Chapter 40 – Animal Form and FunctionAnswer 20 of the 30 Questions

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1) Which choice best describes a reasonable mechanism for animal structures becoming better suited over evolutionary time to specific functions?A) Animals that eat the most food become the most abundant.B) Animals that restrict their food intake will become less abundant.C) Animals with mutations that give rise to effective structures will become more

abundant.D) Animals with inventions that curtail reproduction will become more abundant.E) Animals with parents that continually improve their offspring's structures will

become more abundant.

____ 2) Penguins, seals, and tuna have body forms that permit rapid swimming, becauseA) 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.

____ 3) Evolutionary adaptations that help diverse animals directly exchange matter between cells and the environment includeA) a gastrovascular activity, a two–layered body, and a torpedo–like body shape.B) an external respiratory surface, a small body size, and a two–cell–layered body.C) a large body volume; a long, tubular body; and a set of wings.D) complex internal structures, a small body size, and a large surface area.E) an unbranched internal surface, a small body size, and thick covering.

____ 4) To increase the effectiveness of exchange surfaces lining the lungs and the intestines, evolutionary pressures haveA) increased the exchange surface area with folds and branches.B) increased the thickness of the membranes in these linings.C) increased the number of cell layers in these linings.D) decreased the metabolic rate of the cells in these linings.E) increased the volume of the cells in these linings.

____ 5) The specialized function shared by the cells that line the lungs and those that line the lumen of the gut is that both types of cellsA) receive their oxygen directly from inhaled air and ingested foods.B) provide abundant exchange surface.C) have exceptionally high numbers of cellular organelles in the cytoplasm.D) offer greater protection due to increased membrane thickness.E) have a lowered basal metabolic rate due to cooperative exchange between cells.

____ 6) Interstitial fluid isA) 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.

____ 7) Multicellular organisms must keep their cells awash in an "internal pond" becauseA) their membranes will crystallize if not in contact with interstitial fluid.B) an aqueous medium is needed for the cellular exchange of nutrients, gases, and

wastes.C) this prevents the loss of water due to osmosis.D) their cells need to be protected from dissolved nitrogen gas in the blood.E) terrestrial organisms have not adapted to life in dry environments.

____ 8) An exchange surface in direct contact with the external environment is found in theA) lungs.B) skeletal muscles.C) liver.D) heart.E) brain.

____ 9) Coordinating body functions via chemical signals is accomplished byA) the respiratory system.B) the endocrine system.C) the immune and lymphatic systems.D) the integumentary system.E) the excretory system.

____ 10) The fibers responsible for the elastic resistance properties of tendons areA) elastin fibers.B) fibrin fibers.C) collagenous fibers.D) reticular fibers.E) spindle fibers.

____ 11) If you gently twist your earlobe, it does not remain distorted because it containsA) collagenous fibers.B) elastin fibers.C) reticular fibers.D) adipose tissue.E) loose connective tissue.

____ 12) Most types of communication between cells utilizeA) 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.

____ 13) A matrix of connective tissue is apparent inA) chondroitin sulfate of cartilage.B) actin and myosin of muscle.C) the axon of a neuron.D) nervous tissues.E) spindle–shaped smooth muscle cells.

____ 14) All types of muscle tissue haveA) 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.

____ 15) Cardiac muscle cells are bothA) striated and interconnected by intercalated disks.B) striated and operate independently of other cardiac cells.C) smooth and under voluntary control.D) striated and under voluntary control.E) smooth and under involuntary control.

____ 16) The type of muscle tissue surrounding internal organs, other than the heart, isA) skeletal muscle.B) cardiac muscle.C) striated muscle.D) intercalated cells.E) smooth muscle.

____ 17) Positive feedback has occurred whenA) 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.

____ 18) 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 aA) terrestrial lizard.B) sea star, a marine invertebrate.C) bluefin tuna, a predatory fish.D) hummingbird.E) honeybee in a hive.

____ 19) An overheated and sick dog in a hot environment will have an impaired thermoregulatory response when itsA) 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.

____ 20) EndothermyA) 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.

____ 21) The temperature–regulating center of vertebrate animals is located in theA) medulla oblongata.B) thyroid gland.C) hypothalamus.D) subcutaneous layer of the skin.E) liver.

____ 22) A female Burmese python incubating her eggs can warm them usingA) acclimatization.B) torpor.C) evaporative cooling.D) nonshivering thermogenesis.E) shivering thermogenesis.

