question stringlengths 1 6.54k | choices listlengths 4 4 | answer stringclasses 4
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What type of organism is commonly used in preparation of foods such as cheese and yogurt? | [
"mesophilic organisms",
"viruses",
"protozoa",
"gymnosperms"
] | A | 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 impo... | train | sciq | null |
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? | [
"tropical effect",
"centrifugal effect",
"coriolis effect",
"muon effect"
] | C | 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. | train | sciq | null |
Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always what? | [
"unbalanced",
"reactive",
"exothermic",
"endothermic"
] | C | 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... | train | sciq | null |
What is the least dangerous radioactive decay? | [
"beta decay",
"alpha decay",
"zeta decay",
"gamma decay"
] | B | All radioactive decay is dangerous to living things, but alpha decay is the least dangerous. | train | sciq | null |
Kilauea in hawaii is the world’s most continuously active volcano. very active volcanoes characteristically eject red-hot rocks and lava rather than this? | [
"magma",
"greenhouse gases",
"smoke and ash",
"carbon and smog"
] | C | 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.... | train | sciq | null |
When a meteoroid reaches earth, what is the remaining object called? | [
"meteorite",
"orbit",
"comet",
"meteor"
] | A | 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. | train | sciq | null |
What kind of a reaction occurs when a substance reacts quickly with oxygen? | [
"Fluid Reaction",
"invention reaction",
"combustion reaction",
"nitrogen reaction"
] | C | 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... | train | sciq | null |
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?. | [
"ring species",
"fitting species",
"surface species",
"species complex"
] | A | 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 su... | train | sciq | null |
Alpha emission is a type of what? | [
"heat",
"light",
"radioactivity",
"radiation"
] | C | 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?. | train | sciq | null |
What is the stored food in a seed called? | [
"membrane",
"pollin",
"endosperm",
"larval"
] | C | The stored food in a seed is called endosperm . It nourishes the embryo until it can start making food on its own. | train | sciq | null |
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? | [
"active metal",
"Trap metal",
"much metal",
"usually metal"
] | A | 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 ex... | train | sciq | null |
What is controlled by both genes and experiences in a given envionment? | [
"reflexes",
"animal behaviors",
"learned behaviors",
"instincts"
] | B | Most animal behaviors are controlled by both genes and experiences in a given environment. | train | sciq | null |
What tells you how much of the food you should eat to get the nutrients listed on the label? | [
"longer size",
"serving size",
"scoop size",
"regular size"
] | B | 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 ... | train | sciq | null |
What are used to write nuclear equations for radioactive decay? | [
"critical symbols",
"trigonometric symbols",
"radioactive symbols",
"nuclear symbols"
] | D | 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:. | train | sciq | null |
What is controlled by regulatory proteins that bind to regulatory elements on dna? | [
"amino acids",
"substance transcription",
"mRNA",
"gene transcription"
] | D | Gene transcription is controlled by regulatory proteins that bind to regulatory elements on DNA. The proteins usually either activate or repress transcription. | train | sciq | null |
Boron only occurs naturally in compounds with what element? | [
"nitrogen",
"carbon",
"oxygen",
"helium"
] | C | 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 ... | train | sciq | null |
What organ systems link exchange surfaces with cells throughout the body? | [
"pulmonary",
"nervous",
"vascular",
"circulatory"
] | D | 42.1 Circulatory systems link exchange surfaces with cells throughout the body. | train | sciq | null |
What occurs when the immune system attacks a harmless substance that enters the body from the outside? | [
"allergy",
"nausea",
"panic attack",
"plague"
] | A | 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. | train | sciq | null |
Fertilization is the union of a sperm and egg, resulting in the formation of what? | [
"a nuclei",
"a bacteriophage",
"a zygote",
"a cytoplasm"
