closer to Earth's surface, there is great vertical movement of heat and water vapour, causing turbulence. This turbulence, in conjunction with the presence of water vapour, is the reason that weather occurs within the troposphere.
Following the tropopause is the stratosphere. This layer extends from the tropopause to the stratopause which is located at an altitude of about . Temperatures remain constant with height from the tropopause to an altitude of , after which they start to increase with height. This happening is referred to as an inversion and It is because of this inversion that the stratosphere is not characterised as turbulent. The stratosphere receives its warmth from the sun and the ozone layer which ab
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:::
Aeronomy is the scientific study of the upper atmosphere of the Earth and corresponding regions of the atmospheres of other planets. It is a branch of both atmospheric chemistry and atmospheric physics. Scientists specializing in aeronomy, known as aeronomers, study the motions and chemical composition and properties of the Earth's upper atmosphere and regions of the atmospheres of other planets that correspond to it, as well as the interaction between upper atmospheres and the space environment. In atmospheric regions aeronomers study, chemical dissociation and ionization are important phenomena.
History
The mathematician Sydney Chapman introduced the term aeronomy to describe the study of the Earth's upper atmosphere in 1946 in a letter to the editor of Nature entitled "Some Thoughts on Nomenclature." The term became official in 1954 when the International Union of Geodesy and Geophysics adopted it. "Aeronomy" later also began to refer to the study of the corresponding regions of the atmospheres of other planets.
Branches
Aeronomy can be divided into three main branches: terrestrial aeronomy, planetary aeronomy, and comparative aeronomy.
Terrestrial aeronomy
Terrestrial aeronomy focuses on the Earth's upper atmosphere, which extends from the stratopause to the atmosphere's boundary with outer space and is defined as consisting of the mesosphere, thermosphere, and exosphere and their ionized component, the ionosphere. Terrestrial aeronomy contrasts with meteorology, which is the scientific study of the Earth's lower atmosphere, defined as the troposphere and stratosphere. Although terrestrial aeronomy and meteorology once were completely separate fields of scientific study, cooperation between terrestrial aeronomers and meteorologists has grown as discoveries made since the early 1990s have demonstrated that the upper and lower atmospheres have an impact on one another's physics, chemistry, and biology.
Terrestrial aeronomers study atmospheric tides and upper-
Document 3:::
Biometeorology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or shorter (in contrast with bioclimatology).
Examples of relevant processes
Weather events influence biological processes on short time scales. For instance, as the Sun rises above the horizon in the morning, light levels become sufficient for the process of photosynthesis to take place in plant leaves. Later on, during the day, air temperature and humidity may induce the partial or total closure of the stomata, a typical response of many plants to limit the loss of water through transpiration. More generally, the daily evolution of meteorological variables controls the circadian rhythm of plants and animals alike.
Living organisms, for their part, can collectively affect weather patterns. The rate of evapotranspiration of forests, or of any large vegetated area for that matter, contributes to the release of water vapor in the atmosphere. This local, relatively fast and continuous process may contribute significantly to the persistence of precipitations in a given area. As another example, the wilting of plants results in definite changes in leaf angle distribution and therefore modifies the rates of reflection, transmission and absorption of solar light in these plants. That, in turn, changes the albedo of the ecosystem as well as the relative importance of the sensible and latent heat fluxes from the surface to the atmosphere. For an example in oceanography, consider the release of dimethyl sulfide by biological activity in sea water and its impact on atmospheric aerosols.
Human biometeorology
The methods and measurements traditionally used in biometeorology are not different when applied to study the interactions between human bodies and the atmosphere, but some aspects or applications may have been explored more extensively. For instance, wind chill has been investigated to determine th
Document 4:::
In mathematical psychology and education theory, a knowledge space is a combinatorial structure used to formulate mathematical models describing the progression of a human learner. Knowledge spaces were introduced in 1985 by Jean-Paul Doignon and Jean-Claude Falmagne, and remain in extensive use in the education theory. Modern applications include two computerized tutoring systems, ALEKS and the defunct RATH.
Formally, a knowledge space assumes that a domain of knowledge is a collection of concepts or skills, each of which must be eventually mastered. Not all concepts are interchangeable; some require other concepts as prerequisites. Conversely, competency at one skill may ease the acquisition of another through similarity. A knowledge space marks out which collections of skills are feasible: they can be learned without mastering any other skills. Under reasonable assumptions, the collection of feasible competencies forms the mathematical structure known as an antimatroid.
Researchers and educators usually explore the structure of a discipline's knowledge space as a latent class model.
Motivation
Knowledge Space Theory attempts to address shortcomings of standardized testing when used in educational psychometry. Common tests, such as the SAT and ACT, compress a student's knowledge into a very small range of ordinal ranks, in the process effacing the conceptual dependencies between questions. Consequently, the tests cannot distinguish between true understanding and guesses, nor can they identify a student's particular weaknesses, only the general proportion of skills mastered. The goal of knowledge space theory is to provide a language by which exams can communicate
What the student can do and
What the student is ready to learn.
Model structure
Knowledge Space Theory-based models presume that an educational subject can be modeled as a finite set of concepts, skills, or topics. Each feasible state of knowledge about is then a subset of ; the set of
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The layers of the atmosphere correspond with what changes with altitude?
A. nitrogen
B. oxygen
C. friction
D. temperature
Answer:
|
|
sciq-10828
|
multiple_choice
|
What process determines the dna sequence of an entire genome?
|
[
"genetic factorization",
"chromosomal counting",
"dna replication",
"whole-genome sequencing"
] |
D
|
Relavent Documents:
Document 0:::
DNA sequencing theory is the broad body of work that attempts to lay analytical foundations for determining the order of specific nucleotides in a sequence of DNA, otherwise known as DNA sequencing. The practical aspects revolve around designing and optimizing sequencing projects (known as "strategic genomics"), predicting project performance, troubleshooting experimental results, characterizing factors such as sequence bias and the effects of software processing algorithms, and comparing various sequencing methods to one another. In this sense, it could be considered a branch of systems engineering or operations research. The permanent archive of work is primarily mathematical, although numerical calculations are often conducted for particular problems too. DNA sequencing theory addresses physical processes related to sequencing DNA and should not be confused with theories of analyzing resultant DNA sequences, e.g. sequence alignment. Publications sometimes do not make a careful distinction, but the latter are primarily concerned with algorithmic issues. Sequencing theory is based on elements of mathematics, biology, and systems engineering, so it is highly interdisciplinary. The subject may be studied within the context of computational biology.
