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Context: covid - 19, also known as novel coronavirus disease, is a highly contagious disease that first surfaced in china in late 2019. sars - cov - 2 is a coronavirus that belongs to the vast family of coronaviruses that causes this disease. the sickness originally appeared in wuhan, china in december 2019 and quickly...
B) a bacterial population in the bloodstream
Context: , which would exclude fungi and some algae. plant cells were derived by endosymbiosis of a cyanobacterium into an early eukaryote about one billion years ago, which gave rise to chloroplasts. the first several clades that emerged following primary endosymbiosis were aquatic and most of the aquatic photosynthet...
B) food
Context: in order to obtain the keys in this system, a key must be inserted and turned ( like the key at the bottom of the system of the picture ). once the key is turned, the operator may retrieve the remaining keys that will be used to open other doors. once all keys are returned, then the operator will be allowed to...
D) stop and start the flow of current.
Context: ##tronics, the science of using mechanical devices with human muscular, musculoskeletal, and nervous systems to assist or enhance motor control lost by trauma, disease, or defect. prostheses are typically used to replace parts lost by injury ( traumatic ) or missing from birth ( congenital ) or to supplement d...
A) contact lens
Context: , crystal structure, hazards associated with minerals, and the physical and chemical properties of minerals. petrology is the study of rocks, including the formation and composition of rocks. petrography is a branch of petrology that studies the typology and classification of rocks. = = earth ' s interior = = ...
C) how they formed
Context: ##able. additionally, they must be biocompatible, meaning that they do not cause any adverse effects to cells. silicone, for example, is a synthetic, non - biodegradable material commonly used as a drug delivery material, while gelatin is a biodegradable, natural material commonly used in cell - culture scaffo...
C) neutralizes digestive acid.
Context: grasping an object is a matter of first moving a prehensile organ at some position in the world, and then managing the contact relationship between the prehensile organ and the object. once the contact relationship has been established and made stable, the object is part of the body and it can move in the worl...
A) muscular and skeletal
Context: in which case individual particles retain their shape ) or pulverization ( which involves grinding the particles themselves to a smaller size ). milling is generally done by mechanical means, including attrition ( which is particle - to - particle collision that results in agglomerate break up or particle shea...
C) freezing
Context: electrons, creating radicals. most radicals are comparatively reactive, but some, such as nitric oxide ( no ) can be stable. the " inert " or noble gas elements ( helium, neon, argon, krypton, xenon and radon ) are composed of lone atoms as their smallest discrete unit, but the other isolated chemical elements...
B) iron
Context: often injurious, at least with the plants on which i experimented. " an important adaptive benefit of outcrossing is that it allows the masking of deleterious mutations in the genome of progeny. this beneficial effect is also known as hybrid vigor or heterosis. once outcrossing is established, subsequent switc...
C) segregation of alleles
Context: the best - suited crops ( e. g., those with the highest yields ) to produce enough food to support a growing population. as crops and fields became increasingly large and difficult to maintain, it was discovered that specific organisms and their by - products could effectively fertilize, restore nitrogen, and ...
A) plant decomposition
Context: ##morphology studies the origin of landscapes. structural geology studies the deformation of rocks to produce mountains and lowlands. resource geology studies how energy resources can be obtained from minerals. environmental geology studies how pollution and contaminants affect soil and rock. mineralogy is the...
A) heat
Context: eat them. plants and other photosynthetic organisms are at the base of most food chains because they use the energy from the sun and nutrients from the soil and atmosphere, converting them into a form that can be used by animals. this is what ecologists call the first trophic level. the modern forms of the maj...
B) the mouth, with chewing and saliva.
Context: necessary and sufficient conditions for a term to apply to an object. for example : " a platonic solid is a convex, regular polyhedron in three - dimensional euclidean space. " an extensional definition instead lists all objects where the term applies. for example : " a platonic solid is one of the following :...
B) a bottle of juice
Context: ##morphology studies the origin of landscapes. structural geology studies the deformation of rocks to produce mountains and lowlands. resource geology studies how energy resources can be obtained from minerals. environmental geology studies how pollution and contaminants affect soil and rock. mineralogy is the...
