This Document Contains Chapters 31 to 32 Chapter 31: Plant Responses to Internal and External Signals 31.1 Multiple-Choice Questions 1) All of the following can function in signal transduction in plants except A) calcium ions. B) nonrandom mutations. C) receptor proteins. D) phytochrome. E) secondary messengers. Answer: B 2) Charles and Francis Darwin concluded from their experiments on phototropism by grass seedlings that the part of the seedling that detects the direction of light is the A) tip of the coleoptile. B) part of the coleoptile that bends during the response. C) base of the coleoptile. D) cotyledon. E) phytochrome in the leaves. Answer: A 3) Which of the following conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light? A) When shoots are exposed to light, a chemical substance migrates toward the light. B) Agar contains a chemical substance that mimics a plant hormone. C) A chemical substance involved in shoot bending is produced in shoot tips. D) Once shoot tips have been cut, normal growth cannot be induced. E) Light stimulates the synthesis of a plant hormone that responds to light. Answer: C 4) A plant seedling bends toward sunlight because A) auxin migrates to the lower part of the stem due to gravity. B) there is more auxin on the light side of the stem. C) auxin is destroyed more quickly on the dark side of the stem. D) auxin is found in greatest abundance on the dark side of the stem. E) gibberellins produced at the stem tip cause phototropism. Answer: D 5) The apical bud of a shoot produces ________, resulting in the inhibition of lateral bud growth. A) abscisic acid B) ethylene C) cytokinin D) gibberellin E) auxin Answer: E 6) After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to A) calcium release from the endoplasmic reticulum of shaded cells. B) whether the plant is in the northern or southern hemisphere. C) gibberellin production by stems. D) auxin production in cells receiving red light. E) auxin movement toward the lower side of the stem. Answer: E 7) The ripening of fruit and the dropping of leaves and fruit are principally controlled by A) auxins. B) cytokinins. C) indole acetic acid. D) ethylene. E) carbon dioxide concentration (in air). Answer: D 8) The plant hormone involved in aging and ripening of fruit is A) auxin. B) ethylene. C) florigen. D) abscisic acid. E) gibberellin. Answer: B 9) When growing plants in culture, IAA is used to stimulate cell enlargement. Which plant growth regulator has to now be added to stimulate cell division? A) ethylene B) indoleacetic acid C) gibberellin D) cytokinin E) abscisic acid Answer: D 10) Why do coleoptiles grow toward light? A) Auxin is destroyed by light. B) Gibberellins are destroyed by light. C) Auxin synthesis is stimulated in the dark. D) Auxin moves away from the light to the shady side. E) Gibberellins move away from the light to the shady side. Answer: D 11) Which of the following statements applies to plant growth regulators? A) They only act by altering gene expression. B) They often have a multiplicity of effects. C) They function independently of other hormones. D) They directly control plant protein synthesis and assembly. E) They affect the division and elongation, but not the differentiation, of cells. Answer: B 12) Plant hormones produce their effects by A) altering the expression of genes. B) modifying the permeability of the plasma membrane. C) modifying the structure of the nuclear envelope membrane. D) altering the expression of genes and modifying the permeability of the plasma membrane. E) modifying the permeability of the plasma membrane and modifying the structure of the nuclear envelope membrane. Answer: D 13) Plant hormones can have different effects at different concentrations. This explains how A) some plants are long-day plants and others are short-day plants. B) signal transduction pathways in plants are different from those in animals. C) plant genes recognize pathogen genes. D) auxin can stimulate cell elongation in apical meristems, yet will inhibit the growth of axillary buds. E) gibberellin concentration can both induce and break dormancy. Answer: D 14) Auxins (IAA) in plants are known to affect all of the following processes except A) geotropism of shoots. B) maintenance of seed dormancy. C) phototropism of shoots. D) inhibition of lateral buds. E) fruit development. Answer: B 15) How does indoleacetic acid affect fruit development? A) by preventing pollination B) by inhibiting formation of the ovule C) by promoting gene expression in cambial tissue D) by promoting rapid growth of the ovary E) by inducing the formation of brassinosteroids Answer: D 16) If a farmer wanted more loosely packed clusters of grapes, he would most likely spray the immature bunches with A) auxin. B) gibberellins. C) cytokinins. D) abscisic acid. E) ethylene. Answer: B 17) Which of the following statements best summarizes the acid growth hypothesis in an actively growing shoot? A) Auxin stimulates proton pumps in the plasma membrane and tonoplast. B) Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible C) Auxins and gibberellins together act as a lubricant to help stretch cellulose microfibrils. D) Auxins activate aquaporins that increase turgor pressure in the cells. E) Auxins and gibberellins are transported to the vacuoles to build up turgor pressure. Answer: B 18) According to the acid growth hypothesis, auxin works by A) dissolving sieve plates, permitting more rapid transport of nutrients. B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. D) increasing wall plasticity and allowing the affected cell walls to elongate. E) greatly increasing the rate of deposition of cell wall material. Answer: D 19) Which of the following hormones would be most useful in promoting the rooting of plant cuttings? A) strigolactones B) abscisic acid C) cytokinins D) gibberellins E) indolebutyric acid Answer: E 20) The aleurone layer is stimulated to release ________ as a result of gibberellin release from the embryo. A) amino acids B) carbohydrates C) cytokinins D) amylase E) RNAase Answer: D 21) If you were shipping green bananas to a supermarket thousands of miles away, which of the following chemicals would you want to eliminate from the plants' environment? A) CO2 B) cytokinins C) ethylene D) auxin E) gibberellic acids Answer: C 22) Which of the following plant growth responses is primarily due to the action of auxins? A) leaf abscission B) the triple response of shoots C) cell division D) the detection of photoperiod E) cell elongation Answer: E 23) Experiments on the positive phototropic response of plants indicate that A) light destroys auxin. B) auxin moves down the plant apoplastically. C) auxin is synthesized in the area where the stem bends. D) auxin can move to the shady side of the stem. E) auxin is only of secondary importance in the process. Answer: D 24) Why are axillary buds often inhibited from growing even though a stem may be actively elongating? A) The cells of axillary buds respond differently to auxin than stem cells. B) Axillary buds are high in abscisic acid that prevents elongation. C) Axillary buds are low in gibberellins. D) Stem cells lack receptors for auxin. E) Stem cells can overcome auxin inhibition with high levels of gibberellins. Answer: A 25) The application of which of the