____ 23) 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 limbsB) reduced metabolic rateC) sweating from skin glandsD) a change in the body's thermostat "set point"E) decreased thermogenesis in brown fat

____ 24) Catabolism of specialized brown fat depots in certain animals is substantially increased duringA) acclimatization.B) torpor.C) evaporative cooling.D) nonshivering thermogenesis.E) shivering thermogenesis.

____ 25) A moth preparing for flight on a cold morning warms its flight muscles viaA) acclimatization.B) torpor.C) evaporative cooling.D) nonshivering thermogenesis.E) shivering thermogenesis.

____ 26) Imagine that you are a biologist who is attempting to get an accurate measure of an animal's basal metabolic rate. The best time to measure the metabolic rate is when the animalA) is resting and has not eaten its first meal of the day.B) is resting and has just completed its first meal of the day.C) has recently eaten a sugar–free meal.D) has not consumed any water for at least 48 hours.E) has just completed 30 minutes of vigorous exercise.

____ 27) Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The _____ would have the highest total annual energy expenditure, and the _____would have the highest energy expenditure per unit mass.A) elephant; mouseB) elephant; humanC) human; penguinD) mouse; snakeE) penguin; mouse

____ 28) Compared with a smaller cell, a larger cell of the same shape hasA) less surface area.B) less surface area per unit of volume.C) the same surface–to–volume ratio.D) a smaller average distance between its mitochondria and the external source of

oxygen.E) a smaller cytoplasm–to–nucleus ratio.

____ 29) An animal's inputs of energy and materials would exceed its outputsA) if the animal is an endotherm, which must always take in more energy because of

its high metabolic rate.B) if it is actively foraging for food.C) if it is hibernating.D) if it is growing and increasing its mass.E) never; homeostasis makes these energy and material budgets always balance.

____ 30) Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation?A) a hydraB) a marine jelly (an invertebrate)C) a snake in a temperate forestD) a desert insectE) a desert bird

Chapter 43 - The Immune SystemAnswer 30 of the 40 questions

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1) A fruit fly, internally infected by a potentially pathogenic fungus, is protected byA) its plasma cells.B) its immunoglobulins.C) its antibodies.D) its antimicrobial peptides.E) its B cells.

____ 2) The lymphatic fluidA) is a filtrate of the blood, as is urine.B) is completely separate from the circulatory system for blood.C) carries both red and white blood cells.D) functions in adaptive immunity but not in innate immunity.E) carries a toxic gas that kills cancerous cells.

____ 3) An inflammation-causing signal released by mast cells at the site of an infection isA) an interferon.B) lymphatic fluid.C) histamine.D) mucus.E) sodium ions.

____ 4) A systemic inflammatory response that is often life-threatening isA) mild fever.B) aches and dull pain.C) septic shock.D) high blood pressure.E) increased white blood cell count.

____ 5) Salmonella bacterial poisoning can be initiated whenA) the microbe survives the acidic environment of the stomach and resists lysosomal

degradation in macrophages.B) the chemotactic messengers released by the microbe do not attract sufficient

neutrophils to entirely destroy the infection.C) there is a delay in selection of the population of eosinophils that recognize and

fight these microbes.D) the microbes release chemical messengers that make them resistant to

phagocytosis.E) The combination of foods eaten at the meal reduces the pH of the stomach

sufficiently so that ingested microbes are not destroyed.

____ 6) The complement system isA) 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.

____ 7) Antihistamine treatment reducesA) blood vessel dilation.B) phagocytosis of antigens.C) MHC presentation by macrophages.D) the secondary immune response.E) clonal selection by antigens.

____ 8) Cave art by early humans recognized the existence of the major signs of inflammation. The most inclusive set of symptoms of inflammation that might appear in such early human art isA) heat, pain, and redness.B) pain and whitening of the surrounding tissue.C) swelling and pain.D) antibody-producing cells.E) swelling, heat, redness, and pain.

____ 9) Ancient peoples sought to identify the indicators of inflammation becauseA) seeing such signs would be cause for their seeking out a healer in their community.B) the presence of the signs of inflammation in a patient could be a condemnation of

the healer.C) the ancients probably knew of plant derivatives that could reduce the pain of

inflammation.D) the presence of these signs suggests that healing was taking place; otherwise, the

patient would likely die.E) the signs of inflammation served as a caution to keep people away from the

patient.

____ 10) In some insects, such as Drosophila, fungal cell wall elements can activate the protein Toll, whichA) acts as a receptor that, when activated, signals synthesis of antimicrobial peptides.B) functions directly to attack the fungi presented to it.C) produces antimicrobial peptides by interaction with chitin.D) secretes special recognition signal molecules that identify specific pathogens.E) causes some hemocytes to phagocytize the pathogens.