Theory and sequencing strategies
Sequencing as a covering problem
All mainstream methods of DNA sequencing rely on reading small fragments of DNA and subsequently reconstructing these data to infer the original DNA target, either via assembly or alignment to a reference. The abstraction common to these methods is that of a mathematical covering problem. For example, one can imagine a line segment representing the target and a subsequent process where smaller segments are "dropped" onto random locations of the target. The target is considered "sequenced" when adequate coverage accumulates (e.g., when no gaps remain).
The abstract properties of covering have been studied by mathematicians for over a century. However, dir
Document 1:::
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 2:::
Genome projects are scientific endeavours that ultimately aim to determine the complete genome sequence of an organism (be it an animal, a plant, a fungus, a bacterium, an archaean, a protist or a virus) and to annotate protein-coding genes and other important genome-encoded features. The genome sequence of an organism includes the collective DNA sequences of each chromosome in the organism. For a bacterium containing a single chromosome, a genome project will aim to map the sequence of that chromosome. For the human species, whose genome includes 22 pairs of autosomes and 2 sex chromosomes, a complete genome sequence will involve 46 separate chromosome sequences.
The Human Genome Project is a well known example of a genome project.
Genome assembly
Genome assembly refers to the process of taking a large number of short DNA sequences and reassembling them to create a representation of the original chromosomes from which the DNA originated. In a shotgun sequencing project, all the DNA from a source (usually a single organism, anything from a bacterium to a mammal) is first fractured into millions of small pieces. These pieces are then "read" by automated sequencing machines. A genome assembly algorithm works by taking all the pieces and aligning them to one another, and detecting all places where two of the short sequences, or reads, overlap. These overlapping reads can be merged, and the process continues.
Genome assembly is a very difficult computational problem, made more difficult because many genomes contain large numbers of identical sequences, known as repeats. These repeats can be thousands of nucleotides long, and occur different locations, especially in the large genomes of plants and animals.
The resulting (draft) genome sequence is produced by combining the information sequenced contigs and then employing linking information to create scaffolds. Scaffolds are positioned along the physical map of the chromosomes creating a "golden path".
Assembly soft
Document 3:::
Transmission electron microscopy DNA sequencing is a single-molecule sequencing technology that uses transmission electron microscopy techniques. The method was conceived and developed in the 1960s and 70s, but lost favor when the extent of damage to the sample was recognized.
In order for DNA to be clearly visualized under an electron microscope, it must be labeled with heavy atoms. In addition, specialized imaging techniques and aberration corrected optics are beneficial for obtaining the resolution required to image the labeled DNA molecule. In theory, transmission electron microscopy DNA sequencing could provide extremely long read lengths, but the issue of electron beam damage may still remain and the technology has not yet been commercially developed.
History
Only a few years after James Watson and Francis Crick deduced the structure of DNA, and nearly two decades before Frederick Sanger published the first method for rapid DNA sequencing, Richard Feynman, an American physicist, envisioned the electron microscope as the tool that would one day allow biologists to "see the order of bases in the DNA chain". Feynman believed that if the electron microscope could be made powerful enough, then it would become possible to visualize the atomic structure of any and all chemical compounds, including DNA.
In 1970, Albert Crewe developed the high-angle annular dark-field imaging (HAADF) imaging technique in a scanning transmission electron microscope. Using this technique, he visualized individual heavy atoms on thin amorphous carbon films. In 2010 Krivanek and colleagues reported several technical improvements to the HAADF method, including a combination of aberration corrected electron optics and low accelerating voltage. The latter is crucial for imaging biological objects, as it allows to reduce damage by the beam and increase the image contrast for light atoms. As a result, single atom substitutions in a boron nitride monolayer could be imaged.
Despite the inv
Document 4:::
A sequence in biology is the one-dimensional ordering of monomers, covalently linked within a biopolymer; it is also referred to as the primary structure of a biological macromolecule. While it can refer to many different molecules, the term sequence is most often used to refer to a DNA sequence.
See also
Protein sequence
DNA sequence
Genotype
Self-incompatibility in plants
List of geneticists
Human Genome Project
Dot plot (bioinformatics)
Multiplex Ligation-dependent Probe Amplification
Sequence analysis
Molecular biology
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What process determines the dna sequence of an entire genome?
A. genetic factorization
B. chromosomal counting
C. dna replication
D. whole-genome sequencing
Answer:
|
|
scienceQA-2366
|
multiple_choice
|
What do these two changes have in common?
a crayon melting in the sun
a puddle freezing into ice on a cold night
|
[
"Both are caused by cooling.",
"Both are only physical changes.",
"Both are chemical changes.",
"Both are caused by heating."
] |
B
|
Step 1: Think about each change.
A crayon melting in the sun is a change of state. So, it is a physical change. The crayon changes state from solid to liquid. The crayon is still made of wax, even after it melts.
A puddle freezing into ice on a cold night is a change of state. So, it is a physical change. Liquid water freezes and becomes solid, but it is still made of water. A different type of matter is not formed.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
A crayon melting in the sun is caused by heating. But a puddle freezing is not.
Both are caused by cooling.
A puddle freezing is caused by cooling. But a crayon melting is not.
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 2:::
In physics, a dynamical system is said to be mixing if the phase space of the system becomes strongly intertwined, according to at least one of several mathematical definitions. For example, a measure-preserving transformation T is said to be strong mixing if
whenever A and B are any measurable sets and μ is the associated measure. Other definitions are possible, including weak mixing and topological mixing.
