Chapter 40-46, 51
1) Innate immunity A) is activated immediately upon infection. B) depends on a newly infected animal's previous exposure to the same pathogen. C) is based on recognition of antigens that are specific to different pathogens. D) is found only in vertebrate animals. E) utilizes highly specific antigen receptors on B cells.
a
12) 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.
a
14) Tissues are composed of cells, and tissues functioning together make up A) organs. B) membranes. C) organ systems. D) organelles. E) organisms.
a
21) Septic shock, a systemic response including high fever and low blood pressure, is a response to A) certain bacterial infections. B) specific forms of viruses. C) the presence of natural killer cells. D) a fever of >103°F in adults. E) increased production of neutrophils.
a
33) Glandular secretions that are released initially as inactive precursors of digestive enzymes are the A) protein-digesting enzymes. B) fat-solubilizing bile salts. C) acid-neutralizing bicarbonate. D) carbohydrate-digesting enzymes. E) hormones such as gastrin.
a
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.
a
34) Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because A) even small changes in body weight may signify changes in blood volume and therefore blood pressure. B) many people who have dialysis are diabetic and must control their weight carefully. C) dialysis removes blood proteins and these weigh more than other blood components. D) dialysis is likely to cause edema and such swelling must be controlled. E) reclining posture during dialysis can cause a tendency for weight gain.
a
35) Secondary immune responses upon a second exposure to a pathogen are due to the activation of A) memory cells. B) macrophages. C) stem cells. D) B cells. E) T cells.
a
38) 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.
a
41) 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.
a
42) 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.
a
45) The cell-mediated immunity that destroys virally infected cells involves A) cytotoxic T cells. B) natural killer cells. C) helper T cells. D) macrophages. E) B cells.
a
55) Countercurrent exchange is evident in A) the flow of water across the gills of a fish and that of blood within those gills. B) the flow of blood in the dorsal vessel of an insect and that of air within its tracheae. C) the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins. D) the flow of water across the skin of a frog and that of blood within the ventricle of its heart. E) the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary.
a
62) Air rushes into the lungs of humans during inhalation because A) the rib muscles and diaphragm contract, increasing the lung volume. B) the volume of the alveoli increases as smooth muscles contract. C) gas flows from a region of lower pressure to a region of higher pressure. D) pulmonary muscles contract and pull on the outer surface of the lungs. E) a positive respiratory pressure is created when the diaphragm relaxes.
a
63) The exhalation of air from human lungs is driven by A) a decrease in the volume of the thoracic cavity. B) a decrease in the residual volume of the lungs. C) the contraction of the diaphragm. D) the closure of the epiglottis. E) the expansion of the rib cage.
a
64) As a person goes from rest to full-effort exercise, there is an increase in the A) tidal volume. B) vital capacity. C) residual volume. D) total lung capacity. E) All of the above would be different.
a
65) 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
a
69) A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because A) even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match. B) a blood type match is less stringent than a match required for transplant because blood is more tolerant of change. C) for each gene, there is only one blood allele but many tissue alleles. D) Jane's class II genes are not expressed in bone marrow. E) Bob's immune response has been made inadequate before he receives the transplant.
a
76) Most of the carbon dioxide produced by humans is A) converted to bicarbonate ions by an enzyme in red blood cells. B) bound to hemoglobin. C) transported in the erythrocytes as carbonic acid. D) simply dissolved in the plasma. E) bicarbonate ions bound to hemoglobin.
a
77) Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to A) hemoglobin. B) plasma proteins. C) carbon dioxide. D) carbonic acid. E) plasma buffers.
a
78) Preventing the appearance of the symptoms of an allergy attack would be the likely result of A) blocking the attachment of the IgE antibodies to the mast cells. B) blocking the antigenic determinants of the IgM antibodies. C) reducing the number of helper T cells in the body. D) reducing the number of cytotoxic cells. E) reducing the number of natural killer cells.
a
10) A mineral that is especially important for preventing anemia is A) zinc. B) iron. C) iodine. D) molybdenum. E) folic acid.
b
15) In marine sponges, intracellular digestion of peptides is usually immediately preceded by A) hydrolysis. B) endocytosis. C) absorption. D) elimination. E) secretion.
