HydraLM/sciq_standardized · Datasets at Hugging Face

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What type of organism is commonly used in preparation of foods such as cheese and yogurt? 0. protozoa 1. gymnosperms 2. viruses 3. mesophilic organisms	instruction	0	0
3. mesophilic organisms Mesophiles grow best in moderate temperature, typically between 25°C and 40°C (77°F and 104°F). Mesophiles are often found living in or on the bodies of humans or other animals. The optimal growth temperature of many pathogenic mesophiles is 37°C (98°F), the normal human body temperature. Mesophilic organisms have important uses in food preparation, including cheese, yogurt, beer and wine.	output	1	0
What phenomenon makes global winds blow northeast to southwest or the reverse in the northern hemisphere and northwest to southeast or the reverse in the southern hemisphere? 0. muon effect 1. coriolis effect 2. centrifugal effect 3. tropical effect	instruction	0	1
1. coriolis effect Without Coriolis Effect the global winds would blow north to south or south to north. But Coriolis makes them blow northeast to southwest or the reverse in the Northern Hemisphere. The winds blow northwest to southeast or the reverse in the southern hemisphere.	output	1	1
Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always what? 0. unbalanced 1. reactive 2. exothermic 3. endothermic	instruction	0	2
2. exothermic Summary Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system. Changes from a more-ordered state to a less-ordered state (such as a liquid to a gas) areendothermic. Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always exothermic. The conversion of a solid to a liquid is called fusion (or melting). The energy required to melt 1 mol of a substance is its enthalpy of fusion (ΔHfus). The energy change required to vaporize 1 mol of a substance is the enthalpy of vaporization (ΔHvap). The direct conversion of a solid to a gas is sublimation. The amount of energy needed to sublime 1 mol of a substance is its enthalpy of sublimation (ΔHsub) and is the sum of the enthalpies of fusion and vaporization. Plots of the temperature of a substance versus heat added or versus heating time at a constant rate of heating are calledheating curves. Heating curves relate temperature changes to phase transitions. A superheated liquid, a liquid at a temperature and pressure at which it should be a gas, is not stable. A cooling curve is not exactly the reverse of the heating curve because many liquids do not freeze at the expected temperature. Instead, they form a supercooled liquid, a metastable liquid phase that exists below the normal melting point. Supercooled liquids usually crystallize on standing, or adding a seed crystal of the same or another substance can induce crystallization.	output	1	2
What is the least dangerous radioactive decay? 0. beta decay 1. gamma decay 2. zeta decay 3. alpha decay	instruction	0	3
3. alpha decay All radioactive decay is dangerous to living things, but alpha decay is the least dangerous.	output	1	3
Kilauea in hawaii is the world’s most continuously active volcano. very active volcanoes characteristically eject red-hot rocks and lava rather than this? 0. greenhouse gases 1. smoke and ash 2. carbon and smog 3. magma	instruction	0	4
1. smoke and ash Example 3.5 Calculating Projectile Motion: Hot Rock Projectile Kilauea in Hawaii is the world’s most continuously active volcano. Very active volcanoes characteristically eject red-hot rocks and lava rather than smoke and ash. Suppose a large rock is ejected from the volcano with a speed of 25.0 m/s and at an angle 35.0º above the horizontal, as shown in Figure 3.40. The rock strikes the side of the volcano at an altitude 20.0 m lower than its starting point. (a) Calculate the time it takes the rock to follow this path. (b) What are the magnitude and direction of the rock’s velocity at impact?.	output	1	4
When a meteoroid reaches earth, what is the remaining object called? 0. meteorite 1. comet 2. meteor 3. orbit	instruction	0	5
0. meteorite Meteoroids are smaller than asteroids, ranging from the size of boulders to the size of sand grains. When meteoroids enter Earth’s atmosphere, they vaporize, creating a trail of glowing gas called a meteor. If any of the meteoroid reaches Earth, the remaining object is called a meteorite.	output	1	5
What kind of a reaction occurs when a substance reacts quickly with oxygen? 0. combustion reaction 1. invention reaction 2. Fluid Reaction 3. nitrogen reaction	instruction	0	6
0. combustion reaction A combustion reaction occurs when a substance reacts quickly with oxygen (O 2 ). For example, in the Figure below , charcoal is combining with oxygen. Combustion is commonly called burning, and the substance that burns is usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO 2 ) and water vapor (H 2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is:.	output	1	6
Organisms categorized by what species descriptor demonstrate a version of allopatric speciation and have limited regions of overlap with one another, but where they overlap they interbreed successfully?. 0. surface species 1. fitting species 2. ring species 3. species complex	instruction	0	7
2. ring species Ring species Ring species demonstrate a version of allopatric speciation. Imagine populations of the species A. Over the geographic range of A there exist a number of subpopulations. These subpopulations (A1 to A5) and (Aa to Ae) have limited regions of overlap with one another but where they overlap they interbreed successfully. But populations A5 and Ae no longer interbreed successfully – are these populations separate species? In this case, there is no clear-cut answer, but it is likely that in the link between the various populations will be broken and one or more species may form in the future. Consider the black bear Ursus americanus. Originally distributed across all of North America, its distribution is now much more fragmented. Isolated populations are free to adapt to their own particular environments and migration between populations is limited. Clearly the environment in Florida is different from that in Mexico, Alaska, or Newfoundland. Different environments will favor different adaptations. If, over time, these populations were to come back into contact with one another, they might or might not be able to interbreed successfully - reproductive isolation may occur and one species may become many.	output	1	7
Alpha emission is a type of what? 0. radiation 1. heat 2. radioactivity 3. light	instruction	0	8
2. radioactivity One type of radioactivity is alpha emission. What is an alpha particle? What happens to an alpha particle after it is emitted from an unstable nucleus?.	output	1	8
What is the stored food in a seed called? 0. pollin 1. membrane 2. endosperm 3. larval	instruction	0	9
2. endosperm The stored food in a seed is called endosperm . It nourishes the embryo until it can start making food on its own.	output	1	9
Zinc is more easily oxidized than iron because zinc has a lower reduction potential. since zinc has a lower reduction potential, it is a more what? 0. much metal 1. Trap metal 2. active metal 3. usually metal	instruction	0	10
2. active metal One way to keep iron from corroding is to keep it painted. The layer of paint prevents the water and oxygen necessary for rust formation from coming into contact with the iron. As long as the paint remains intact, the iron is protected from corrosion. Other strategies include alloying the iron with other metals. For example, stainless steel is mostly iron with a bit of chromium. The chromium tends to collect near the surface, where it forms an oxide layer that protects the iron. Zinc-plated or galvanized iron uses a different strategy. Zinc is more easily oxidized than iron because zinc has a lower reduction potential. Since zinc has a lower reduction potential, it is a more active metal. Thus, even if the zinc coating is scratched, the zinc will still oxidize before the iron. This suggests that this approach should work with other active metals. Another important way to protect metal is to make it the cathode in a galvanic cell. This is cathodic protection and can be used for metals other than just iron. For example, the rusting of underground iron storage tanks and pipes can be prevented or greatly reduced by connecting them to a more active metal such as zinc or magnesium (Figure 17.18). This is also used to protect the metal parts in water heaters. The more active metals (lower reduction potential) are called sacrificial anodes because as they get used up as they corrode (oxidize) at the anode. The metal being protected serves as the cathode, and so does not oxidize (corrode). When the anodes are properly monitored and periodically replaced, the useful lifetime of the iron storage tank can be greatly extended.	output	1	10