following hormones would be a logical first choice in an attempt to produce normal growth in mutant dwarf plants? A) indoleacetic acid B) cytokinin C) gibberellin D) abscisic acid E) ethylene Answer: C 26) Plant hormonal regulation differs from animal hormonal regulation in that A) there are no dedicated hormone-producing organs in plants as there are in animals. B) all production of hormones is local in plants with little long-distance transport. C) plants do not exhibit feedback mechanisms like animals. D) only animal hormone concentrations are developmentally regulated. E) only animal hormones may have either external or internal receptors. Answer: A 27) Vines in tropical rain forests must grow toward large trees before being able to grow toward the sun. To reach a large tree, the most useful kind of growth movement for a tropical vine presumably would be the opposite of A) positive thigmotropism. B) positive phototropism. C) positive gravitropism. D) sleep movements. E) circadian rhythms. Answer: B 28) Which of the following best explains both the growth of a vine up the trunk of a tree as well as the directional growth of a houseplant toward a window? A) nastic movement B) taxic movement C) tropism response D) morphological response E) acclimation Answer: C 29) The detector of light during de-etiolation (greening) of a tomato plant is (are) A) carotenoids. B) xanthophylls. C) phytochrome. D) chlorophyll. E) auxin. Answer: C 30) Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only ¼ inch of soil is that the A) seedlings do not produce a hypocotyl. B) seedlings do not have an etiolation response. C) seeds require light to germinate. D) seeds require a higher temperature to germinate. E) seeds are very sensitive to waterlogging. Answer: C 31) A short-day plant will flower only when A) days are shorter than nights. B) days are shorter than a certain critical value. C) nights are shorter than a certain critical value. D) nights are longer than a certain critical value. E) days and nights are of equal length. Answer: D 32) A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely A) cause increased flower production. B) have no effect upon flowering. C) inhibit flowering. D) stimulate flowering. E) convert florigen to the active form. Answer: B 33) Many plants flower in response to day-length cues. Which of the following statements best summarizes this phenomenon? A) As a rule, short-day plants flower in the summer. B) As a rule, long-day plants flower in the spring or fall. C) Long-day plants flower in response to long days, not short nights. D) Flowering in day-neutral plants is only influenced by day length if there is an exceptionally warm spring. E) Flowering in short-day and long-day plants is controlled by phytochrome. Answer: E 34) Which of the following treatments would enhance the level of the Pfr form of phytochrome? A) exposure to far-red light B) exposure to red light C) long dark period D) inhibition of protein synthesis E) synthesis of phosphorylating enzymes Answer: B 35) In legumes, it has been shown that "sleep" (nastic) movements are correlated with A) positive thigmotropisms. B) rhythmic opening and closing of K+ channels in motor cell membranes. C) senescence (the aging process in plants). D) flowering and fruit development. E) ABA-stimulated closing of guard cells caused by loss of K+. Answer: B 36) Which of the following statements is correct with regard to a "circadian rhythm" in plants? A) It may have the same signal transduction pathway in all organisms. B) Once set, it cannot be changed. C) It works independently of photoperiodic responses. D) Once set, it is independent of external signals. E) It can be changed to a longer or shorter period by altering the light quality. Answer: A 37) The biological clock controlling circadian rhythms must ultimately A) depend on environmental cues. B) affect gene transcription. C) stabilize on a 24-hour cycle. D) speed up or slow down with increasing or decreasing temperature. E) do all of the above. Answer: B 38) Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes A) are more predictable than air temperature changes. B) alter the amount of energy available to the plant. C) are modified by soil temperature changes. D) can reset the biological clock. E) are correlated with moisture availability. Answer: A 39) If the range of a species of plants expands to a higher latitude, which of the following processes is the most likely to be modified by natural selection? A) circadian rhythm B) photoperiodic response C) phototropic response D) biological clock E) thigmomorphogenesis Answer: B 40) What does a short-day plant require in order to flower? A) a burst of red light in the middle of the night B) a burst of far-red light in the middle of the night C) a day that is longer than a certain length D) a night that is longer than a certain length E) a higher ratio of Pr to Pfr Answer: D 41) If a short-day plant has a critical night length of 15 hours, then which of the following 24-hour cycles will prevent flowering? A) 8 hours light/16 hours dark B) 4 hours light/20 hours dark C) 6 hours light/2 hours dark/light flash/16 hours dark D) 8 hours light/8 hours dark/light flash/8 hours dark E) 2 hours light/20 hours dark/2 hours light Answer: D 42) A long-day plant will flower if A) the duration of continuous light exceeds a critical length. B) the duration of continuous light is less than a critical length. C) the duration of continuous darkness exceeds a critical length. D) the duration of continuous darkness is less than a critical length. E) it is kept in continuous far-red light. Answer: D 43) Plants that have their flowering inhibited by being exposed to bright lights at night are A) day-neutral plants. B) short-night plants. C) devoid of phytochrome. D) short-day plants. E) long-day plants. Answer: D 44) Classic experiments suggested that a floral stimulus, florigen, could move across a graft from an induced plant to a noninduced plant and trigger flowering. Recent evidence using Arabidopsis has recently shown that florigen is probably A) a phytochrome molecule that is activated by red light. B) a protein that is synthesized in leaves, travels to the shoot apical meristems, and initiates flowering. C) a membrane signal that travels through the symplast from leaves to buds. D) a second messenger that induces Ca++ ions to change membrane potential. E) a transcription factor that controls the activation of florigen-specific genes. Answer: B 45) A short-day plant exposed to nights longer than the minimum for flowering but interrupted by short flashes of light A) will never flower. B) might flower depending upon the duration of the light flash. C) will not be affected and will flower. D) might flower depending upon the wavelengths of the light flashes. E) will still flower if ethylene is administered. Answer: D 46) A long-day plant will flower A) in the late fall. B) when the night is shorter than a critical value. C) only under artificial light in the summer. D) during short days with proper fertilization. E) regardless of the photoperiod imposed. Answer: B 47) You are part of a desert plant research team trying to discover crops that will be productive in arid climates. You discover a plant that produces a hormone under water-deficit conditions