Mastering Biology Practice Questions Chapters 40, 45, 46, 47, 48, 49, 54

Biologists have been able to produce mice that lack functioning genes for aquaporins. How would the urine of these mice compare with that of mice with normal aquaporins? A. Higher volume and higher osmolarity B. Higher volume and lower osmolarity C. Lower volume and higher osmolarity D. Lower volume and lower osmolarity

B. Higher volume and lower osmolarity

Which of the following is an osmoregulatory challenge that saltwater fishes need to overcome? A. Diffusion of sodium ions out of the gills and body B. High urine excretion from the kidneys C. Low intake of water into the body D. Diffusion of water out of the gills and body surfaces

D. Diffusion of water out of the gills and body surfaces

Consider the experience of rapid relaxation of smooth muscles surrounding blood vessels of the heart, brain, and muscles following a release of epinephrine. Which of the following would most likely lead to this physiological activity? A. A small animal detecting the presence of a nearby predator B. A large, grazing mammal experiencing an extended period of starvation during a long drought C. Human consumption of a large, high-calorie meal D. Exposure of a lizard's parietal eye to sunlight

A. A small animal detecting the presence of a nearby predator

In muscle cells, myosin molecules continue moving along actin molecules unless _______. A. ATP bound to the myosin head is not hydrolyzed. B. Ca2+ binds to tropomyosin. C. ADP is present and Ca2+ concentrations are low. D. The intracellular acetylcholine level is low.

A. ATP bound to the myosin head is not hydrolyzed.

Rigor mortis is the stiffening of a body after death that occurs when myosin binds to actin but cannot unbind. What prevents myosin from unbinding? A. ATP is required for myosin and actin to unbind. B. ATP bound to the myosin head is hydrolyzed. C. ADP is released from the myosin head. D. P is released from the ADP bound to the myosin head.

A. ATP is required for myosin and actin to unbind.

Which of the following could be used to conclude with high confidence that an organism has a strictly hydrostatic skeleton? A. Absence of any rigid structural components of the skeletal system B. Presence of hydrostats C. Inability to move D. The organism residing in an aquatic habitat

A. Absence of any rigid structural components of the skeletal system

Diuretics, such as caffeine, promote the production of dilute urine. Which of the following would not contribute to the diuretic response of someone consuming coffee or another caffeinated beverage? A. An increase in salt reabsorption in the thick portion of the ascending Loop of Henle B. Inhibition of the Na+/K+-ATPase pumps of the proximal tubule C. Increased blood flow to the glomerulus D. The removal of aquaporins from the collecting ducts

A. An increase in salt reabsorption in the thick portion of the ascending Loop of Henle

Which of these features is not characteristic of smooth, cardiac, or skeletal muscle? A. Cardiac muscle−−only muscle type with activity that is involuntary. B. Skeletal muscle−−multinucleate. C. Smooth muscle−−no sarcomeres. D. Cardiac muscle−−branched.

A. Cardiac muscle−−only muscle type with activity that is involuntary.

Which of these steps is not required when most B cells become fully activated and differentiate into plasma cells? A. Cytokines from TH2 helper T cells bind to Class II MHC proteins on the B cell's surface to trigger activation of the B cell. B. Most B cells become fully activated when one of their class II MHC−−peptide complexes interacts with an activated CD4+ T cell (TH2 helper T cell) that has a complementary TCR. C. Once fully activated by cytokines from the TH2 helper T cells, the B cell replicates. Some of the daughter cells differentiate into effector B cells called plasma cells. D. B cells are first activated to divide via interactions between the BCRs and the antigens they recognize.

A. Cytokines from TH2 helper T cells bind to Class II MHC proteins on the B cell's surface to trigger activation of the B cell.

Consider the locomotion of swimming fish, walking insects, flying birds, and slithering snakes. What forces are most difficult for each one to overcome? A. Flying birds−−the drag of the air while flying fast. B. Slithering snakes−−friction between the ground and the snake, related to gravity. C. Walking insects−−the pull of gravity on their bodies. D. Swimming fish−−the drag of the water while swimming fast.

A. Flying birds−−the drag of the air while flying fast.

Which of these assertions about hormones is not accurate? A. Hormonal changes during puberty and pregnancy are forms of endocrine disruption. B. Cortisol is released in response to the release of ACTH from the pituitary. C. Hormones produced by the hypothalamus are considered neurohormones. D. Growth and metamorphosis are controlled by hormones.

A. Hormonal changes during puberty and pregnancy are forms of endocrine disruption.

Which of these organisms is not matched to the main type of nitrogenous waste it excretes? A. Marine fishes−−ammonia B. Terrestrial insects−−uric acid C. Reptiles−−uric acid D. Freshwater fishes−−ammonia

A. Marine fishes−−ammonia

One way your body increases blood pressure is to contract muscles in large veins. What muscle tissue type will be responsible for this function? A. Smooth muscle B. Cardiac muscle C. Slow-twitch skeletal muscle D. Fast-twitch skeletal muscle

A. Smooth muscle

Which of these is not a change induced by elevated cortisol levels in response to long-term stress? A. Stimulating immune system function to reduce susceptibility to infection B. Promoting the release of fatty acids from storage cells for energy production C. Promoting the release of amino acids from muscle cells for energy production D. Preventing the uptake of glucose by adipocytes and resting muscle cells in response to signals from insulin