A) chemical weathering
Context: navigable capabilities of rivers. in tropical countries subject to periodical rains, the rivers are in flood during the rainy season and have hardly any flow during the rest of the year, while in temperate regions, where the rainfall is more evenly distributed throughout the year, evaporation causes the availa...
A) It would be mostly light brown beetles.
Context: becomes quite gentle. accordingly, in large basins, rivers in most cases begin as torrents with a variable flow, and end as gently flowing rivers with a comparatively regular discharge. the irregular flow of rivers throughout their course forms one of the main difficulties in devising works for mitigating inun...
D) years.
Context: is also higher at high temperature, as shown by carnot ' s theorem. in a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste heat in order to prevent a meltdown of the metallic parts. despite all of these desirable properties, such engines are not in production b...
A) air pollution.
Context: in this article i explain in detail a method for making small amounts of liquid oxygen in the classroom if there is no access to a cylinder of compressed oxygen gas. i also discuss two methods for identifying the fact that it is liquid oxygen as opposed to liquid nitrogen. the motion of a pendulum is described...
B) a reflection of sound
Context: is also higher at high temperature, as shown by carnot ' s theorem. in a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste heat in order to prevent a meltdown of the metallic parts. despite all of these desirable properties, such engines are not in production b...
A) chemical
Context: ambient air ( see lockheed f - 117 nighthawk, rectangular nozzles on the lockheed martin f - 22 raptor, and serrated nozzle flaps on the lockheed martin f - 35 lightning ). often, cool air is deliberately injected into the exhaust flow to boost this process ( see ryan aqm - 91 firefly and northrop b - 2 spirit...
C) radiation
Context: inherited traits such as shape in pisum sativum ( peas ). what mendel learned from studying plants has had far - reaching benefits outside of botany. similarly, " jumping genes " were discovered by barbara mcclintock while she was studying maize. nevertheless, there are some distinctive genetic differences bet...
B) both white
Context: a detailed analysis of primordial nucleosynthesis predictions for light element abundances is performed. contents : 1. the standard cosmology : an overview. 2. primordial nucleosynthesis. 3. the born rates for n < - > p reactions. 4. finite nucleon mass corrections. 5. qed thermal radiative corrections. 6. cal...
B) the distance light travels in one year.
Context: a state of semi - perpetual convection. this convection process causes the lithospheric plates to move, albeit slowly. the resulting process is known as plate tectonics. areas of the crust where new crust is created are called divergent boundaries, those where it is brought back into the earth are convergent b...
D) divergent
Context: , tertiary, and quaternary ). the similarities among all known present - day species indicate that they have diverged through the process of evolution from their common ancestor. biologists regard the ubiquity of the genetic code as evidence of universal common descent for all bacteria, archaea, and eukaryotes...
A) bacteria
Context: elongation and the control of flowering. abscisic acid ( aba ) occurs in all land plants except liverworts, and is synthesised from carotenoids in the chloroplasts and other plastids. it inhibits cell division, promotes seed maturation, and dormancy, and promotes stomatal closure. it was so named because it wa...
A) to attract bees for pollination
Context: navigable capabilities of rivers. in tropical countries subject to periodical rains, the rivers are in flood during the rainy season and have hardly any flow during the rest of the year, while in temperate regions, where the rainfall is more evenly distributed throughout the year, evaporation causes the availa...
A) tree rings
Context: 1975. skin tissue - engineered skin is a type of bioartificial organ that is often used to treat burns, diabetic foot ulcers, or other large wounds that cannot heal well on their own. artificial skin can be made from autografts, allografts, and xenografts. autografted skin comes from a patient ' s own skin, wh...
D) wash the area with warm, soapy water
Context: a review of mhd dynamos and turbulence. fluid dynamics video demonstrating the evolution of dynamic stall on a wind turbine blade. masculinity and warmth. the five phases – fire, earth, metal, wood, and water – described a cycle of transformations in nature. the water turned into wood, which turned into the fi...
