questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
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What is a disease in which the immune system makes an inflammatory response to a harmless antigen?
Here are the choices:
A. bronchitis
B. heartburn
C. an allergy
D. cancer | An allergy is a disease in which the immune system makes an inflammatory response to a harmless antigen . Any antigen that causes an allergy is called an allergen. Allergens may be inhaled or ingested, or they may come into contact with the skin. Two common causes of allergies are shown in Figure below . Inhaling ragweed pollen may cause coughing and sneezing. Skin contact with oils in poison ivy may cause an itchy rash. Other common causes of allergies include dust mites, mold, animal dander, insect stings, latex, and certain food and medications. Symptoms of a common allergy such as pollen can include sneezing, a runny nose, nasal congestion and itchy, watery eyes. | C: an allergy. |
The umbilical cord connects the fetus to what structure?
Here are the choices:
A. Ovaries
B. placenta
C. cell
D. uterus | The fetus is connected to the placenta through the umbilical cord. This is a long tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries. It exchanges gases and other substances with the mother’s blood. Then it travels back to the fetus through the umbilical vein. | B: placenta. |
The vector of what organism is significant on a map showing the location of malaria?
Here are the choices:
A. virus
B. fungi
C. mosquito
D. worm | Worldwide Distribution of Malaria. This map shows where malaria is found. The area is determined by the mosquito vector. The mosquito can live year-round only in the red-shaded areas. | C: mosquito. |
What is the smallest particle of an element that still has the properties of that element is called?
Here are the choices:
A. atom
B. neutron
C. proton
D. nucleus | The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure below . An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. | A: atom. |
What is already causing food and water shortages and species extinctions?
Here are the choices:
A. global warming
B. immigration
C. zero population growth
D. urbanization | Adding more heat energy to Earth’s atmosphere also causes more extreme weather and changes in precipitation patterns. Global warming is already causing food and water shortages and species extinctions. These problems will only grow worse unless steps are taken to curb greenhouse gases and global climate change. | A: global warming. |
What is the foundation species of coral reef ecosystems?
Here are the choices:
A. crystals
B. anemones
C. molluscs
D. coral | Figure 19.24 Coral is the foundation species of coral reef ecosystems. (credit: Jim E. Maragos, USFWS). | D: coral. |
When the ph of precipitation is lowered because of air pollution, what results?
Here are the choices:
A. climate change
B. acid rain
C. abnormal rain
D. sleet | All life relies on a relatively narrow range of pH, or acidity. That’s because protein structure and function are very sensitive to pH. Air pollution can cause precipitation to become acidic. Nitrogen and sulfur oxides, mainly from motor vehicle exhaust and coal burning, create acids when they combine with water in the air. The acids lower the pH of precipitation, forming acid rain . If acid rain falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may kill them (see Figure below ). If it falls into lakes, it lowers the pH of the water and kills aquatic organisms. | B: acid rain. |
What type of barrier physically blocks pathogens from entering the body?
Here are the choices:
A. Solid
B. potential
C. molecular
D. mechanical | Mechanical barriers physically block pathogens from entering the body. The skin is the most important mechanical barrier. In fact, it is the single most important defense the body has. The outer layer of the skin is tough and very difficult for pathogens to penetrate. | D: mechanical. |
In what do a roundworm's eggs pass from host to the environment?
Here are the choices:
A. arms
B. skin
C. mouth
D. feces | Some parasites live on the surface of their host. Others live inside their host. They may enter the host through a break in the skin or in food or water. For example, roundworms are parasites of mammals, including humans, cats, and dogs (see Figure below ). The worms produce huge numbers of eggs, which are passed in the host’s feces to the environment. Other individuals may be infected by swallowing the eggs in contaminated food or water. | D: feces. |
What is the name of the command center of the cell?
Here are the choices:
A. molecules
B. nucleus
C. vacuole
D. mitochondria | 3.3 The Nucleus and DNA Replication The nucleus is the command center of the cell, containing the genetic instructions for all of the materials a cell will make (and thus all of its functions it can perform). The nucleus is encased within a membrane of two interconnected lipid bilayers, side-by-side. This nuclear envelope is studded with protein-lined pores that allow materials to be trafficked into and out of. | B: nucleus. |
What does the ending 'ology' refer to?
Here are the choices:
A. Application Of
B. study of
C. theory of
D. focus of | Oceanography is the study of the oceans. The word oceanology might be more accurate, since “ology” is “the study of. ” “Graph” is “to write” and refers to map making. But mapping the oceans is how oceanography started. | B: study of. |
What is the only natural phenomenon that causes more damage than earthquakes?
Here are the choices:
A. landslides
B. volcanos
C. hurricanes
D. blizzards | Only hurricanes cause more damage than earthquakes. Only one source of earthquake damage is ground shaking. More damage may be done from the tsunami, fires, and landslides that can happen afterwards. Communities along faults can prepare for earthquakes. One way is to use earthquake-safe construction methods and to make older buildings stronger. If you live in earthquake country, it is important to secure heavy objects and put together an emergency kit. | C: hurricanes. |
What is the hypothesis that states that the biosphere is its own living organism?
Here are the choices:
A. Pascal's hypothesis
B. Big Bang theory
C. gaia hypothesis
D. Geiger theory | The Gaia hypothesis states that the biosphere is its own living organism. The hypothesis suggests that the Earth is self-regulating and tends to achieve a stable state, known as homeostasis . For example the composition of our atmosphere stays fairly consistent, providing the ideal conditions for life. When carbon dioxide levels increase in the atmosphere, plants grow more quickly. As their growth continues, they remove more carbon dioxide from the atmosphere. In this way, the amount of carbon dioxide stays fairly constant without human intervention. | C: gaia hypothesis. |
The kinetic energy of molecules is generally proportionate to what other property that they have?
Here are the choices:
A. precipitation
B. temperature
C. variation
D. mass | The average kinetic energy of the molecules is proportional to the temperature of the sample. | B: temperature. |
Several neuropeptides, relatively short chains of amino acids, serve as neurotransmitters that operate via metabotropic what?