that triggers a suite of drought responses. Most likely the hormone is A) ABA. B) GA. C) IAA. D) 2, 4-D. E) salicylic acid. Answer: A 48) What do the results of research on gravitropic responses of roots and stems show? A) Different tissues have the same response to auxin. B) The effect of a plant hormone can depend on the tissue. C) Some responses of plants require no hormones at all. D) Light is required for the gravitropic response. E) Cytokinin can only function in the presence of auxin. Answer: B 49) A botanist discovers a plant that lacks the ability to form starch grains in root cells, yet the roots still grow downward. This evidence refutes the long-standing hypothesis that A) falling statoliths trigger gravitropism. B) starch accumulation triggers the negative phototropic response of roots. C) starch grains block the acid growth response in roots. D) starch is converted to auxin, which causes the downward bending in roots. E) starch and downward movement are necessary for thigmotropism. Answer: A 50) Most scientists agree that global warming is under way; thus, it is important to know how plants respond to heat stress. Which of the following would be a useful line of inquiry to try to improve plant response to and survival of heat stress? A) the production of heat-stable carbohydrates B) increased production of heat-shock proteins C) the opening of stomata to increase evaporational heat loss D) protoplast fusion experiments with xerophytic plants E) all of the above Answer: B 51) In extremely cold regions, woody species may survive freezing temperatures by A) emptying water from the vacuoles to prevent freezing. B) decreasing the numbers of phospholipids in cell membranes. C) decreasing the fluidity of all cellular membranes. D) producing canavanine as a natural antifreeze. E) increasing cytoplasmic levels of specific solute concentrations, such as sugars. Answer: E 52) The initial response of the root cells of a tomato plant watered with seawater would be to A) rapidly produce organic solutes in the cytoplasm. B) rapidly expand until the cells burst. C) begin to plasmolyze as water is lost. D) actively transport water from the cytoplasm into the vacuole. E) actively absorb salts from the seawater. Answer: C 53) The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve A) rapid growth response. B) potassium channels. C) nervous tissue. D) aquaporins. E) stress proteins. Answer: B 54) Which of the following is the most likely plant response to an attack by herbivores? A) leaf abscission to prevent further loss B) early flowering to try to reproduce before being eaten C) production of chemical compounds for defense or to attract predators D) production of physical defenses, such as thorns E) production of thicker bark and cuticle to make it more difficult to eat Answer: C 55) In order for a plant to initiate chemical responses to herbivory, A) the plant must be directly attacked by an herbivore. B) volatile "signal" compounds must be perceived. C) gene-for-gene recognition must occur. D) phytoalexins must be released. E) it must be past a certain developmental age. Answer: B 56) The transduction pathway that activates systemic acquired resistance in plants is initially signaled by A) antisense RNA. B) Pfr phytochrome. C) salicylic acid. D) abscisic acid. E) red, but not far-red, light. Answer: C 57) Which of the following would only be activated or upregulated after a plant has already been infected by a pathogen? A) phytochrome B) salicylic acid C) molecular chaperones D) stress proteins E) brassinosteroids Answer: B 58) A plant will recognize a pathogenic invader A) if it has many specific plant-disease-resistance (R) genes. B) when the pathogen has an R gene complementary to the plant's antivirulence (Avr) gene. C) only if the pathogen and the plant have the same R genes. D) if it has the specific R gene that corresponds to the pathogen molecule encoded by an Avr gene. E) when the pathogen secretes Avr protein. Answer: D 59) What is the probable role of salicylic acid in the defense responses of plants? A) to destroy pathogens directly B) to activate the systemic acquired resistance of plants C) to close stomata, thus preventing the entry of pathogens D) to activate heat-shock proteins E) to sacrifice infected tissues by hydrolyzing cells Answer: B 60) When an arborist prunes a limb off a valuable tree, he or she usually paints the cut surface. The primary purpose of the paint is to A) minimize water loss by evaporation from the cut surface. B) improve the appearance of the cut surface. C) stimulate growth of the cork cambium to "heal" the wound. D) block entry of pathogens through the wound. E) induce the production of phytoalexins. Answer: D 61) In cases where plants exhibit generalized defense responses in organs distant from the infection site, this is termed A) a hyperactive response. B) systemic acquired resistance. C) pleiotropy. D) hyperplasia. E) a general systemic response. Answer: B 31.2 Art Questions Figure 31.1 1) The heavy line in Figure 31.1 illustrates the relationship between auxin concentration and cell growth in stem tissues. If the same range of concentrations were applied to lateral buds, what curve(s) would probably be produced? A) I B) II C) III D) II or III E) I or III Answer: A Refer to Figure 31.2 to answer the following questions. Figure 31.2 2) The results of this experiment, shown on the left of the graph (area A), may be used to A) show that these plants can live without gibberellin. B) show that gibberellin is necessary in positive gravitropism. C) show that taller plants with more gibberellin produce fruit (pods). D) show a correlation between plant height and gibberellin concentration. E) study phytoalexins in plants. Answer: D 3) This experiment suggests that the unknown amount of gibberellin in the experimental plant (B) is approximately A) zero. B) 0.01 μg/mL. C) 0.1 μg/mL. D) 1.0 μg/mL. E) equal to the amount of gibberellin in the shortest plant. Answer: C 31.3 Scenario Questions 1) In nature, poinsettias bloom in early March. Research has shown that the flowering process is triggered 3 months before blooming occurs. In order to make poinsettias bloom in December, florists change the length of the light—dark cycle in September. Given this information and clues, which of the following is a correct statement about poinsettias? A) They are short-day plants. B) They require a light period longer than some set minimum. C) They require a shorter dark period than is available in September. D) The dark period can be interrupted without affecting flowering. E) They will flower even if there are brief periods of far-red illumination during the nighttime. Answer: A 2) A botanist exposed two groups of the same plant species to two photoperiods–one with 14 hours of light and 10 hours of dark and the other with 10 hours of light and 14 hours of dark. Under the first set of conditions, the plants flowered, but they failed to flower under the second set of conditions. Which of the following conclusions would be consistent with these results? A) The critical night length is 14 hours. B) The plants are short-day plants. C) The critical day length is 10 hours. D) The plants can convert phytochrome to florigen. E) The plants flower in the late spring. Answer: E 31.4 