b
17) An advantage of a complete digestive system over a gastrovascular cavity is that the complete system A) excludes the need for extracellular digestion. B) allows specialized functions in specialized regions. C) allows digestive enzymes to be more specific. D) allows extensive branching. E) facilitates intracellular digestion.
b
2) Circulatory systems have the primary benefit of overcoming the shortcomings of A) temperature differences between the lungs and the active tissue. B) the slow rate at which diffusion occurs across cells. C) communication systems involving only the nervous system. D) having to cushion animals from trauma. E) fetal organisms maintaining an optimal body temperature.
b
21) After ingestion by humans, the first category of macromolecules to be chemically digested by enzymes in the mouth is A) proteins. B) carbohydrates. C) cholesterol and other lipids. D) nucleic acids. E) minerals.
b
21) 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.
b
23) Adaptive immunity depends on A) traits common to groups of pathogens. B) pathogen-specific recognition. C) maternal provision of antibodies to offspring. D) plants being exposed to new pathogens. E) having exhausted all options for innate immunity responses.
b
26) The receptors on T cells and B cells bind to A) antibodies. B) antigens. C) natural killer cells. D) double-stranded RNA. E) immunoglobulins.
b
29) An enzyme with high activity in an acidic environment is A) amylase. B) pepsin. C) gastrin. D) trypsin. E) sucrose.
b
38) Among these choices, the biggest set that includes only those "cells" that lack nuclei is A) platelets. B) platelets and erythrocytes. C) platelets, erythrocytes, and basophils. D) platelets, erythrocytes, basophils, and neutrophils. E) platelets, erythrocytes, basophils, neutrophils, and monocytes.
b
40) Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having A) a sufficient colony of H. pylori. B) a thick, mucous secretion and active mitosis of epithelial cells. C) a high level of secretion by chief cells. D) a high level of secretion from parietal cells. E) secretions enter the stomach from the pancreas.
b
41) 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.
b
46) The meshwork that forms the fabric of a blood clot is A) chymotrypsin. B) fibrin. C) thrombin. D) prothrombin. E) collagen.
b
48) 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.
b
48) Select the pathway that would lead to the activation of cytotoxic T cells. A) B cell contact antigen → helper T cell is activated → clonal selection occurs B) body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface C) self-tolerance of immune cells → B cells contact antigen → cytokines released D) complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released E) cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis
b
50) Endothermy A) is a characteristic of most animals found in tropical zones. B) is a characteristic of animals that have a fairly constant body temperature. C) is a term equivalent to cold-blooded. D) is a characteristic of mammals but not of birds. E) is seen only in insects and in certain predatory fishes.
b
54) Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because A) water is less dense than air. B) water contains much less O₂ than air per unit volume. C) gills have less surface area than lungs. D) gills allow only unidirectional transport. E) gills allow water to flow in one direction.
b
57) 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.
b
59) 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+ 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 its receptors in the urinary bladder. E) by combining at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.
b
71) Carbon dioxide levels in the blood and cerebrospinal fluid affect its pH. This enables the organism to sense a disturbance in gas levels as A) the brain directly measures and monitors carbon dioxide and causes breathing changes accordingly. B) the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing. C) the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide. D) stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing. E) the medulla oblongata is able to control the concentration of bicarbonate ions in the blood.
b
71) The transfusion of type A blood to a person who has type O blood would result in A) the recipient's B antigens reacting with the donated anti-B antibodies. B) the recipient's anti-A antibodies clumping the donated red blood cells. C) the recipient's anti-A and anti-O antibodies reacting with the donated red blood cells if the donor was a heterozygote (Ai) for blood type. D) no reaction because type O is a universal donor. E) no reaction because the O-type individual does not have antibodies.
b
8) 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.
b
8) Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have A) an open circulatory system. B) a closed circulatory system. C) a gastrovascular cavity. D) branched tracheae. E) hemolymph.
b
86) In Cases 1 and 2 in the table, the mothers would be able, if needed, to supply blood to the newborn even seven to nine months after birth; the same would not be true for Case 3. This is because A) the fetus in Case 3 would provoke an immune response in the mother that would carry over after the birth. B) the newborn in Case 3 would soon be able to make antibodies to the B antigen of the mother. C) newborn children, until about age 2, do not make appreciable antibodies, except against Rh+ antigen. D) passive immunity would have worn off for the third newborn, but not for the other two. E) this difference is based on which of the mothers has been nursing her children, not on blood antigens.