Here are the choices:
A. receptors
B. lipids
C. membranes
D. organelles | A: receptors. | |
What kind of process is boiling?
Here are the choices:
A. cavitation
B. chemical
C. spheroidal
D. isothermal | As with melting, the energy in boiling goes exclusively to changing the phase of a substance; it does not go into changing the temperature of a substance. So boiling is also an isothermal process. Only when all of a substance has boiled does any additional energy go to changing its temperature. What happens when a liquid becomes a gas? We have already established that a liquid is composed of particles in contact with each other. When a liquid becomes a gas, the particles separate from each other, with each particle going its own way in space. This is how gases tend to fill their containers. Indeed, in the gas phase most of the volume is empty space; only about 1/1,000th of the volume is actually taken up by matter (Figure 10.4 "Liquids and Gases"). It is this property of gases that explains why they can be compressed, a fact that is considered in Chapter 6 "Gases". Figure 10.4 Liquids and Gases. | D: isothermal. |
In science, what is constantly tested, sometimes revised, sometimes thrown out and sometimes well-established?
Here are the choices:
A. a variable
B. a theory
C. a study
D. a technique | A theory is constantly tested. If some data does not agree with the theory, the theory can be revised. If the theory cannot match the data, it is thrown out. That being said, sometimes a theory is well-established; it has a lot of evidence to back it up. A well-established theory is unlikely to be overthrown. It may just need to be modified a bit. But science does not prove anything beyond a shadow of a doubt. | B: a theory. |
What is the name of the process in which both the system and its environment can return to exactly the states they were in by following the reverse path?
Here are the choices:
A. Different Process
B. conductive process
C. Remote process
D. reversible process | Reversible Processes Both isothermal and adiabatic processes such as shown in Figure 15.13 are reversible in principle. A reversible process is one in which both the system and its environment can return to exactly the states they were in by following the reverse path. The reverse isothermal and adiabatic paths are BA and CA, respectively. Real macroscopic processes are never exactly reversible. In the previous examples, our system is a gas (like that in Figure 15.9), and its environment is the piston, cylinder, and the rest of the universe. If there are any energy-dissipating mechanisms, such as friction or turbulence, then heat transfer to the environment occurs for either direction of the piston. So, for example, if the path BA is followed and there is friction, then the gas will be returned to its original state but the environment will not—it will have been heated in both directions. Reversibility requires the direction of heat transfer to reverse for the reverse path. Since dissipative mechanisms cannot be completely eliminated, real processes cannot be reversible. There must be reasons that real macroscopic processes cannot be reversible. We can imagine them going in reverse. For example, heat transfer occurs spontaneously from hot to cold and never spontaneously the reverse. Yet it would not violate the first law of thermodynamics for this to happen. In fact, all spontaneous processes, such as bubbles bursting, never go in reverse. There is a second thermodynamic law that forbids them from going in reverse. When we study this law, we will learn something about nature and also find that such a law limits the efficiency of heat engines. We will find that heat engines with the greatest possible theoretical efficiency would have to use reversible processes, and even they cannot convert all heat transfer into doing work. Table 15.2 summarizes the simpler thermodynamic processes and their definitions. | D: reversible process. |
What must be present on a plant where ladybugs will lay their eggs?
Here are the choices:
A. mites
B. butterflies
C. aphids
D. dew drops | Ladybugs, also known as ladybird beetles, have a life cycle of four to six weeks. In one year as many as six generations of ladybird beetles may hatch. In the spring, each adult female lays up to 300 eggs in small clusters on plants where aphids are present. After a week the wingless larvae hatch. Both the ladybird beetle larvae and adults are active predators, eating only aphids, scales, mites and other plant-eating insects. The ladybugs live on the vegetation where their prey is found, which includes roses, oleander, milkweed and broccoli. Adult ladybugs don’t taste very good. A bird careless enough to try to eat one will not swallow it. | C: aphids. |
In birds, lightweight air-filled bones and a large four-chambered heart are examples of adaptations for what purpose?
Here are the choices:
A. mating
B. flight
C. speed
D. long lifespan | Birds are endothermic tetrapod vertebrates. They are bipedal and have wings and feathers. Their organ systems are adapted for flight. For example, they have light-weight air-filled bones and a large four-chambered heart. Birds also have relatively large brains and a high level of intelligence. | B: flight. |
Chemical and solar cells are devices that change chemical or light energy to what?
Here are the choices:
A. temperature energy
B. occurring energy
C. cellular
D. electrical energy | Chemical and solar cells are devices that change chemical or light energy to electrical energy. You can read about both types of cells and how they work below. | D: electrical energy. |
Stoichiometric coefficients are used in chemical equations to indicate the amounts of reactants and what?
Here are the choices:
A. consumers
B. fuels
C. products
D. imports | Stoichiometric coefficients are used in chemical equations to indicate the amounts of reactants and products. | C: products. |
Like acetic acid, pentanoic acid is what kind of acid?
Here are the choices:
A. carbonic
B. amino
C. hydroxyl
D. carboxylic | Like acetic acid, pentanoic acid is a carboxylic acid. Unlike acetic acid, however, the alkyl group is rather large, consisting of a 4-carbon chain as in butanol. As with butanol, the nonpolar character of the alkyl group is likely to be as important as the polar character of the carboxylic acid group, making it unlikely that pentanoic. | D: carboxylic. |
A solute generally has what effect on the boiling point of a solvent?
Here are the choices:
A. randomizes
B. none
C. raises
D. lowers | In harmonic motion there is always a restorative force , which acts in the opposite direction of the velocity. The restorative force changes during oscillation and depends on the position of the object. In a pendulum it is the component of gravity along the path of motion. The force on the oscillating object is directly opposite that of the direction of velocity. | C: raises. |
What type of climates are found around the equator?
Here are the choices:
A. tundras
B. arid
C. tropical
D. arctics | Tropical climates are found around the Equator. As you'd expect, these climates have warm temperatures year round. The warm air rises at the Equator. As it rises, it cools, causing it to rain. Tropical climates may be very wet, or wet and dry. | C: tropical. |
What kind of planet do we consider ceres to be?