____ 11) 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 viralA) lipopolysaccharides.B) double-stranded DNA.C) double-stranded RNA.D) glycoproteins.E) phospholipids.

____ 12) Bacterial infection in a previously uninfected house cat would most quickly activate itsA) Toll-like receptors that bind to lipopolysaccharides.B) memory cells to produce antibodies.C) plasma cells to produce antigens.D) cytotoxic T cells.E) humoral immune responses.

____ 13) 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 thatA) 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.

____ 14) Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished byA) polyadenylase.B) RNA polymerase.C) reverse transcriptase.D) epitopase.E) recombinase.

____ 15) Clonal selection implies thatA) brothers and sisters have similar immune responses.B) antigens increase mitosis in specific lymphocytes.C) only certain cells can produce interferon.D) a B cell has multiple types of antigen receptors.E) the body selects which antigens it will respond to.

____ 16) Clonal selection is an explanation for howA) a single type of stem cell can produce both red blood cells and white blood cells.B) V, J, and C gene segments are rearranged.C) an antigen can provoke production of high levels of specific antibodies.D) HIV can disrupt the immune system.E) macrophages can recognize specific T cells and B cells.

____ 17) Secondary immune responses upon a second exposure to a pathogen are due to the activation ofA) memory cells.B) macrophages.C) stem cells.D) B cells.E) T cells.

____ 18) The MHC is important in a T cell's ability toA) distinguish self from nonself.B) recognize specific parasitic pathogens.C) identify specific bacterial pathogens.D) identify specific viruses.E) recognize differences among types of cancer.

____ 19) 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 toA) 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.

____ 20) Immunological memory accounts forA) the human body's ability to distinguish self from nonself.B) the observation that some strains of the pathogen that causes dengue fever cause

worse disease than others.C) the ability of a helper T cell to signal B cells via cytokines.D) the ancient observation that someone who had recovered from the plague could

safely care for those newly diseased.E) the ability of the immune system to present antigen fragments in association with

MHC antigens.

____ 21) Yearly vaccination of humans for influenza viruses is necessary becauseA) of an increase in immunodeficiency diseases.B) flu can generate anaphylactic shock.C) surviving the flu one year exhausts the immune system to nonresponsiveness the

second year.D) rapid mutation in flu viruses alters the surface proteins in infected host cells.E) flu leads to autoimmune disorders.

____ 22) The cell-mediated immunity that destroys virally infected cells involvesA) cytotoxic T cells.B) natural killer cells.C) helper T cells.D) macrophages.E) B cells.

____ 23) Among the last line of defenses against prolonged exposure to an extracellular pathogen isA) lysozyme production.B) phagocytosis by neutrophils.C) antibody production by plasma cells.D) histamine release by basophils.E) lysis by natural killer cells.

____ 24) A cell type that interacts with both the humoral and cell -mediated immune pathways is aA) plasma cell.B) cytotoxic T cell.C) natural killer cell.D) CD8 cell.E) helper T cell.

____ 25) B cells interacting with helper T cells are stimulated to differentiate whenA) B cells produce IgE antibodies.B) B cells release cytokines.C) helper T cells present the class II MHC molecule -antigen complex on their

surface.D) helper T cells differentiate into cytotoxic T cells.E) helper T cells release cytokines.

____ 26) The primary function of humoral immunity isA) 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.

____ 27) Jenner's successful use of cowpox virus as a vaccine against the smallpox virus is due to the fact thatA) the immune system responds nonspecifically to antigens.B) the cowpox virus made antibodies in response to the presence of smallpox.C) cowpox and smallpox are antibodies with similar immunizing properties.D) there are some antigenic determinants common to both pox viruses.E) cowpox and smallpox are caused by the same virus.

____ 28) An individual who has been bitten by a poisonous snake that has a fast -acting toxin would likely benefit fromA) vaccination with a weakened form of the toxin.B) injection of antibodies to the toxin.C) injection of interleukin-1.D) injection of interleukin-2.E) injection of interferon.

____ 29) For the successful development of a vaccine to be used against a pathogen, it is necessary thatA) the surface antigens of the pathogen not change.B) a rearrangement of the B cell receptor antibodies takes place.C) all of the surface antigens on the pathogen be identified.D) the pathogen has only one epitope.E) the MHC molecules are heterozygous.