End-of-Chapter Questions 1) The hormone that helps plants respond to drought is A) auxin. B) gibberellin. C) cytokinin. D) ethylene. E) abscisic acid. Answer: E 2) Auxin enhances cell elongation in all of these ways except A) increased uptake of solutes. B) gene activation. C) acid-induced denaturation of cell wall proteins. D) increased activity of plasma membrane proton pumps. E) cell wall loosening. Answer: C 3) Charles and Francis Darwin discovered that A) auxin is responsible for phototropic curvature. B) auxin can pass through agar. C) light destroys auxin. D) light is perceived by the tips of coleoptiles. E) red light is most effective in shoot phototropism. Answer: D 4) The signaling molecule for flowering might be released earlier than usual in a long-day plant exposed to flashes of A) far-red light during the night. B) red light during the night. C) red light followed by far-red light during the night. D) far-red light during the day. E) red light during the day. Answer: B 5) If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering? A) 16 hours light/8 hours dark B) 14 hours light/10 hours dark C) 15.5 hours light/8.5 hours dark D) 4 hours light/8 hours dark/4 hours light/8 hours dark E) 8 hours light/8 hours dark/light flash/8 hours dark Answer: B 6) A plant mutant that showed normal gravitropic bending but did not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism. A) auxin B) calcium C) statoliths D) light E) differential growth Answer: C Chapter 32: Homeostasis and Endocrine Signaling 32.1 Multiple-Choice Questions 1) Which of the following has (have) both endocrine and exocrine activity? A) the pituitary gland B) parathyroid glands C) salivary glands D) the pancreas E) adrenal glands Answer: D 2) Penguins, seals, and tuna have body forms that permit rapid swimming, because A) all share a common ancestor at some point in the past. B) all of their bodies have been compressed since birth by intensive underwater pressures. C) flying, pregnancy, and gill-breathing all require similar adaptations in form. D) the shape is a convergent evolutionary solution to the need to reduce drag while swimming. E) this is the only shape that will allow them to maintain a constant body temperature in water. Answer: D 3) Interstitial fluid is A) the fluid inside the gastrovascular cavity of Hydra. B) the internal environment inside animal cells. C) identical to the composition of blood. D) the route for the exchange of materials between blood and body cells. E) found only in the lumen of the small intestine. Answer: D 4) Tissues are composed of cells, and tissues functioning together make up A) organs. B) membranes. C) organ systems. D) organelles. E) organisms. Answer: A 5) An exchange surface in direct contact with the external environment is found in the A) lungs. B) skeletal muscles. C) liver. D) heart. E) brain. Answer: A 6) The absorptive epithelia in the gut are considered "polarized" because A) thick and thin filaments are present. B) they pump wastes into the lumen while pumping nutrients toward the blood. C) the colors seen on the top and bottom of the cells are different. D) they must fire action potentials to absorb most nutrients. E) the structures on the apical surface are different than those on the basal surface. Answer: E 7) An example of a connective tissue is the A) skin. B) nerves. C) blood. D) cuboidal epithelium. E) smooth muscles. Answer: C 8) Connective tissues typically have A) many densely packed cells with direct connections between the membranes of adjacent cells. B) a supporting material such as chondroitin sulfate. C) the ability to shorten upon stimulation. D) relatively few cells and a large amount of extracellular matrix. E) the ability to transmit electrochemical impulses. Answer: D 9) If you gently twist your earlobe, it does not remain distorted because it contains A) collagenous fibers. B) elastic fibers. C) reticular fibers. D) adipose tissue. E) loose connective tissue. Answer: B 10) The nourishment, insulation, and support for neurons is the result of activity by the A) smooth muscles. B) adipose tissue. C) endocrine system. D) intercalated disks. E) glial cells. Answer: E 11) Fibroblasts secrete A) fats. B) chondroitin sulfate. C) interstitial fluids. D) calcium phosphate for bone. E) proteins for connective fibers. Answer: E 12) Blood is best classified as connective tissue because A) its cells are separated from each other by an extracellular matrix. B) it contains more than one type of cell. C) it is contained in vessels that "connect" different parts of an organism's body. D) its cells can move from place to place. E) it is found within all the organs of the body. Answer: A 13) Muscles are joined to bones by A) ligaments. B) tendons. C) loose connective tissue. D) Haversian systems. E) spindle fibers. Answer: B 14) With its abundance of collagenous fibers, cartilage is an example of A) connective tissue. B) reproductive tissue. C) nervous tissue. D) epithelial tissue. E) adipose tissue. Answer: A 15) All types of muscle tissue have A) intercalated disks that allow cells to communicate. B) striated banding patterns seen under the microscope. C) cells that lengthen when appropriately stimulated. D) a response that can be consciously controlled. E) interactions between actin and myosin. Answer: E 16) All skeletal muscle fibers are both A) smooth and under involuntary control. B) smooth and operate independently of other skeletal muscle fibers. C) striated and under voluntary control. D) smooth and under voluntary control. E) striated and electrically coupled to neighboring fibers. Answer: C 17) The type of muscle tissue surrounding internal organs, other than the heart, is A) skeletal muscle. B) cardiac muscle. C) striated muscle. D) intercalated cells. E) smooth muscle. Answer: E 18) Food moves along the digestive tract as the result of contractions by A) cardiac muscle. B) smooth muscle. C) voluntary muscle. D) striated muscle. E) skeletal muscle. Answer: B 19) The body's automatic tendency to maintain a constant and optimal internal environment is termed A) balanced equilibrium. B) physiological chance. C) homeostasis. D) static equilibrium. E) estivation. Answer: C 20) An example of a properly functioning homeostatic control system is seen when A) the core body temperature of a runner rises gradually from 37°C to 45°C. B) the kidneys excrete salt into the urine when dietary salt levels rise. C) a blood cell shrinks when placed in a solution of salt and water. D) the blood pressure increases in response to an increase in blood volume. E) the level of glucose in the blood is abnormally high whether or not a meal has been eaten. Answer: B 21) An example of effectors' roles in homeostatic responses is observable when A) an increase in body temperature results from involuntary shivering. B) an increase in body temperature results from exercise. C) the rising sun causes an increase in body temperature in a stationary animal. D) an increase in body temperature results from fever. E) a decrease in body temperature results from shock. Answer: A 22) In a survivably cold environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm A) maintains a higher basal metabolic rate. B) expends more energy per kg of body mass than does the endotherm. C) invests little energy