A. Stimulating immune system function to reduce susceptibility to infection

Which of the following hormones does not play a significant role in the regulation of the menstrual cycle in humans? A. Testosterone B. Luteinizing hormone (LH) C. Estradiol D. Progesterone

A. Testosterone

Which type of signaling involves chemical messengers carried between cells by the blood? A. Paracrine B. Autocrine C. Neural D. Endocrine

D. Endocrine

Why does the orientation of the Na+/Cl-/K+ cotransporter "flip" from the basolateral membrane of epithelial cells of the gill to the apical side of that membrane when salmon and sea bass move from seawater to freshwater? A. The Na+/Cl-/K+ cotransporter is found on opposite cell surfaces in response to the different osmotic stresses of seawater and freshwater environments, in which ion excretion or uptake, respectively, is required to maintain a constant internal osmolarity. B. The Na+/Cl-/K+ cotransporter is found on opposite cell surfaces in different aquatic environments in order to maintain a constant uptake of ions into tissues. C. The Na+/Cl-/K+ cotransporter is found on opposite cell surfaces in seawater and freshwater because these fish are osmoconformers and must allow their tissues to conform to the osmolarity of different external environments. D. The Na+/Cl-/K+ cotransporter is found on opposite cell surfaces in different aquatic environments in order to maintain a constant excretion of ions into the external environment.

A. The Na+/Cl-/K+ cotransporter is found on opposite cell surfaces in response to the different osmotic stresses of seawater and freshwater environments, in which ion excretion or uptake, respectively, is required to maintain a constant internal osmolarity.

According to data shared by physiologist Knut Schmidt-Nielsen, how does the cost of locomotion (i.e., energy use per distance traveled) tend to change with body mass? A. The cost of locomotion tends to decrease with increasing body mass for all types of locomotion measured, including flying, swimming, and running. B. The cost of locomotion does not appear to change significantly with body mass or type of movement (flying, swimming, or running). C. The cost of locomotion changes with locomotion type but not with body mass. D. The cost of locomotion tends to increase with increasing body mass for all types of locomotion measured, including flying, swimming, and running.

A. The cost of locomotion tends to decrease with increasing body mass for all types of locomotion measured, including flying, swimming, and running.

Which of these actions is not matched to the correct category of chemical signals: autocrine, paracrine, endocrine, or neuroendocrine? A. The cytokine interleukin 2 activates white blood cells in nearby tissues to fight infections−− autocrine B. Testosterone stimulates aggression in roosters−− endocrine C. Antidiuretic hormone binds to collecting duct cells in the kidney−− neuroendocrine D. A cell releases a chemical signal into the extracellular fluid, where it diffuses to bind to a neighboring cell−− paracrine

A. The cytokine interleukin 2 activates white blood cells in nearby tissues to fight infections−− autocrine

During contraction, what change in appearance is observed in the sarcomere? A. The light band narrows. B. The light band lengthens. C. The z-disk contracts. D. The dark band narrows.

A. The light band narrows.

Which of the following statements regarding animal development is not accurate? A. The neural tube forms after organogenesis is complete. B. During cleavage, the zygote divides rapidly without growth, forming a mass of cells. C. Animals have three germ layers. D.The blastocyst is formed during cleavage.

A. The neural tube forms after organogenesis is complete.

Which of the following outcomes would be expected if somatic hypermutation did not occur? A. The secondary immune response to a repeat infection would produce the same antibodies as those made in the primary immune response. B. The adaptive immune response would not be activated by pathogens. C. B and T lymphocytes would not be able to produce receptors that recognize antigens. D. The diversity of pattern-recognition receptors would be significantly lowered.

A. The secondary immune response to a repeat infection would produce the same antibodies as those made in the primary immune response.

What is the function of Malpighian tubules? A. They produce filtrate that contains nitrogenous waste, electrolytes, and water B. They digest food C. They reabsorb water to concentrate urine D. They close to prevent air movement in the tracheids

A. They produce filtrate that contains nitrogenous waste, electrolytes, and water

Which hormone signals the developmental transition from tadpole to adult frog? A. Triiodothyronine (T3) B. Growth hormone C. Melatonin D. Juvenile hormone (JH)

A. Triiodothyronine (T3)

Hoyt and Taylor conducted experiments with horses in order to test the hypothesis that animals locomote using the most energy-efficient gait at each speed. What did these two physiologists conclude following their experiments? A. Unrestricted horses walked, trotted, or galloped at speeds that minimized energy use for each gait. B. Horses can be trained to walk, trot, or gallop at a variety of speeds. C. The most energy-efficient gait involves walking at a speed between 1 and 2 meters per second. D. Unrestricted horses trot when they travel very fast.