b
1) 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.
c
13) 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.
c
16) 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.
c
19) Mammals have Toll-like receptors (TLRs) that can recognize a kind of macromolecule that is absent from vertebrates but present in/on certain groups of pathogens, including viral A) lipopolysaccharides. B) double-stranded DNA. C) double-stranded RNA. D) glycoproteins. E) phospholipids.
c
23) Among mammals, it is generally true that A) all types of foods begin their enzymatic digestion in the mouth. B) after leaving the oral cavity, the bolus enters the larynx. C) the epiglottis prevents swallowed food from entering the trachea. D) the esophagus is a key source of digestive enzymes. E) the trachea leads to the esophagus and then to the stomach.
c
30) 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.
c
40) The ability of one person to produce over a million different antibody molecules does not require over a million different genes; rather, this wide range of antibody production is due to A) alternative splicing of exons after transcription. B) increased rate of mutation in the RNA molecules. C) DNA rearrangements. D) rearrangements of cytosolic proteins in the thymus cells. E) crossing over between the light and heavy chains of each antibody molecule during meiosis I.
c
40) 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.
c
41) Dissolved proteins in human plasma include which of the following? I. fibrinogen II. hemoglobin III. immunoglobulin A) I only B) II only C) I and III only D) II and III only E) I, II, and III
c
41) The molar teeth of herbivorous mammals are especially effective at A) cutting. B) ripping. C) grinding. D) splitting. E) piercing.
c
43) Positive feedback has occurred when A) an increase in blood sugar increases the secretion of a hormone that stimulates the movement of sugar out of the blood. B) a decrease in blood sugar increases the secretion of a hormone that increases the conversion of glycogen to glucose. C) uterine contractions needed for the birthing process are expedited by the pressure of a moving baby in its mother's uterus. D) an increase in calcium concentration increases the secretion of a hormone that promotes the storage of calcium in bone. E) a decrease in blood calcium increases the amount of the hormone that causes the release of calcium from bone.
c
45) A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that A) it stores the body's excess fats. B) it has membranes of varying permeability to water. C) it operates an extensive set of active-transport ion pumps. D) it is the body's only means of shedding excess nutrients. E) it has an abundance of myogenic smooth muscle.
c
46) 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.
c
47) A normal event in the process of blood clotting is the A) production of erythropoietin. B) conversion of fibrin to fibrinogen. C) activation of prothrombin to thrombin. D) increase in platelets. E) synthesis of hemoglobin.
c
48) When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO₂ is A) 400 mm Hg. B) 82 mm Hg. C) 40 mm Hg. D) 21 mm Hg. E) 4 mm Hg.
c
49) An overheated and sick dog in a hot environment will have an impaired thermoregulatory response when its A) evaporative heat loss increases. B) metabolic heat production decreases. C) body temperature increases to match the environmental temperature. D) blood vessels near its skin increase vasoconstriction. E) behavioral response takes it to a cooler location.
c
49) 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.
c
49) When the digestion and absorption of organic molecules results in more energy-rich molecules than are immediately required by an animal, the excess is A) eliminated in the feces. B) stored as starch in the liver. C) stored as glycogen in the liver and muscles. D) oxidized and converted to ATP. E) hydrolyzed and converted to ADP.
c
51) A fasting animal whose energy needs exceed those provided in its diet draws on its stored resources in which order? A) fat, then glycogen, then protein B) glycogen, then protein, then fat C) liver glycogen, then muscle glycogen, then fat D) muscle glycogen, then fat, then liver glycogen E) fat, then protein, then glycogen
c
56) Countercurrent exchange in the fish gill helps to maximize A) endocytosis. B) blood pressure. C) diffusion. D) active transport. E) osmosis.
c
7) A significant increase in the amount of interstitial fluid surrounding the capillary beds of a human's lungs will cause A) an increase in the amount of carbon dioxide moving from the blood to the lungs. B) an increase in the amount of oxygen moving from the lungs into the blood. C) a decrease in the amount of oxygen moving from the lungs into the blood. D) an increase of pressure that would cause the capillary beds to burst. E) a decrease in the amount of work needed for effective ventilation of the lungs.