A) because the temperatures over land and over water change
Context: remediation include ; soil contamination, hazardous waste, groundwater contamination, oil, gas and chemical spills. there are three most common types of environmental remediation. these include soil, water, and sediment remediation. soil remediation consists of removing contaminants in soil, as these pose grea...
B) building terraces into the sides of a slope.
Context: casting, foundry methods, blast furnace extraction, and electrolytic extraction are all part of the required knowledge of a materials engineer. often the presence, absence, or variation of minute quantities of secondary elements and compounds in a bulk material will greatly affect the final properties of the m...
A) hardness
Context: smallest genomes among flowering plants. arabidopsis was the first plant to have its genome sequenced, in 2000. the sequencing of some other relatively small genomes, of rice ( oryza sativa ) and brachypodium distachyon, has made them important model species for understanding the genetics, cellular and molecul...
A) seed develops inside fruit -> seed is dispersed -> seed germinates -> plant grows
Context: the paper is withdrawn by the author because it is superseded by cond - mat / 0303357. weather than in the winter months, so that the rivers fall to their low stage in the summer and are liable to be in flood in the winter. in fact, with a temperate climate, the year may be divided into a warm and a cold seaso...
C) solid to a liquid
Context: is collected and processed to extract valuable metals. ore bodies often contain more than one valuable metal. tailings of a previous process may be used as a feed in another process to extract a secondary product from the original ore. additionally, a concentrate may contain more than one valuable metal. that ...
A) magnet
Context: plant cells and tissues, whereas plant morphology is the study of their external form. all plants are multicellular eukaryotes, their dna stored in nuclei. the characteristic features of plant cells that distinguish them from those of animals and fungi include a primary cell wall composed of the polysaccharide...
A) They need energy.
Context: while the modern stellar imf shows a rapid decline with increasing mass, theoretical investigations suggest that very massive stars ( > 100 solar masses ) may have been abundant in the early universe. other calculations also indicate that, lacking metals, these same stars reach their late evolutionary stages w...
B) birds with thick, strong beaks
Context: ##ochondria and chloroplasts, both of which are now part of modern - day eukaryotic cells. the major lineages of eukaryotes diversified in the precambrian about 1. 5 billion years ago and can be classified into eight major clades : alveolates, excavates, stramenopiles, plants, rhizarians, amoebozoans, fungi, a...
B) Both descended from a common ancestor.
Context: reaction to proceed more rapidly without being consumed by it — by reducing the amount of activation energy needed to convert reactants into products. enzymes also allow the regulation of the rate of a metabolic reaction, for example in response to changes in the cell ' s environment or to signals from other c...
A) cell membrane.
Context: invertebrates, or protozoans, the protist grouping is not a formal taxonomic group but is used for convenience. most protists are unicellular ; these are called microbial eukaryotes. plants are mainly multicellular organisms, predominantly photosynthetic eukaryotes of the kingdom plantae, which would exclude f...
D) Every cell performs all life functions.
Context: the cross section of elastic electron - proton scattering taking place in an electron gas is calculated within the closed time path method. it is found to be the sum of two terms, one being the expression in the vacuum except that it involves dressing due to the electron gas. the other term is due to the scatt...
D) Particles move back and forth perpendicular to the wave.
Context: two planetary nebulae are shown to belong to the sagittarius dwarf galaxy, on the basis of their radial velocities. this is only the second dwarf spheroidal galaxy, after fornax, found to contain planetary nebulae. their existence confirms that this galaxy is at least as massive as the fornax dwarf spheroidal ...
D) their great distance from Earth
Context: be the more significant to modern soil theory than fallou ' s. previously, soil had been considered a product of chemical transformations of rocks, a dead substrate from which plants derive nutritious elements. soil and bedrock were in fact equated. dokuchaev considers the soil as a natural body having its own...
B) by adding nitrogen
Context: polyatomic ions that do not split up during acid – base reactions are hydroxide ( oh− ) and phosphate ( po43− ). plasma is composed of gaseous matter that has been completely ionized, usually through high temperature. = = = acidity and basicity = = = a substance can often be classified as an acid or a base. th...