A. Unrestricted horses walked, trotted, or galloped at speeds that minimized energy use for each gait.

What is not true about how athletes' skeletal muscles might change when they train for a marathon? A. With training, some slow fibers could change to fast fibers to increase contraction rates. B. Training can increase the density of mitochondria to improve muscle performance. C. Training for a marathon would likely cause many of the muscle fibers to become redder in color due to increased myoglobin. D. Endurance training can increase the number of blood vessels in muscles. Submit

A. With training, some slow fibers could change to fast fibers to increase contraction rates.

The mammalian anterior pituitary functions in the hormonal regulation of all of the following except ___________________. A. blood sugar concentration B. cell growth and development C. milk production D. glucocorticoid production

A. blood sugar concentration

Which statement best describes the role of cyclic AMP (cAMP) in hormonal signaling? A. cAMP is a second messenger that relays signals from membrane bound receptors into the cell by activating protein kinase A. B. cAMP binds to an endocrine response element on a cell's DNA. C. cAMP converts glycogen into glucose. D. cAMP directs the expression of new proteins in the cell. Submit

A. cAMP is a second messenger that relays signals from membrane bound receptors into the cell by activating protein kinase A.

What is the correct order of the flow of sperm in the male reproductive system of mammals? A. Vas deferens -> urethra ->epididymis B. Epididymis -> vas deferens -> urethra C. Bulbourethral gland -> urethra -> vas deferens D. Urethra -> vas deferens -> epididymis

B. Epididymis -> vas deferens -> urethra

Which hormone would you expect to enter target cells via passive diffusion across the plasma membrane? A. Growth hormone B. Estrogen C. Insulin D. Epinephrine

B. Estrogen

Why is there still no successful HIV vaccine? A. It has not been possible to create inactivated viruses for a vaccine using chemical treatments or exposure to ultraviolet light. B. A vaccine requires an antigen to stimulate an appropriate adaptive immune response. Vaccines have not worked for HIV because the antigens on this virus are constantly changed through mutation, rendering them unrecognizable to memory cells generated following vaccination. C. The human immune system is not able to recognize the epitopes on the antigens of HIV. D. It has not been possible to create an attenuated virus for a vaccine by culturing HIV on cells from other species.

B. A vaccine requires an antigen to stimulate an appropriate adaptive immune response. Vaccines have not worked for HIV because the antigens on this virus are constantly changed through mutation, rendering them unrecognizable to memory cells generated following vaccination.

In the sliding filament model of muscle contraction, what two proteins make up the filaments that move past one another during contraction? A. Acetylcholine and myosin B. Actin and myosin C. Actin and tropomyosin D. Tropomyosin and troponin

B. Actin and myosin

How might the breast (or pectoralis) muscles differ in terms of skeletal muscle fiber type between the poor-flying chicken and the long-distance-flying duck? A. Chicken breast muscle is composed of white, or fast, fibers, while duck breast muscle is composed of cardiac muscle. B. Chicken breast muscle is composed of white, or fast, fibers, while duck breast muscle is composed of red, or slow, fibers. C. Duck breast muscle is composed of white, or fast, fibers, while chicken breast muscle is composed of red, or slow, fibers. D. Chicken breast muscle is smooth muscle, while duck breast muscle is skeletal muscle fibers.

B. Chicken breast muscle is composed of white, or fast, fibers, while duck breast muscle is composed of red, or slow, fibers.

Which of these events would result in increased production of dilute urine? A. Eating large amounts of salt B. Drinking large amounts of water C. Intake of nicotine D. Refraining from drinking water for 48 hours

B. Drinking large amounts of water

Which of the following is not a form of asexual reproduction? A. Fission B. Fusion of sperm and egg C. Parthenogenesis D. Budding

B. Fusion of sperm and egg

The hygiene hypothesis attempts to explain the correlation between hygienic practices and increases in autoimmune and allergic responses. Which of these factors seems to contribute to the effect? A. Inappropriate IgE-based hypersensitivity triggers autoimmune reactions that target some of the body's own cells. B. Improved hygienic practices results in less exposure to certain microorganisms and parasites. C. The overuse of hygienic practices results in the proliferation of resistant bacteria that trigger the hypersensitive reaction. D. The use of cleansers and antibiotics trigger inappropriate IgE-based hypersensitivity reactions.

B. Improved hygienic practices results in less exposure to certain microorganisms and parasites.

Consider this statement: "A major difference between internal fertilization and external fertilization is that the gametes are never exposed to dangers of the external environment with internal fertilization." Which of the following correctly addresses why this statement is inaccurate? A. All gametes are at some point exposed to dangers of the external environment regardless of the fertilization method used. B. It is inaccurate to suggest that gametes are never exposed to the external environment with internal fertilization. C. In the statement, internal and external fertilization are reversed, as external fertilization results in no exposure of gametes to the environment. D. The gametes are never exposed to dangers of the external environment regardless of the fertilization method used.

B. It is inaccurate to suggest that gametes are never exposed to the external environment with internal fertilization.

Predict the consequences of a drug that inhibits the release of FSH. Which of these processes would not happen? A. Follicles would not begin producing estradiol and progesterone. B. LH secretion would be suppressed. C. Follicles would not mature. D. The uterine lining would not thicken.

B. LH secretion would be suppressed.

Which statement most accurately describes the expression of melatonin? A. Melatonin is released by the hypothalamus during the day and increases metabolic rate. B. Melatonin's secretion by the pineal gland is highest at night. C. The pineal gland releases melatonin during the day to elevate animal activity. D. The adrenal gland releases melatonin during times of stress. Submit

B. Melatonin's secretion by the pineal gland is highest at night.

Which of the following is critical to function of most exoskeletons, endoskeletons, and hydrostatic skeletons? A. Muscles extend joints by pushing skeletal elements. B. Muscles interact with the skeleton in antagonistic groups. C. Muscles attach to each of these types of skeleton via tendons. D. Segments of the body or limbs are extended when paired muscles relax in unison.