in temperature regulation. D) metabolizes its stored energy more readily than can the endotherm. E) has greater insulation on its body surface. Answer: C 23) Humans can lose, but cannot gain, heat through the process of A) conduction. B) convection. C) radiation. D) evaporation. E) metabolism. Answer: D 24) An example of an ectothermic organism that has few or no behavioral options when it comes to its ability to adjust its body temperature is a A) terrestrial lizard. B) sea star, a marine invertebrate. C) bluefin tuna, a predatory fish. D) hummingbird. E) honeybee in a hive. Answer: B 25) The thermoregulatory response of an overheated dog in a very hot environment is impaired if the response causes A) evaporative heat loss to increase. B) metabolic heat production to decrease. C) body temperature to increase to match the environmental temperature. D) blood vessels near the skin to vasoconstrict. E) a behavioral response that takes the dog to a cooler location. Answer: C 26) The panting responses that are observed in overheated birds and mammals dissipates excess heat by A) countercurrent exchange. B) acclimation. C) vasoconstriction. D) hibernation. E) evaporation. Answer: E 27) An example of an organism that has only behavioral controls over its body temperature is the A) green frog. B) penguin. C) bluefin tuna. D) house sparrow. E) gray wolf. Answer: A 28) Most land-dwelling invertebrates and all of the amphibians A) are ectothermic organisms with variable body temperatures. B) alter their metabolic rates to maintain a constant body temperature of 37°C. C) have a net loss of heat across a moist body surface, even in direct sun. D) are endotherms but become thermoconformers only when they are in water. E) become more active when environmental temperatures drop below 15°C. Answer: A 29) The temperature-regulating center of vertebrate animals is located in the A) medulla oblongata. B) thyroid gland. C) hypothalamus. D) subcutaneous layer of the skin. E) liver. Answer: C 30) Seasonal changes in snake activity are due to the fact that the snake A) is less active in winter because the food supply is decreased. B) is less active in winter because it does not need to avoid predators. C) is more active in summer because that is the period for mating. D) is more active in summer because it can gain body heat by conduction. E) is more active in summer as a result of being disturbed by other animals. Answer: D 31) Panting by an overheated dog achieves cooling by A) acclimatization. B) torpor. C) evaporation. D) nonshivering thermogenesis. E) shivering thermogenesis. Answer: C 32) Positive feedback differs from negative feedback in that A) positive feedback benefits the organism, whereas negative feedback is detrimental. B) the positive feedback's effector responses are in the same direction as the initiating stimulus rather than opposite to it. C) the effector's response increases some parameter (such as body temperature), whereas in negative feedback it can only decrease the parameter. D) positive feedback systems have only effectors, whereas negative feedback systems have only receptors. E) positive feedback systems have control centers that are lacking in negative feedback systems. Answer: B 33) In a typical nerve cell, the nucleus is found in the A) cell body. B) synaptic terminals. C) axonal region. D) dendritic region. E) synapse. Answer: A 34) Most types of communication between cells utilize A) the exchange of cytosol between the cells. B) a direct electrical connection between the cells. C) the release of chemical signals by the cell sending the message. D) the exchange of DNA between the cells. E) the movement of the cells. Answer: C 35) Coordinating body functions via chemical signals is accomplished by A) the respiratory system. B) the endocrine system. C) the immune and lymphatic systems. D) the integumentary system. E) the excretory system. Answer: B 36) All hormones A) are produced by endocrine glands. B) are lipid-soluble molecules. C) are carried to target cells in the blood. D) are protein molecules. E) elicit the same biological response from all of their target cells. Answer: C 37) A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's A) secretory cell. B) plasma cell. C) endocrine cell. D) target cell. E) regulatory cell. Answer: D 38) The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that A) only its target cells get exposed to aldosterone. B) only its target cells contain aldosterone receptors. C) it is unable to enter nontarget cells. D) nontarget cells destroy aldosterone before it can produce any effect. E) nontarget cells convert aldosterone to a hormone to which they do respond. Answer: B 39) Different body cells can respond differently to the same peptide hormones because A) different target cells have different sets of genes. B) each cell converts that hormone to a different metabolite. C) a target cell's response is determined by the components of its signal transduction pathways. D) the circulatory system regulates responses to hormones by routing the hormones to specific targets. E) the hormone is chemically altered in different ways as it travels through the circulatory system. Answer: C 40) When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then A) the steroid and peptide hormones must use the same biochemical mechanisms. B) the steroid and peptide hormones must bind to the same receptor protein. C) the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell. D) the steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA. E) the steroid hormones affect only the release of proteins from the target cell, whereas peptide hormones affect only the synthesis of proteins that remain in the target cell. Answer: C 41) For hormones that homeostatically regulate cellular functions, A) negative feedback typically regulates hormone secretion. B) the circulating level of a hormone is held constant through a series of positive feedback loops. C) both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors. D) endocrine organs release their contents into the bloodstream via specialized ducts. E) it is impossible to also have neural regulation of that system. Answer: A 42) Hormones that promote homeostasis A) are not found as members of antagonistic signaling mechanisms. B) travel to target cells without passage in the plasma. C) utilize receptors that bind any hormone. D) initiate signal transduction in the target cell without binding to receptors. E) usually operate as part of a negative feedback system. Answer: E 43) During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of A) a negative feedback system. B) a hormone that acts in an antagonistic way with another hormone. C) a hormone that is involved in a positive feedback loop. D) signal transduction immediately changing gene expression in its target cells. E) the key role of the anterior pituitary gland in regulating uterine contraction. Answer: C 44) The interrelationships between the endocrine and the nervous systems are especially apparent in A) a neuron in the spinal cord. B) a steroid-producing cell in the adrenal cortex. C) a neurosecretory cell in the hypothalamus. D) a brain cell in the cerebral cortex. E) a cell in the pancreas that produces digestive enzymes. Answer: C 45) Portal blood vessels connect two