] | C | Fertilization is the union of a sperm and egg, resulting in the formation of a zygote. | train | sciq | null |
The plants alternation between haploid and diploud generations allow it to do what? | [
"reproduce asexually and biologically",
"reproduce asexually and sexually",
"reproduce asexually and simultaneously",
"reproduce sexually and autonomously"
] | B | 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 reproduc... | train | sciq | null |
Most of the chemical reactions in the body are facilitated by what? | [
"enzymes",
"vitamins",
"proteins",
"carbohydrates"
] | A | 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. | train | sciq | null |
What is the termination of a pregnancy in progress called? | [
"abortion",
"delivery",
"miscarriage",
"contraception"
] | A | train | sciq | null | |
Cutting down on the use of chemical fertilizers and preserving wetlands are ways to prevent what "unlivable" regions in bodies of water? | [
"fresh zones",
"dead zones",
"hostile zones",
"inhabitable zones"
] | B | 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 bod... | train | sciq | null |
Which muscles allow your fingers to also make precise movements for actions? | [
"motoric muscles",
"fine movement muscles",
"paired muscles",
"intrinsic muscles"
] | D | 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... | train | sciq | null |
Testing what usually requires making observations or performing experiments? | [
"conclusion",
"homeostasis",
"hypothesis",
"variables"
] | C | 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. | train | sciq | null |
This sharing of electrons produces what is known as a covalent bond. covalent bonds are ~20 to 50 times stronger than what? | [
"van der waals interactions",
"Mendelian systems",
"gravitational pull",
"Newton's third law"
] | A | 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 b... | train | sciq | null |
Water molecules move about continuously due to what type of energy? | [
"kinetic",
"potential",
"optical",
"seismic"
] | A | 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 be... | train | sciq | null |
A small scale version of what type of map displays individual rock units? | [
"polar map",
"seismic map",
"geographic map",
"geologic map"
] | D | Geologic maps display rock units and geologic features. A small scale map displays individual rock units while a large scale map shows geologic provinces. | train | sciq | null |
What is defined as a change in the inherited traits of organisms over time? | [
"evolution",
"generation",
"variation",
"divergence"
] | A | 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. | train | sciq | null |
What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty? | [
"estrogen",
"steroids",
"epinephrine",
"testosterone"
] | D | 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 ... | train | sciq | null |
Where do angiosperms produce seeds in flowers? | [
"cones",
"germs",
"ovaries",
"testes"
] | C | Seed plants called angiosperms produce seeds in the ovaries of flowers. | train | sciq | null |
In order to create food, what do photosynthetic protists use? | [
"hydrocarbons",
"decayed matter",
"thermal energy",
"light energy"
] | D | Photosynthetic protists use light energy to make food. They are major producers in aquatic ecosystems. | train | sciq | null |
What type of vertebrates are birds? | [
"exothermic",
"epidermal tetrapod",
"invertebrates",
"endothermic tetrapod"
] | D | 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 ... | train | sciq | null |
What type of ions do ionic compounds contain? | [
"negative and neutal",
"positive and charged",
"positive and negative",
"regular and irregular"
] | C | An ionic compound contains positive and negative ions. | train | sciq | null |
All living things need air and this to survive? | [
"water",
"stimuli",
"ecosystem",
"habitat"
] | A | train | sciq | null | |
The cells of all eukarya have a what? | [
"epidermis",
"chloroplast",
"necrosis",
"nucleus"
] | D | 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. | train | sciq | null |
What type of plate boundaries produce huge mountain ranges in the ocean basin? | [
"parallel",
"tractional",
"divergent",
"coherent"
] | C | Divergent plate boundaries produce huge mountain ranges under water in every ocean basin. | train | sciq | null |
Interstitial carbides are produced by the reaction of most transition metals at high temperatures with what element? | [
"hydrogen",
"nitrogen",
"carbon",
"oxygen"
] | C | 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 ... | train | sciq | null |
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? | [