Here are the choices:
A. dwarf planet
B. minor planet
C. binary planet
D. gas planet | Is Ceres a planet? Ceres only has about 1.3% of the mass of the Earth’s Moon. Its orbit is full of other smaller bodies. Its gravity was not high enough to clear its orbit. Ceres fails the fourth criterion for being a planet. Ceres is now considered a dwarf planet, the closest to the Sun. | A: dwarf planet. |
How many pairs of legs does a millipede have per body segment?
Here are the choices:
A. eight
B. two
C. four
D. one | Most millipedes are slower than centipedes and feed on leaf litter and loose organic material. They can be distinguished from centipedes by looking at the number of legs per body segment. Millipedes have two pairs of legs per body segment, while centipedes have a single pair of legs per body segment. Millipedes protect their eggs from predators by using a nest of hard soil. Millipedes are not poisonous. They lack the pair of fangs containing a poison gland that centipedes have. | B: two. |
What is the fertilization step in the sexual reproduction of plants?
Here are the choices:
A. hibernation
B. evolution
C. pollination
D. Fornications | To research how characteristics are passed from parents to offspring, Mendel needed to control pollination. Pollination is the fertilization step in the sexual reproduction of plants. Pollen consists of tiny grains that are the male gametes of plants. They are produced by a male flower part called the anther (see Figure below ). Pollination occurs when pollen is transferred from the anther to the stigma of the same or another flower. The stigma is a female part of a flower. It passes the pollen grains to female gametes in the ovary. | C: pollination. |
How do you add two dimensional vectors?
Here are the choices:
A. graphically
B. topologically
C. geometrically
D. linearly | Vectors that are in two dimensions are added geometrically. | C: geometrically. |
The fact that all living things share the same biochemical building blocks is molecular evidence of what theorized process?
Here are the choices:
A. emergence
B. generation
C. evolution
D. creation | Molecular evidence for evolution includes that all living things share the same biochemical building blocks. | C: evolution. |
When the monocilia are defective, what is disrupted?
Here are the choices:
A. triggering
B. signaling
C. inhibiting
D. predicting | B: signaling. | |
What is a copy of an object that is formed by reflected light?
Here are the choices:
A. example
B. image
C. deflection
D. instance | Reflection is one of several ways that light can interact with matter. Light reflects off surfaces such as mirrors that do not transmit or absorb light. When light is reflected from a smooth surface, it may form an image. An image is a copy of an object that is formed by reflected (or refracted) light. | B: image. |
Hypoxia is a condition of the reduced supply of what?
Here are the choices:
A. nitrogen
B. methane
C. oxygen
D. food | Figure 10.14 The role of normal p53 is to monitor DNA and the supply of oxygen (hypoxia is a condition of reduced oxygen supply). If damage is detected, p53 triggers repair mechanisms. If repairs are unsuccessful, p53 signals apoptosis. A cell with an abnormal p53 protein cannot repair damaged DNA and thus cannot signal apoptosis. Cells with abnormal p53 can become cancerous. (credit: modification of work by Thierry Soussi). | C: oxygen. |
What part of an atom is positive due to the presence of positively charged protons?
Here are the choices:
A. Electron
B. Neutron
C. Proton
D. nucleus | Charge Carried by Electrons and Protons Franklin wrote in his letters and books that he could see the effects of electric charge but did not understand what caused the phenomenon. Today we have the advantage of knowing that normal matter is made of atoms, and that atoms contain positive and negative charges, usually in equal amounts. Figure 18.5 shows a simple model of an atom with negative electrons orbiting its positive nucleus. The nucleus is positive due to the presence of positively charged protons. Nearly all charge in nature is due to electrons and protons, which are two of the. | D: nucleus. |
Organs of what male biological system include the penis, testes, and epididymis?
Here are the choices:
A. circulatory system
B. reproductive system
C. romantic system
D. immune system | Male Reproductive Structures. Organs of the male reproductive system include the penis, testes, and epididymis. Several ducts and glands are also part of the system. Do you know the reproductive functions of any of these structures?. | B: reproductive system. |
At certain times of year, a stream or river may overflow its banks. what is the area of land that is flooded called?
Here are the choices:
A. lowland
B. inlet
C. run off
D. floodplain | At certain times of year, a stream or river may overflow its banks. The area of land that is flooded is called the floodplain. The floodplain may be very wide where the river flows over a nearly flat surface. | D: floodplain. |
What are the major types anchoring proteins?
Here are the choices:
A. claudins and semimetals
B. claudins and occludins
C. semimetals and occludins
D. amino and fatty acids | Tight junctions are composed of strands of transmembrane proteins embedded in the plasma membranes of two adjacent cells. The extracellular domains of these proteins directly join to one another. These joining proteins associate with peripheral membrane proteins located on the intracellular side of plasma membrane. These peripheral proteins anchor the strands to the actin component of the cytoskeleton, effectively forming a molecular complex that joins together the cytoskeletons of adjacent cells. The major types anchoring proteins of tight junctions are the claudins and the occludins. | B: claudins and occludins. |
The process where an atomic nucleus breaks apart into two less massive nuclei is known as ______.
Here are the choices:
A. fission
B. diffusion
C. collision
D. fusion | Fission is the process in which an atomic nucleus breaks apart into two less massive nuclei. Energy is released in the process in many forms, heat, gamma rays and the kinetic energy of neutrons. If these neutrons collide with nuclei and induce more fission, then a runaway chain reaction can take place. Fission is responsible for nuclear energy and atom-bomb explosions: the fission of uranium acts as a heat source for the Earth’s molten interior. | A: fission. |
Sugar and starch are examples of what type of nutrient?
Here are the choices:
A. vitamins
B. fat
C. proteins
D. carbohydrates | Producers such as plants or algae use carbon dioxide in the air to make food. The organisms combine carbon dioxide with water to make sugar. They store the sugar as starch. Both sugar and starch are carbohydrates. Consumers get carbon when they eat producers or other consumers. | D: carbohydrates. |
What term describes a property of a liquid based on the strength of its intermolecular forces?