The mathematical definition of mixing is meant to capture the notion of physical mixing. A canonical example is the Cuba libre: suppose one is adding rum (the set A) to a glass of cola. After stirring the glass, the bottom half of the glass (the set B) will contain rum, and it will be in equal proportion as it is elsewhere in the glass. The mixing is uniform: no matter which region B one looks at, some of A will be in that region. A far more detailed, but still informal description of mixing can be found in the article on mixing (mathematics).
Every mixing transformation is ergodic, but there are ergodic transformations which are not mixing.
Physical mixing
The mixing of gases or liquids is a complex physical process, governed by a convective diffusion equation that may involve non-Fickian diffusion as in spinodal decomposition. The convective portion of the governing equation contains fluid motion terms that are governed by the Navier–Stokes equations. When fluid properties such as viscosity depend on composition, the governing equations may be coupled. There may also be temperature effects. It is not clear that fluid mixing processes are mixing in the mathematical sense.
Small rigid objects (such as rocks) are sometimes mixed in a rotating drum or tumbler. The 1969 Selective Service draft lottery was carried out by mixing plastic capsules which contained a slip of paper (marked with a day of the year).
See also
Miscibility
Document 3:::
Adaptive comparative judgement is a technique borrowed from psychophysics which is able to generate reliable results for educational assessment – as such it is an alternative to traditional exam script marking. In the approach, judges are presented with pairs of student work and are then asked to choose which is better, one or the other. By means of an iterative and adaptive algorithm, a scaled distribution of student work can then be obtained without reference to criteria.
Introduction
Traditional exam script marking began in Cambridge 1792 when, with undergraduate numbers rising, the importance of proper ranking of students was growing. So in 1792 the new Proctor of Examinations, William Farish, introduced marking, a process in which every examiner gives a numerical score to each response by every student, and the overall total mark puts the students in the final rank order. Francis Galton (1869) noted that, in an unidentified year about 1863, the Senior Wrangler scored 7,634 out of a maximum of 17,000, while the Second Wrangler scored 4,123. (The 'Wooden Spoon' scored only 237.)
Prior to 1792, a team of Cambridge examiners convened at 5pm on the last day of examining, reviewed the 19 papers each student had sat – and published their rank order at midnight. Marking solved the problems of numbers and prevented unfair personal bias, and its introduction was a step towards modern objective testing, the format it is best suited to. But the technology of testing that followed, with its major emphasis on reliability and the automatisation of marking, has been an uncomfortable partner for some areas of educational achievement: assessing writing or speaking, and other kinds of performance need something more qualitative and judgemental.
The technique of Adaptive Comparative Judgement is an alternative to marking. It returns to the pre-1792 idea of sorting papers according to their quality, but retains the guarantee of reliability and fairness. It is by far the most rel
Document 4:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
a crayon melting in the sun
a puddle freezing into ice on a cold night
A. Both are caused by cooling.
B. Both are only physical changes.
C. Both are chemical changes.
D. Both are caused by heating.
Answer:
|
sciq-3923
|
multiple_choice
|
What are 3 types of light?
|
[
"diffuse, ambient, opaque",
"infrared, visible, ultraviolet",
"solar , visible , ultraviolet",
"complementary, incandescent, fluorescent"
] |
B
|
Relavent Documents:
Document 0:::
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:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 2:::
The Kruithof curve describes a region of illuminance levels and color temperatures that are often viewed as comfortable or pleasing to an observer. The curve was constructed from psychophysical data collected by Dutch physicist Arie Andries Kruithof, though the original experimental data is not present on the curve itself. Lighting conditions within the bounded region were empirically assessed as being pleasing or natural, whereas conditions outside the region were considered uncomfortable, displeasing or unnatural. sources that are considered natural or closely resemble Planckian black bodies, but its value in describing human preference has been consistently questioned by further studies on interior lighting.
For example, natural daylight has a color temperature of 6500 K and an illuminance of about 104 to 105 lux. This color temperature–illuminance pair results in natural color rendition, but if viewed at a low illuminance, would appear bluish. At typical indoor office illuminance levels of about 400 lux, pleasing color temperatures are lower (between 3000 and 6000 K), and at typical home illuminance levels of about 75 lux, pleasing color temperatures are even lower (between 2400 and 2700 K). These color temperature-illuminance pairs are often achieved with fluorescent and incandescent sources, respectively. The pleasing region of the curve contains color temperatures and illuminance levels comparable to naturally lit environments.
History
At the emergence of fluorescent lighting in 1941, Kruithof conducted psychophysical experiments to provide a technical guide to design artificial lighting. Using gas-discharge fluorescent lamps, Kruithof was able to manipulate the color of emitted light and ask observers to report as to whether or not the source was pleasing to them. The sketch of his curve as presented consists of three major regions: the middle region, which corresponds to light sources considered pleasing; the lower region, which corresponds to colors tha
Document 3:::
Illumination is an important concept in visual arts.
The illumination of the subject of a drawing or painting is a key element in creating an artistic piece, and the interplay of light and shadow is a valuable method in the artist's toolbox. The placement of the light sources can make a considerable difference in the type of message that is being presented. Multiple light sources can wash out any wrinkles in a person's face, for instance, and give a more youthful appearance. In contrast, a single light source, such as harsh daylight, can serve to highlight any texture or interesting features.
Processing of illumination is an important concept in computer vision and computer graphics.
See also
Chiaroscuro
Artistic techniques
Lighting
Computer graphics
Image processing
Document 4:::
In visual physiology, adaptation is the ability of the retina of the eye to adjust to various levels of light. Natural night vision, or scotopic vision, is the ability to see under low-light conditions. In humans, rod cells are exclusively responsible for night vision as cone cells are only able to function at higher illumination levels. Night vision is of lower quality than day vision because it is limited in resolution and colors cannot be discerned; only shades of gray are seen. In order for humans to transition from day to night vision they must undergo a dark adaptation period of up to two hours in which each eye adjusts from a high to a low luminescence "setting", increasing sensitivity hugely, by many orders of magnitude. This adaptation period is different between rod and cone cells and results from the regeneration of photopigments to increase retinal sensitivity. Light adaptation, in contrast, works very quickly, within seconds.