"aphids",
"fluxes",
"Soil",
"decomposers"
] | D | 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 s... | train | sciq | null |
What are the sites of protein synthesis or assembly? | [
"plasma",
"chloroplasts",
"chromosomes",
"ribosomes"
] | D | 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... | train | sciq | null |
What must replicate in the cell cycle before meiosis i takes place? | [
"dna",
"meiotic fluid",
"cell walls",
"sperm"
] | A | 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... | train | sciq | null |
What phenomenon is primarily the result of plate tectonic motions? | [
"eruption",
"tsunamis",
"volcanoes",
"earthquake"
] | D | 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?. | train | sciq | null |
What is a group of neuron cell bodies in the periphery called? | [
"gangism",
"crystals",
"organism",
"ganglion"
] | D | 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 ... | train | sciq | null |
Where does most of our food come from? | [
"gymnosperms",
"lichen",
"angiosperms",
"microbes"
] | C | train | sciq | null | |
Gases are most ideal at high temperature and what pressure? | [
"high",
"absolute",
"low",
"stable"
] | C | 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 val... | train | sciq | null |
Hard igneous rocks and easily dissolved sedimentary rocks respond very differently to what natural force? | [
"evaporation",
"sunlight",
"weathering",
"gravity"
] | C | 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. L... | train | sciq | null |
A diet rich in calcium and what vitamin may reduce the risk of osteoporosis and related bone fractures? | [
"niacin",
"vitamin d",
"vitamin A",
"vitamin C"
] | B | 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. | train | sciq | null |
How many people die from air pollution each year? | [
"14 million",
"17 million",
"5 million",
"22 million"
] | D | 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 l... | train | sciq | null |
What substances serve as catalysts in most of the biochemical reactions that take place in organisms? | [
"hormones",
"carbohydrates",
"iseotrops",
"enzymes"
] | D | 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. | train | sciq | null |
The formation of an amalgam allows the metal to react with what? | [
"air and water",
"cloth and plastic",
"blood and sweat",
"helium and oxygen"
] | A | 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.... | train | sciq | null |
A pulley changes the direction of the force t exerted by the cord without changing its what? | [
"latitude",
"longitude",
"magnitude",
"position"
] | C | automobile axle drives a wheel, which has a much larger diameter than the axle. The MA is less than 1. (c) An ordinary pulley is used to lift a heavy load. The pulley changes the direction of the force T exerted by the cord without changing its magnitude. Hence, this machine has an MA of 1. | train | sciq | null |
What is the name of the small bumps that contain taste buds and covers the tongue? | [
"papillae",
"cuticle",
"lingual tonsils",
"palatine tonsils"
] | A | Figure 14.3 The Tongue The tongue is covered with small bumps, called papillae, which contain taste buds that are sensitive to chemicals in ingested food or drink. Different types of papillae are found in different regions of the tongue. The taste buds contain specialized gustatory receptor cells that respond to chemic... | train | sciq | null |
In the absence of air resistance, all falling objects accelerate at the same rate due to what force? | [
"velocity",
"weight",
"gravity",
"motion"
] | C | What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at the same t... | train | sciq | null |
The ability for a plasma membrane to only allow certain molecules in or out of the cell is referred to as what? | [
"periodic permeability",
"total permeability",
"moderate permeability",
"selective permeability"
] | D | The plasma membrane forms a barrier between the cytoplasm inside the cell and the environment outside the cell. It protects and supports the cell and also controls everything that enters and leaves the cell. It allows only certain substances to pass through, while keeping others in or out. The ability to allow only cer... | train | sciq | null |
In the presence of oxygen, hydrogen can interact to make what? | [
"acid",
"helium",
"carbon",
"water"
] | D | A pile of leaves slowly rots in the backyard. In the presence of oxygen, hydrogen can interact to make water. Gold can be stretched into very thin wires. | train | sciq | null |
What galaxy is our solar system a part of? | [
"Bode's Galaxy",
"Centaurus",
"milky way",