capillary beds found in the A) hypothalamus and thalamus. B) anterior pituitary and posterior pituitary. C) hypothalamus and anterior pituitary. D) posterior pituitary and thyroid gland. E) anterior pituitary and adrenal gland. Answer: C 46) Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin A) is a nonspecific hormone. B) has a unique mechanism for eliciting its effects. C) is an evolutionarily conserved hormone. D) is derived from two separate sources. E) interacts with many different receptor molecules. Answer: C 47) In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are A) prolactin and calcitonin. B) prolactin and oxytocin. C) follicle-stimulating hormone and luteinizing hormone. D) luteinizing hormone and oxytocin. E) prolactin and luteinizing hormone. Answer: B 48) Oxytocin and antidiuretic hormone are synthesized in the A) hypothalamus. B) adenohypophysis. C) anterior pituitary. D) adrenal cortex. E) posterior pituitary. Answer: A 49) Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the A) parathyroid glands. B) adrenal glands. C) thyroid glands. D) the endocrine pancreas. E) the exocrine pancreas. Answer: C 50) Fight-or-flight reactions include activation of A) the parathyroid glands, leading to increased metabolic rate. B) the thyroid gland, leading to an increase in the blood calcium concentration. C) the anterior pituitary gland, leading to cessation of gonadal function. D) the adrenal medulla, leading to increased secretion of epinephrine. E) the pancreas, leading to a reduction in the blood sugar concentration. Answer: D 51) The endocrine glands include the A) parathyroid glands. B) salivary glands. C) sweat glands. D) sebaceous glands. E) gallbladder. Answer: A 52) The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed by A) thyroxine. B) epinephrine. C) growth hormone. D) calcitonin. E) glucagon. Answer: D 53) The autonomic nervous system includes an endocrine gland known as the A) ovary. B) adrenal medulla. C) adrenal cortex. D) testis. E) thyroid. Answer: B 54) Melatonin is secreted by A) the hypothalamus during the day. B) the pineal gland during the night. C) the autonomic nervous system during the winter. D) the posterior pituitary gland during the day. E) the thyroid gland during cold seasons. Answer: B 55) The increased contraction of the human uterus during labor and delivery is at least partially due to the actions of A) ecdysteroid. B) glucagon. C) thyroxine. D) oxytocin. E) growth hormone. Answer: D 56) Abnormally reduced somatic growth (dwarfism) can be a consequence of decreased hormone secretion from the A) kidneys. B) pancreas. C) adrenal gland. D) posterior pituitary gland. E) anterior pituitary gland. Answer: E 57) In a positive-feedback system where hormone A alters the amount of protein X, A) an increase in A always produces an increase in X, which results in an increase in A. B) an increase in X always produces a decrease in A, which results in a decrease in X. C) a decrease in A always produces an increase in X, which results in an increase in A. D) a decrease in X always causes a decrease in A, which causes an increase in X. E) it is impossible to predict how A and X affect each other. Answer: A 58) The hypothalamus A) functions only as an endocrine target, by having lots of receptors on its cells. B) functions only in neuronal transmission. C) does not have any hormone receptors on its cells. D) secretes tropic hormones that act directly on the gonads. E) includes neuronal cells that terminate in the posterior pituitary. Answer: E 59) Most of the exchange surfaces of multicellular animals are lined with A) connective tissue. B) smooth muscle cells. C) neural tissue. D) epithelial tissue. E) adipose tissue. Answer: D 60) A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because A) it was stressed and needed more time to acclimate to the new conditions. B) it was so hyperosmotic to the fresh water that it could not osmoregulate. C) the sea star's kidneys could not handle the change in ionic content presented by the fresh water. D) its contractile vacuoles ruptured. E) its cells dehydrated and lost the ability to metabolize. Answer: B 61) Organisms categorized as Osmo conformers are most likely A) found in freshwater lakes and streams. B) marine. C) amphibious. D) found in arid terrestrial environments. E) found in terrestrial environments with adequate moisture. Answer: B 62) The body fluids of an Osmo conformer would be ________ with its ________ environment. A) hyperosmotic; freshwater B) isotonic; freshwater C) hyperosmotic; saltwater D) isoosmotic; saltwater E) hypoosmotic; saltwater Answer: D 63) Compared to the seawater around them, most marine invertebrates are A) hyperosmotic. B) hypoosmotic. C) isoosmotic. D) hyperosmotic and isoosmotic. E) hypoosmotic and isoosmotic. Answer: C 64) The fluid with the highest osmolarity is A) distilled water. B) plasma in birds. C) plasma in mammals. D) seawater in a tidal pool. E) estuarine water. Answer: D 65) A human who has no access to fresh water but is forced to drink seawater instead A) will thrive under such conditions, as long as he has lived at the ocean most of his life. B) will excrete more water molecules than taken in, because of the high load of ion ingestion. C) will develop structural changes in the kidneys to accommodate the salt overload. D) will find that drinking saltwater satiates his thirst. E) will risk becoming overhydrated within 12 hours. Answer: B 66) Many marine and freshwater bony fish achieve osmoregulation via A) loss of water through the gills. B) gain of salt through the gills. C) loss of water in the urine. D) no drinking of water. E) gain of water through food. Answer: E 67) Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so they are considered by many to be Osmo conformers. Nonetheless, these sharks osmoregulate at least partially by A) using their gills and kidneys to rid themselves of sea salts. B) monitoring dehydration at the cellular level with special gated aquaporins. C) tolerating high urea concentrations that balance internal salt concentrations to seawater osmolarity. D) synthesizing trimethylamine oxide, a chemical that binds and precipitates salts inside cells. E) possessing a special adaptation that allows their cells to operate at an extraordinarily high salt concentration. Answer: C 68) The necropsy (postmortem analysis) of a freshwater fish that died after being placed accidentally in saltwater would likely show that A) loss of water by osmosis from cells in vital organs resulted in cell death and organ failure. B) high amounts of salt had diffused into the fish's cells, causing them to swell and lyse. C) the kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment, creating an irrevocable loss of homeostasis. D) the gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation. E) brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment, leading to death by loss of autonomic function. Answer: A 69) Urea is produced in the A) liver from NH3 and CO2. B) liver from glycogen. C) kidneys from glucose. D) kidneys from glycerol and fatty acids. E) bladder from uric acid and H2O. Answer: A 70) Urea is A) insoluble in water. B) more toxic to human cells than ammonia. C) the primary nitrogenous waste product of humans. D) the primary nitrogenous waste