Efficiency
The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of 1,000. What enables the wider reach is that the eye adapts its definition of what is black.
The eye takes approximately 20–30 minutes to fully adapt from bright sunlight to complete darkness and becomes 10,000 to 1,000,000 times more sensitive than at full daylight. In this process, the eye's perception of color changes as well (this is called the Purkinje effect). However, it takes approximately five minutes for the eye to adapt from darkness to bright sunlight. This is due to cones obtaining more sensitivity when first entering the dark for the first five minutes but the rods taking over after five or more minutes. Cone cells are able to regain maximum retinal sensitivity in 9
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What are 3 types of light?
A. diffuse, ambient, opaque
B. infrared, visible, ultraviolet
C. solar , visible , ultraviolet
D. complementary, incandescent, fluorescent
Answer:
|
|
sciq-7904
|
multiple_choice
|
The planet neptune has strange dark spots that sometimes appear on its surface? what are these spots?
|
[
"black holes",
"storms",
"seas",
"earthquakes"
] |
B
|
Relavent Documents:
Document 0:::
Starspots are stellar phenomena, so-named by analogy with sunspots.
Spots as small as sunspots have not been detected on other stars, as they would cause undetectably small fluctuations in brightness. The commonly observed starspots are in general much larger than those on the Sun: up to about 30% of the stellar surface may be covered, corresponding to starspots 100 times larger than those on the Sun.
Detection and measurements
To detect and measure the extent of starspots one uses several types of methods.
For rapidly rotating stars – Doppler imaging and Zeeman-Doppler imaging. With the Zeeman-Doppler imaging technique the direction of the magnetic field on stars can be determined since spectral lines are split according to the Zeeman effect, revealing the direction and magnitude of the field.
For slowly rotating stars – Line Depth Ratio (LDR). Here one measures two different spectral lines, one sensitive to temperature and one which is not. Since starspots have a lower temperature than their surroundings the temperature-sensitive line changes its depth. From the difference between these two lines the temperature and size of the spot can be calculated, with a temperature accuracy of 10K.
For eclipsing binary stars – Eclipse mapping produces images and maps of spots on both stars.
For giant binary stars - Very-long-baseline interferometry
For stars with transiting extrasolar planets – Light curve variations.
Temperature
Observed starspots have a temperature which is in general 500–2000 kelvins cooler than the stellar photosphere. This temperature difference could give rise to a brightness variation up to 0.6 magnitudes between the spot and the surrounding surface. There also seems to be a relation between the spot temperature and the temperature for the stellar photosphere, indicating that starspots behave similarly for different types of stars (observed in G–K dwarfs).
Lifetimes
The lifetime for a starspot depends on its size.
For small spots the lifetim
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:::
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:::
In astronomy, a disrupted planet is a planet or exoplanet or, perhaps on a somewhat smaller scale, a planetary-mass object, planetesimal, moon, exomoon or asteroid that has been disrupted or destroyed by a nearby or passing astronomical body or object such as a star. Necroplanetology is the related study of such a process.
The result of such a disruption may be the production of excessive amounts of related gas, dust and debris, which may eventually surround the parent star in the form of a circumstellar disk or debris disk. As a consequence, the orbiting debris field may be an "uneven ring of dust", causing erratic light fluctuations in the apparent luminosity of the parent star, as may have been responsible for the oddly flickering light curves associated with the starlight observed from certain variable stars, such as that from Tabby's Star (KIC 8462852), RZ Piscium and WD 1145+017. Excessive amounts of infrared radiation may be detected from such stars, suggestive evidence in itself that dust and debris may be orbiting the stars.
Examples
Planets
Examples of planets, or their related remnants, considered to have been a disrupted planet, or part of such a planet, include: ‘Oumuamua and WD 1145+017 b, as well as asteroids, hot Jupiters and those that are hypothetical planets, like Fifth planet, Phaeton, Planet V and Theia.
Stars
Examples of parent stars considered to have disrupted a planet include: EPIC 204278916, Tabby's Star (KIC 8462852), PDS 110, RZ Piscium, WD 1145+017 and 47 Ursae Majoris.
Tabby's Star light curve
Tabby's Star (KIC 8462852) is an F-type main-sequence star exhibiting unusual light fluctuations, including up to a 22% dimming in brightness. Several hypotheses have been proposed to explain these irregular changes, but none to date fully explain all aspects of the curve. One explanation is that an "uneven ring of dust" orbits Tabby's Star. However, in September 2019, astronomers reported that the observed dimmings of Tabby's Star may ha
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The planet neptune has strange dark spots that sometimes appear on its surface? what are these spots?
A. black holes
B. storms
C. seas
D. earthquakes
Answer:
|
|
sciq-9513
|
multiple_choice
|
In which part of a bird stomach is food stored, soaked and mechanically ground?
|
[
"gizzard",
"pancreas",
"Gall bladder",
"digestion"
] |
A
|
Relavent Documents:
Document 0:::
The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (birds and other dinosaurs, crocodiles, alligators, pterosaurs), earthworms, some gastropods, some fish, and some crustaceans. This specialized stomach constructed of thick muscular walls is used for grinding up food, often aided by particles of stone or grit. In certain insects and molluscs, the gizzard features chitinous plates or teeth.
Etymology
The word gizzard comes from the Middle English giser, which derives from a similar word in Old French gésier, which itself evolved from the Latin gigeria, meaning giblets.
Structure
In birds
Birds swallow food and store it in their crop if necessary. Then the food passes into their glandular stomach, also called the proventriculus, which is also sometimes referred to as the true stomach. This is the secretory part of the stomach. Then the food passes into the gizzard (also known as the muscular stomach or ventriculus). The gizzard can grind the food with previously swallowed grit and pass it back to the true stomach, and vice versa. In layman's terms, the gizzard 'chews' the food for the bird because it does not have teeth to chew food the way humans and other mammals do.