A) water
Context: substrate - level phosphorylation, which does not require oxygen. = = = photosynthesis = = = photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organism ' s metabolic activities via cellular respiration. this chemic...
A) chemical energy
Context: invertebrates, or protozoans, the protist grouping is not a formal taxonomic group but is used for convenience. most protists are unicellular ; these are called microbial eukaryotes. plants are mainly multicellular organisms, predominantly photosynthetic eukaryotes of the kingdom plantae, which would exclude f...
B) bacteria
Context: variation in total solar irradiance is thought to have little effect on the earth ' s surface temperature because of the thermal time constant - - the characteristic response time of the earth ' s global surface temperature to changes in forcing. this time constant is large enough to smooth annual variations b...
D) melting of polar ice caps
Context: = = = = = = environmental remediation = = = environmental remediation is the process through which contaminants or pollutants in soil, water and other media are removed to improve environmental quality. the main focus is the reduction of hazardous substances within the environment. some of the areas involved i...
D) excretory system
Context: the status of the theory of color confinemnt is discussed. shuttle from the heat of re - entry into the earth ' s atmosphere. one example is reinforced carbon - carbon ( rcc ), the light gray material, which withstands re - entry temperatures up to 1, 510 °c ( 2, 750 °f ) and protects the space shuttle ' s win...
C) arctic tundra
Context: is collected and processed to extract valuable metals. ore bodies often contain more than one valuable metal. tailings of a previous process may be used as a feed in another process to extract a secondary product from the original ore. additionally, a concentrate may contain more than one valuable metal. that ...
C) a magnet
Context: is further subdivided into two broad categories : chemical metallurgy and physical metallurgy. chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. subjects of study in chemical metallurgy include mineral processing, the extraction of meta...
B) Mg
Context: usability engineering, it ' s important target and identify human errors when interacting with the product of interest because if a user is expected to engage with a product, interface, or service in some way, the very introduction of a human in that engagement increases the potential of encountering human err...
A) bias
Context: ; austrian experts have established that the wheel is between 5, 100 and 5, 350 years old. the invention of the wheel revolutionized trade and war. it did not take long to discover that wheeled wagons could be used to carry heavy loads. the ancient sumerians used a potter ' s wheel and may have invented it. a ...
A) a system that is used to move people and products
Context: analyzing their radiation spectra. the term chemical energy is often used to indicate the potential of a chemical substance to undergo a transformation through a chemical reaction or to transform other chemical substances. = = = reaction = = = when a chemical substance is transformed as a result of its interac...
D) mechanical energy
Context: and their competitive or mutualistic interactions with other species. some ecologists even rely on empirical data from indigenous people that is gathered by ethnobotanists. this information can relay a great deal of information on how the land once was thousands of years ago and how it has changed over that ti...
A) weight
Context: single carbon atom can form four single covalent bonds such as in methane, two double covalent bonds such as in carbon dioxide ( co2 ), or a triple covalent bond such as in carbon monoxide ( co ). moreover, carbon can form very long chains of interconnecting carbon – carbon bonds such as octane or ring - like ...
C) burning fossil fuels
Context: ##lling, pipe jacking and other operations. a caisson is sunk by self - weight, concrete or water ballast placed on top, or by hydraulic jacks. the leading edge ( or cutting shoe ) of the caisson is sloped out at a sharp angle to aid sinking in a vertical manner ; it is usually made of steel. the shoe is gener...
D) north.
Context: higher concentrations of atmospheric nitrous oxide ( n2o ) are expected to slightly warm earth ' s surface because of increases in radiative forcing. radiative forcing is the difference in the net upward thermal radiation flux from the earth through a transparent atmosphere and radiation through an otherwise i...
D) white
Context: joints. = = = metal alloys = = = the alloys of iron ( steel, stainless steel, cast iron, tool steel, alloy steels ) make up the largest proportion of metals today both by quantity and commercial value. iron alloyed with various proportions of carbon gives low, mid and high carbon steels. an iron - carbon alloy...