What is controlled by both genes and experiences in a given envionment? 0. reflexes 1. instincts 2. animal behaviors 3. learned behaviors	instruction	0	11
2. animal behaviors Most animal behaviors are controlled by both genes and experiences in a given environment.	output	1	11
What tells you how much of the food you should eat to get the nutrients listed on the label? 0. regular size 1. scoop size 2. longer size 3. serving size	instruction	0	12
3. serving size The information listed at the right of the label tells you what to look for. At the top of the label, look for the serving size. The serving size tells you how much of the food you should eat to get the nutrients listed on the label. A cup of food from the label pictured below is a serving. The calories in one serving are listed next. In this food, there are 250 calories per serving.	output	1	12
What are used to write nuclear equations for radioactive decay? 0. nuclear symbols 1. trigonometric symbols 2. critical symbols 3. radioactive symbols	instruction	0	13
0. nuclear symbols Nuclear symbols are used to write nuclear equations for radioactive decay. Let’s consider the example of the beta-minus decay of thorium-234 to protactinium-234. This reaction is represented by the equation:.	output	1	13
What is controlled by regulatory proteins that bind to regulatory elements on dna? 0. amino acids 1. gene transcription 2. mRNA 3. substance transcription	instruction	0	14
1. gene transcription Gene transcription is controlled by regulatory proteins that bind to regulatory elements on DNA. The proteins usually either activate or repress transcription.	output	1	14
Boron only occurs naturally in compounds with what element? 0. helium 1. oxygen 2. nitrogen 3. carbon	instruction	0	15
1. oxygen Occurrence, Preparation, and Compounds of Boron and Silicon Boron constitutes less than 0.001% by weight of the earth’s crust. In nature, it only occurs in compounds with oxygen. Boron is widely distributed in volcanic regions as boric acid, B(OH)3, and in dry lake regions, including the desert areas of California, as borates and salts of boron oxyacids, such as borax, Na2B4O7⋅10H2O. Elemental boron is chemically inert at room temperature, reacting with only fluorine and oxygen to form boron trifluoride, BF3, and boric oxide, B2O3, respectively. At higher temperatures, boron reacts with all nonmetals, except tellurium and the noble gases, and with nearly all metals; it oxidizes to B2O3 when heated with concentrated nitric or sulfuric acid. Boron does not react with nonoxidizing acids. Many boron compounds react readily with water to give boric acid, B(OH)3 (sometimes written as H3BO3). Reduction of boric oxide with magnesium powder forms boron (95–98.5% pure) as a brown, amorphous powder: B 2 O 3(s) + 3Mg(s) ⟶ 2B(s) + 3MgO(s) An amorphous substance is a material that appears to be a solid, but does not have a long-range order like a true solid. Treatment with hydrochloric acid removes the magnesium oxide. Further purification of the boron begins with conversion of the impure boron into boron trichloride. The next step is to heat a mixture of boron trichloride and hydrogen: 1500 °C.	output	1	15
What organ systems link exchange surfaces with cells throughout the body? 0. circulatory 1. vascular 2. pulmonary 3. nervous	instruction	0	16
0. circulatory 42.1 Circulatory systems link exchange surfaces with cells throughout the body.	output	1	16
What occurs when the immune system attacks a harmless substance that enters the body from the outside? 0. panic attack 1. allergy 2. nausea 3. plague	instruction	0	17
1. allergy An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy.	output	1	17
Fertilization is the union of a sperm and egg, resulting in the formation of what? 0. a cytoplasm 1. a nuclei 2. a bacteriophage 3. a zygote	instruction	0	18
3. a zygote Fertilization is the union of a sperm and egg, resulting in the formation of a zygote.	output	1	18
The plants alternation between haploid and diploud generations allow it to do what? 0. reproduce asexually and sexually 1. reproduce asexually and simultaneously 2. reproduce sexually and autonomously 3. reproduce asexually and biologically	instruction	0	19
0. reproduce asexually and sexually All plants have a characteristic life cycle that includes alternation of generations . Plants alternate between haploid and diploid generations. Alternation of generations allows for both asexual and sexual reproduction. Asexual reproduction with spores produces haploid individuals called gametophytes . Sexual reproduction with gametes and fertilization produces diploid individuals called sporophytes . A typical plant’s life cycle is diagrammed in Figure below .	output	1	19
Most of the chemical reactions in the body are facilitated by what? 0. proteins 1. enzymes 2. vitamins 3. carbohydrates	instruction	0	20
1. enzymes Enzymes are critical to the body’s healthy functioning. They assist, for example, with the breakdown of food and its conversion to energy. In fact, most of the chemical reactions in the body are facilitated by enzymes.	output	1	20
What is the termination of a pregnancy in progress called? 0. abortion 1. contraception 2. miscarriage 3. delivery	instruction	0	21
0. abortion	output	1	21
Cutting down on the use of chemical fertilizers and preserving wetlands are ways to prevent what "unlivable" regions in bodies of water? 0. inhabitable zones 1. hostile zones 2. fresh zones 3. dead zones	instruction	0	22
3. dead zones Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms.	output	1	22
Which muscles allow your fingers to also make precise movements for actions? 0. paired muscles 1. intrinsic muscles 2. motoric muscles 3. fine movement muscles	instruction	0	23
1. intrinsic muscles Intrinsic Muscles of the Hand The intrinsic muscles of the hand both originate and insert within it (Figure 11.28). These muscles allow your fingers to also make precise movements for actions, such as typing or writing. These muscles are divided into three groups. The thenar muscles are on the radial aspect of the palm. The hypothenar muscles are on the medial aspect of the palm, and the intermediate muscles are midpalmar. The thenar muscles include the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and the adductor pollicis. These muscles form the thenar eminence, the rounded contour of the base of the thumb, and all act on the thumb. The movements of the thumb play an integral role in most precise movements of the hand. The hypothenar muscles include the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti minimi. These muscles form the hypothenar eminence, the rounded contour of the little finger, and as such, they all act on the little finger. Finally, the intermediate muscles act on all the fingers and include the lumbrical, the palmar interossei, and the dorsal interossei.	output	1	23
Testing what usually requires making observations or performing experiments? 0. hypothesis 1. variables 2. conclusion 3. homeostasis	instruction	0	24
0. hypothesis Usually, testing a hypothesis requires making observations or performing experiments. In this case, we will look into existing scientific literature to see if either of these hypotheses can be disproved, or if one or both can be supported by the data.	output	1	24
This sharing of electrons produces what is known as a covalent bond. covalent bonds are ~20 to 50 times stronger than what? 0. Mendelian systems 1. Newton's third law 2. gravitational pull 3. van der waals interactions	instruction	0	25