B. Muscles interact with the skeleton in antagonistic groups.

In which structure does fertilization typically occur in mammals? A. Uterus B. Oviduct (also known as the fallopian tube or uterine tube) C. Vagina D. Ovary

B. Oviduct (also known as the fallopian tube or uterine tube)

What term describes the mode of asexual reproduction in which offspring develop from unfertilized eggs? A. Regeneration B. Parthenogenesis C. Budding D. Fission

B. Parthenogenesis

Which of these is not one of the structural changes triggered by the thyroid hormone T3 during the metamorphosis of a tadpole into a frog? A. The tadpole's tail gradually disintegrates or gets absorbed. B. T3 in young tadpoles inhibits the growth of legs until later when metamorphosis begins the transition to a frog. C. The tadpole's long intestine, specialized for digesting plant material, is converted into the frog's short intestine, specialized for digesting insects and other prey. D. In the liver, cells are modified to manufacture the enzymes required to excrete urea in the frog instead of ammonia released by tadpoles.

B. T3 in young tadpoles inhibits the growth of legs until later when metamorphosis begins the transition to a frog.

Which statement best describes the role of Toll-like receptors (TLR) in the innate immune response? A. TLRs are viral invaders that activate the immune response. These receptors digest the mucus lining of the respiratory tract and permit the invasion of viruses into the body. B. TLRs are found on leukocytes, or white blood cells. When a TLR is activated by the presence of its specific antigen, it stimulates and recruits various cells of the immune system. C. TLRs are found on bacterial pathogens and signal the presence of these pathogens to leukocytes. D. TLRs are antimicrobial enzymes found in the tears that coat eyes.

B. TLRs are found on leukocytes, or white blood cells. When a TLR is activated by the presence of its specific antigen, it stimulates and recruits various cells of the immune system.

How is the cell-mediated immune response different from the humoral immune response? A. The cell-mediated response involves B cells attacking other cells infected with a pathogen, while the humoral response involves T cells releasing secreted antibodies that bind to extracellular pathogens. B. The cell-mediated response involves cytotoxic T cells attacking other cells infected with an intracellular pathogen, while the humoral response involves B cells releasing secreted antibodies that bind to extracellular pathogens. C. The cell-mediated response involves an element of immunological memory, while the humoral response does not. D. The cell-mediated response involves opsonization of pathogens for subsequent phagocytosis, while the humoral response targets intracellular pathogens.

B. The cell-mediated response involves cytotoxic T cells attacking other cells infected with an intracellular pathogen, while the humoral response involves B cells releasing secreted antibodies that bind to extracellular pathogens.

Which of these is not an advantage of oviparity in birds? A. Before egg laying, mothers provide the egg with all the nutrition the embryo will require. B. The eggs are well protected after they are laid. C. Mothers do not have to carry eggs around as long−−meaning that they can lay more eggs and be more mobile. D. Oviparity usually requires less energy input from the mother after egg laying.

B. The eggs are well protected after they are laid.

What is the first step in the process of an action potential triggering muscle contraction? A. Ca2+ binds troponin B. The neurotransmitter acetylcholine (Ach) is released into the synaptic cleft. C. Ca2+ diffuses from the sarcoplasmic reticulum into the cytoplasm of the muscle cel. D. The action potential travels to the interior of the muscle via T tubules.

B. The neurotransmitter acetylcholine (Ach) is released into the synaptic cleft.

In sperm competition, what is "second-male advantage"? A. The observation that females routinely mate with at least two males before laying eggs or becoming pregnant B. The observation that when females mate with two males, the second male fertilizes most of the eggs C. The observation that accessory fluids prevent matings by second males−−for example, by forming copulatory plugs D. The observation that when females mate with two males, each male fertilizes the same number of eggs

B. The observation that when females mate with two males, the second male fertilizes most of the eggs

What is the function of antidiuretic hormone, or ADH? A. To signal an increase in blood flow to the kidneys to increase the production of urine B. To signal the insertion of aquaporins in the collecting duct, promoting the reabsorption of water C. To promote the production of a large volume of dilute urine D. To promote the reabsorption of salt ions such as Na+ and Cl-

B. To signal the insertion of aquaporins in the collecting duct, promoting the reabsorption of water

Why do insects use uric acid during the excretion of nitrogenous waste? A. The Malpighian tubules in insects cannot form urea. B. Uric acid has very low solubility in water and can be excreted with the feces without much water loss. C. Accumulating ammonia in the hemolymph would damage the internal organs and tissues. D. Uric acid has more solubility in water than urea.