product of most birds. E) the primary nitrogenous waste product of most aquatic invertebrates. Answer: C 71) Which nitrogenous waste has the greatest number of nitrogen atoms? A) ammonia B) ammonium ions C) urea D) uric acid Answer: D 72) Ammonia is likely to be the primary nitrogenous waste in living conditions that include A) lots of fresh water flowing across the gills of a fish. B) lots of seawater, such as a bird living in a marine environment. C) lots of seawater, such as the environment of a marine mammal (e.g., a polar bear). D) a terrestrial environment, such as that supporting crickets. E) a moist system of burrows, such as those of naked mole rats. Answer: A 73) Among vertebrate animals, urea A) is made in the kidneys and immediately excreted. B) is added to the air in the lungs to be exhaled, along with carbon dioxide. C) is made in the liver by combining two ammonia molecules with one carbon dioxide. D) is made in the pancreas and added to the intestinal contents, along with bile salts, for excretion. E) is rarely the nitrogenous waste of choice. Answer: C 74) The nitrogenous waste that requires the most energy to produce is A) ammonia. B) ammonium. C) urea. D) uric acid. Answer: D 75) Ammonia A) is soluble in water. B) can be stored in the body as a precipitate. C) has low toxicity relative to urea. D) is metabolically more expensive to synthesize than urea. E) is the major nitrogenous waste excreted by insects. Answer: A 76) The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that A) urea can be exchanged for Na+. B) urea is less toxic than ammonia. C) urea requires more water for excretion than ammonia. D) urea does not affect the osmolar gradient. E) less nitrogen is removed from the body. Answer: B 77) The primary nitrogenous waste excreted by birds is A) ammonia. B) nitrate. C) nitrite. D) urea. E) uric acid. Answer: E 78) Which nitrogenous waste requires hardly any water for its excretion? A) amino acids B) urea C) uric acid D) ammonia E) nitrogen gas Answer: C 79) In animals, nitrogenous wastes are produced mostly from the catabolism of A) starch and cellulose. B) triglycerides and steroids. C) proteins and nucleic acids. D) phospholipids and glycolipids. E) fatty acids and glycerol. Answer: C 80) Birds secrete uric acid as their nitrogenous waste because uric acid A) is readily soluble in water. B) is metabolically less expensive to synthesize than other excretory products. C) requires little water for nitrogenous waste disposal, thus reducing body mass. D) excretion allows birds to live in desert environments. Answer: C 81) Among the following choices, the most concentrated urine is excreted by A) frogs. B) kangaroo rats. C) humans. D) desert tortoises. E) birds. Answer: B 82) Materials are returned to the blood from the filtrate by which of the following processes? A) filtration B) ultrafiltration C) selective reabsorption D) secretion E) excretion Answer: C 83) Excretory structures known as protonephridia are present in A) flatworms. B) earthworms. C) insects. D) vertebrates. E) cnidarians. Answer: A 84) Excretory organs known as Malpighian tubules are present in A) earthworms. B) flatworms. C) insects. D) jellyfish. E) sea stars. Answer: C 85) The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of A) protonephridia. B) metanephridia. C) Malpighian tubules. D) nephrons. E) ananephredia. Answer: A 86) The osmoregulatory process called secretion refers to the A) formation of filtrate at an excretory structure. B) reabsorption of nutrients from a filtrate. C) selective elimination of excess ions and toxins from body fluids. D) formation of an osmotic gradient along an excretory structure. E) expulsion of urine from the body. Answer: C 87) The osmoregulatory/excretory system of an earthworm is based on the operation of A) protonephridia. B) metanephridia. C) Malpighian tubules. D) nephrons. E) ananephredia. Answer: B 88) The osmoregulatory/excretory system of an insect is based on the operation of A) protonephridia. B) metanephridia. C) Malpighian tubules. D) nephrons. E) ananephredia. Answer: C 89) Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid? A) mice and birds B) insects and birds C) lions and horses D) humans and frogs E) fish and turtles Answer: B 90) Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal. A) metanephridium—flatworm B) Malpighian tubule—frog C) kidney—insect D) flame bulb—snake E) exchange across the body surface—marine invertebrate Answer: E 91) An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the A) flame bulb system of flatworms. B) protonephridia of rotifers. C) metanephridia of earthworms. D) Malpighian tubules of insects. E) kidneys of vertebrates. Answer: E 92) Freshwater flatworms form urine that is typically A) of high solute concentration in order to conserve body fluids. B) of very low volume in order to conserve body fluids. C) of high solute concentration and very low volume in order to conserve body fluids. D) of high solute concentration and high volume, similar to their normal fluid uptake. E) of low solute concentration and high volume, similar to their normal fluid uptake. Answer: E 93) The transfer of fluid from the glomerulus to Bowman's capsule A) results from active transport. B) transfers large molecules as easily as small ones. C) is very selective as to which sub protein-sized molecules are transferred. D) is mainly a consequence of blood pressure in the capillaries of the glomerulus. E) usually includes the transfer of red blood cells into Bowman's capsule. Answer: D 94) Within a normally functioning kidney, blood can be found in A) the vasa recta. B) Bowman's capsule. C) the loop of Henle. D) the proximal tubule. E) the collecting duct. Answer: A 95) The filtrate in the renal pelvis enters directly from A) the loop of Henle. B) the collecting duct. C) Bowman's capsule. D) the proximal tubule. E) the glomerulus. Answer: B 96) Juxtamedullary nephrons can concentrate salt effectively in the renal medulla because of their long A) loops of Henle. B) distal convoluted tubules. C) Bowman's capsules. D) proximal convoluted tubules. E) glomeruli. Answer: A 97) The filtrate in the proximal convoluted tubule of the human does not normally include A) ions. B) glucose. C) plasma proteins. D) amino acids. E) dissolved gasses. Answer: C 98) The osmolarity of human urine A) can be four times as great as the normal osmolarity of human plasma. B) is always exactly equal to the plasma osmolarity. C) is always less than the plasma osmolarity. D) is always greater than the plasma osmolarity. E) is determined primarily by the concentration of glucose. Answer: A 99) A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that A) they store the body's excess fats. B) they have membranes of varying permeability to water. C) they operate an extensive set of active-transport ion pumps. D) they are the body's only means of shedding excess nutrients. E) they have an abundance of myogenic smooth muscle. Answer: C 100) Low selectivity of solute movement is a characteristic of A) salt pumping to control osmolarity. B) H+ pumping to control pH. C) reabsorption mechanisms along the proximal tubule. D) filtration from the glomerular capillaries. E) secretion along the distal tubule. Answer: D 101) If ATP production in a human kidney was suddenly