By comparison, although in birds the stomach occurs in the digestive tract prior to the gizzard, in grasshoppers the gizzard occurs prior to the stomach, while in earthworms there is only a gizzard, and no stomach.
Koilin lining
In order to protect the muscles of the gizzard, the organ has a multi-layered membrane - or gastric cuticle - made of koilin, a carbohydrate-protein complex (and not keratin as once believed) to protect the muscles. The thickness of this membrane varies with the types of food the animal eats, with diets heavier in grains, seeds, and insects creating thicker membranes than those consisting of fruits, worms, meat, and other softer edibles. In some animals the membrane
Document 1:::
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small compounds that the body can use.
In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva. Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work, and electrolytes (Na+, K+, Cl−, HCO−3). About 30% of starch is hydrolyzed into disaccharide in the oral cavity (mouth). After undergoing mastication and starch digestion, the food will be in the form of a small, round slurry mass called a bolus. It will then travel down the esophagus and into the stomach by the action of peristalsis. Gastric juice in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and pepsin. In infants and toddlers, gastric juice also contains rennin to digest milk proteins. As the first two chemicals may damage the stomach wall, mucus and bicarbonates are secreted by the stomach. They provide a slimy layer that acts as a shield against the damag
Document 2:::
Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria. The microbial fermentation occurs in the digestive organs that follow the small intestine: the large intestine and cecum. Examples of hindgut fermenters include proboscideans and large odd-toed ungulates such as horses and rhinos, as well as small animals such as rodents, rabbits and koalas. In contrast, foregut fermentation is the form of cellulose digestion seen in ruminants such as cattle which have a four-chambered stomach, as well as in sloths, macropodids, some monkeys, and one bird, the hoatzin.
Cecum
Hindgut fermenters generally have a cecum and large intestine that are much larger and more complex than those of a foregut or midgut fermenter. Research on small cecum fermenters such as flying squirrels, rabbits and lemurs has revealed these mammals to have a GI tract about 10-13 times the length of their body. This is due to the high intake of fiber and other hard to digest compounds that are characteristic to the diet of monogastric herbivores. Unlike in foregut fermenters, the cecum is located after the stomach and small intestine in monogastric animals, which limits the amount of further digestion or absorption that can occur after the food is fermented.
Large intestine
In smaller hindgut fermenters of the order Lagomorpha (rabbits, hares, and pikas), cecotropes formed in the cecum are passed through the large intestine and subsequently reingested to allow another opportunity to absorb nutrients. Cecotropes are surrounded by a layer of mucus which protects them from stomach acid but which does not inhibit nutrient absorption in the small intestine. Coprophagy is also practiced by some rodents, such as the capybara, guinea pig and related species, and by the marsupial common ringtail possum. This process is also beneficial in allowing for restoration of the microflora pop
Document 3:::
The esophagus (American English) or oesophagus (British English, see spelling differences; both ; : (o)esophagi or (o)esophaguses), colloquially known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω (phérō, “I carry”) + ἔφαγον (éphagon, “I ate”).
The wall of the esophagus from the lumen outwards consists of mucosa, submucosa (connective tissue), layers of muscle fibers between layers of fibrous tissue, and an outer layer of connective tissue. The mucosa is a stratified squamous epithelium of around three layers of squamous cells, which contrasts to the single layer of columnar cells of the stomach. The transition between these two types of epithelium is visible as a zig-zag line. Most of the muscle is smooth muscle although striated muscle predominates in its upper third. It has two muscular rings or sphincters in its wall, one at the top and one at the bottom. The lower sphincter helps to prevent reflux of acidic stomach content. The esophagus has a rich blood supply and venous drainage. Its smooth muscle is innervated by involuntary nerves (sympathetic nerves via the sympathetic trunk and parasympathetic nerves via the vagus nerve) and in addition voluntary nerves (lower motor neurons) which are carried in the vagus nerve to innervate its striated muscle.
The esophagus passes through the thoracic cavity into the diaphragm into the stomach.
Document 4:::
The Joan Mott Prize Lecture is a prize lecture awarded annually by The Physiological Society in honour of Joan Mott.
Laureates
Laureates of the award have included:
- Intestinal absorption of sugars and peptides: from textbook to surprises
See also
Physiological Society Annual Review Prize Lecture
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
In which part of a bird stomach is food stored, soaked and mechanically ground?
A. gizzard
B. pancreas
C. Gall bladder
D. digestion
Answer:
|
|
scienceQA-3828
|
multiple_choice
|
What do these two changes have in common?
a sidewalk heating up in the sun
water vapor condensing on a bathroom mirror
|
[
"Both are only physical changes.",
"Both are chemical changes.",
"Both are caused by cooling.",
"Both are caused by heating."
] |
A
|
Step 1: Think about each change.
A sidewalk heating up in the sun is a physical change. The temperature of the sidewalk goes up, but the sidewalk is still made of the same type of matter.
Water vapor condensing on a bathroom mirror is a change of state. So, it is a physical change. The water changes state from gas in the air to liquid water on the mirror. But the water vapor and the liquid water are both made of water.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
A sidewalk getting warm in the sun is caused by heating. But water vapor condensing is not.
Both are caused by cooling.
Water vapor condensing is caused by cooling. But a sidewalk heating up in the sun is not.
|
Relavent Documents:
Document 0:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 1:::
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances. In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
An example of a physical change is the process of tempering steel to form a knife blade. A steel blank is repeatedly heated and hammered which changes the hardness of the steel, its flexibility and its ability to maintain a sharp edge.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Examples
Heating and cooling
Many elements and some compounds change from solids to liquids and from liquids to gases when heated and the reverse when cooled. Some substances such as iodine and carbon dioxide go directly from solid to gas in a process called sublimation.
Magnetism
Ferro-magnetic materials can become magnetic. The process is reve
Document 2:::
A pre-STEM program is a course of study at any two-year college that prepares a student to transfer to a four-year school to earn a bachelor's degree in a STEM field.