B. Uric acid has very low solubility in water and can be excreted with the feces without much water loss.

Which structure in the male reproductive tract delivers the sperm from the testis in the scrotum to the base of the penis on its way to ejaculation? A. Urethra B. Vas deferens C. Epididymis D. Ejaculatory duct

B. Vas deferens

Corticosterone is ________. A. a polypeptide hormone B. a neurohormone C. an amino-acid-derived hormone D. a steroid hormone

B. a neurohormone

What is meant by the term somite? A. Rod-like mesoderm that provides longitudinal support to the growing embryo B. The endodermal lining of the stomach C. A block of mesodermal tissue that gives rise to muscles, bone, and skin D. A tubular structure derived from ectoderm that runs the length of the animal

C. A block of mesodermal tissue that gives rise to muscles, bone, and skin

What is a hormone-response element? A. An enzyme that is activated in response to hormone binding and produces a second messenger B. A receptor for a polypeptide hormone C. A segment of DNA where a hormone-receptor complex binds D. A receptor for a steroid hormone

C. A segment of DNA where a hormone-receptor complex binds

Which of the following statements regarding lymphocytes is not accurate? A. Lymphocytes circulate throughout the body via the lymphatic system, which consists of blood, bone marrow, lymph nodes, and other organs. B. Lymphocytes are primarily divided into one of two categories, which include B cells and T cells. C. All lymphocytes in humans originate and mature in the bone marrow. D. Gene recombination that occurs during lymphocyte development and maturation results in nearly limitless variation in the receptors found on their membrane surfaces.

C. All lymphocytes in humans originate and mature in the bone marrow.

What is the difference between an epitope and an antigen? A. Epitopes are recognized by B-cell receptors, and antigens are recognized by T-cell receptors. B. There are more different kinds of antigens than different kinds of epitomes. C. An epitope is the part of an antigen that is recognized by a B-cell or T-cell receptor or an antibody produced by a B cell. D. Epitopes are inserted in the plasma membrane of B cells, while antibodies are secreted from B cells.

C. An epitope is the part of an antigen that is recognized by a B-cell or T-cell receptor or an antibody produced by a B cell.

What is a common feature of the longitudinal and circumferential muscles in an earthworm and the quadriceps and hamstring muscles in a human? A. Both pairs of muscle contract at the same time to create movement. B. Both pairs of muscles work against a hydrostatic skeleton. C. Both pairs of muscles act as antagonistic muscle groups. D. Both pairs of muscle work against an endoskeleton.

C. Both pairs of muscles act as antagonistic muscle groups.

Which statement best describes the hormonal regulation of the adrenal gland? A. Cortisol from the adrenal gland increases the release of corticotropin from the hypothalamus. B. The hypothalamus releases cortisol to regulate the adrenal cortex. C. Corticotropin-releasing hormone from the hypothalamus leads to the release of corticotropin (ACTH) from the pituitary gland, which leads to the release of cortisol from the adrenal cortex. D. Cortisol release from the adrenal cortex leads to the release of corticotropin from the pituitary gland, which leads to the release of corticotropin-releasing hormone from the hypothalamus.

C. Corticotropin-releasing hormone from the hypothalamus leads to the release of corticotropin (ACTH) from the pituitary gland, which leads to the release of cortisol from the adrenal cortex.

Experimental evidence showed that Daphnia require what cues to trigger a switch from asexual parthenogenesis in spring and summer to sexual reproduction in the fall? A. Daphnia females switched to sexual reproduction when they were exposed to short day lengths. These conditions occur in the fall. B. Daphnia females switched to sexual reproduction with low food concentration. These conditions are likely to occur in the fall. C. Daphnia females switched to sexual reproduction only when they were exposed to short day lengths, water from crowded populations, and low food concentration. These conditions are likely to occur in the fall. D. The percentage of Daphnia females that switched to sexual reproduction increased with increasing population density.

C. Daphnia females switched to sexual reproduction only when they were exposed to short day lengths, water from crowded populations, and low food concentration. These conditions are likely to occur in the fall.

In which environment are you most likely to find animals that employ uric acid as their primary form of nitrogenous waste? A. Rain forest B. Freshwater C. Desert D. Marine

C. Desert

Which statement accurately describes a difference between spermatogenesis and oogenesis in mammals? A. The production of sperm stops early in development, while oocytes are produced through the life of mammals. B. Sperm contain extensive, nutrient-rich cytoplasm, while eggs are stripped-down cells specialized for locomotion. C. Each spermatogonium produces four haploid sperm, but each oogonium only produces one mature egg. D. Each spermatogonium produces one haploid sperm, but each oogonium produces four mature eggs.

C. Each spermatogonium produces four haploid sperm, but each oogonium only produces one mature egg.

Which of the following is not a mechanism by which fertilized eggs prevent polyspermy? A. Membrane depolarization B. Protease digestion of sperm receptor proteins C. Formation of a vaginal plug D. Formation of a fertilization envelope

C. Formation of a vaginal plug

In addition to functioning as antibodies, the IgD and IgM classes of immunoglobulins have what additional role? A. Respond to infection by parasitic worms B. Help immunize breastfed newborns C. Function as BCRs or B-cell receptors D. Clump viruses and other pathogens to facilitate phagocytosis

C. Function as BCRs or B-cell receptors

Which hormone is a good indicator of pregnancy in humans? A. Follicle-stimulating hormone B. Progesterone C. Human chorionic gonadotropin D. Gonadotropin-releasing hormone

C. Human chorionic gonadotropin

Which of these does not occur during the inflammatory response? A. Mast cells at the site of infection secrete histamine that dilates surrounding blood vessels, making them more permeable. B. Vasodilation and increased blood flow cause redness and increased heat. C. Increased blood flow at the site of a wound helps to flush out invading pathogens. D. Injured tissues and macrophages at the site of infection release chemokines, which recruit immune system cells to the site.