3. van der waals interactions any other electron, they become a part of the molecule’s electron system.204 This sharing of electrons produces what is known as a covalent bond. Covalent bonds are ~20 to 50 times stronger than van der Waals interactions. What exactly does that mean? Basically, it takes 20 to 50 times more energy to break a covalent bond compared to a van der Waals interaction. While the bonded form of atoms in a molecule is always more stable than the unbounded form, it may not be stable enough to withstand the energy delivered through collisions with neighboring molecules. Different bonds between different atoms in different molecular contexts differ in terms of bond stability; the bond energy refers the energy needed to break a particular bond. A molecule is stable if the bond energies associated with bonded atoms within the molecule are high enough to survive the energy delivered to the molecule through either collisions with neighboring molecules or the absorption of energy (light). When atoms form a covalent bond, their individual van der Waals surfaces merge to produce a new molecular van der Waals surface. There are a number of ways to draw molecules, but the spacefilling or van der Waals surface view is the most realistic (at least for our purposes). While realistic it can also be confusing, since it obscures the underlying molecular structure, that is, how the atoms in the molecule are linked together. This can be seen in this set of representations of the simple molecule 2methylpropane (→).205 As molecules become larger, as is the case with many biologically important molecules, it can become impossible to appreciate their underlying organization based on a van der Waals surface representation. Because they form a new stable entity, it is not surprising (perhaps) that the properties of a molecule are quite distinct from, although certainly influenced by, the properties of the atoms from which they are composed. To a first order approximation, a molecule’s properties are based on its shape, which is dictated by how the various atoms withjn the molecule are connected to one another. These geometries are imposed by each atom’s underlying quantum mechanical properties and (particularly as molecules get larger, as they so often do in biological systems) the interactions between different parts of the molecule with one another. Some atoms, common to biological systems, such as hydrogen (H), can form only a single covalent bond. Others can make two (oxygen (O) and sulfur (S)), three (nitrogen (N)), four (carbon (C)), or five (phosphorus (P)) bonds. In addition to smaller molecules, biological systems contain a number of distinct types of extremely large molecules, composed of many thousands of atoms; these are known as macromolecules. Such macromolecules are not rigid; they can often fold back on themselves leading to intramolecular interactions. There are also interactions between molecules. The strength and specificity of these interactions can vary dramatically and even small changes in molecular structure (such as caused by mutations and allelic variations) can have dramatic effects.	output	1	25
Water molecules move about continuously due to what type of energy? 0. seismic 1. potential 2. kinetic 3. optical	instruction	0	26
2. kinetic Water molecules move about continuously due to their kinetic energy. When a crystal of sodium chloride is placed into water, the water’s molecules collide with the crystal lattice. Recall that the crystal lattice is composed of alternating positive and negative ions. Water is attracted to the sodium chloride crystal because water is polar and has both a positive and a negative end. The positively charged sodium ions in the crystal attract the oxygen end of the water molecules because they are partially negative. The negatively charged chloride ions in the crystal attract the hydrogen end of the water molecules because they are partially positive. The action of the polar water molecules takes the crystal lattice apart (see image below).	output	1	26
A small scale version of what type of map displays individual rock units? 0. seismic map 1. geographic map 2. polar map 3. geologic map	instruction	0	27
3. geologic map Geologic maps display rock units and geologic features. A small scale map displays individual rock units while a large scale map shows geologic provinces.	output	1	27
What is defined as a change in the inherited traits of organisms over time? 0. variation 1. evolution 2. divergence 3. generation	instruction	0	28
1. evolution One idea is that evolution happens. Evolution is a change in the inherited traits of organisms over time. Living things have changed as descendants diverged from common ancestors in the past.	output	1	28
What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty? 0. testosterone 1. steroids 2. epinephrine 3. estrogen	instruction	0	29
0. testosterone What causes puberty to begin? The hypothalamus in the brain “tells” the pituitary gland to secrete hormones that target the testes. The main pituitary hormone involved is luteinizing hormone (LH) . It stimulates the testes to secrete testosterone. Testosterone, in turn, promotes protein synthesis and growth. It brings about most of the physical changes of puberty, some of which are shown in Figure below . In addition to the changes shown below, during puberty male facial hair begins to grow, the shoulders broaden, and the male voice deepens. You can watch an animation of these and other changes that occur in boys during puberty at the Interactive Body link: http://www. bbc. co. uk/science/humanbody/body/interactives/lifecycle/teenagers/ .	output	1	29
Where do angiosperms produce seeds in flowers? 0. ovaries 1. germs 2. cones 3. testes	instruction	0	30
0. ovaries Seed plants called angiosperms produce seeds in the ovaries of flowers.	output	1	30
In order to create food, what do photosynthetic protists use? 0. thermal energy 1. hydrocarbons 2. decayed matter 3. light energy	instruction	0	31
3. light energy Photosynthetic protists use light energy to make food. They are major producers in aquatic ecosystems.	output	1	31
What type of vertebrates are birds? 0. epidermal tetrapod 1. endothermic tetrapod 2. invertebrates 3. exothermic	instruction	0	32
1. endothermic tetrapod Birds are endothermic tetrapod vertebrates. They are bipedal, which means they walk on two legs. Birds also lay amniotic eggs, and the eggs have hard, calcium carbonate shells. Although birds are the most recent class of vertebrates to evolve, they are now the most numerous vertebrates on Earth. Why have birds been so successful? What traits allowed them to increase and diversify so rapidly?.	output	1	32
What type of ions do ionic compounds contain? 0. regular and irregular 1. positive and charged 2. negative and neutal 3. positive and negative	instruction	0	33
3. positive and negative An ionic compound contains positive and negative ions.	output	1	33
All living things need air and this to survive? 0. stimuli 1. habitat 2. ecosystem 3. water	instruction	0	34
3. water	output	1	34
The cells of all eukarya have a what? 0. chloroplast 1. epidermis 2. nucleus 3. necrosis	instruction	0	35
2. nucleus Some Eukarya are also single-celled, but many are multicellular. Some have a cell wall; others do not. However, the cells of all Eukarya have a nucleus and other organelles.	output	1	35
What type of plate boundaries produce huge mountain ranges in the ocean basin? 0. coherent 1. parallel 2. divergent 3. tractional	instruction	0	36
2. divergent Divergent plate boundaries produce huge mountain ranges under water in every ocean basin.	output	1	36
Interstitial carbides are produced by the reaction of most transition metals at high temperatures with what element? 0. hydrogen 1. carbon 2. oxygen 3. nitrogen	instruction	0	37