Overview
The concept of a pre-STEM program is being developed to address America's need for more college-trained professionals in science, technology, engineering, and mathematics (STEM). It is an innovation meant to fill a gap at community colleges that do not have 'major' degree paths that students identify with on their way to earning an Associates degree. Students must complete a considerable amount of STEM coursework before transferring from a two-year school to a four-year school and earn a baccalaureate degree in a STEM field. Schools with a pre-STEM program are able to identify those students and support them with STEM-specific academic and career advising, increasing the student's chances of going on to earn a STEM baccalaureate degree in a timely fashion.
With over 50% of America's college-bound students starting their college career at public or private two-year school, and with a very small proportion of students who start college at a two-year school matriculating to and earning STEM degrees from four-year schools, pre-STEM programs have great potential for broadening participation in baccalaureate STEM studies.
Example programs
The effectiveness of pre-STEM programs is being investigated by a consortium of schools in Missouri: Moberly Area Community College, St. Charles Community College, Metropolitan Community College, and Truman State University.
A larger group of schools met at the Belknap Springs Meetings in October 2009 to discuss the challenges and opportunities presented by STEM-focused partnerships between 2-year and 4-year schools. Each program represented a two-year school and a four-year school that were trying to increase the number of people who earn a baccalaureate degree in a STEM area through various means, some of which were pre-STEM programs. Other methods includes
Document 3:::
Thermofluids is a branch of science and engineering encompassing four intersecting fields:
Heat transfer
Thermodynamics
Fluid mechanics
Combustion
The term is a combination of "thermo", referring to heat, and "fluids", which refers to liquids, gases and vapors. Temperature, pressure, equations of state, and transport laws all play an important role in thermofluid problems. Phase transition and chemical reactions may also be important in a thermofluid context. The subject is sometimes also referred to as "thermal fluids".
Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the transfer of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer. Engineers also consider the transfer of mass of differing chemical species, either cold or hot, to achieve heat transfer.
Sections include :
Energy transfer by heat, work and mass
Laws of thermodynamics
Entropy
Refrigeration Techniques
Properties and nature of pure substances
Applications
Engineering : Predicting and analysing the performance of machines
Thermodynamics
Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.
Fluid mechanics
Fluid Mechanics the study of the physical forces at work during fluid flow. Fluid mechanics can be divided into fluid kinematics, the study of fluid motion, and fluid kinetics, the study of the effect of forces on fluid motion. Fluid mechanics can further be divided into fluid statics, the study of fluids at rest, and fluid dynamics, the study of fluids in motion. Some of its more interesting concepts include momentum and reactive forces in fluid flow and fluid machinery theory and performance.
Sections include:
Flu
Document 4:::
In physics, a dynamical system is said to be mixing if the phase space of the system becomes strongly intertwined, according to at least one of several mathematical definitions. For example, a measure-preserving transformation T is said to be strong mixing if
whenever A and B are any measurable sets and μ is the associated measure. Other definitions are possible, including weak mixing and topological mixing.
The mathematical definition of mixing is meant to capture the notion of physical mixing. A canonical example is the Cuba libre: suppose one is adding rum (the set A) to a glass of cola. After stirring the glass, the bottom half of the glass (the set B) will contain rum, and it will be in equal proportion as it is elsewhere in the glass. The mixing is uniform: no matter which region B one looks at, some of A will be in that region. A far more detailed, but still informal description of mixing can be found in the article on mixing (mathematics).
Every mixing transformation is ergodic, but there are ergodic transformations which are not mixing.
Physical mixing
The mixing of gases or liquids is a complex physical process, governed by a convective diffusion equation that may involve non-Fickian diffusion as in spinodal decomposition. The convective portion of the governing equation contains fluid motion terms that are governed by the Navier–Stokes equations. When fluid properties such as viscosity depend on composition, the governing equations may be coupled. There may also be temperature effects. It is not clear that fluid mixing processes are mixing in the mathematical sense.
Small rigid objects (such as rocks) are sometimes mixed in a rotating drum or tumbler. The 1969 Selective Service draft lottery was carried out by mixing plastic capsules which contained a slip of paper (marked with a day of the year).
See also
Miscibility
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What do these two changes have in common?
a sidewalk heating up in the sun
water vapor condensing on a bathroom mirror
A. Both are only physical changes.
B. Both are chemical changes.
C. Both are caused by cooling.
D. Both are caused by heating.
Answer:
|
sciq-2914
|
multiple_choice
|
The viscosity of a liquid is a measure of what?
|
[
"resistance to flow",
"adaptability to surroundings",
"resistance to change form",
"ability to absorb flow"
] |
A
|
Relavent Documents:
Document 0:::
Rheometry () generically refers to the experimental techniques used to determine the rheological properties of materials, that is the qualitative and quantitative relationships between stresses and strains and their derivatives. The techniques used are experimental. Rheometry investigates materials in relatively simple flows like steady shear flow, small amplitude oscillatory shear, and extensional flow.
The choice of the adequate experimental technique depends on the rheological property which has to be determined. This can be the steady shear viscosity, the linear viscoelastic properties (complex viscosity respectively elastic modulus), the elongational properties, etc.
For all real materials, the measured property will be a function of the flow conditions during which it is being measured (shear rate, frequency, etc.) even if for some materials this dependence is vanishingly low under given conditions (see Newtonian fluids).
Rheometry is a specific concern for smart fluids such as electrorheological fluids and magnetorheological fluids, as it is the primary method to quantify the useful properties of these materials.
Rheometry is considered useful in the fields of quality control, process control, and industrial process modelling, among others. For some, the techniques, particularly the qualitative rheological trends, can yield the classification of materials based on the main interactions between different possible elementary components and how they qualitatively affect the rheological behavior of the materials. Novel applications of these concepts include measuring cell mechanics in thin layers, especially in drug screening contexts.
Of non-Newtonian fluids
The viscosity of a non-Newtonian fluid is defined by a power law:
where η is the viscosity after shear is applied, η0 is the initial viscosity, γ is the shear rate, and if
, the fluid is shear thinning,
, the fluid is shear thickening,
, the fluid is Newtonian.