D) The specific heat of iron is less than that of aluminum.
Context: the less of it people would be prepared to buy ( other things unchanged ). as the price of a commodity falls, consumers move toward it from relatively more expensive goods ( the substitution effect ). in addition, purchasing power from the price decline increases ability to buy ( the income effect ). other fac...
B) decrease.
Context: and their competitive or mutualistic interactions with other species. some ecologists even rely on empirical data from indigenous people that is gathered by ethnobotanists. this information can relay a great deal of information on how the land once was thousands of years ago and how it has changed over that ti...
C) cycling phosphorus into the soil
Context: analyzing their radiation spectra. the term chemical energy is often used to indicate the potential of a chemical substance to undergo a transformation through a chemical reaction or to transform other chemical substances. = = = reaction = = = when a chemical substance is transformed as a result of its interac...
D) A water pipe freezes and cracks on a cold night.
Context: one phenomenological explanation of superluminal propagation of neutrinos, which may have been observed by opera and minos, is that neutrinos travel faster inside of matter than in vacuum. if so neutrinos exhibit refraction inside matter and should exhibit other manifestations of refraction, such as deflection...
C) beam of light does not travel toward the students.
Context: cellular and molecular biology of cereals, grasses and monocots generally. model plants such as arabidopsis thaliana are used for studying the molecular biology of plant cells and the chloroplast. ideally, these organisms have small genomes that are well known or completely sequenced, small stature and short g...
A) the amount of fertilizer added
Context: which could be used as tools, primarily in the form of choppers or scrapers. these tools greatly aided the early humans in their hunter - gatherer lifestyle to perform a variety of tasks including butchering carcasses ( and breaking bones to get at the marrow ) ; chopping wood ; cracking open nuts ; skinning a...
B) Lever
Context: is collected and processed to extract valuable metals. ore bodies often contain more than one valuable metal. tailings of a previous process may be used as a feed in another process to extract a secondary product from the original ore. additionally, a concentrate may contain more than one valuable metal. that ...
B) iron and oxygen
Context: ##resistibly funky. and at their heaviest — notably on the frantic ' favorite things ' — they ' re reminiscent of faith no more at their wildest. " elliot added that people who were upset about the split of faith no more " [ should go along ] to an incubus gig. " the daily nebraskan referred to them as a " fun...
B) products.
Context: of these cellular components. the different stages of mitosis all together define the mitotic phase of an animal cell cycle — the division of the mother cell into two genetically identical daughter cells. the cell cycle is a vital process by which a single - celled fertilized egg develops into a mature organis...
D) It is the area of attachment for chromatids.
Context: the word " ceramic " is derived from the greek word κεραμικος ( keramikos ) meaning pottery. it is related to the older indo - european language root " to burn ". " ceramic " may be used as a noun in the singular to refer to a ceramic material or the product of ceramic manufacture, or as an adjective. ceramics...
B) melt at -95°C.
Context: vehicle crashes. fuel economy / emissions : fuel economy is the measured fuel efficiency of the vehicle in miles per gallon or kilometers per liter. emissions - testing covers the measurement of vehicle emissions, including hydrocarbons, nitrogen oxides ( nox ), carbon monoxide ( co ), carbon dioxide ( co2 ), ...
C) the waste heat from the combustion of fuel in the engine
Context: the thickness of freshly made soap films is usually in the micron range, and interference colors make thickness fluctuations easily visible. circular patterns of constant thickness are commonly observed, either a thin film disc in a thicker film or the reverse. in this letter, we evidence the line tension at t...
B) line graph
Context: in mathematics, a reflection ( also spelled reflexion ) is a mapping from a euclidean space to itself that is an isometry with a hyperplane as the set of fixed points ; this set is called the axis ( in dimension 2 ) or plane ( in dimension 3 ) of reflection. the image of a figure by a reflection is its mirror ...
A) reflected.
Context: becomes quite gentle. accordingly, in large basins, rivers in most cases begin as torrents with a variable flow, and end as gently flowing rivers with a comparatively regular discharge. the irregular flow of rivers throughout their course forms one of the main difficulties in devising works for mitigating inun...