C. Increased blood flow at the site of a wound helps to flush out invading pathogens.

What effect does antidiuretic hormone (ADH) have on the nephron? A. It increases water permeability of the descending limb of the loop of Henle. B. It activates sodium-potassium pumps in the distal tubule, causing reabsorption of Na+ and secretion of K+. C. It increases water permeability of the collecting duct. D. It decreases urea permeability of the collecting duct.

C. It increases water permeability of the collecting duct.

What functions are carried out by macrophages at wound sites? A. Macrophages release histamines to cause capillaries to dilate and allow the release of leukocytes. B. Macrophages mature into dermal cells that repair the wound and stop the invasion of pathogens. C. Macrophages recruit other leukocytes by releasing cytokines and remove pathogens through phagocytosis. D. Macrophages release blood-clotting factors at the wound site to stop bleeding.

C. Macrophages recruit other leukocytes by releasing cytokines and remove pathogens through phagocytosis.

Why must marine bony fishes drink large amounts of seawater? A. Marine bony fishes are osmoconformers living in a hyperosmotic environment. B. Marine bony fishes are osmoregulators living in a hyposmotic environment. C. Marine bony fishes are osmoregulators living in a hyperosmotic environment. D. Marine bony fishes are osmoconformers living in a hyposmotic environment.

C. Marine bony fishes are osmoregulators living in a hyperosmotic environment.

Which of the following hypothetical drug actions is not paired with a likely effect on muscle function? A. Blocking release of calcium ions from the sarcoplasmic reticulum -> prevent muscle contractions. B. Increased acetylcholine released -> increased rate of action potentials in the muscle cells and more forceful muscle contraction. C. Prevent binding of ATP to the myosin head -> myosin head releases from the actin filament, relaxing the muscle. D. Preventing conformational changes in troponin -> prevent muscle contraction.

C. Prevent binding of ATP to the myosin head -> myosin head releases from the actin filament, relaxing the muscle.

German biologist Arnold Berthold conducted experiments with roosters in the mid-1800s. His experiments included three treatment groups: castrated roosters, uncastrated roosters, and castrated roosters with reimplantation of testes in the abdominal cavity. Which of the following was a critical piece of evidence for the involvement of chemical hormone activity in development and behavior? A. Reimplanted testes experienced regeneration of neural connections, but failed to establish new blood vessels. B. Fully castrated roosters (no reimplantation of testes) and uncastrated roosters acted aggressively. C. Reimplanted testes experienced regeneration of blood vessels but failed to develop neural connections. D. Fully castrated roosters and castrated roosters having reimplanted testes both acted unaggressively and failed to develop typical combs and wattles. Submit

C. Reimplanted testes experienced regeneration of blood vessels but failed to develop neural connections.

What type of muscle tissue is multinucleate, striated, and unbranched? A. All muscle B. Cardiac muscle C. Skeletal muscle D. Smooth muscle

C. Skeletal muscle

Which statement best describes the generation of the enormous variety of B-cell antibodies and antigen recognition? A. Each antibody involves randomly variable C regions of light and heavy chains combined with stable J regions, resulting in many different antibody forms. B. Each antibody forms from combinations of each class of immunoglobin into pentamers. C. The variable regions of light and heavy chains of immunoglobulin result from the random genetic recombination of one of many V regions, one of several J regions, and, in the case of heavy chains, one of many D regions. D. The recombination of variable segments of the alpha and beta arms of immunoglobulin permits the formation of millions of possible antigen-recognizing forms.

C. The variable regions of light and heavy chains of immunoglobulin result from the random genetic recombination of one of many V regions, one of several J regions, and, in the case of heavy chains, one of many D regions.

Why is clonal selection necessary for the adaptive immune response but not the innate immune response? A. The adaptive immune response uses receptors to recognize pathogens and trigger clonal selection, while the innate immune response does not. B. Clonal selection is used for targeting pathogens, and the innate immune response is used only to stop blood flow from the wound. C. There is more receptor diversity in the adaptive immune response than in the innate immune response. Only a few specific cells are selected and cloned in response to an infection. D. Cells in the innate immune response do not require activation, and those in the adaptive immune response do.

C. There is more receptor diversity in the adaptive immune response than in the innate immune response. Only a few specific cells are selected and cloned in response to an infection.

Which of the following actions regarding fishes that live in fresh water does not happen? A. Water enters epithelial cells in their gills via osmosis. Electrolytes leave the same cells via diffusion. B. They have specialized epithelia that actively pump electrolytes from the environment into the blood. C. They lose water to their environment primarily through the gills. They replace this water by drinking. D. They excrete large volumes of water in dilute urine.