Here are the choices:
A. cellular pressure
B. tissue pressure
C. vapor pressure
D. analogous pressure | Because they cannot escape the container, the vapor molecules above the surface of the liquid exert a pressure on the walls of the container. The vapor pressure is a measure of the presure (force per unit area) exerted by a gas above a liquid in a sealed container. Vapor pressure is a property of a liquid based on the strength of its intermolecular forces. A liquid with weak intermolecular forces evaporates more easily and has a high vapor pressure. A liquid with stronger intermolecular forces does not evaporate easily and thus has a lower vapor pressure. For example, diethyl ether is a nonpolar liquid with weak dispersion forces. Its vapor pressure at 20°C is 58.96 kPa. Water is a polar liquid whose molecules are attracted to one another by relatively strong hydrogen bonding. The vapor pressure of water at 20°C is only 2.33 kPa, far less than that of diethyl ether. | C: vapor pressure. |
What do a river and all its tributaries make up?
Here are the choices:
A. abundance system
B. river system
C. food system
D. water system | Small streams often flow into bigger streams or rivers. The small streams are called tributaries. A river and all its tributaries make up a river system. | B: river system. |
What structure is the site of all of the basic biochemical processes that keep organisms alive?
Here are the choices:
A. Atom
B. particle
C. Element
D. cell | The cell is the site of all of the basic biochemical processes that keep organisms alive. To do its work, the cell needs substances such as oxygen, water, and glucose. The cell also must get rid of substances, including wastes such as carbon dioxide. In addition, harmful substances must be kept out of the cell. Controlling what enters or leaves a cell is an important role of the cell membrane. | D: cell. |
How does the magnetic field produced by a current in a wire move?
Here are the choices:
A. counterclockwise
B. intermittently
C. in concentric circles
D. slowly | The magnetic field produced by a current in a wire moves around the wire in concentric circles. More current creates a stronger magnetic field, and the direction of the current determines the direction of the magnetic field. | C: in concentric circles. |
What are the 3 types of volcanoes?
Here are the choices:
A. crude , shield , cinder cones
B. composite , atop , cinder cones
C. composite, shield, cinder cones
D. composite, seismic, fault | A volcano is a vent through which molten rock and gas escape from a magma chamber. Volcanoes differ in many features, such as height, shape, and slope steepness. Some volcanoes are tall cones, and others are just cracks in the ground ( Figure below ). As you might expect, the shape of a volcano is related to the composition of its magma. The three types of volcanoes are composite, shield, and cinder cones. | C: composite, shield, cinder cones. |
The fast motion of gas particles gives them a relatively large amount of what energy?
Here are the choices:
A. Potential energy
B. residual energy
C. kinetic energy
D. Chemical energy | Gas particles are in constant rapid motion in random directions . The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container. | C: kinetic energy. |
When do alkane reactions usually occur?
Here are the choices:
A. underwater
B. at high altitudes
C. in cold climates
D. under extreme conditions | Because alkanes contain only C–C and C–H bonds, which are strong and not very polar (the electronegativities of C and H are similar; Figure 7.15 "Pauling Electronegativity Values of the "), they are not easily attacked by nucleophiles or electrophiles. Consequently, their reactivity is limited, and often their reactions occur only under extreme conditions. For example, catalytic cracking can be used to convert straight-chain alkanes to highly branched alkanes, which are better fuels for internal combustion engines. Catalytic cracking is one example of a pyrolysis reaction (from the Greek pyros, meaning “fire,” and lysis, meaning “loosening”), in which alkanes are heated to a sufficiently high temperature to induce cleavage of the weakest bonds: the C–C single bonds. The result is a mixture of radicals derived from essentially random cleavage of the various C–C bonds in the chain. Pyrolysis of n-pentane, for example, is nonspecific and can produce these four radicals: Equation 24.7. | D: under extreme conditions. |
What do you call scientists that study the weather, specifically?
Here are the choices:
A. forecasters
B. hydrologists
C. geologists
D. meteorologists | Predicting the weather requires a lot of weather data. Technology is used to gather the data and computers are used to analyze the data. Using this information gives meteorologists the best chance of predicting the weather. | D: meteorologists. |
What replicates in the s phase of interphase, resulting in chromosomes composed of two linked sister chromatids?
Here are the choices:
A. dna
B. hormones
C. protein
D. RNA | DNA replicates in the S phase of interphase. After replication, the chromosomes are composed of two linked sister chromatids. When fully compact, the pairs of identically packed chromosomes are bound to each other by cohesin proteins. The connection between the sister chromatids is closest in a region called the centromere. The conjoined sister chromatids, with a diameter of about 1 µm, are visible under a light microscope. The centromeric region is highly condensed and thus will appear as a constricted area. | A: dna. |
What is located beneath the lithosphere?
Here are the choices:
A. asthenosphere
B. magnetosphere
C. hydropshere
D. troposphere | Beneath the lithosphere, the asthenosphere is solid rock that can flow. | A: asthenosphere. |
What travels 9.5 trillion kilometers a year?
Here are the choices:
A. air
B. electricity
C. light
D. Sound | the distance light can travel in one year, 9.5 trillion kilometers. | C: light. |
What population on earth is already harming the environment due to less resources to go around?
Here are the choices:
A. humans
B. insects
C. rats
D. whales | Bundles of vascular tissue run through the ground tissue of a stem and transport fluids. Plants may vary in how these bundles are arranged. | A: humans. |
What is the female reproductive structure of a flower called?
Here are the choices:
A. the pollinator
B. the stigma
C. the pistil
D. the stamen | The pistil is the female reproductive structure of a flower. It consists of a stigma, style, and ovary. The stigma is raised and sticky to help it catch pollen. The style supports the stigma and connects it to the ovary, which contains the egg. Petals attract pollinators to the flower. Petals are often brightly colored so pollinators will notice them. | C: the pistil. |
Red giants are stars that fuse what element into larger atoms?
Here are the choices:
A. helium
B. hydrogen
C. carbon
D. oxygen | When stars fuse helium into larger atoms, they become red giants. | A: helium. |
What normal bodily occurrence can cause skeletal muscles to involuntarily contract?