____ 30) A diseased patient is exposed to an unknown agent while out of the country. The patient's blood is found to have a high proportion of lymphocytes with CD8 surface proteins in her blood, a likely result ofA) the patient having encountered a bacterial infection which elicited CD8 + T cells.B) the disease having been caused by a multicellular parasite, such as can be

encountered in polluted water sources.C) the CD8 proteins having been discharged from these lymphocytes to lyse the

infected cells.D) a viral infection eliciting proliferation of CD8+ cytotoxic T cells.E) the CD8 proteins having "marked" the surface of cells that accumulate after the

infection is over and signal patient recovery.

____ 31) Infection with HIV typicallyA) increases the level of helper T cells for the first year after infection.B) eliminates all T cells immediately.C) leads to an immediate decrease in the number of HIV in the blood.D) alters mitochondrial but not genomic DNA sequences.E) is found in B cells but not in T cells.

____ 32) An immune response to a tissue graft will differ from an immune response to a bacterium becauseA) MHC molecules of the donor may stimulate rejection of the graft tissue, but

bacteria lack MHC molecules.B) the tissue graft, unlike the bacterium, is isolated from the circulation and will not

enter into an immune response.C) a response to the graft will involve B cells and a response to the bacterium will not.D) a bacterium cannot escape the immune system by replicating inside normal body

cells.E) the graft will stimulate an autoimmune response in the recipient.

____ 33) 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 asA) an allergy.B) an immunodeficiency.C) an autoimmune disease.D) an antigenic variation.E) a cancer.

____ 34) A patient who has a parasitic worm infection and another patient responding to an allergen such as ragweed pollen have which of the following in common?A) an increase in cytotoxic T cell numberB) suffering from anaphylactic shockC) risking development of an autoimmune diseaseD) suffering from a decreased level of innate immunityE) an increase in the levels of IgE

____ 35) Mutant fruit flies that make only one antimicrobial peptide were tested for survival after infection with Neurospora crassa fungi or with Micrococcus luteus bacteria.

The results shown in the graphs support the hypothesis thatA) adding the defensin gene to such mutants protects them from fungal infection.B) adding the drosomycin gene to such mutants protects them from fungal infection.C) wild-type flies with the full set of genes for antimicrobial peptides are highly

susceptible to these infective agents.D) the presence of any single antimicrobial peptide protects against both infective

agents.E) even the wild-type flies rarely, if ever, survive for five days.

____ 36) Study the table. The mother could exhibit an anti-Rh-factor reaction to the developing fetus inA) Case 1 only.B) Case 3 only.C) Cases 1 and 2 only.D) Cases 1, 2, and 3.E) It cannot be determined from the data given.

____ 37) After a long and cold winter, Jim was excited to start exploring the woods behind his new home. His first adventure included exposure to poison ivy without any reaction. A month later, though, a second walk through the woods was not so great, since two days later Jim had a terrible rash that lasted for weeks. The fact that the rash took two days to develop indicates that this immune response was an example ofA) humoral immunity.B) cell-mediated immunity.C) innate immunity.D) the activation of Toll-like receptors.E) the activation of the complement system.

Use the following information as background for the next few questions.

Immunodeficiencies can be genetic in origin, and two examples are Bruton’s agammaglobulinemia, an X -linked disorder, and DiGeorge syndrome, caused by a deletion from chromosome 22. Bruton’s disorder results in underdeveloped B cells, whereas DiGeorge syndrome results in a missing or seriously underdeveloped thymus.

____ 38) Select the description that likely indicates a child with Bruton's disease.A) baby girl Denise, with low level of antibody response to streptococcal infectionB) baby boy John, with immature T cells, missing CD4 receptorsC) baby boy Jeff, with no plasma cells following infection by bacterial pneumoniaD) baby girl Susan, with no evidence of a thymus glandE) baby boy Matt, with very low circulating antigens

____ 39) Which of the following statements is not true?A) An antibody has more than one antigen -binding site.B) An antigen can have different epitopes.C) A pathogen makes more than one antigen.D) A lymphocyte has receptors for multiple different antigens.E) A liver cell makes one class of MHC molecule.

____ 40) Which of the following would not help a virus avoid triggering an adaptive immune response?A) having frequent mutations in genes for surface proteinsB) infecting cells that produce very few MHC moleculesC) producing proteins very similar to those of other virusesD) infecting and killing helper T cellsE) building the viral shell from host proteins

Chapter 45 - Hormones and the Endocrine systemAnswer 30 of the 40 Questions

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1) In a positive-feedback system where hormone A alters the amount of protein XA) an increase in A always produces an increase in X.B) an increase in X always produces a decrease in A.C) a decrease in A always produces an increase in X.D) a decrease in X always causes a decrease in A.E) it is impossible to predict how A and X affect each other.