"Andromeda"
] | C | Compared to Earth, the solar system is a big place. But galaxies are bigger - a lot bigger. A galaxy is a very large group of stars held together by gravity. How enormous a galaxy is and how many stars it contains are impossible for us to really understand. A galaxy contains up to a few billion stars! Our solar system ... | train | sciq | null |
The angle at which light bends when it enters a different medium is known as what? | [
"bounce",
"frequency",
"refraction",
"resonance"
] | C | The angle at which light bends when it enters a different medium depends on its change in speed. The greater the change in speed, the greater the angle of refraction is. For example, light refracts more when it passes from air to diamond than it does when it passes from air to water. That’s because the speed of light i... | train | sciq | null |
Whether the organism is a bacterium, plant, or animal, all living things access energy by breaking down these? | [
"carbohydrate molecules",
"lipid molecules",
"protein molecules",
"oxygen molecules"
] | A | The Energy Cycle Whether the organism is a bacterium, plant, or animal, all living things access energy by breaking down carbohydrate molecules. But if plants make carbohydrate molecules, why would they need to break them down, especially when it has been shown that the gas organisms release as a “waste product” (CO2) ... | train | sciq | null |
Increasing the temperature of n2 molecules increases what energy of motion? | [
"emotional energy",
"residual energy",
"kinetic energy",
"compression energy"
] | C | Increasing the temperature increases the average kinetic energy of the N2molecules. | train | sciq | null |
Which radio frequency should you listen to if you want less noise? | [
"cb",
"am",
"wave",
"fm"
] | D | FM radio is inherently less subject to noise from stray radio sources than AM radio. The reason is that amplitudes of waves add. So an AM receiver would interpret noise added onto the amplitude of its carrier wave as part of the information. An FM receiver can be made to reject amplitudes other than that of the basic c... | train | sciq | null |
What form of radiation is the energy emitted by the sun? | [
"electromagnetic",
"magnetic",
"thermal",
"seismic"
] | A | Figure 8.11 The sun emits energy in the form of electromagnetic radiation. This radiation exists at different wavelengths, each of which has its own characteristic energy. All electromagnetic radiation, including visible light, is characterized by its wavelength. | train | sciq | null |
What is the suns innermost layer called? | [
"flare",
"solar",
"core",
"surface"
] | C | The core is the Sun's innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer layers of th... | train | sciq | null |
A growth spurt requires constant divisions of what? | [
"seeds",
"proteins",
"cells",
"hairs"
] | C | To grow and develop, you must form new cells. Imagine how often your cells must divide during a growth spurt. Growing just an inch requires countless cell divisions. Your body must produce new bone cells, new skin cells, new cells in your blood vessels and so on. | train | sciq | null |
What's the term for the gradual progression from simple plants to larger more complex ones in an area? | [
"primary pattern",
"primary succession",
"pattern progression",
"complex progression"
] | B | The pioneer species is soon replaced by other populations. Abiotic factors such as soil quality, water, and climate will determine the species that continue the process of succession. Mosses and grasses will be able to grow in the newly created soil. During early succession, plant species like grasses that grow and rep... | train | sciq | null |
Fungi may form mutualistic relationships with plants, algae, cyanobacteria, and what? | [
"eggs",
"farmers",
"plants",
"animals"
] | D | train | sciq | null | |
Which cycle tracks the flow of nitrogen through an ecosystem? | [
"water cycle",
"nitrogen cycle",
"nitrogen reaction",
"life cycle"
] | B | Mariana Ruiz Villarreal (LadyofHats) for CK-12 Foundation. The nitrogen cycle tracks the flow of nitrogen through an ecosystem . CC BY-NC 3.0. | train | sciq | null |
What consequence of a tornado is responsible for most injuries and deaths? | [
"falling debris",
"catching debris",
"flying debris",
"touring debris"
] | C | A tornado only strikes a small area. But it can destroy everything in its path. Most injuries and deaths from tornadoes are caused by flying debris ( Figure below ). In the United States, an average of 90 people are killed by tornadoes each year. The most violent two percent of tornadoes account for 70% of the deaths b... | train | sciq | null |