Here are the choices:
A. reflexes
B. thinking
C. movement
D. respiration | Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. | A: reflexes. |
What is the outer layer of the adrenal gland called?
Here are the choices:
A. adrenal skin
B. zona reticularis
C. medulla
D. adrenal cortex | 17.6 The Adrenal Glands The adrenal glands, located superior to each kidney, consist of two regions: the adrenal cortex and adrenal medulla. The adrenal cortex—the outer layer of the gland—produces mineralocorticoids, glucocorticoids, and androgens. The adrenal medulla at the core of the gland produces epinephrine and norepinephrine. The adrenal glands mediate a short-term stress response and a long-term stress response. A perceived threat results in the secretion of epinephrine and norepinephrine from the adrenal medulla, which mediate the fight-or-flight response. The long-term stress response is mediated by the secretion of CRH from the hypothalamus, which triggers ACTH, which in turn stimulates the secretion of corticosteroids from the adrenal cortex. The mineralocorticoids, chiefly aldosterone, cause sodium and fluid retention, which increases blood volume and blood pressure. | D: adrenal cortex. |
Why would prokaryotes be chemotrophs instead of phototrophs in a deep-sea hydrothermal vent?
Here are the choices:
A. lack of light
B. too much heat
C. too cold
D. too much light | Chapter 22 1 Figure 22.8 The extracellular matrix and outer layer of cells protects the inner bacteria. The close proximity of cells also facilitates lateral gene transfer, a process by which genes such as antibiotic resistance genes are transferred from one bacterium to another. And even if lateral gene transfer does not occur, one bacterium that produces an exo-enzyme that destroys antibiotic may save neighboring bacteria. 3 Figure 22.19 D 4 A 6 A 8 B 10 B 12 A 14 B 16 C 18 B 20 D 22 D 24 B 25 As the organisms are non-culturable, the presence could be detected through molecular techniques, such as PCR. 27 Responses will vary. A possible answer is: Bacteria contain peptidoglycan in the cell wall; archaea do not. The cell membrane in bacteria is a lipid bilayer; in archaea, it can be a lipid bilayer or a monolayer. Bacteria contain fatty acids on the cell membrane, whereas archaea contain phytanyl. 29 Responses will vary. In a deep-sea hydrothermal vent, there is no light, so prokaryotes would be chemotrophs instead of phototrophs. The source of carbon would be carbon dioxide dissolved in the ocean, so they would be autotrophs. There is not a lot of organic material in the ocean, so prokaryotes would probably use inorganic sources, thus they would be chemolitotrophs. The temperatures are very high in the hydrothermal vent, so the prokaryotes would be thermophilic. 31 E. coli colonizes the surface of the leaf, forming a biofilm that is more difficult to remove than free (planktonic) cells. Additionally, bacteria can be taken up in the water that plants are grown in, thereby entering the plant tissues rather than simply residing on the leaf surface. | A: lack of light. |
How do wolves learn to hunt as a group?
Here are the choices:
A. trial and error
B. mirroring
C. primordial learning
D. observational learning | Observational learning explains how wolves know how to hunt as a group. | D: observational learning. |
What is the common term for water in its solid state?
Here are the choices:
A. ice
B. vapor
C. precipitation
D. sea | A: ice. | |
If an air mass forms over an ocean it is called what type of air mass?
Here are the choices:
A. cumulus
B. tropical
C. hurricane
D. maritime | Most air masses form over polar or tropical regions. They may form over continents or oceans. Air masses are moist if they form over oceans. They are dry if they form over continents. Air masses that form over oceans are called maritime air masses. Those that form over continents are called continental air masses. The image below shows air masses that form over or near North America ( Figure below ). | D: maritime. |
What is the middle layer that hair pass through before exiting at the surface of the skin?
Here are the choices:
A. dermis
B. epithelial tissue
C. cuticle
D. epidermis | Hair follicles are the structures where hairs originate. Hairs grow out of follicles, pass through the epidermis, and exit at the surface of the skin. | D: epidermis. |
High per capita use of what means the ecological footprint of the united states is large?
Here are the choices:
A. food
B. resources
C. green energy
D. money | B: resources. | |
Lakes, ponds, streams, springs, and wetlands are?
Here are the choices:
A. land formations
B. salt water bodies
C. fresh water bodies
D. man-made structures | Lakes, ponds, streams, springs, and wetlands are fresh water bodies. The organisms that live in them are part of freshwater ecosystems. These ecosystems vary by temperature, pressure (in lakes), and the amount of light that penetrates. The type of plants that grow in these ecosystems varies. | C: fresh water bodies. |
What is the the force of attraction that holds together ions?
Here are the choices:
A. magnetic bond
B. soluble bond
C. ionic bond
D. covalent bond | An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. | C: ionic bond. |
What is the ability of a material to return to its original shape after being stretched or compressed?
Here are the choices:
A. solubility
B. viscosity
C. elasticity
D. acidity | Elasticity is the ability of a material to return to its original shape after being stretched or compressed. Elastic force is the counter force that resists the stretching or compressing of an elastic material. | C: elasticity. |
How much of the soil is made of pieces of rock and minerals?
Here are the choices:
A. three fourth
B. one third
C. two third
D. about half | We can think about soil as a living resource. Soil is an ecosystem all by itself! Soil is a complex mixture of different materials. Some of them are inorganic . Inorganic materials are made from non-living substances like pebbles and sand. Soil also contains bits of organic materials from plants and animals. In general, about half of the soil is made of pieces of rock and minerals. The other half is organic materials. In the spaces of soil are millions of living organisms. These include earthworms, ants, bacteria, and fungi. In some soils, the organic portion is entirely missing. This is true of desert sand. At the other extreme, a soil may be completely organic. Peat, found in a bog or swamp, is totally organic soil. Organic materials are necessary for a soil to be fertile. The organic portion provides the nutrients needed for strong plant growth. | D: about half. |
Comprised mainly of collagen and associated with long bones and the skull, hyaline is the most widespread type of what?