C. They lose water to their environment primarily through the gills. They replace this water by drinking.

What is the function of the Loop of Henle in mammalian kidneys? A. To use active transport to recover glucose B. To produce the initial filtrate from blood entering the glomerulus C. To create the kidney's osmotic gradient that permits the reabsorption of water and various solutes D. To produce highly concentrated urine

C. To create the kidney's osmotic gradient that permits the reabsorption of water and various solutes

Which of the following is not an advantage of the short gestation time of marsupials? A. With the short gestation time, the marsupial mother does not need to develop a placenta to nourish the embryo. B. The short gestation time of marsupials allows them to immediately conceive again. C. With the short gestation period, marsupial mothers do not have to invest a great deal in their offspring. D. With the short gestation time, they can have offspring more frequently.

C. With the short gestation period, marsupial mothers do not have to invest a great deal in their offspring.

Which of these is not a difference between CD4+ and CD8+ T cells? A. CD4+ cells interact with class II MHC proteins, and CD8+ cells interact with class I MHC proteins. B. CD4+ cells differentiate into two distinct types of helper T cells, while CD8+ differentiate into one type of cytotoxic T cells. C. The daughter cells of activated CD4+ T cells differentiate into effector cells called helper T cells, while the daughter cells of activated CD8+ T cells develop into effector cells called cytotoxic T cells. D. Following activation and clonal expansion, CD4+ cells become effector cells in the lymphatic system, while CD8+ cells become effector cells that enter the blood.

D. Following activation and clonal expansion, CD4+ cells become effector cells in the lymphatic system, while CD8+ cells become effector cells that enter the blood.

Which of the following organisms would lose the least water by osmosis across its gills? A. Marine bony fish B. Freshwater invertebrate C. Shark D. Freshwater fish

D. Freshwater fish

What barrier(s) prevent the entry of pathogens and protect the ears of humans? A. An acidic environment B. The antibacterial enzyme lysozyme C. Mucous secretions and hairs D. Hairs and wax

D. Hairs and wax

Which of these is an example of positive feedback in the hormonal control of the human menstrual cycle? A. LH triggers secretion of estradiol, but at low levels estradiol inhibits further release of LH. B. Hormone-based contraceptive methods deliver synthetic versions of progesterone to suppress GnRH, FSH, and LH. C. LH and FSH trigger secretion of progesterone, but progesterone inhibits further release of LH and FSH. D. High levels of estradiol trigger release of more LH. The follicle can produce high levels of estradiol only if it has grown and matured.

D. High levels of estradiol trigger release of more LH. The follicle can produce high levels of estradiol only if it has grown and matured.

A mutation that results in the inability of a terrestrial insect to close the spiracles would likely be most disadvantageous in what environment? A. A tropical rain forest B. A marsh C. A marine environment D. A desert environment

D. A desert environment

How do allergies arise? A. Allergies are caused by an inactive immune response, leading to immunodeficiency. B. Allergies arise when a person's immune system attacks molecules or antigens that are normally part of the body. C. Allergies arise when the commonly secreted IgG antibodies do not find their proper antigen but activate the immune system through other means. D. Allergies are generated when overexpressed IgE antibodies match environmental allergens and initiate an immune response by activating mast cells.

D. Allergies are generated when overexpressed IgE antibodies match environmental allergens and initiate an immune response by activating mast cells.

Which of these is not a characteristic of an attenuated virus vaccine that would result in a more effective cell-mediated immune response? A. Attenuated viruses consist of complete virus particles; they can infect the cells of a host, but not well enough to cause disease. B. Attenuated viruses are made harmless by culturing them on atypical cells so that the viruses lose the ability to replicate rapidly in their normal host cells and are eliminated by the immune response before causing disease. C. Since attenuated viruses can infect cells, their antigens will be processed and presented by class I MHC−−peptide complexes. This will produce a strong cell-mediated immune response. D. Attenuated viruses have been damaged by chemical treatments and cannot infect cells at all; they remain as extracellular particles that safely trigger the cell-mediated immune response.

D. Attenuated viruses have been damaged by chemical treatments and cannot infect cells at all; they remain as extracellular particles that safely trigger the cell-mediated immune response.

What is the origin of the cytotoxic cells that attack other cells infected with a specific intracellular pathogen? A. CD4+ T cells activated by antigen presenting dendritic cells become cytotoxic cells that then activate additional lymphocytes. B. Activated B cells expand significantly in size as cytotoxic cells with enlarged endoplasmic reticulum responsible for the production of secreted antibodies. C. Cytotoxic cells arise from dendritic cells that have encountered foreign antigens that signal pathogenic invasion. D. CD8+ T cells differentiate into cytotoxic T cells when they are activated by antigen-presenting dendritic cells, typically requiring cytokines released by activated CD4+ T cells.

D. CD8+ T cells differentiate into cytotoxic T cells when they are activated by antigen-presenting dendritic cells, typically requiring cytokines released by activated CD4+ T cells.

Which of these events during insect metamorphosis is not related to changes in the relative concentrations of juvenile hormone (JH) versus ecdysone? A. If JH is present at high concentration in the larva, increases in ecdysone induce the growth of the larva via periodic moltings. B. If JH concentration is low, increased levels of ecdysone trigger metamorphosis and the complete remodeling of the body from larva to pupa to adult. C. As the name implies, JH in high concentrations maintains the larva in the juvenile form. As the concentration of JH decreases over time, eventually surges in ecdysone will trigger not only molting but the transition to pupa. D. If JH is low and ecdysone is high, after a molt, the juvenile will secrete a tough covering called a pupal case.