What are the only truly innate behaviors in humans called? | [
"reflexes",
"automatic movements",
"feats",
"flinches"
] | A | All animals have innate behaviors, even human beings. Can you think of human behaviors that do not have to be learned? Chances are, you will have a hard time thinking of any. The only truly innate behaviors in humans are called reflex behaviors . They occur mainly in babies. Like innate behaviors in other animals, refl... | train | sciq | null |
What happens to the density of air as the altitude decreases? | [
"multiplies",
"increases",
"remains the same",
"decreases"
] | D | The pressure of the earth’s atmosphere, as with any fluid, increases with the height of the column of air. In the case of earth’s atmosphere, there are some complications. The density of the air is not uniform but decreases with altitude. Additionally there is no distinct top surface from which height can be measured. ... | train | sciq | null |
How do some animals change their depth? | [
"metamorphosis",
"mass migration",
"spontaneous mutations",
"by changing their density"
] | D | Some animals change their depth by changing their density. Recall that things that are denser than their surroundings sink while those that are less dense than their surroundings float. Most fish have a swim bladder, a special sac that is filled with gases from their blood. When the fish's swim bladder is full, it is l... | train | sciq | null |
What phenomenon is crowding out other species and making all the other causes of extinction worse? | [
"climate change",
"migration",
"human overpopulation",
"human suburbanization"
] | C | Human overpopulation, which is crowding out other species. It also makes all the other causes of extinction worse. | train | sciq | null |
Dessication is an extreme and usually fatal form of what in animals? | [
"depletion",
"starvation",
"diarrhea",
"dehydration"
] | D | train | sciq | null | |
Internal and external forms of what life process occur as simple diffusion due to a partial pressure gradient? | [
"reproduction",
"photosynthesis",
"metabolism",
"respiration"
] | D | Internal Respiration Internal respiration is gas exchange that occurs at the level of body tissues (Figure 22.23). Similar to external respiration, internal respiration also occurs as simple diffusion due to a partial pressure gradient. However, the partial pressure gradients are opposite of those present at the respir... | train | sciq | null |
The fossil record shows that this type of event is followed by the evolution of new species to fill the habitats where old species lived? | [
"mass extinction",
"moderate extinction",
"formation extinction",
"minor extinction"
] | A | After each mass extinction, new species evolve to fill the habitats where old species lived. This is well documented in the fossil record. | train | sciq | null |
Soluble minerals and clays accumulate in what soil layer, allowing it to hold more water? | [
"silt",
"subsoil",
"subsurface",
"topsoil"
] | B | Below the topsoil is the “B” horizon. This is also called the subsoil . Soluble minerals and clays accumulate in the subsoil. Because it has less organic material, this layer is lighter brown in color than topsoil. It also holds more water due to the presence of iron and clay. There is less organic material in this lay... | train | sciq | null |
What is the common word for potential difference in a circuit? | [
"frequency",
"voltage",
"watt",
"velocity"
] | B | Conceptual Questions 19.1 Electric Potential Energy: Potential Difference 1. Voltage is the common word for potential difference. Which term is more descriptive, voltage or potential difference? 2. If the voltage between two points is zero, can a test charge be moved between them with zero net work being done? Can this... | train | sciq | null |
How many chambers does the stomach of a crocodile have? | [
"six",
"two",
"ten",
"three"
] | B | The crocodilian digestive system is highly adapted to their lifestyle. Crocodilians are known to swallow stones, known as gastroliths , which help digest their prey. The crocodilian stomach is divided into two chambers. The first is powerful and muscular. The other stomach is the most acidic digestive system of any ani... | train | sciq | null |
When populations get close to the carrying capacity, what happens to growth? | [
"halts",
"dies",
"spikes",
"slows"
] | D | Populations usually grow bigger when they have what they need. How fast they grow depends on birth and death rates. They grow more slowly as they get close to the carrying capacity. This is the biggest population the environment can support. | train | sciq | null |