C) The water changes from one form to another.
Context: fluid dynamics video demonstrating the evolution of dynamic stall on a wind turbine blade. made of steel. the shoe is generally wider than the caisson to reduce friction, and the leading edge may be supplied with pressurised bentonite slurry, which swells in water, stabilizing settlement by filling depressions...
D) to absorb nutrients
Context: ( division of the nucleus ) is preceded by the s stage of interphase ( during which the dna is replicated ) and is often followed by telophase and cytokinesis ; which divides the cytoplasm, organelles and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components....
A) growth and repair
Context: ), electron transport chain, and oxidative phosphorylation. glycolysis is a metabolic process that occurs in the cytoplasm whereby glucose is converted into two pyruvates, with two net molecules of atp being produced at the same time. each pyruvate is then oxidized into acetyl - coa by the pyruvate dehydrogena...
A) flow of protons across an electrochemical gradient
Context: , tertiary, and quaternary ). the similarities among all known present - day species indicate that they have diverged through the process of evolution from their common ancestor. biologists regard the ubiquity of the genetic code as evidence of universal common descent for all bacteria, archaea, and eukaryotes...
A) Parents pass their physical traits to their offspring; those offspring with traits that help them survive in the environment are able to reproduce.
Context: 10 kgy most food, which is ( with regard to warming ) physically equivalent to water, would warm by only about 2. 5 °c ( 4. 5 °f ). the specialty of processing food by ionizing radiation is the fact, that the energy density per atomic transition is very high, it can cleave molecules and induce ionization ( hen...
B) testing the beaker of uncolored tap water
Context: ##morphology studies the origin of landscapes. structural geology studies the deformation of rocks to produce mountains and lowlands. resource geology studies how energy resources can be obtained from minerals. environmental geology studies how pollution and contaminants affect soil and rock. mineralogy is the...
C) broken up and deposited in layers.
Context: the walls of a victim ' s stomach. toxicology, a subfield of forensic chemistry, focuses on detecting and identifying drugs, poisons, and other toxic substances in biological samples. forensic toxicologists work on cases involving drug overdoses, poisoning, and substance abuse. their work is critical in determ...
B) mimicry.
Context: inherited traits such as shape in pisum sativum ( peas ). what mendel learned from studying plants has had far - reaching benefits outside of botany. similarly, " jumping genes " were discovered by barbara mcclintock while she was studying maize. nevertheless, there are some distinctive genetic differences bet...
A) the shape of its leaves
Context: world made wide use of hydropower, along with early uses of tidal power, wind power, fossil fuels such as petroleum, and large factory complexes ( tiraz in arabic ). a variety of industrial mills were employed in the islamic world, including fulling mills, gristmills, hullers, sawmills, ship mills, stamp mills...
D) It turned into water vapor.
Context: from the oil of jasminum grandiflorum which regulates wound responses in plants by unblocking the expression of genes required in the systemic acquired resistance response to pathogen attack. in addition to being the primary energy source for plants, light functions as a signalling device, providing informatio...
A) make food
Context: the gas giant planets in the solar system have a retinue of icy moons, and we expect giant exoplanets to have similar satellite systems. if a jupiter - like planet were to migrate toward its parent star the icy moons orbiting it would evaporate, creating atmospheres and possible habitable surface oceans. here,...
D) Mercury, Mars, Venus, Earth
Context: stems mainly provide support to the leaves and reproductive structures, but can store water in succulent plants such as cacti, food as in potato tubers, or reproduce vegetatively as in the stolons of strawberry plants or in the process of layering. leaves gather sunlight and carry out photosynthesis. large, fl...
B) one with dry conditions
Context: major stellar - wind emission features in the spectrum of eta car have recently decreased by factors of order 2 relative to the continuum. this is unprecedented in the modern observational record. the simplest, but unproven, explanation is a rapid decrease in the wind density. higher concentrations of atmosphe...
B) when fluorocarbons are released into the atmosphere.