Here are the choices:
A. enzymes
B. tissue
C. collagen
D. cytoplasm | Cartilage: There are three cartilage types: 1. hyaline cartilage 2. fibrocartilage (fibrous cartilage) 3. elastic cartilage Hyaline cartilage: most widespread cartilage type, in adults forms articular surfaces of long bones, rib tips, rings of trachea, and parts of skull. Mostly collagen, name refers to glassy appearance. In embryo, bones form first as hyaline cartilage, later ossifies. Found in tracheal rings. Few collagen fibers. Fibrous cartilage: have lots of collagen fibers. Found in intervertebral discs, pubic symphesis. Grades into dense tendon and ligament tissue. Elastic cartilage: springy and elastic. Found in internal support of external ear and in epiglottis, yellow when fresh. Chondrocites (cartilage cells) rely on diffusion for nutrients, as cartilage has no direct blood supply, and no enervation (nerves). Can be loaded with calcium salts. | C: collagen. |
Bacterial dna is contained in one circular chromosome, located where?
Here are the choices:
A. cytoplasm
B. neuron
C. cerebellum
D. mucus | Bacteria lack many of the structures that eukaryotic cells contain. For example, they don't have a nucleus. They also lack membrane-bound organelles, such as mitochondria or chloroplasts. The DNA of a bacterial cell is also different from a eukaryotic cell. Bacterial DNA is contained in one circular chromosome, located in the cytoplasm. Eukaryotes have several linear chromosomes. Bacteria also have two additional unique features: a cell wall and flagella. | A: cytoplasm. |
During which phase is the moon more than half lit but not full?
Here are the choices:
A. gibbous phase
B. crescent
C. waxing
D. new | Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. | A: gibbous phase. |
What force is caused by microscopic bumps, lumps, and imperfections colliding?
Here are the choices:
A. motion
B. friction
C. gravitational
D. tension | Every surface has microscopic bumps, lumps, and imperfections, emphasized as in the image above. If we try to slide the top block over the lower block, there will be numerous collisions as the bumps impact each other. The forward motion causes the collisions with bumps which then exert a force in opposite way the block is moving. The force of friction always opposes whatever motion is causing the friction. | B: friction. |
What is the period during which humans become sexually mature called?
Here are the choices:
A. maturity
B. adulthood
C. puberty
D. adolescence | The reproductive organs grow very slowly during childhood and do not mature until puberty. Puberty is the period during which humans become sexually mature. In the U. S. , boys generally begin puberty at about age 12 and complete it at about age 18. | C: puberty. |
What is another word for brooding- keeping eggs warm while the embryos develop?
Here are the choices:
A. fertilization
B. incubation
C. hibernation
D. spawning | After birds lay their eggs, they generally keep the eggs warm with their body heat while the embryos inside continue to develop. This is called incubation, or brooding. In most species, parents stay together for at least the length of the breeding season. In some species, they stay together for life. By staying together, the males as well as females can incubate the eggs and later care for the hatchlings. Birds are the only nonhuman vertebrates with this level of male parental involvement. | B: incubation. |
Which type of natural disturbance in temperate grasslands, can be caused by a lightning strike?
Here are the choices:
A. fire
B. avalanche
C. drought
D. mass extinction | Fires, which are a natural disturbance in temperate grasslands, can be ignited by lightning strikes. It also appears that the lightning-caused fire regime in North American grasslands was enhanced by intentional burning by humans. When fire is suppressed in temperate grasslands, the vegetation eventually converts to scrub and dense forests. Often, the restoration or. | A: fire. |
What is another name for mother of pearl?
Here are the choices:
A. enamel
B. nacre
C. calcium
D. pigment | Mother of pearl is also known as nacre. Nacre is the iridescent inner shell layer. It can be found in buttons, watch faces, knives, guns, and jewelry. It is also used to decorate various musical instruments. | B: nacre. |
What type of salts are secreted into the small intestine to aid in the digestion of fats?
Here are the choices:
A. sodium
B. Table Salt
C. bile
D. zinc | Bile salts are secreted into the small intestine to aid in the digestion of fats. | C: bile. |
Lavas that cool underwater are called what?
Here are the choices:
A. pillow lavas
B. sea lavas
C. bed lavas
D. water lavas | Different lava types create different rock types, such as pahoehoe and a'a. Lavas that cool underwater become pillow lavas. | A: pillow lavas. |
What is oceanography the study of?
Here are the choices:
A. bodies of water
B. oceans
C. seas
D. waters | Oceanography is the study of the oceans. The word oceanology might be more accurate, since “ology” is “the study of. ” “Graph” is “to write” and refers to mapmaking. But mapping the oceans is how oceanography started. | B: oceans. |
What tissue system has neither dermal nor vascular tissues?
Here are the choices:
A. ground tissue system
B. external tissue system
C. work tissue system
D. internal tissue system | A: ground tissue system. | |
Around 97% of all water on earth is what type of water?
Here are the choices:
A. excess water
B. salt water
C. fresh water
D. rivers water | The Water Cycle Water is essential for all living processes. The human body is more than one-half water and human cells are more than 70 percent water. Thus, most land animals need a supply of fresh water to survive. Of the stores of water on Earth, 97.5 percent is salt water (Figure 20.9). Of the remaining water, 99 percent is locked as underground water or ice. Thus, less than one percent of fresh water is present in lakes and rivers. Many living things are dependent on this small amount of surface fresh water supply, a lack of which can have important effects on ecosystem dynamics. Humans, of course, have developed technologies to increase water availability, such as digging wells to harvest groundwater, storing rainwater, and using desalination to obtain drinkable water from the ocean. Although this pursuit of drinkable water has been ongoing throughout human history, the supply of fresh water continues to be a major issue in modern times. | B: salt water. |
Which type of diabetes is more common?
Here are the choices:
A. type 1
B. juvenile diabetes
C. gestational diabetes
D. type 2 | Type 2 diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body can’t use it. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before. | D: type 2. |
All waves are the way energy travels through what?
Here are the choices:
A. vacuums
B. matter
C. space
D. time | All waves are the way energy travels through matter. Ocean waves are energy traveling through water. They form when wind blows over the surface of the ocean. Wind energy is transferred to the sea surface. Then, the energy is carried through the water by the waves. Figure below shows ocean waves crashing against rocks on a shore. They pound away at the rocks and anything else they strike. | B: matter. |
What is the cause of behavioral difference between populations?