Although air can transfer heat rapidly by convection, it is a poor conductor and thus a good what? | [
"insulator",
"absorber",
"transporter",
"magnet"
] | A | Although air can transfer heat rapidly by convection, it is a poor conductor and thus a good insulator. The amount of available space for airflow determines whether air acts as an insulator or conductor. The space between the inside and outside walls of a house, for example, is about 9 cm (3.5 in) —large enough for con... | train | sciq | null |
Most plants grow continuously, except for what periods? | [
"abnormal",
"mutant",
"winter",
"dormant"
] | D | train | sciq | null | |
What man-made devices in space are used to observe the earth's surface? | [
"telescopes",
"crystals",
"satellites",
"sensors"
] | C | Observations can happen on many scales. You can use a microscope to observe tiny things. You can use a telescope to observe distant things in space. To learn about the effects of climate change, you could observe Earth's surface. How would you make observations of Earth's surface? You could do this from the land surfac... | train | sciq | null |
Carboxylic acids are weak acids, meaning they are not 100% ionized in what? | [
"water",
"liquid",
"air",
"ethanol"
] | A | Carboxylic acids are weak acids (see the chapter on acids and bases), meaning they are not 100% ionized in water. Generally only about 1% of the molecules of a carboxylic acid dissolved in water are ionized at any given time. The remaining molecules are undissociated in solution. We prepare carboxylic acids by the oxid... | train | sciq | null |
An endocrine disease usually involves the secretion of too much or not enough of what? | [
"metabolite",
"hormone",
"sweat",
"enzyme"
] | B | Diseases of the endocrine system are relatively common. An endocrine disease usually involves the secretion of too much or not enough hormone. When too much hormone is secreted, it is called hypersecretion. When not enough hormone is secreted, it is called hyposecretion. | train | sciq | null |
In experiments with garden peas, austrian monk gregor mendel described the basic patterns of what? | [
"behavior",
"inheritance",
"color",
"preference"
] | B | For thousands of years, humans have understood that characteristics such as eye color, hair color, or even flower color are passed from one generation to the next. The passing of characteristics from parent to offspring is called heredity . Humans have long been interested in understanding heredity. Many hereditary mec... | train | sciq | null |
Nutrition and diet affect your metabolism. more energy is required to break down fats and proteins than this? | [
"carbohydrates",
"minerals",
"vitamins",
"electrolytes"
] | A | 24.7 Nutrition and Diet Nutrition and diet affect your metabolism. More energy is required to break down fats and proteins than carbohydrates; however, all excess calories that are ingested will be stored as fat in the body. On average, a person requires 1500 to 2000 calories for normal daily activity, although routine... | train | sciq | null |
What are unsaturated hydrocarbons with at least one double bond between carbon atoms called? | [
"enzymes",
"alkenes",
"amines",
"peptides"
] | B | Alkenes are unsaturated hydrocarbons with at least one double bond between carbon atoms. | train | sciq | null |
What is the opposite of melting? | [
"evaporation",
"compression",
"freezing",
"liquidation"
] | C | All of the changes of state that occur between solid, liquid and gas are summarized in the diagram in the figure below. Freezing is the opposite of melting and both represent the equilibrium between the solid and liquid states. Evaporation occurs when a liquid turns to a gas. Condensation is the opposite of vaporizatio... | train | sciq | null |
A unique characteristic of mammals is the ability to chew, this happens by the temporalis and the masseter allowing what? | [
"Bakward and forward",
"side-to-side movement",
"Up and down",
"Grinding"
] | B | The adductor muscle that closes the jaw is composed of two muscles in mammals: the temporalis and the masseter. These allow side-to-side movement of the jaw, making chewing possible, which is unique to mammals. Most mammals have heterodont teeth, meaning that they have different types and shapes of teeth rather than ju... | train | sciq | null |
Most of the pathogens that cause stis enter the body through mucous membranes of which organs? | [
"reproductive organs",
"stomach",
"kidneys",
"eyes"