____ 2) Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example ofA) an autocrine signal.B) a paracrine signal.C) an endocrine signal.D) both an autocrine signal and a paracrine signal.E) an autocrine signal, a paracrine signal, and an endocrine signal.

____ 3) Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins?A) neurohormonesB) estrogensC) androgensD) vitamin DE) neurohormones, estrogens, androgens, and vitamin D

____ 4) A paracrine signal that relaxes smooth muscle cells isA) nitric oxide.B) vitamin D.C) testosterone.D) cortisol.E) antidiuretic hormone.

____ 5) A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone'sA) secretory cell.B) plasma cell.C) endocrine cell.D) target cell.E) regulatory cell.

____ 6) Insect hormones and their receptorsA) act independently of each other.B) are a focus in pest-control research.C) utilize cell-surface receptors only.D) are active independently of environmental cues.E) are not relevant to the study of steroid hormones.

____ 7) Endocrine glands that are sources of steroid hormonesA) secrete the steroids through ducts into the blood.B) store those hormones in membrane-bound vesicles.C) have a very short latency between steroid synthesis and steroid release.D) are all controlled by the autonomic nervous system.E) operate independently of other hormonal cuing systems.

____ 8) A chemical signal operating in a paracrine manner is one thatA) is active at a neuronal synapse.B) affects only the cells that synthesize the paracrine signal.C) requires transport in the blood before it can act on its target cells.D) evokes responses from all parts of the vascular system.E) must move through the air before it reaches its target cells.

____ 9) When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, thenA) 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.

____ 10) Suppose that substance X is secreted by one cell, travels via interstitial fluid to a neighboring cell, and produces an effect on that cell. All of the following terms could describe this substance exceptA) paracrine signal.B) neurotransmitter.C) prostaglandin.D) pheromone.E) growth factor.

____ 11) Hormones that promote homeostasisA) 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.

____ 12) During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example ofA) 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.

____ 13) During short-term starvation, most available fuel molecules are catabolized to provide energy for metabolism rather than being used as building blocks for growth and repair, a trade-off that is hormonally regulated byA) acetylcholine.B) glucagon.C) oxytocin.D) antidiuretic hormone.E) insulin.

____ 14) Portal blood vessels connect two capillary beds found in theA) 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.

____ 15) 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 theA) anterior pituitary.B) posterior pituitary.C) adrenal gland.D) bladder.E) kidney.

____ 16) 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 prolactinA) 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.

____ 17) In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, areA) prolactin and calcitonin.B) prolactin and oxytocin.C) follicle-stimulating hormone and luteinizing hormone.D) luteinizing hormone and oxytocin.E) prolactin and luteinizing hormone.

____ 18) Oxytocin and antidiuretic hormone are synthesized in theA) hypothalamus.B) adenohypophysis.C) anterior pituitary.D) adrenal cortex.E) posterior pituitary.

____ 19) Endocrine structures derived from nervous tissue include theA) thymus and the thyroid.B) ovaries and the testes.C) liver and the pancreas.D) anterior pituitary gland and the adrenal cortex.E) posterior pituitary gland and the adrenal medulla.

____ 20) A tropic hormone from the anterior pituitary gland regulates the secretion ofA) parathyroid hormone.B) calcitonin.C) epinephrine.D) thyroxine.E) glucagon.

____ 21) The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed byA) thyroxine.B) epinephrine.C) growth hormone.D) calcitonin.E) glucagon.

____ 22) Which of the following has both endocrine and exocrine activity?A) the pituitary glandB) parathyroid glandsC) salivary glandsD) the pancreasE) adrenal glands

____ 23) A chemical signal that has both endocrine and neural roles isA) parathyroid hormone.B) calcitonin.C) epinephrine.D) acetylcholine.E) ecdysone.

____ 24) The autonomic nervous system includes an endocrine gland known as theA) ovary.B) adrenal medulla.C) adrenal cortex.D) testis.E) thyroid.

____ 25) During a stressful intervalA) TSH stimulates the adrenal cortex and medulla to secrete acetylcholine.B) the alpha cells of islets secrete insulin and simultaneously the beta cells of the

islets secrete glucagon.C) ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous

system stimulate the adrenal medulla.D) the posterior pituitary gland secretes more growth hormones.E) the calcium levels in the blood are increased due to actions of two antagonistic

hormones, epinephrine and norepinephrine.