Here are the choices:
A. environmental factors
B. genetic wavelengths
C. electromagnetic differences
D. genetic differences | D: genetic differences. | |
What is the term for the process in which glucose is made using light energy?
Here are the choices:
A. compress
B. photosynthesis
C. hydration
D. glycolysis | Most living things use glucose for energy. The process in which glucose is made using light energy is photosynthesis. Water and carbon dioxide are needed for this process, and oxygen is produced as a byproduct. Photosynthetic organisms include plants, algae, and some bacteria. | B: photosynthesis. |
Skeletal muscle tissue is arranged in bundles surrounded by this?
Here are the choices:
A. connective tissue
B. cartilage
C. epithelial tissue
D. soft tissue | develops from myoblasts derived from the mesoderm. Myocytes and their numbers remain relatively constant throughout life. Skeletal muscle tissue is arranged in bundles surrounded by connective tissue. Under the light microscope, muscle cells appear striated with many nuclei squeezed along the membranes. The striation is due to the regular alternation of the contractile proteins actin and myosin, along with the structural proteins that couple the contractile proteins to connective tissues. The cells are multinucleated as a result of the fusion of the many myoblasts that fuse to form each long muscle fiber. Cardiac muscle forms the contractile walls of the heart. The cells of cardiac muscle, known as cardiomyocytes, also appear striated under the microscope. Unlike skeletal muscle fibers, cardiomyocytes are single cells typically with a single centrally located nucleus. A principal characteristic of cardiomyocytes is that they contract on their own intrinsic rhythms without any external stimulation. Cardiomyocyte attach to one another with specialized cell junctions called intercalated discs. Intercalated discs have both anchoring junctions and gap junctions. Attached cells form long, branching cardiac muscle fibers that are, essentially, a mechanical and electrochemical syncytium allowing the cells to synchronize their actions. The cardiac muscle pumps blood through the body and is under involuntary control. The attachment junctions hold adjacent cells together across the dynamic pressures changes of the cardiac cycle. Smooth muscle tissue contraction is responsible for involuntary movements in the internal organs. It forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and arteries. Each cell is spindle shaped with a single nucleus and no visible striations (Figure 4.18). | A: connective tissue. |
What element on the periodic table forms the most diverse compounds?
Here are the choices:
A. hydrogen
B. oxygen
C. carbon
D. helium | Life on Earth is based on carbon. A possible explanation is that no other element in the periodic table forms compounds that are so diverse in their chemistry and physical properties. Discuss the chemistry of carbon with regard to. | C: carbon. |
As the number of unpaired electrons increases, what happens to the magnetic moment?
Here are the choices:
A. gets larger
B. is destroyed
C. remains the same
D. gets smaller | Magnetic Moments of Molecules and Ions Experimental evidence of magnetic measurements supports the theory of high- and low-spin complexes. Remember that molecules such as O2 that contain unpaired electrons are paramagnetic. Paramagnetic substances are attracted to magnetic fields. Many transition metal complexes have unpaired electrons and hence are paramagnetic. Molecules such as N2 and ions such as Na+ and [Fe(CN)6]4− that contain no unpaired electrons are diamagnetic. Diamagnetic substances have a slight tendency to be repelled by magnetic fields. When an electron in an atom or ion is unpaired, the magnetic moment due to its spin makes the entire atom or ion paramagnetic. The size of the magnetic moment of a system containing unpaired electrons is related directly to the number of such electrons: the greater the number of unpaired electrons, the larger the magnetic moment. Therefore, the observed magnetic moment is used to determine the number of unpaired electrons present. The measured magnetic moment of low-spin d6 [Fe(CN)6]4− confirms that iron is diamagnetic, whereas high-spin d6 [Fe(H2O)6]2+ has four unpaired electrons with a magnetic moment that confirms this arrangement. | A: gets larger. |
What kind of container is used to measure heat changes during a chemical reaction or physical process?
Here are the choices:
A. calorimeter
B. thermal flask
C. graduated cylinder
D. hydrostatic | Calorimetry is the measurement of the transfer of heat into or out of a system during a chemical reaction or physical process. A calorimeter is an insulated container that is used to measure heat changes. The majority of reactions that can be analyzed in a calorimetry experiment are either liquids or aqueous solutions. A frequently used and inexpensive calorimeter is a set of nested foam cups fitted with a lid to limit the heat exchange between the liquid in the cup and the air in the surroundings (see Figure below ). In a typical calorimetry experiment, specific volumes of the reactants are dispensed into separate containers and the temperature of each is measured. They are then mixed into the calorimeter, which starts the reaction. The reactant mixture is stirred until the reaction is complete, while the temperature of the reaction is continuously monitored. | A: calorimeter. |
In the mammal family, what is the name for hoofed animals, such as deer, sheep, goats, pigs, buffalo, elephants and giraffes?
Here are the choices:
A. ungulates
B. rodents
C. primates
D. bovines | Ungulates include hoofed animals, such as deer, sheep, goats, pigs, buffalo, elephants and giraffes ( Figure below ). These mammals use their hoofs to sustain their whole body weight while moving. Hoofs are formed by a thick nail rolled around the tip of the toe. | A: ungulates. |
In the nematic phase, only the long axes of the molecules are parallel, and the ends are staggered at random intervals. in the smectic phase, the long axes of the molecules are parallel, and the molecules are also arranged in planes. finally, in thecholesteric phase, the molecules are arranged in layers; each layer is rotated with respect to the ones above and below it to give it this?