D. If JH is low and ecdysone is high, after a molt, the juvenile will secrete a tough covering called a tough covering called a pupal case.

What is the correct order of flow of urine as it leaves the human body? A. Kidney to urethra to bladder to ureter B. Urethra to bladder to ureter to kidney C. Bladder to ureter to kidney to urethra D. Kidney to ureter to bladder to urethra

D. Kidney to ureter to bladder to urethra

In an endocrine signaling pathway, what is the process called in which the product of the pathway inhibits its production? A. Cytokine signaling B. Exocrine signaling C. Positive feedback D. Negative feedback

D. Negative feedback

Which of these is not a characteristic of being an osmoregulating fish in a marine environment? A. Osmoregulating marine fish do not need to make special proteins to protect their cells from high urea concentrations in their tissues. B. Osmoregulating marine fish need to drink large amounts of seawater. C. Osmoregulating marine fish need to expend energy to excrete NaCl. D. Osmoregulating marine fish excrete large volumes of dilute urine.

D. Osmoregulating marine fish excrete large volumes of dilute urine.

Which structure in the female reproductive system is the longest path for the ovum as it travels from the ovary to the uterus? A. Vagina B. Uterus C. Cervix D. Oviduct

D. Oviduct

Which structure contains intertwined capillaries from the mother and the developing embryo? A. Cervix B. Fallopian tube C. Umbilical cord D. Placenta

D. Placenta

If you understand muscle fiber types, you should be able to predict the most abundant fiber type in the postural muscles of the human neck. A. Fast glycolytic fibers B. Fast oxidative/glycolytic fibers C. Smooth muscle fibers D. Slow oxidative fibers

D. Slow oxidative fibers

Movies such as Jurassic Park often show Tyrannosaurus rex moving in ways that are not possible in terms of biomechanics. Which of these type of movements is the only one that would be possible for a T. rex? A. Chasing fast-moving prey over long distances. B. Jumping on prey. C. Running fast. D. Sneaking up on prey.

D. Sneaking up on prey

Why is it often difficult to differentiate between the functions of the nervous and endocrine systems? A. Neurohormones and endocrine hormones sometimes target the same receptors. B. Neurohormones and endocrine hormones both produce rapid responses. C. Neurohormones and endocrine hormones can only act on distant cells. D. Some neurons secrete hormones and some endocrine glands respond to neural signals before releasing hormones.

D. Some neurons secrete hormones and some endocrine glands respond to neural signals before releasing hormones.

How do steroid hormones differ from polypeptide hormones and most amino-acid-derived hormones? A. Only steroid hormones bind to receptors in the plasma membrane. B. Polypeptide and amino-acid-derived hormones are longer lived in the bloodstream and thus exert greater signal amplification. C. Polypeptide hormones are the most structurally complex and induce permanent changes in target cells. D. Steroid hormones are lipid soluble and cross plasma membranes readily.

D. Steroid hormones are lipid soluble and cross plasma membranes readily.

According to the model shown here, why is the dark band in a sarcomere dark and the light band light? A. In the light band zone, the myosin filaments are more stretched and thinner. B. Mitochondria are clustered in the dark band to provide energy for contraction. C. When the action potentials trigger Ca2+ channels to open, Ca2+ floods the cytoplasm, discoloring the dark band area. D. The dark band includes thin filaments as well as thick filaments; the light band consists of thin filaments only.

D. The dark band includes thin filaments as well as thick filaments; the light band consists of thin filaments only.

Which of these is not true about the innate immune compared to the adaptive immune response? A. The innate immune response does not kill cells; the adaptive immune response does. B. Only the adaptive immune response has both cell-mediated and secreted components. C. Both innate and adaptive immune responses are found in all animals. D. The innate immune response does not distinguish between pathogens, while the adaptive immune response does.

D. The innate immune response does not distinguish between pathogens, while the adaptive immune response does.

Which of these is not true about the posterior pituitary gland? A. The posterior pituitary is an extension of the hypothalamus. B. Releasing hormones in the posterior pituitary stimulates the release of other hormones from the anterior pituitary gland. C. The posterior pituitary is a storage area for hypothalamic hormones. D. The posterior pituitary develops from nonneural tissue.

D. The posterior pituitary develops from nonneural tissue.

What is clonal selection in lymphocytes? A. The accumulation of large amounts of secreted antibody that matches a given pathogenic antigen B. The replication of clones of invading bacteria, preventing an adaptive immune response C. The recognition of foreign antigens by class I MHC proteins D. The replication and persistence of B and T cells that have encountered the specific antigen match to their immunoglobulin receptor

D. The replication and persistence of B and T cells that have encountered the specific antigen match to their immunoglobulin receptor

Which type of nitrogenous waste would you expect to be produced by embryos inside eggs laid on land? A. Ammonia B. Nitrate C. Urea D. Uric acid

D. Uric acid

In the rectal gland of sharks, the Na+/K+-ATPase functions to __________. A. facilitate the uptake of chloride from the environment B. increase the sodium content of rectal gland cells C. pump potassium out of the cell D. create a sodium concentration gradient

D. create a sodium concentration gradient