____ 26) Melatonin is secreted byA) 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.

____ 27) Winter hibernation and spring reproduction in bears are cued by seasonal changes in the secretion ofA) melatonin from the pineal gland.B) melatonin from the hypothalamus.C) thyroxine from the anterior pituitary gland.D) acetylcholine from the pineal gland.E) thyroid-stimulating hormone from the posterior pituitary gland.

____ 28) The steroid hormone that coordinates molting in arthropods isA) ecdysone.B) glucagon.C) thyroxine.D) oxytocin.E) growth hormone.

____ 29) After eating a carbohydrate-rich meal, the mammalian pancreas increases its secretion ofA) ecdysone.B) glucagon.C) thyroxine.D) oxytocin.E) insulin.

____ 30) The increased contraction of the human uterus during labor and delivery is at least partially due to the actions ofA) ecdysone.B) glucagon.C) thyroxine.D) oxytocin.E) growth hormone.

____ 31) Abnormally reduced somatic growth (dwarfism) can be a consequence of decreased hormone secretion from theA) kidneys.B) pancreas.C) adrenal gland.D) posterior pituitary gland.E) anterior pituitary gland.

____ 32) DES is called an "endocrine disrupting chemical" because it structurally resembles, and interferes with, the endocrine secretions of theA) pancreatic islet cells.B) thyroid gland.C) adrenal medulla.D) ovaries.E) hypothalamus.

____ 33) Estradiol is an example ofA) an androgen.B) an estrogen.C) a progestin.D) a catecholamine.E) a glucocorticoid.

____ 34) Epinephrine is an example ofA) an androgen.B) an estrogen.C) a progestin.D) a catecholamine.E) a glucocorticoid.

____ 35)

In an experiment, rats' ovaries were removed immediately after impregnation and then the rats were divided into two groups. Treatments and results are summarized in the table. The results most likely occurred because progesterone exerts an effect on theA) general health of the rat.B) size of the fetus.C) metabolism of the uterus.D) gestation period of rats.E) number of eggs fertilized.

____ 36) A fantasy movie features a caterpillar that never matures into an adult, but simply gets larger and larger with each molt. It might be possible that the caterpillar did not mature into an adult because ofA) a lack of ecdysone.B) a lack of juvenile hormone.C) a decreased level of ecdysone.D) an increased level of juvenile hormone.E) a lack of melatonin.

____ 37) An example of antagonistic hormones controlling homeostasis isA) thyroxine and parathyroid hormone in calcium balance.B) insulin and glucagon in glucose metabolism.C) progestins and estrogens in sexual differentiation.D) epinephrine and norepinephrine in fight-or-flight responses.E) oxytocin and prolactin in milk production.

____ 38) Growth factors are local regulators thatA) are produced by the anterior pituitary.B) are modified fatty acids that stimulate bone and cartilage growth.C) are found on the surface of cancer cells and stimulate abnormal cell division.D) bind to cell-surface receptors and stimulate growth and development of target cells.E) convey messages between nerve cells.

____ 39) Which hormone is incorrectly paired with its action?A) oxytocin — stimulates uterine contractions during childbirthB) thyroxine — stimulates metabolic processesC) insulin — stimulates glycogen breakdown in the liverD) ACTH — stimulates the release of glucocorticoids by the adrenal cortexE) melatonin — affects biological rhythms, seasonal reproduction

____ 40) The relationship between the insect hormones ecdysteroid and PTTH is an example ofA) an interaction of the endocrine and nervous systems.

B) homeostasis achieved by positive feedback.C) how peptide-derived hormones have more widespread effects than steroid

hormones.D) homeostasis maintained by antagonistic hormones.E) competitive inhibition of a hormone receptor.

Chapter 48 - Neurons, Synapses, and SignalingAnswer 30 of the 40 Questions

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1) A simple nervous systemA) must include chemical senses, mechanoreception, and vision.B) includes a minimum of 12 effector neurons.C) has information flow in only one direction: toward an integrating center.D) has information flow in only one direction: away from an integrating center.E) includes sensory information, an integrating center, and effectors.

____ 2) In certain large animals, this type of neuron can extend beyond 1 meter in length.A) glial cell in the brainB) a sensory neuronC) an interneuronD) a glial cell at a ganglionE) a neuron that controls eye movements

____ 3) In a simple synapse, neurotransmitter chemicals are received byA) the dendritic membrane.B) the presynaptic membrane.C) axon hillocks.D) cell bodies.E) ducts on the smooth endoplasmic reticulum.