1. carbon temperatures with electropositive metals such as those of groups 1 and 2 and aluminum produces ionic carbides, which contain discrete metal cations and carbon anions. The identity of the anions depends on the size of the second element. For example, smaller elements such as beryllium and aluminum give methides such as Be2C and Al4C3, which formally contain the C4− ion derived from methane (CH4) by losing all four H atoms as protons. In contrast, larger metals such as sodium and calcium give carbides with stoichiometries of Na2C2 and CaC2. Because these carbides contain the C4− ion, which is derived from acetylene (HC≡CH) by losing both H atoms as protons, they are more properly called acetylides. As discussed in Chapter 21 "Periodic Trends and the ", Section 21.4 "The Alkaline Earth Metals (Group 2)", reacting ionic carbides with dilute aqueous acid results in protonation of the anions to give the parent hydrocarbons: CH4 or C2H2. For many years, miners’ lamps used the reaction of calcium carbide with water to produce a steady supply of acetylene, which was ignited to provide a portable lantern. The reaction of carbon with most transition metals at high temperatures produces interstitial carbides. Due to the less electropositive nature of the transition metals, these carbides contain covalent metal– carbon interactions, which result in different properties: most interstitial carbides are good conductors of electricity, have high melting points, and are among the hardest substances known. Interstitial carbides exhibit a variety of nominal compositions, and they are often nonstoichiometric compounds whose carbon content can vary over a wide range. Among the most important are tungsten carbide (WC), which is used industrially in high-speed cutting tools, and cementite (Fe3C), which is a major component of steel. Elements with an electronegativity similar to that of carbon form covalent carbides, such as silicon carbide (SiC; Equation 22.15) and boron carbide (B4C). These substances are extremely hard, have high melting points, and are chemically inert. For example, silicon carbide is highly resistant to chemical attack at temperatures as high as 1600°C. Because it also maintains its strength at high temperatures, silicon carbide is used in heating elements for electric furnaces and in variable-temperature resistors.	output	1	37
Fungus-like protist saprobes play what role in a food chain and are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes? 0. aphids 1. decomposers 2. Soil 3. fluxes	instruction	0	38
1. decomposers Agents of Decomposition The fungus-like protist saprobes are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes. For instance, many types of oomycetes grow on dead animals or algae. Saprobic protists have the essential function of returning inorganic nutrients to the soil and water. This process allows for new plant growth, which in turn generates sustenance for other organisms along the food chain. Indeed, without saprobe species, such as protists, fungi, and bacteria, life would cease to exist as all organic carbon became “tied up” in dead organisms.	output	1	38
What are the sites of protein synthesis or assembly? 0. chloroplasts 1. ribosomes 2. chromosomes 3. plasma	instruction	0	39
1. ribosomes Ribosomes are small organelles and are the sites of protein synthesis (or assembly). They are made of ribosomal protein and ribosomal RNA, and are found in both eukaryotic and prokaryotic cells. Unlike other organelles, ribosomes are not surrounded by a membrane. Each ribosome has two parts, a large and a small subunit, as shown in Figure below . The subunits are attached to one another. Ribosomes can be found alone or in groups within the cytoplasm. Some ribosomes are attached to the endoplasmic reticulum (ER) (as shown in Figure below ), and others are attached to the nuclear envelope.	output	1	39
What must replicate in the cell cycle before meiosis i takes place? 0. dna 1. cell walls 2. sperm 3. meiotic fluid	instruction	0	40
0. dna Meiosis I begins after DNA replicates during interphase of the cell cycle. In both meiosis I and meiosis II , cells go through the same four phases as mitosis - prophase, metaphase, anaphase and telophase. However, there are important differences between meiosis I and mitosis. The eight stages of meiosis are summarized below. The stages will be described for a human cell, starting with 46 chromosomes.	output	1	40
What phenomenon is primarily the result of plate tectonic motions? 0. eruption 1. earthquake 2. tsunamis 3. volcanoes	instruction	0	41
1. earthquake Earthquakes are primarily the result of plate tectonic motions. What type of stress would cause earthquakes at each of the three types of plate boundaries?.	output	1	41
What is a group of neuron cell bodies in the periphery called? 0. crystals 1. ganglion 2. organism 3. gangism	instruction	0	42
1. ganglion Ganglia A ganglion is a group of neuron cell bodies in the periphery. Ganglia can be categorized, for the most part, as either sensory ganglia or autonomic ganglia, referring to their primary functions. The most common type of sensory ganglion is a dorsal (posterior) root ganglion. These ganglia are the cell bodies of neurons with axons that are sensory endings in the periphery, such as in the skin, and that extend into the CNS through the dorsal nerve root. The ganglion is an enlargement of the nerve root. Under microscopic inspection, it can be seen to include the cell bodies of the neurons, as well as bundles of fibers that are the posterior nerve root (Figure 13.19). The cells of the dorsal root ganglion are unipolar cells, classifying them by shape. Also, the small round nuclei of satellite cells can be seen surrounding—as if they were orbiting—the neuron cell bodies.	output	1	42
Where does most of our food come from? 0. angiosperms 1. microbes 2. lichen 3. gymnosperms	instruction	0	43
0. angiosperms	output	1	43
Gases are most ideal at high temperature and what pressure? 0. low 1. absolute 2. high 3. stable	instruction	0	44
0. low Under what conditions then, do gases behave least ideally? When a gas is put under high pressure, its molecules are forced closer together as the empty space between the particles is diminished. A decrease in the empty space means that the assumption that the volume of the particles themselves is negligible is less valid. When a gas is cooled, the decrease in kinetic energy of the particles causes them to slow down. If the particles are moving at slower speeds, the attractive forces between them are more prominent. Another way to view it is that continued cooling the gas will eventually turn it into a liquid and a liquid is certainly not an ideal gas anymore (see liquid nitrogen in the Figure below ). In summary, a real gas deviates most from an ideal gas at low temperatures and high pressures. Gases are most ideal at high temperature and low pressure.	output	1	44
Hard igneous rocks and easily dissolved sedimentary rocks respond very differently to what natural force? 0. weathering 1. gravity 2. sunlight 3. evaporation	instruction	0	45
0. weathering Each type of rock weathers in its own way. Certain types of rock are very resistant to weathering. Igneous rocks tend to weather slowly because they are hard. Water cannot easily penetrate them. Granite is a very stable igneous rock. Other types of rock are easily weathered because they dissolve easily in weak acids. Limestone is a sedimentary rock that dissolves easily. When softer rocks wear away, the more resistant rocks form ridges or hills.	output	1	45
A diet rich in calcium and what vitamin may reduce the risk of osteoporosis and related bone fractures? 0. niacin 1. vitamin A 2. vitamin C 3. vitamin d	instruction	0	46
3. vitamin d Skeletal system problems include osteoporosis, bone fractures, and ligament sprains. A diet rick in calcium and vitamin D may reduce the risk of osteoporosis and related bone fractures. Following safe practices may also reduce the risk of fractures as well as sprains.	output	1	46
How many people die from air pollution each year? 0. 14 million 1. 17 million 2. 5 million 3. 22 million	instruction	0	47
3. 22 million Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment.	output	1	47
What substances serve as catalysts in most of the biochemical reactions that take place in organisms? 0. hormones 1. carbohydrates 2. enzymes 3. iseotrops	instruction	0	48
2. enzymes Enzymes are involved in most of the biochemical reactions that take place in organisms. About 4,000 such reactions are known to be catalyzed by enzymes, but the number may be even higher. Enzymes allow reactions to occur at the rate necessary for life.	output	1	48
The formation of an amalgam allows the metal to react with what? 0. helium and oxygen 1. cloth and plastic 2. air and water 3. blood and sweat	instruction	0	49
2. air and water The metals of group 13 (Al, Ga, In, and Tl) are all reactive. However, passivation occurs as a tough, hard, thin film of the metal oxide forms upon exposure to air. Disruption of this film may counter the passivation, allowing the metal to react. One way to disrupt the film is to expose the passivated metal to mercury. Some of the metal dissolves in the mercury to form an amalgam, which sheds the protective oxide layer to expose the metal to further reaction. The formation of an amalgam allows the metal to react with air and water.	output	1	49