halted, urine production would A) come to a complete halt. B) decrease, and the urine would be hypoosmotic compared to plasma. C) increase, and the urine would be isoosmotic compared to plasma. D) increase, and the urine would be hyperosmotic compared to plasma. E) decrease, and the urine would be isoosmotic compared to plasma. Answer: C 102) Compared to wetland mammals, water conservation in mammals of arid regions is enhanced by having more A) juxtamedullary nephrons. B) Bowman's capsules. C) ureters. D) podocytes. E) urinary bladders. Answer: A 103) Processing of filtrate in the proximal and distal tubules A) achieves the sorting of plasma proteins according to size. B) achieves the conversion of toxic ammonia to less toxic urea. C) maintains homeostasis of pH in body fluids. D) regulates the speed of blood flow through the nephrons. E) reabsorbs urea to maintain osmotic balance. Answer: C 104) In humans, the transport epithelial cells in the ascending loop of Henle A) are the largest epithelial cells in the body. B) are not in contact with interstitial fluid. C) have plasma membranes of low permeability to water. D) have 50% of their cell mass made of smooth endoplasmic reticulum. E) are not affected by high levels of nitrogenous wastes. Answer: C 105) The typical osmolarity of human blood is A) 30 mosm/L. B) 100 mosm/L. C) 200 mosm/L. D) 300 mosm/L. E) 500 mosm/L. Answer: D 106) When stimulated by aldosterone, the reabsorption of Na+ is increased along A) the loop of Henle. B) the glomerulus. C) Bowman's capsule. D) the proximal tubule. E) the distal tubule. Answer: E 107) Increased ADH secretion is likely after A) drinking lots of pure water. B) sweating-induced dehydration increases plasma osmolarity. C) ingestion of ethanol (drinking alcoholic drinks). D) eating a small sugary snack. E) blood pressure is abnormally high. Answer: B 108) After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as A) erythropoietin. B) angiotensinogen. C) renin. D) antidiuretic hormone. E) atrial natriuretic peptide. Answer: C 109) After drinking alcoholic beverages, increased urine excretion is the result of A) increased aldosterone production. B) increased blood pressure. C) inhibited secretion of antidiuretic hormone (ADH). D) increased reabsorption of water in the proximal tubule. E) the osmoregulator cells of the brain increasing their activity. Answer: C 110) Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be triggered by A) sleeping for one hour. B) severe sweating on a hot day. C) eating a bag of potato chips. D) eating a pizza with olives and pepperoni. E) drinking several glasses of water. Answer: B 111) Antidiuretic hormone (ADH) functions at the cellular level by A) stimulating the reabsorption of glucose through channel proteins. B) triggering the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. C) causing membranes to include more phospholipids that have unsaturated fatty acids. D) causing an increase in the number of aquaporin molecules of collecting duct cells. E) decreasing the speed at which filtrate flows through the nephron, leading to increased reabsorption of water. Answer: D 112) ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways? A) ADH regulates the osmolarity of the blood and RAAS regulates the volume of the blood. B) ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption. C) ADH and RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS causes increased excretion of water when it is in excess in body fluids. D) both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via receptors in the urinary bladder. E) by combining at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place. Answer: B 113) If a person loses a large amount of water in a short period of time, he or she may die from dehydration. ADH can help reduce water loss through its interaction with its target cells in the A) anterior pituitary. B) posterior pituitary. C) adrenal gland. D) bladder. E) kidney. Answer: E 32.2 Art Questions Figure 32.1 1) The thin horizontal arrows in Figure 32.1 show that A) the warmer arterial blood can bypass the legs as needed, when the legs are too cold to function well. B) the warmer venous blood transfers heat to the cooler arterial blood. C) the warmer arterial blood transfers heat to the cooler venous blood. D) the arterial blood is always cooler in the abdomen, compared to the temperature of the venous blood in the feet of the goose. E) the goose's legs get progressively warmer as the blood moves away from the abdomen to the feet. Answer: C 2) Examine Figure 32.1. Near a goose's abdomen, the countercurrent arrangement of the arterial and venous blood vessels causes A) the temperature difference between the contents of the two sets of vessels to be minimized. B) the venous blood to be as cold near the abdomen as it is near the feet. C) the blood in the feet to be as warm as the blood in the abdomen. D) the temperature at the abdomen to be less than the temperature at the feet. E) the loss of the maximum possible amount of heat to the environment. Answer: A 32.3 End-of-Chapter Questions 1) The body tissue that consists largely of material located outside of cells is A) epithelial tissue. B) connective tissue. C) skeletal muscle. D) smooth muscle. E) nervous tissue. Answer: B 2) Which of the following would increase the rate of heat exchange between an animal and its environment? A) feathers or fur B) vasoconstriction C) wind blowing across the body surface D) countercurrent heat exchanger E) blubber or fat layer Answer: C 3) Which process in the nephron is least selective? A) filtration B) reabsorption C) active transport D) secretion E) salt pumping by the loop of Henle Answer: A 4) Homeostasis typically relies on negative feedback because positive feedback A) requires a response but not a stimulus. B) drives processes to completion rather than to a balance point. C) acts within, but not beyond, a normal range. D) can decrease but not increase a variable. E) involves one location rather than several across the body. Answer: B 5) Which of the following is an accurate statement about thermoregulation? A) Endotherms are regulators and ectotherms are conformers. B) Endotherms maintain a constant body temperature and ectotherms do not. C) Endotherms are warm-blooded and ectotherms are cold-blooded. D) Endotherms and ectotherms differ in their primary source of heat for thermoregulation. E) Endothermy has a lower energy cost than ectothermy. Answer: D 6) Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? A) a river otter B) a mouse species living in a tropical rain forest C) a mouse species living in a temperate broadleaf forest D) a mouse species living in a desert E) a beaver Answer: D 7) African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? A) Urea takes less energy to synthesize than ammonia. B) Small stagnant pools do not provide enough water to dilute the toxic ammonia. C) The highly toxic urea makes the pool uninhabitable to potential competitors. D) Urea forms an insoluble precipitate. E) Urea makes lungfish tissue hypoosmotic to the pool. Answer: B Test Bank for Campbell Biology in Focus Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson, Jane B. Reece 9780321813664, 9780321962751, 9780134710679
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