____ 4) In the communication between a motor neuron and a skeletal muscle,A) the motor neuron is considered the presynaptic cell and the skeletal muscle is the

postsynaptic cell.B) the motor neuron is considered the postsynaptic cell and the skeletal muscle is the

presynaptic cell.C) action potentials are possible on the motor neuron but not the skeletal muscle.D) action potentials are possible on the skeletal muscle but not the motor neuron.E) the motor neuron fires action potentials but the skeletal muscle is not

electrochemically excitable.

____ 5) For a neuron with an initial membrane potential at –70 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result inA) the depolarization of the neuron.B) the hyperpolarization of the neuron.C) the replacement of potassium ions with sodium ions.D) the replacement of potassium ions with calcium ions.E) the neuron switching on its sodium–potassium pump to restore the initial

conditions.

____ 6) A cation that is more abundant as a solute in the cytosol of a neuron than it is in the interstitial fluid outside the neuron isA) HCO3–.B) Cl–.C) Ca2+.D) Na+.E) K+.

____ 7) ATP hydrolysis directly powers the movement ofA) K+ out of cells.B) Na+ out of cells.C) Na+ into cells.D) Ca2+ into cells.E) Cl– into cells.

____ 8) Two fundamental concepts about the ion channels of a "resting" neuron are that the channelsA) are always open, but the concentration gradients of ions frequently change.B) are always closed, but ions move closer to the channels during excitation.C) open and close depending on stimuli, and are specific as to which ion can traverse

them.D) open and close depending on chemical messengers, and are nonspecific as to

which ion can traverse them.E) open in response to stimuli, and then close simultaneously, in unison.

____ 9) A graded hyperpolarization of a membrane can be induced byA) increasing its membrane's permeability to Na+.B) decreasing its membrane's permeability to H+.C) decreasing its membrane's permeability to Cl–.D) increasing its membrane's permeability to Ca2+.E) increasing its membrane's permeability to K+.

____ 10) The "selectivity" of a particular ion channel refers to itsA) permitting passage by positive but not negative ions.B) permitting passage by negative but not positive ions.C) ability to change its size depending on the ion needing transport.D) binding with only one type of neurotransmitter.E) permitting passage only to a specific ion.

____ 11) Action potentials move along axonsA) more slowly in axons of large than in small diameter.B) by the direct action of acetylcholine on the axonal membrane.C) by activating the sodium–potassium "pump" at each point along the axonal

membrane.D) more rapidly in myelinated than in non–myelinated axons.E) by reversing the concentration gradients for sodium and potassium ions.

____ 12) After the depolarization phase of an action potential, the resting potential is restored byA) the opening of sodium activation gates.B) the opening of voltage–gated potassium channels and the closing of sodium

channels.C) a decrease in the membrane's permeability to potassium and chloride ions.D) a brief inhibition of the sodium–potassium pump.E) the opening of more voltage –gated sodium channels.

____ 13) An action potential can start in the middle of an axon and proceed in both opposite directions whenA) the neuron is an inhibitory neuron and operating normally.B) only the middle section of the axon has been artificially stimulated by an electrode.C) the dendritic region fires an action potential.D) it is in its typical refractory state.E) its membrane potential is above the threshold.

____ 14) The primary means by which a neuron can communicate to a second neuron is byA) the frequency of its action potentials.B) the peak of the depolarization phase of an action potential.C) the peak of the undershoot/hyperpolarization of an action potential.D) varying how much neurotransmitter it releases for a given action potential.E) remaining in the depolarization phase of the action potential for an extended

interval.

____ 15) Saltatory conduction is a term applied toA) conduction of impulses across electrical synapses.B) an action potential that skips the axon hillock in moving from the dendritic region

to the axon terminal.C) rapid movement of an action potential reverberating back and forth along a neuron.D) jumping from one neuron to an adjacent neuron.E) jumping from one node of Ranvier to the next in a myelinated neuron.

____ 16) The fastest possible conduction velocity of action potentials is observed inA) thin, non–myelinated neurons.B) thin, myelinated neurons.C) thick, non–myelinated neurons.D) thick, myelinated neurons.

____ 17) One possible disadvantage to a nerve net is that it might conduct impulses in two directions from the point of the stimulus. Most of the synapses in vertebrates conduct information in only one directionA) as a result of the nodes of Ranvier.B) as a result of voltage–gated sodium channels found only in the vertebrate system.C) because vertebrate nerve cells have dendrites.D) because only the postsynaptic cells can bind and respond to neurotransmitters.E) because the sodium–potassium pump moves ions in one direction.