Here are the choices:
A. layer structure
B. symmetry
C. spiral structure
D. kinetic energy | In the nematic phase, only the long axes of the molecules are parallel, and the ends are staggered at random intervals. In the smectic phase, the long axes of the molecules are parallel, and the molecules are also arranged in planes. Finally, in thecholesteric phase, the molecules are arranged in layers; each layer is rotated with respect to the ones above and below it to give a spiral structure. The molecular order increases from the nematic phase to the smectic phase to the cholesteric phase, and the phases become increasingly opaque. Molecules that form liquid crystals tend to be rigid molecules with polar groups that exhibit relatively strong dipole–dipole or dipole–induced dipole interactions, hydrogen bonds, or some combination of both. Some examples of substances that form liquid crystals are listed in Figure 11.27 "Structures of Typical Molecules That Form Liquid Crystals*" along with their characteristic phase transition temperature ranges. In most cases, the intermolecular interactions are due to the presence of polar or polarizable groups. Aromatic rings and multiple bonds between carbon and nitrogen or oxygen are especially common. Moreover, many liquid crystals are composed of molecules with two similar halves connected by a unit having a multiple bond. Figure 11.27 Structures of Typical Molecules That Form Liquid Crystals*. | C: spiral structure. |
What term means the force of attraction that holds together oppositely charged ions?
Here are the choices:
A. ionic bond
B. solvent bond
C. electron bond
D. magnetic bond | An ionic bond is the force of attraction that holds together oppositely charged ions. Ionic bonds form crystals instead of molecules. Table salt contains ionic bonds. | A: ionic bond. |
In single-celled organisms, plasma membrane extensions, such as whip-like flagella or brush-like cilia, aid in what?
Here are the choices:
A. movement
B. sensation
C. sound
D. pressure | The plasma membrane may have extensions, such as whip-like flagella or brush-like cilia. In single-celled organisms, like those shown in Figure below , the membrane extensions may help the organisms move. In multicellular organisms, the extensions have other functions. For example, the cilia on human lung cells sweep foreign particles and mucus toward the mouth and nose. | A: movement. |
What is defined as male gametes that form in the testes and mature in the epididymis?
Here are the choices:
A. sperm
B. plasma
C. stereocilia
D. mucus | Sperm are male gametes that form in the testes and mature in the epididymis. | A: sperm. |
All planets exhibit the same or nearly the same direction and shape of what path around the sun?
Here are the choices:
A. ellipse
B. nucleus
C. revolution
D. orbit | To figure out how the solar system formed, we need to put together what we have learned. There are two other important features to consider. First, all the planets orbit in nearly the same flat, disk-like region. Second, all the planets orbit in the same direction around the Sun. These two features are clues to how the solar system formed. | D: orbit. |
What do you call a change in the dna or rna sequence?
Here are the choices:
A. degradation
B. mutation
C. adaptation
D. infection | Mutations, a change in the DNA or RNA sequence, may have no effect, may be beneficial or may be harmful. There are numerous ways that the genetic information can be changed. Some of these changes can be inherited. In multicellular organisms, mutations can be subdivided into germline mutations , which can be passed on to descendants, and somatic mutations , which cannot be transmitted to the next generation. Germline mutations change the DNA sequence within a sperm or egg cell, and therefore can be inherited. This inherited mutation may result in a class of diseases known as a genetic disease. The mutation may lead to a nonfunctional protein, and the embryo may not develop properly or survive. Somatic mutations may affect the proper functioning of the cell with the mutation. During DNA replication, the mutation will be copied. The two daughter cells formed after cell division will both carry the mutation. This may lead to the development of many cells that do not function optimally, resulting a less than optimal phenotype. Various types of mutations can all have severe effects on the individual. These include point mutations, framehift mutations and chromosomal alterations. Keep in mind, some mutations may be beneficial or have no effect. Mutations that have no effect will not affect the expression of the gene or the sequence of amino acids in an encoded protein. | B: mutation. |
What is produced when hydrogen gas and oxygen gas are ignited?
Here are the choices:
A. liquid
B. water
C. air
D. Fire | Hydrogen gas and oxygen gas are ignited to produce water. | B: water. |
What is the term for the buildup of electric charge on an object, which can be transferred to another when touched?
Here are the choices:
A. electromagnetic electricity
B. static cling
C. static electricity
D. electric potential | Static electricity is a buildup of electric charges on objects. It occurs when electrons are transferred from one object to another. | C: static electricity. |
What is the basis of the classification of protists?
Here are the choices:
A. conditions shared
B. mutations shared
C. tails shared
D. traits shared | Protists are classified based on traits they share with other eukaryotes. There are animal-like, plant-like, and fungus-like protists. The three groups differ mainly in how they get carbon and energy. | D: traits shared. |
What is the movement of animals from one place to another called?
Here are the choices:
A. extinction
B. hibernation
C. evacuation
D. migration | Migration is the movement of animals from one place to another. Migration is most common in birds, fish, and insects. In the Northern Hemisphere, many species of birds, such as finches and swallows, travel south for the winter. They migrate to areas where it is warmer and where more food is available. They return north in the spring. Migrating animals generally follow the same route each year. They may be guided by the position of the sun, Earth’s magnetic field, or other clues in the environment. | D: migration. |
What does the respiratory system exchange between the body and the outside air?
Here are the choices:
A. gases
B. blood
C. nutrients
D. fluids | The job of the respiratory system is the exchange of gases between the body and the outside air. This process, called respiration , actually consists of two parts. In the first part, oxygen in the air is drawn into the body and carbon dioxide is released from the body through the respiratory tract. In the second part, the circulatory system delivers the oxygen to body cells and picks up carbon dioxide from the cells in return. The lungs are organs of the respiratory system. It is in the lungs where oxygen is transferred from the respiratory system to the circulatory system. | A: gases. |
In the body, second in volume to intracellular fluid is what type of fluid, which surrounds cells that are not blood cells?
Here are the choices:
A. circuitry fluid
B. concomitant fluid
C. watery fluid
D. interstitial fluid | Figure 26.4 A Pie Graph Showing the Proportion of Total Body Fluid in Each of the Body’s Fluid Compartments Most of the water in the body is intracellular fluid. The second largest volume is the interstitial fluid, which surrounds cells that are not blood cells. | D: interstitial fluid. |
How many sperm does it take to fertilize an egg?
Here are the choices:
A. 1
B. 4
C. 2
D. 3 | It might only take one sperm to fertilize an egg, but that sperm is not alone. Hundreds of millions of sperm can be released during sexual intercourse. | A: 1. |
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