In rheometry, shear forces are applied t
Document 1:::
Saybolt universal viscosity (SUV), and the related Saybolt FUROL viscosity (SFV), are specific standardised tests producing measures of kinematic viscosity. FUROL is an acronym for fuel and road oil. Saybolt universal viscosity is specified by the ASTMD2161. Both tests are considered obsolete to other measures of kinematic viscosity, but their results are quoted widely in technical literature.
In both tests, the time taken for 60ml of the liquid, held at a specific temperature, to flow through a calibrated tube, is measured, using a Saybolt viscometer. The Saybolt universal viscosity test occurs at , or more recently, . The Saybolt FUROL viscosity test occurs at , or more recently, , and uses a larger calibrated tube. This provides for the testing of more viscous fluids, with the result being approximately of the universal viscosity.
The test results are specified in seconds (s), more often than not referencing the test: Saybolt universal seconds (SUS); seconds, Saybolt universal (SSU); seconds, Saybolt universal viscosity (SSUV); and Saybolt FUROL seconds (SFS); seconds, Saybolt FUROL (SSF). The precise temperature at which the test is performed is often specified as well.
Document 2:::
A non-Newtonian fluid is a fluid that does not follow Newton's law of viscosity, that is, it has variable viscosity dependent on stress. In non-Newtonian fluids, viscosity can change when under force to either more liquid or more solid. Ketchup, for example, becomes runnier when shaken and is thus a non-Newtonian fluid. Many salt solutions and molten polymers are , as are many commonly found substances such as custard, toothpaste, starch suspensions, corn starch, paint, blood, melted butter, and shampoo.
Most commonly, the viscosity (the gradual deformation by shear or tensile stresses) of non-Newtonian fluids is dependent on shear rate or shear rate history. Some non-Newtonian fluids with shear-independent viscosity, however, still exhibit normal stress-differences or other non-Newtonian behavior. In a Newtonian fluid, the relation between the shear stress and the shear rate is linear, passing through the origin, the constant of proportionality being the coefficient of viscosity. In a non-Newtonian fluid, the relation between the shear stress and the shear rate is different. The fluid can even exhibit time-dependent viscosity. Therefore, a constant coefficient of viscosity cannot be defined.
Although the concept of viscosity is commonly used in fluid mechanics to characterize the shear properties of a fluid, it can be inadequate to describe non-Newtonian fluids. They are best studied through several other rheological properties that relate stress and strain rate tensors under many different flow conditions—such as oscillatory shear or extensional flow—which are measured using different devices or rheometers. The properties are better studied using tensor-valued constitutive equations, which are common in the field of continuum mechanics.
Types of non-Newtonian behavior
Summary
Shear thickening fluid
The viscosity of a shear thickening fluid, or dilatant fluid, appears to increase when the shear rate increases. Corn starch suspended in water ("oobleck", see be
Document 3:::
Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in
Document 4:::
In physics, shear rate is the rate at which a progressive shearing deformation is applied to some material.
Simple shear
The shear rate for a fluid flowing between two parallel plates, one moving at a constant speed and the other one stationary (Couette flow), is defined by
where:
is the shear rate, measured in reciprocal seconds;
is the velocity of the moving plate, measured in meters per second;
is the distance between the two parallel plates, measured in meters.
Or:
For the simple shear case, it is just a gradient of velocity in a flowing material. The SI unit of measurement for shear rate is s−1, expressed as "reciprocal seconds" or "inverse seconds". However, when modelling fluids in 3D, it is common to consider a scalar value for the shear rate by calculating the second invariant of the strain-rate tensor
.
The shear rate at the inner wall of a Newtonian fluid flowing within a pipe is
where:
is the shear rate, measured in reciprocal seconds;
is the linear fluid velocity;
is the inside diameter of the pipe.
The linear fluid velocity is related to the volumetric flow rate by
where is the cross-sectional area of the pipe, which for an inside pipe radius of is given by
thus producing
Substituting the above into the earlier equation for the shear rate of a Newtonian fluid flowing within a pipe, and noting (in the denominator) that :
which simplifies to the following equivalent form for wall shear rate in terms of volumetric flow rate and inner pipe radius :
For a Newtonian fluid wall, shear stress () can be related to shear rate by where is the dynamic viscosity of the fluid. For non-Newtonian fluids, there are different constitutive laws depending on the fluid, which relates the stress tensor to the shear rate tensor.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
The viscosity of a liquid is a measure of what?
A. resistance to flow
B. adaptability to surroundings
C. resistance to change form
D. ability to absorb flow
Answer:
|
|
ai2_arc-111
|
multiple_choice
|
Which phrase does not describe asexual reproduction in organisms?
|
[
"requires two parents",
"little variation in offspring",
"only one type of cell involved",
"duplicates its genetic material"
] |
A
|
Relavent Documents:
Document 0:::
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee.
Human offspring (descendants) are referred to as children (without reference to age, thus one can refer to a parent's "minor children" or "adult children" or "infant children" or "teenage children" depending on their age); male children are sons and female children are daughters (see kinship). Offspring can occur after mating or after artificial insemination.
Overview
Offspring contains many parts and properties that are precise and accurate in what they consist of, and what they define. As the offspring of a new species, also known as a child or f1 generation, consist of genes of the father and the mother, which is also known as the parent generation. Each of these offspring contains numerous genes which have coding for specific tasks and properties. Males and females both contribute equally to the genotypes of their offspring, in which gametes fuse and form. An important aspect of the formation of the parent offspring is the chromosome, which is a structure of DNA which contains many genes.
To focus more on the offspring and how it results in the formation of the f1 generation, is an inheritance called sex linkage, which is a gene located on the sex chromosome, and patterns of this inheritance differ in both male and female. The explanation that proves the theory of the offspring having genes from both parent generations is proven through a process called crossing over, which consists of taking genes from the male chromosomes and genes from the female chromosome, resulting in a process of meiosis occurring, and leading to the splitting of the chromosomes evenly. Depending on which
Document 1:::
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes.
Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such as bacteria and archaea. However, some processes in bacteria, including bacterial conjugation, transformation and transduction, may be considered analogous to sexual reproduction in that they incorporate new genetic information. Some proteins and other features that are key for sexual reproduction may have arisen in bacteria, but sexual reproduction is believed to have developed in an ancient eukaryotic ancestor.
In eukaryotes, diploid precursor cells divide to produce haploid cells in a process called meiosis. In meiosis, DNA is replicated to produce a total of four copies of each chromosome. This is followed by two cell divisions to generate haploid gametes. After the DNA is replicated in meiosis, the homologous chromosomes pair up so that their DNA sequences are aligned with each other. During this period before cell divisions, genetic information is exchanged between homologous chromosomes in genetic recombination. Homologous chromosomes contain highly similar but not identical information, and by exchanging similar but not identical regions, genetic recombination increases genetic diversity among future generations.
During sexual reproduction, two haploid gametes combine into one diploid ce
Document 2:::
In biology and genetics, the germline is the population of a multicellular organism's cells that pass on their genetic material to the progeny (offspring). In other words, they are the cells that form the egg, sperm and the fertilised egg. They are usually differentiated to perform this function and segregated in a specific place away from other bodily cells.
As a rule, this passing-on happens via a process of sexual reproduction; typically it is a process that includes systematic changes to the genetic material, changes that arise during recombination, meiosis and fertilization for example. However, there are many exceptions across multicellular organisms, including processes and concepts such as various forms of apomixis, autogamy, automixis, cloning or parthenogenesis. The cells of the germline are called germ cells. For example, gametes such as a sperm and an egg are germ cells. So are the cells that divide to produce gametes, called gametocytes, the cells that produce those, called gametogonia, and all the way back to the zygote, the cell from which an individual develops.
In sexually reproducing organisms, cells that are not in the germline are called somatic cells. According to this view, mutations, recombinations and other genetic changes in the germline may be passed to offspring, but a change in a somatic cell will not be. This need not apply to somatically reproducing organisms, such as some Porifera and many plants. For example, many varieties of citrus, plants in the Rosaceae and some in the Asteraceae, such as Taraxacum, produce seeds apomictically when somatic diploid cells displace the ovule or early embryo.
In an earlier stage of genetic thinking, there was a clear distinction between germline and somatic cells. For example, August Weismann proposed and pointed out, a germline cell is immortal in the sense that it is part of a lineage that has reproduced indefinitely since the beginning of life and, barring accident, could continue doing so indef
Document 3:::
Mating types are the microorganism equivalent to sexes in multicellular lifeforms and are thought to be the ancestor to distinct sexes. They also occur in macro-organisms such as fungi.
Definition
Mating types are the microorganism equivalent to sex in higher organisms and occur in isogamous and anisogamous species. Depending on the group, different mating types are often referred to by numbers, letters, or simply "+" and "−" instead of "male" and "female", which refer to "sexes" or differences in size between gametes. Syngamy can only take place between gametes carrying different mating types.
Occurrence
Reproduction by mating types is especially prevalent in fungi. Filamentous ascomycetes usually have two mating types referred to as "MAT1-1" and "MAT1-2", following the yeast mating-type locus (MAT). Under standard nomenclature, MAT1-1 (which may informally be called MAT1) encodes for a regulatory protein with an alpha box motif, while MAT1-2 (informally called MAT2) encodes for a protein with a high motility-group (HMG) DNA-binding motif, as in the yeast mating type MATα1. The corresponding mating types in yeast, a non-filamentous ascomycete, are referred to as MATa and MATα.
Mating type genes in ascomycetes are called idiomorphs rather than alleles due to the uncertainty of the origin by common descent. The proteins they encode are transcription factors which regulate both the early and late stages of the sexual cycle. Heterothallic ascomycetes produce gametes, which present a single Mat idiomorph, and syngamy will only be possible between gametes carrying complementary mating types. On the other hand, homothallic ascomycetes produce gametes that can fuse with every other gamete in the population (including its own mitotic descendants) most often because each haploid contains the two alternate forms of the Mat locus in its genome.
Basidiomycetes can have thousands of different mating types.
In the ascomycete Neurospora crassa matings are restricted to intera
Document 4:::
Sexual characteristics are physical traits of an organism (typically of a sexually dimorphic organism) which are indicative of or resultant from biological sexual factors. These include both primary sex characteristics, such as gonads, and secondary sex characteristics.
Humans
In humans, sex organs or primary sexual characteristics, which are those a person is born with, can be distinguished from secondary sex characteristics, which develop later in life, usually during puberty. The development of both is controlled by sex hormones produced by the body after the initial fetal stage where the presence or absence of the Y-chromosome and/or the SRY gene determine development.
Male primary sex characteristics are the penis, the scrotum and the ability to ejaculate when matured. Female primary sex characteristics are the vagina, uterus, fallopian tubes, clitoris, cervix, and the ability to give birth and menstruate when matured.
Hormones that express sexual differentiation in humans include:
estrogens
progesterone
androgens such as testosterone
The following table lists the typical sexual characteristics in humans (even though some of these can also appear in other animals as well):
Other organisms
In invertebrates and plants, hermaphrodites (which have both male and female reproductive organs either at the same time or during their life cycle) are common, and in many cases, the norm.
In other varieties of multicellular life (e.g. the fungi division, Basidiomycota) sexual characteristics can be much more complex, and may involve many more than two sexes. For details on the sexual characteristics of fungi, see: Hypha and Plasmogamy.
Secondary sex characteristics in non-human animals include manes of male lions, long tail feathers of male peafowl, the tusks of male narwhals, enlarged proboscises in male elephant seals and proboscis monkeys, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes.
See also
Mammalian gesta
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
Which phrase does not describe asexual reproduction in organisms?
A. requires two parents
B. little variation in offspring
C. only one type of cell involved
D. duplicates its genetic material
Answer:
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.