What type of organism is commonly used in preparation of foods such as cheese and yogurt? 0. protozoa 1. gymnosperms 2. viruses 3. mesophilic organisms

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3. mesophilic organisms Mesophiles grow best in moderate temperature, typically between 25°C and 40°C (77°F and 104°F). Mesophiles are often found living in or on the bodies of humans or other animals. The optimal growth temperature of many pathogenic mesophiles is 37°C (98°F), the normal human body temperature. Mesophilic organisms have important uses in food preparation, including cheese, yogurt, beer and wine.

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What phenomenon makes global winds blow northeast to southwest or the reverse in the northern hemisphere and northwest to southeast or the reverse in the southern hemisphere? 0. muon effect 1. coriolis effect 2. centrifugal effect 3. tropical effect

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1. coriolis effect Without Coriolis Effect the global winds would blow north to south or south to north. But Coriolis makes them blow northeast to southwest or the reverse in the Northern Hemisphere. The winds blow northwest to southeast or the reverse in the southern hemisphere.

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Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always what? 0. unbalanced 1. reactive 2. exothermic 3. endothermic

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2. exothermic Summary Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system. Changes from a more-ordered state to a less-ordered state (such as a liquid to a gas) areendothermic. Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always exothermic. The conversion of a solid to a liquid is called fusion (or melting). The energy required to melt 1 mol of a substance is its enthalpy of fusion (ΔHfus). The energy change required to vaporize 1 mol of a substance is the enthalpy of vaporization (ΔHvap). The direct conversion of a solid to a gas is sublimation. The amount of energy needed to sublime 1 mol of a substance is its enthalpy of sublimation (ΔHsub) and is the sum of the enthalpies of fusion and vaporization. Plots of the temperature of a substance versus heat added or versus heating time at a constant rate of heating are calledheating curves. Heating curves relate temperature changes to phase transitions. A superheated liquid, a liquid at a temperature and pressure at which it should be a gas, is not stable. A cooling curve is not exactly the reverse of the heating curve because many liquids do not freeze at the expected temperature. Instead, they form a supercooled liquid, a metastable liquid phase that exists below the normal melting point. Supercooled liquids usually crystallize on standing, or adding a seed crystal of the same or another substance can induce crystallization.

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What is the least dangerous radioactive decay? 0. beta decay 1. gamma decay 2. zeta decay 3. alpha decay

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3. alpha decay All radioactive decay is dangerous to living things, but alpha decay is the least dangerous.

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Kilauea in hawaii is the world’s most continuously active volcano. very active volcanoes characteristically eject red-hot rocks and lava rather than this? 0. greenhouse gases 1. smoke and ash 2. carbon and smog 3. magma

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1. smoke and ash Example 3.5 Calculating Projectile Motion: Hot Rock Projectile Kilauea in Hawaii is the world’s most continuously active volcano. Very active volcanoes characteristically eject red-hot rocks and lava rather than smoke and ash. Suppose a large rock is ejected from the volcano with a speed of 25.0 m/s and at an angle 35.0º above the horizontal, as shown in Figure 3.40. The rock strikes the side of the volcano at an altitude 20.0 m lower than its starting point. (a) Calculate the time it takes the rock to follow this path. (b) What are the magnitude and direction of the rock’s velocity at impact?.

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When a meteoroid reaches earth, what is the remaining object called? 0. meteorite 1. comet 2. meteor 3. orbit

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0. meteorite Meteoroids are smaller than asteroids, ranging from the size of boulders to the size of sand grains. When meteoroids enter Earth’s atmosphere, they vaporize, creating a trail of glowing gas called a meteor. If any of the meteoroid reaches Earth, the remaining object is called a meteorite.

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What kind of a reaction occurs when a substance reacts quickly with oxygen? 0. combustion reaction 1. invention reaction 2. Fluid Reaction 3. nitrogen reaction

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0. combustion reaction A combustion reaction occurs when a substance reacts quickly with oxygen (O 2 ). For example, in the Figure below , charcoal is combining with oxygen. Combustion is commonly called burning, and the substance that burns is usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO 2 ) and water vapor (H 2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is:.

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Organisms categorized by what species descriptor demonstrate a version of allopatric speciation and have limited regions of overlap with one another, but where they overlap they interbreed successfully?. 0. surface species 1. fitting species 2. ring species 3. species complex

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2. ring species Ring species Ring species demonstrate a version of allopatric speciation. Imagine populations of the species A. Over the geographic range of A there exist a number of subpopulations. These subpopulations (A1 to A5) and (Aa to Ae) have limited regions of overlap with one another but where they overlap they interbreed successfully. But populations A5 and Ae no longer interbreed successfully – are these populations separate species? In this case, there is no clear-cut answer, but it is likely that in the link between the various populations will be broken and one or more species may form in the future. Consider the black bear Ursus americanus. Originally distributed across all of North America, its distribution is now much more fragmented. Isolated populations are free to adapt to their own particular environments and migration between populations is limited. Clearly the environment in Florida is different from that in Mexico, Alaska, or Newfoundland. Different environments will favor different adaptations. If, over time, these populations were to come back into contact with one another, they might or might not be able to interbreed successfully - reproductive isolation may occur and one species may become many.

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Alpha emission is a type of what? 0. radiation 1. heat 2. radioactivity 3. light

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2. radioactivity One type of radioactivity is alpha emission. What is an alpha particle? What happens to an alpha particle after it is emitted from an unstable nucleus?.

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What is the stored food in a seed called? 0. pollin 1. membrane 2. endosperm 3. larval

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2. endosperm The stored food in a seed is called endosperm . It nourishes the embryo until it can start making food on its own.