] | A | Most of the pathogens that cause STIs enter the body through mucous membranes of the reproductive organs. All sexual behaviors that involve contact between mucous membranes put a person at risk for infection. This includes vaginal, anal, and oral sexual behaviors. Many STIs can also be transmitted through body fluids s... | train | sciq | null |
The activation of what kind of buds induces branching? | [
"arterial buds",
"lymphatic buds",
"axillary buds",
"leafy buds"
] | C | train | sciq | null | |
Sexual reproduction involves haploid gametes and produces a diploid zygote through what process? | [
"vivisection",
"fertilization",
"sedimentation",
"infection"
] | B | Sexual reproduction involves haploid gametes and produces a diploid zygote through fertilization. | train | sciq | null |
All alkanes are composed of carbon and hydrogen atoms, and have similar bonds, structures, and formulas; noncyclic alkanes all have a formula of cnh2n+2. the number of carbon atoms present in an alkane has what? | [
"done limit",
"such limit",
"no limit",
"crippling limit"
] | C | All alkanes are composed of carbon and hydrogen atoms, and have similar bonds, structures, and formulas; noncyclic alkanes all have a formula of CnH2n+2. The number of carbon atoms present in an alkane has no limit. Greater numbers of atoms in the molecules will lead to stronger intermolecular attractions (dispersion f... | train | sciq | null |
What percentage of men suffer from some form of erectile dysfunction by age 40? | [
"approximately 80 percent",
"approximately 10 percent",
"approximately 60 percent",
"approximately 40 percent"
] | D | Male Reproductive System Erectile dysfunction (ED) is a condition in which a man has difficulty either initiating or maintaining an erection. The combined prevalence of minimal, moderate, and complete ED is approximately 40 percent in men at age 40, and reaches nearly 70 percent by 70 years of age. In addition to aging... | train | sciq | null |
What secures together immovable joints and prevents them from moving? | [
"dense cartilage",
"light collagen",
"light cartilage",
"dense collagen"
] | D | Immovable joints allow no movement because the bones at these joints are held securely together by dense collagen . The bones of the skull are connected by immovable joints. | train | sciq | null |
Transform faults are the site of massive what? | [
"storms",
"tornadoes",
"vibrations",
"earthquakes"
] | D | Transform faults are the site of massive earthquakes. | train | sciq | null |
When water goes above and below its freezing point, what rock-breaking phenomenon is common? | [
"ice locking",
"ice crushing",
"ice wedging",
"ice inverting"
] | C | Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point ( Figure below ). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions like the Sierra Nevada pictured above. | train | sciq | null |
The diatoms are unicellular photosynthetic protists that encase themselves in intricately patterned, glassy cell walls composed of silicon dioxide in a matrix of organic particles. these protists are a component of freshwater and these? | [
"waste plankton",
"land plankton",
"marine plankton",
"source plankton"
] | C | The diatoms are unicellular photosynthetic protists that encase themselves in intricately patterned, glassy cell walls composed of silicon dioxide in a matrix of organic particles (Figure 23.18). These protists are a component of freshwater and marine plankton. Most species of diatoms reproduce asexually, although some... | train | sciq | null |
What type of reactions form compounds? | [
"physical reactions",
"consumption reactions",
"mineral reactions",
"chemical reactions"
] | D | A compound is a unique substance that forms when two or more elements combine chemically. Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons. For a video ... | train | sciq | null |
Millions of years ago, plants used energy from the sun to form what? | [
"carbon compounds",
"evolution",
"greenhouse gases",
"fossil fuels"
] | A | Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this r... | train | sciq | null |
What is the term for the process in which living things with beneficial traits produce more offspring than others do? | [
"natural survival",
"natural process",
"natural selection",
"natural variety"
] | C | The other idea is that evolution occurs by natural selection. Natural selection is the process in which living things with beneficial traits produce more offspring than others do. This results in changes in the traits of living things over time. | train | sciq | null |
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