Context: one may identify the general properties of the neutrino mass matrix by generating many random mass matrices and testing them against the results of the neutrino experiments. building block. ceramics – not to be confused with raw, unfired clay – are usually seen in crystalline form. the vast majority of commerc...
D) streak
Context: consume organic material, breathe oxygen, are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. over 1. 5 million living animal species have been described — of which around 1 million are insects — but it has been estimated there are over ...
B) human
Context: ##ctonics, mountain ranges, volcanoes, and earthquakes are geological phenomena that can be explained in terms of physical and chemical processes in the earth ' s crust. beneath the earth ' s crust lies the mantle which is heated by the radioactive decay of heavy elements. the mantle is not quite solid and con...
D) metamorphic rock
Context: venus flytrap and bladderworts, and the pollinia of orchids. the hypothesis that plant growth and development is coordinated by plant hormones or plant growth regulators first emerged in the late 19th century. darwin experimented on the movements of plant shoots and roots towards light and gravity, and conclud...
A) conduct a controlled experiment
Context: in a voltaic cell, positive ( negative ) ions flow from the low ( high ) potential electrode to the high ( low ) potential electrode, driven by an ` electromotive force ' which points in opposite direction and overcomes the electric force. similarly in a superconductor charge flows in direction opposite to tha...
B) a flashlight
Context: are single - celled organisms such as bacteria, whereas eukaryotes can be single - celled or multicellular. in multicellular organisms, every cell in the organism ' s body is derived ultimately from a single cell in a fertilized egg. = = = cell structure = = = every cell is enclosed within a cell membrane that...
A) Mitochondria and chloroplasts arise from preexisting mitochondria and chloroplasts.
Context: remediation include ; soil contamination, hazardous waste, groundwater contamination, oil, gas and chemical spills. there are three most common types of environmental remediation. these include soil, water, and sediment remediation. soil remediation consists of removing contaminants in soil, as these pose grea...
D) Growing crops
Context: species occupying the same geographical area at the same time. a biological interaction is the effect that a pair of organisms living together in a community have on each other. they can be either of the same species ( intraspecific interactions ), or of different species ( interspecific interactions ). these ...
B) a raccoon in a hollow log
Context: and their competitive or mutualistic interactions with other species. some ecologists even rely on empirical data from indigenous people that is gathered by ethnobotanists. this information can relay a great deal of information on how the land once was thousands of years ago and how it has changed over that ti...
B) become dormant for long periods
Context: three of what is called the six simple machines, from which all machines are based. these machines are the inclined plane, the wedge, and the lever, which allowed the ancient egyptians to move millions of limestone blocks which weighed approximately 3. 5 tons ( 7, 000 lbs. ) each into place to create structure...
B) The erosion of the walls of a canyon
Context: ##ctonics, mountain ranges, volcanoes, and earthquakes are geological phenomena that can be explained in terms of physical and chemical processes in the earth ' s crust. beneath the earth ' s crust lies the mantle which is heated by the radioactive decay of heavy elements. the mantle is not quite solid and con...
B) changes speed.
Context: it is also possible to define analogs in two - dimensional systems, which has received attention for its relevance to systems in biology. = = = bonding = = = atoms sticking together in molecules or crystals are said to be bonded with one another. a chemical bond may be visualized as the multipole balance betwe...
B) magnetic force
Context: variation in total solar irradiance is thought to have little effect on the earth ' s surface temperature because of the thermal time constant - - the characteristic response time of the earth ' s global surface temperature to changes in forcing. this time constant is large enough to smooth annual variations b...
A) an earthquake shaking the ground
Context: ##nik, in present - day serbia. the site of plocnik has produced a smelted copper axe dating from 5, 500 bc, belonging to the vinca culture. the balkans and adjacent carpathian region were the location of major chalcolithic cultures including vinca, varna, karanovo, gumelnita and hamangia, which are often grou...
A) gold
Context: the heart beat data recorded from samples before and during meditation are analyzed using two different scaling analysis methods. these analyses revealed that mediation severely affects the long range correlation of heart beat of a normal heart. moreover, it is found that meditation induces periodic behavior i...
D) have the students run for the same amount of time