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Zinc is more easily oxidized than iron because zinc has a lower reduction potential. since zinc has a lower reduction potential, it is a more what? 0. much metal 1. Trap metal 2. active metal 3. usually metal

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2. active metal One way to keep iron from corroding is to keep it painted. The layer of paint prevents the water and oxygen necessary for rust formation from coming into contact with the iron. As long as the paint remains intact, the iron is protected from corrosion. Other strategies include alloying the iron with other metals. For example, stainless steel is mostly iron with a bit of chromium. The chromium tends to collect near the surface, where it forms an oxide layer that protects the iron. Zinc-plated or galvanized iron uses a different strategy. Zinc is more easily oxidized than iron because zinc has a lower reduction potential. Since zinc has a lower reduction potential, it is a more active metal. Thus, even if the zinc coating is scratched, the zinc will still oxidize before the iron. This suggests that this approach should work with other active metals. Another important way to protect metal is to make it the cathode in a galvanic cell. This is cathodic protection and can be used for metals other than just iron. For example, the rusting of underground iron storage tanks and pipes can be prevented or greatly reduced by connecting them to a more active metal such as zinc or magnesium (Figure 17.18). This is also used to protect the metal parts in water heaters. The more active metals (lower reduction potential) are called sacrificial anodes because as they get used up as they corrode (oxidize) at the anode. The metal being protected serves as the cathode, and so does not oxidize (corrode). When the anodes are properly monitored and periodically replaced, the useful lifetime of the iron storage tank can be greatly extended.

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What is controlled by both genes and experiences in a given envionment? 0. reflexes 1. instincts 2. animal behaviors 3. learned behaviors

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2. animal behaviors Most animal behaviors are controlled by both genes and experiences in a given environment.

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What tells you how much of the food you should eat to get the nutrients listed on the label? 0. regular size 1. scoop size 2. longer size 3. serving size

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3. serving size The information listed at the right of the label tells you what to look for. At the top of the label, look for the serving size. The serving size tells you how much of the food you should eat to get the nutrients listed on the label. A cup of food from the label pictured below is a serving. The calories in one serving are listed next. In this food, there are 250 calories per serving.

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What are used to write nuclear equations for radioactive decay? 0. nuclear symbols 1. trigonometric symbols 2. critical symbols 3. radioactive symbols

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0. nuclear symbols Nuclear symbols are used to write nuclear equations for radioactive decay. Let’s consider the example of the beta-minus decay of thorium-234 to protactinium-234. This reaction is represented by the equation:.

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What is controlled by regulatory proteins that bind to regulatory elements on dna? 0. amino acids 1. gene transcription 2. mRNA 3. substance transcription

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1. gene transcription Gene transcription is controlled by regulatory proteins that bind to regulatory elements on DNA. The proteins usually either activate or repress transcription.

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Boron only occurs naturally in compounds with what element? 0. helium 1. oxygen 2. nitrogen 3. carbon

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1. oxygen Occurrence, Preparation, and Compounds of Boron and Silicon Boron constitutes less than 0.001% by weight of the earth’s crust. In nature, it only occurs in compounds with oxygen. Boron is widely distributed in volcanic regions as boric acid, B(OH)3, and in dry lake regions, including the desert areas of California, as borates and salts of boron oxyacids, such as borax, Na2B4O7⋅10H2O. Elemental boron is chemically inert at room temperature, reacting with only fluorine and oxygen to form boron trifluoride, BF3, and boric oxide, B2O3, respectively. At higher temperatures, boron reacts with all nonmetals, except tellurium and the noble gases, and with nearly all metals; it oxidizes to B2O3 when heated with concentrated nitric or sulfuric acid. Boron does not react with nonoxidizing acids. Many boron compounds react readily with water to give boric acid, B(OH)3 (sometimes written as H3BO3). Reduction of boric oxide with magnesium powder forms boron (95–98.5% pure) as a brown, amorphous powder: B 2 O 3(s) + 3Mg(s) ⟶ 2B(s) + 3MgO(s) An amorphous substance is a material that appears to be a solid, but does not have a long-range order like a true solid. Treatment with hydrochloric acid removes the magnesium oxide. Further purification of the boron begins with conversion of the impure boron into boron trichloride. The next step is to heat a mixture of boron trichloride and hydrogen: 1500 °C.

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What organ systems link exchange surfaces with cells throughout the body? 0. circulatory 1. vascular 2. pulmonary 3. nervous

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0. circulatory 42.1 Circulatory systems link exchange surfaces with cells throughout the body.

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What occurs when the immune system attacks a harmless substance that enters the body from the outside? 0. panic attack 1. allergy 2. nausea 3. plague

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1. allergy An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy.

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Fertilization is the union of a sperm and egg, resulting in the formation of what? 0. a cytoplasm 1. a nuclei 2. a bacteriophage 3. a zygote

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3. a zygote Fertilization is the union of a sperm and egg, resulting in the formation of a zygote.

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The plants alternation between haploid and diploud generations allow it to do what? 0. reproduce asexually and sexually 1. reproduce asexually and simultaneously 2. reproduce sexually and autonomously 3. reproduce asexually and biologically

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0. reproduce asexually and sexually All plants have a characteristic life cycle that includes alternation of generations . Plants alternate between haploid and diploid generations. Alternation of generations allows for both asexual and sexual reproduction. Asexual reproduction with spores produces haploid individuals called gametophytes . Sexual reproduction with gametes and fertilization produces diploid individuals called sporophytes . A typical plant’s life cycle is diagrammed in Figure below .

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Most of the chemical reactions in the body are facilitated by what? 0. proteins 1. enzymes 2. vitamins 3. carbohydrates

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1. enzymes Enzymes are critical to the body’s healthy functioning. They assist, for example, with the breakdown of food and its conversion to energy. In fact, most of the chemical reactions in the body are facilitated by enzymes.

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What is the termination of a pregnancy in progress called? 0. abortion 1. contraception 2. miscarriage 3. delivery

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0. abortion

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Cutting down on the use of chemical fertilizers and preserving wetlands are ways to prevent what "unlivable" regions in bodies of water? 0. inhabitable zones 1. hostile zones 2. fresh zones 3. dead zones

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3. dead zones Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms.

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Which muscles allow your fingers to also make precise movements for actions? 0. paired muscles 1. intrinsic muscles 2. motoric muscles 3. fine movement muscles

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1. intrinsic muscles Intrinsic Muscles of the Hand The intrinsic muscles of the hand both originate and insert within it (Figure 11.28). These muscles allow your fingers to also make precise movements for actions, such as typing or writing. These muscles are divided into three groups. The thenar muscles are on the radial aspect of the palm. The hypothenar muscles are on the medial aspect of the palm, and the intermediate muscles are midpalmar. The thenar muscles include the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and the adductor pollicis. These muscles form the thenar eminence, the rounded contour of the base of the thumb, and all act on the thumb. The movements of the thumb play an integral role in most precise movements of the hand. The hypothenar muscles include the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti minimi. These muscles form the hypothenar eminence, the rounded contour of the little finger, and as such, they all act on the little finger. Finally, the intermediate muscles act on all the fingers and include the lumbrical, the palmar interossei, and the dorsal interossei.

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Testing what usually requires making observations or performing experiments? 0. hypothesis 1. variables 2. conclusion 3. homeostasis

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0. hypothesis Usually, testing a hypothesis requires making observations or performing experiments. In this case, we will look into existing scientific literature to see if either of these hypotheses can be disproved, or if one or both can be supported by the data.