c
7) A systemic inflammatory response that is often life-threatening is A) mild fever. B) aches and dull pain. C) septic shock. D) high blood pressure. E) increased white blood cell count.
c
73) In the human disease known as lupus, there is an immune reaction against a patient's own DNA from broken or dying cells, which categorizes lupus as A) an allergy. B) an immunodeficiency. C) an autoimmune disease. D) an antigenic variation. E) a cancer.
c
1) Gas exchange in the aquatic salamander known as the axolotl is correctly described as A) active transport to move oxygen into the salamander from the water. B) carrier-mediated transport to move oxygen into the salamander from the water. C) facilitated diffusion of carbon dioxide from the salamander into the water. D) simple diffusion of oxygen into the salamander from the water. E) active transport of carbon dioxide from the salamander into the water.
d
10) The complement system is A) a set of proteins involved in innate but not acquired immunity. B) a set of proteins secreted by cytotoxic T cells and other CD8 cells. C) a group of proteins that includes interferons and interleukins. D) a group of antimicrobial proteins that act together in a cascade fashion. E) a set of proteins that act individually to attack and lyse microbes.
d
11) Folic acid supplements have become especially important for pregnant women because A) folic acid supplies vitamins that only pregnant women can use. B) the folic acid is stored in adipose tissue by pregnant women so supplements are needed to make more available in the circulation. C) the fetus makes high levels of folic acid. D) folic acid deprivation is associated with neural tube abnormalities in a fetus. E) folic acid deprivation is a cause of heart abnormalities in a newborn.
d
14) Ingested dietary substances must cross cell membranes to be used by the body, a process known as A) ingestion. B) digestion. C) hydrolysis. D) absorption. E) elimination.
d
19) Damage to the sinoatrial node in humans A) is a major contributor to heart attacks. B) would block conductance between the bundle branches and the Purkinje fibers. C) would have a negative effect on peripheral resistance. D) would disrupt the rate and timing of cardiac muscle contractions. E) would have a direct effect on blood pressure monitors in the aorta.
d
21) The semilunar valves of the mammalian heart A) are the route by which blood flows from the atria to the ventricles. B) are found only on the right side of the heart. C) are the attachment site where the pulmonary veins empty into the heart. D) prevent backflow of blood in the aorta and pulmonary arteries. E) are at the places where the anterior and posterior venae cavae empty into the heart.
d
22) The material present in arterioles that is not present in capillaries is A) fully oxygenated blood. B) plasma in which carbon dioxide has been added. C) a lining of endothelial cells. D) circular smooth muscle cells that can alter the size of the arterioles. E) white blood cells and platelets.
d
28) B cells have antigen receptors that bind to antigens that are either freely dissolved or present on the surface of invading/foreign cells. T cells have antigen receptors that A) are active only in lymph nodes. B) bind only to antigens present on the surface of the invading/foreign cells. C) bind only to freely dissolved antigens in the plasma. D) bind to antigens presented on major histocompatability complexes by host cells. E) bind to antigens that are either freely dissolved or present on the surface of invading/foreign cells.
d
3) The body fluids of an osmoconformer would be ________ with its ________ environment. A) hyperosmotic; freshwater B) isotonic; freshwater C) hyperosmotic; saltwater D) isoosmotic; saltwater E) hypoosmotic; saltwater
d
31) Antigens are A) proteins found in the blood that cause foreign blood cells to clump. B) proteins embedded in B cell membranes. C) proteins that consist of two light and two heavy polypeptide chains. D) foreign molecules that trigger the generation of antibodies. E) proteins released during an inflammatory response.
d
42) A group of animals among which a relatively long cecum is likely to be found is the A) carnivores. B) herbivores. C) autotrophs. D) heterotrophs. E) omnivores.
d
44) Heart rate will increase in the presence of increased A) low-density lipoproteins. B) immunoglobulins. C) erythropoietin. D) epinephrine. E) platelets.
d
47) Humans can lose, but cannot gain, heat through the process of A) conduction. B) convection. C) radiation. D) evaporation. E) metabolism.
d
56) In mammals this response is known as fever, but it is known to raise body temperature in other bacterially infected animals, including lizards, fishes, and cockroaches. A) growth of hair on the limbs B) reduced metabolic rate C) sweating from skin glands D) a change in the body's thermostat "set point" E) decreased thermogenesis in brown fat
d
58) 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.
d
58) 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.
d
60) Some human infants, especially those born prematurely, suffer serious respiratory failure because of A) the sudden change from the uterine environment to the air. B) the overproduction of surfactants. C) the incomplete development of the lung surface. D) lung collapse due to inadequate production of surfactant. E) mutations in the genes involved in lung formation.
d
60) The primary function of humoral immunity is A) to defend against fungi and protozoa. B) to reject transplanted tissues. C) to protect the body against cells that become cancerous. D) to protect the body against extracellular pathogens. E) to defend against bacteria and viruses that have already infected cells.
d
62) In active immunity, but not passive immunity, there is A) acquisition and activation of antibodies. B) proliferation of lymphocytes in bone marrow. C) the transfer of antibodies from the mother across the placenta. D) the requirement for direct exposure to a living or simulated pathogen. E) the requirement of secretion of interleukins from macrophages.
d
67) Breathing is usually regulated by A) erythropoietin levels in the blood. B) the concentration of red blood cells. C) hemoglobin levels in the blood. D) CO₂ and O₂ concentration and pH-level sensors. E) the lungs and the larynx.
d
9) The most likely reason that some of the vitamins and minerals in this supplement are found at less than 100% is A) that it would be chemically impossible to add more. B) these vitamins and minerals are too large in size to reach 100%. C) it is too easy to overdose on minerals such as phosphorus and calcium. D) it is dangerous to overdose on fat-soluble vitamins such as A and K. E) these supplements are meant for those who have been deprived of healthy foods.
d
20) In the digestive system, peristalsis is A) a process of fat emulsification in the small intestine. B) voluntary control of the rectal sphincters regulating defecation. C) the transport of nutrients to the liver through the hepatic portal vessel. D) a common cause of loss of appetite, fatigue, and dehydration. E) smooth muscle contractions that move food along the esophagus.
e
28) The velocity of blood flow is the lowest in capillaries because A) the capillary walls are not thin enough to allow oxygen to exchange with the cells. B) the capillaries are far from the heart, and blood flow slows as distance from the heart increases. C) the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. D) the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle. E) the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system.
e
29) Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by A) polyadenylase. B) RNA polymerase. C) reverse transcriptase. D) epitopase. E) recombinase.
e
3) To become bound to hemoglobin for transport in a mammal, atmospheric molecules of oxygen must cross A) zero membranes oxygen binds directly to hemoglobin, a protein dissolved in the plasma of the blood. B) one membrane that of the lining in the lungs and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood. C) two membranes in and out of the cell lining the lung and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood. D) four membranes in and out of the cell lining the lung, in and out of the endothelial cell lining the pulmonary capillary-and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood. E) five membranes in and out of the cell lining the lung, in and out of the endothelial cell lining the pulmonary capillary, and into the red blood cell to bind with hemoglobin.
e
36) 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.
e
42) The function of antibodies is to A) inject toxins into living pathogens. B) secrete cytokines that attract macrophages to infection sites. C) release perforins to disrupt infected cells. D) act as Toll-like receptors. E) mark pathogenic cells for destruction.
e
50) Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because A) they are too large for a circulatory system to operate well. B) they live without need for oxygen. C) they do not produce carbon dioxide. D) countercurrent exchange mechanisms cannot function well in their living conditions. E) nearly all of their cells are in direct contact with the external environment.
e
53) In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the A) trachea. B) larynx. C) bronchi. D) bronchioles. E) alveoli.
e
75) The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in A) the partial pressure of oxygen. B) the partial pressure of carbon monoxide. C) hemoglobin concentration. D) temperature. E) pH.
e
Standard metabolic rate (SMR) and basal metabolic rate (BMR) are A) used differently: SMR is measured during exercise, whereas BMR is measured at rest. B) used to compare metabolic rate between hibernating and nonhibernating states. C) both measured across a wide range of temperatures for a given species. D) both standard measurements of fat metabolism in mammals. E) both measured in animals in a resting and fasting state.
e