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This sharing of electrons produces what is known as a covalent bond. covalent bonds are ~20 to 50 times stronger than what? 0. Mendelian systems 1. Newton's third law 2. gravitational pull 3. van der waals interactions

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3. van der waals interactions any other electron, they become a part of the molecule’s electron system.204 This sharing of electrons produces what is known as a covalent bond. Covalent bonds are ~20 to 50 times stronger than van der Waals interactions. What exactly does that mean? Basically, it takes 20 to 50 times more energy to break a covalent bond compared to a van der Waals interaction. While the bonded form of atoms in a molecule is always more stable than the unbounded form, it may not be stable enough to withstand the energy delivered through collisions with neighboring molecules. Different bonds between different atoms in different molecular contexts differ in terms of bond stability; the bond energy refers the energy needed to break a particular bond. A molecule is stable if the bond energies associated with bonded atoms within the molecule are high enough to survive the energy delivered to the molecule through either collisions with neighboring molecules or the absorption of energy (light). When atoms form a covalent bond, their individual van der Waals surfaces merge to produce a new molecular van der Waals surface. There are a number of ways to draw molecules, but the spacefilling or van der Waals surface view is the most realistic (at least for our purposes). While realistic it can also be confusing, since it obscures the underlying molecular structure, that is, how the atoms in the molecule are linked together. This can be seen in this set of representations of the simple molecule 2methylpropane (→).205 As molecules become larger, as is the case with many biologically important molecules, it can become impossible to appreciate their underlying organization based on a van der Waals surface representation. Because they form a new stable entity, it is not surprising (perhaps) that the properties of a molecule are quite distinct from, although certainly influenced by, the properties of the atoms from which they are composed. To a first order approximation, a molecule’s properties are based on its shape, which is dictated by how the various atoms withjn the molecule are connected to one another. These geometries are imposed by each atom’s underlying quantum mechanical properties and (particularly as molecules get larger, as they so often do in biological systems) the interactions between different parts of the molecule with one another. Some atoms, common to biological systems, such as hydrogen (H), can form only a single covalent bond. Others can make two (oxygen (O) and sulfur (S)), three (nitrogen (N)), four (carbon (C)), or five (phosphorus (P)) bonds. In addition to smaller molecules, biological systems contain a number of distinct types of extremely large molecules, composed of many thousands of atoms; these are known as macromolecules. Such macromolecules are not rigid; they can often fold back on themselves leading to intramolecular interactions. There are also interactions between molecules. The strength and specificity of these interactions can vary dramatically and even small changes in molecular structure (such as caused by mutations and allelic variations) can have dramatic effects.

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Water molecules move about continuously due to what type of energy? 0. seismic 1. potential 2. kinetic 3. optical

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2. kinetic Water molecules move about continuously due to their kinetic energy. When a crystal of sodium chloride is placed into water, the water’s molecules collide with the crystal lattice. Recall that the crystal lattice is composed of alternating positive and negative ions. Water is attracted to the sodium chloride crystal because water is polar and has both a positive and a negative end. The positively charged sodium ions in the crystal attract the oxygen end of the water molecules because they are partially negative. The negatively charged chloride ions in the crystal attract the hydrogen end of the water molecules because they are partially positive. The action of the polar water molecules takes the crystal lattice apart (see image below).

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A small scale version of what type of map displays individual rock units? 0. seismic map 1. geographic map 2. polar map 3. geologic map

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3. geologic map Geologic maps display rock units and geologic features. A small scale map displays individual rock units while a large scale map shows geologic provinces.

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What is defined as a change in the inherited traits of organisms over time? 0. variation 1. evolution 2. divergence 3. generation

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1. evolution One idea is that evolution happens. Evolution is a change in the inherited traits of organisms over time. Living things have changed as descendants diverged from common ancestors in the past.

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What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty? 0. testosterone 1. steroids 2. epinephrine 3. estrogen

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0. testosterone What causes puberty to begin? The hypothalamus in the brain “tells” the pituitary gland to secrete hormones that target the testes. The main pituitary hormone involved is luteinizing hormone (LH) . It stimulates the testes to secrete testosterone. Testosterone, in turn, promotes protein synthesis and growth. It brings about most of the physical changes of puberty, some of which are shown in Figure below . In addition to the changes shown below, during puberty male facial hair begins to grow, the shoulders broaden, and the male voice deepens. You can watch an animation of these and other changes that occur in boys during puberty at the Interactive Body link: http://www. bbc. co. uk/science/humanbody/body/interactives/lifecycle/teenagers/ .

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Where do angiosperms produce seeds in flowers? 0. ovaries 1. germs 2. cones 3. testes

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0. ovaries Seed plants called angiosperms produce seeds in the ovaries of flowers.

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In order to create food, what do photosynthetic protists use? 0. thermal energy 1. hydrocarbons 2. decayed matter 3. light energy

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3. light energy Photosynthetic protists use light energy to make food. They are major producers in aquatic ecosystems.

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What type of vertebrates are birds? 0. epidermal tetrapod 1. endothermic tetrapod 2. invertebrates 3. exothermic

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1. endothermic tetrapod Birds are endothermic tetrapod vertebrates. They are bipedal, which means they walk on two legs. Birds also lay amniotic eggs, and the eggs have hard, calcium carbonate shells. Although birds are the most recent class of vertebrates to evolve, they are now the most numerous vertebrates on Earth. Why have birds been so successful? What traits allowed them to increase and diversify so rapidly?.

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What type of ions do ionic compounds contain? 0. regular and irregular 1. positive and charged 2. negative and neutal 3. positive and negative

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3. positive and negative An ionic compound contains positive and negative ions.

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All living things need air and this to survive? 0. stimuli 1. habitat 2. ecosystem 3. water

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3. water

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The cells of all eukarya have a what? 0. chloroplast 1. epidermis 2. nucleus 3. necrosis

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2. nucleus Some Eukarya are also single-celled, but many are multicellular. Some have a cell wall; others do not. However, the cells of all Eukarya have a nucleus and other organelles.

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What type of plate boundaries produce huge mountain ranges in the ocean basin? 0. coherent 1. parallel 2. divergent 3. tractional

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2. divergent Divergent plate boundaries produce huge mountain ranges under water in every ocean basin.

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Interstitial carbides are produced by the reaction of most transition metals at high temperatures with what element? 0. hydrogen 1. carbon 2. oxygen 3. nitrogen

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1. carbon temperatures with electropositive metals such as those of groups 1 and 2 and aluminum produces ionic carbides, which contain discrete metal cations and carbon anions. The identity of the anions depends on the size of the second element. For example, smaller elements such as beryllium and aluminum give methides such as Be2C and Al4C3, which formally contain the C4− ion derived from methane (CH4) by losing all four H atoms as protons. In contrast, larger metals such as sodium and calcium give carbides with stoichiometries of Na2C2 and CaC2. Because these carbides contain the C4− ion, which is derived from acetylene (HC≡CH) by losing both H atoms as protons, they are more properly called acetylides. As discussed in Chapter 21 "Periodic Trends and the ", Section 21.4 "The Alkaline Earth Metals (Group 2)", reacting ionic carbides with dilute aqueous acid results in protonation of the anions to give the parent hydrocarbons: CH4 or C2H2. For many years, miners’ lamps used the reaction of calcium carbide with water to produce a steady supply of acetylene, which was ignited to provide a portable lantern. The reaction of carbon with most transition metals at high temperatures produces interstitial carbides. Due to the less electropositive nature of the transition metals, these carbides contain covalent metal– carbon interactions, which result in different properties: most interstitial carbides are good conductors of electricity, have high melting points, and are among the hardest substances known. Interstitial carbides exhibit a variety of nominal compositions, and they are often nonstoichiometric compounds whose carbon content can vary over a wide range. Among the most important are tungsten carbide (WC), which is used industrially in high-speed cutting tools, and cementite (Fe3C), which is a major component of steel. Elements with an electronegativity similar to that of carbon form covalent carbides, such as silicon carbide (SiC; Equation 22.15) and boron carbide (B4C). These substances are extremely hard, have high melting points, and are chemically inert. For example, silicon carbide is highly resistant to chemical attack at temperatures as high as 1600°C. Because it also maintains its strength at high temperatures, silicon carbide is used in heating elements for electric furnaces and in variable-temperature resistors.

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Fungus-like protist saprobes play what role in a food chain and are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes? 0. aphids 1. decomposers 2. Soil 3. fluxes

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1. decomposers Agents of Decomposition The fungus-like protist saprobes are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes. For instance, many types of oomycetes grow on dead animals or algae. Saprobic protists have the essential function of returning inorganic nutrients to the soil and water. This process allows for new plant growth, which in turn generates sustenance for other organisms along the food chain. Indeed, without saprobe species, such as protists, fungi, and bacteria, life would cease to exist as all organic carbon became “tied up” in dead organisms.

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What are the sites of protein synthesis or assembly? 0. chloroplasts 1. ribosomes 2. chromosomes 3. plasma

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1. ribosomes Ribosomes are small organelles and are the sites of protein synthesis (or assembly). They are made of ribosomal protein and ribosomal RNA, and are found in both eukaryotic and prokaryotic cells. Unlike other organelles, ribosomes are not surrounded by a membrane. Each ribosome has two parts, a large and a small subunit, as shown in Figure below . The subunits are attached to one another. Ribosomes can be found alone or in groups within the cytoplasm. Some ribosomes are attached to the endoplasmic reticulum (ER) (as shown in Figure below ), and others are attached to the nuclear envelope.

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What must replicate in the cell cycle before meiosis i takes place? 0. dna 1. cell walls 2. sperm 3. meiotic fluid

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0. dna Meiosis I begins after DNA replicates during interphase of the cell cycle. In both meiosis I and meiosis II , cells go through the same four phases as mitosis - prophase, metaphase, anaphase and telophase. However, there are important differences between meiosis I and mitosis. The eight stages of meiosis are summarized below. The stages will be described for a human cell, starting with 46 chromosomes.

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What phenomenon is primarily the result of plate tectonic motions? 0. eruption 1. earthquake 2. tsunamis 3. volcanoes

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1. earthquake Earthquakes are primarily the result of plate tectonic motions. What type of stress would cause earthquakes at each of the three types of plate boundaries?.

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What is a group of neuron cell bodies in the periphery called? 0. crystals 1. ganglion 2. organism 3. gangism

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1. ganglion Ganglia A ganglion is a group of neuron cell bodies in the periphery. Ganglia can be categorized, for the most part, as either sensory ganglia or autonomic ganglia, referring to their primary functions. The most common type of sensory ganglion is a dorsal (posterior) root ganglion. These ganglia are the cell bodies of neurons with axons that are sensory endings in the periphery, such as in the skin, and that extend into the CNS through the dorsal nerve root. The ganglion is an enlargement of the nerve root. Under microscopic inspection, it can be seen to include the cell bodies of the neurons, as well as bundles of fibers that are the posterior nerve root (Figure 13.19). The cells of the dorsal root ganglion are unipolar cells, classifying them by shape. Also, the small round nuclei of satellite cells can be seen surrounding—as if they were orbiting—the neuron cell bodies.

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Where does most of our food come from? 0. angiosperms 1. microbes 2. lichen 3. gymnosperms

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0. angiosperms

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Gases are most ideal at high temperature and what pressure? 0. low 1. absolute 2. high 3. stable

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0. low Under what conditions then, do gases behave least ideally? When a gas is put under high pressure, its molecules are forced closer together as the empty space between the particles is diminished. A decrease in the empty space means that the assumption that the volume of the particles themselves is negligible is less valid. When a gas is cooled, the decrease in kinetic energy of the particles causes them to slow down. If the particles are moving at slower speeds, the attractive forces between them are more prominent. Another way to view it is that continued cooling the gas will eventually turn it into a liquid and a liquid is certainly not an ideal gas anymore (see liquid nitrogen in the Figure below ). In summary, a real gas deviates most from an ideal gas at low temperatures and high pressures. Gases are most ideal at high temperature and low pressure.

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Hard igneous rocks and easily dissolved sedimentary rocks respond very differently to what natural force? 0. weathering 1. gravity 2. sunlight 3. evaporation

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0. weathering Each type of rock weathers in its own way. Certain types of rock are very resistant to weathering. Igneous rocks tend to weather slowly because they are hard. Water cannot easily penetrate them. Granite is a very stable igneous rock. Other types of rock are easily weathered because they dissolve easily in weak acids. Limestone is a sedimentary rock that dissolves easily. When softer rocks wear away, the more resistant rocks form ridges or hills.

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A diet rich in calcium and what vitamin may reduce the risk of osteoporosis and related bone fractures? 0. niacin 1. vitamin A 2. vitamin C 3. vitamin d

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3. vitamin d Skeletal system problems include osteoporosis, bone fractures, and ligament sprains. A diet rick in calcium and vitamin D may reduce the risk of osteoporosis and related bone fractures. Following safe practices may also reduce the risk of fractures as well as sprains.

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How many people die from air pollution each year? 0. 14 million 1. 17 million 2. 5 million 3. 22 million

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3. 22 million Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment.

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What substances serve as catalysts in most of the biochemical reactions that take place in organisms? 0. hormones 1. carbohydrates 2. enzymes 3. iseotrops

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2. enzymes Enzymes are involved in most of the biochemical reactions that take place in organisms. About 4,000 such reactions are known to be catalyzed by enzymes, but the number may be even higher. Enzymes allow reactions to occur at the rate necessary for life.

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The formation of an amalgam allows the metal to react with what? 0. helium and oxygen 1. cloth and plastic 2. air and water 3. blood and sweat

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2. air and water The metals of group 13 (Al, Ga, In, and Tl) are all reactive. However, passivation occurs as a tough, hard, thin film of the metal oxide forms upon exposure to air. Disruption of this film may counter the passivation, allowing the metal to react. One way to disrupt the film is to expose the passivated metal to mercury. Some of the metal dissolves in the mercury to form an amalgam, which sheds the protective oxide layer to expose the metal to further reaction. The formation of an amalgam allows the metal to react with air and water.

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