____ 18) The release of acetylcholine from the terminal of a motor neuron is most directly linked toA) the entry of potassium into the axon terminal.B) the exit of potassium from the axon terminal.C) the entry of sodium into the axon terminal.D) the exit of sodium from the axon terminal.E) the entry of calcium into the axon terminal.

____ 19) The observation that the acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it is an example ofA) a voltage–gated sodium channel.B) a voltage–gated potassium channel.C) a ligand–gated sodium channel.D) a second–messenger–gated sodium channel.E) a chemical that inhibits action potentials.

____ 20) An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable toA) potassium ions.B) sodium ions.C) calcium ions.D) ATP.E) all neurotransmitter molecules.

____ 21) The following steps refer to various stages in transmission at a chemical synapse.1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.2. Calcium ions rush into neuron's cytoplasm.3. An action potential depolarizes the membrane of the axon terminal.4. The ligand–gated ion channels open.5. The synaptic vesicles release neurotransmitter into the synaptic cleft.Which sequence of events is correct?

A) 1 2 3 4 5B) 2 3 5 4 1C) 3 2 5 1 4D) 4 3 1 2 5E) 5 1 2 4 3

____ 22) The activity of acetylcholine in a synapse is terminated byA) its active transport across the presynaptic membrane.B) its diffusion across the presynaptic membrane.C) its active transport across the postsynaptic membrane.D) its diffusion across the postsynaptic membrane.E) its degradation by a hydrolytic enzyme on the postsynaptic membrane.

____ 23) Adjacent neurons with direct (non–neurotransmitter) action potential transfer are said to have electrical synapses, based on the presence ofA) tight junctions at their point of contact.B) gap junctions at their point of contact.C) leaky junctions at their point of contact.D) anchoring junctions at their point of contact.E) desmosomes at their point of contact.

____ 24) Ionotropic receptors are found at synapses operated viaA) ligand–gated ion channels.B) second–messenger–gated ion channels.C) electrical synapses.D) inhibitory, but not excitatory, synapses.E) excitatory, but not inhibitory, synapses.

____ 25) When several EPSPs arrive at the axon hillock from different dendritic locations, depolarizing the postsynaptic cell to threshold for an action potential, this is an example ofA) temporal summation.B) spatial summation.C) tetanus.D) the refractory state.E) an action potential with an abnormally high peak of depolarization.

____ 26) When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an example ofA) temporal summation.B) spatial summation.C) tetanus.D) the refractory state.E) an action potential with an abnormally high peak of depolarization.

____ 27) Receptors for neurotransmitters are of primary functional importance in assuring one –way synaptic transmission because they are mostly found on theA) axonal membrane.B) axon hillock.C) dendritic membrane.D) mitochondrial membrane.E) presynaptic membrane.

____ 28) Functionally, which cellular location is the neuron's "decision–making site" as to whether or not an action potential will be initiated?A) axonal membranesB) axon hillocksC) dendritic membranesD) mitochondrial membranesE) presynaptic membranes

____ 29) The primary neurotransmitter from the parasympathetic system that influences its autonomic targets isA) acetylcholine.B) adenosine.C) norepinephrine.D) adrenaline.E) dopamine.

____ 30) The major excitatory neurotransmitter of the human brain isA) acetylcholine.B) epinephrine.C) glutamate.D) nitric oxide.E) GABA.

____ 31) A neuropeptide that might function as a natural analgesic isA) acetylcholine.B) epinephrine.C) endorphin.D) nitric oxide.E) GABA.

____ 32) The botulinum toxin reduces the synaptic release ofA) acetylcholine.B) epinephrine.C) endorphin.D) nitric oxide.E) GABA.

For the following questions, refer to the graph of an action potential.

____ 33) The membrane potential is closest to the equilibrium potential for potassium at labelA) A.B) B.C) C.D) D.E) E.

____ 34) The neuronal membrane is at its resting potential at labelA) A.B) B.C) C.D) D.E) E.

____ 35) Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals. If you experimentally depolarize the middle of the axon to threshold, using an electronic probe, thenA) no action potential will be initiated.B) an action potential will be initiated and proceed only in the normal direction

toward the axon terminal.C) an action potential will be initiated and proceed only back toward the axon hillock.D) two action potentials will be initiated, one going toward the axon terminal and one

going back toward the hillock.E) an action potential will be initiated, but it will die out before it reaches the axon

terminal.

____ 36) What happens when a resting neuron's membrane depolarizes?A) There is a net diffusion of Na+ out of the cell.B) The equilibrium potential for K+ (EK) becomes more positive.C) The neuron's membrane voltage becomes more positive.D) The neuron is less likely to generate an action potential.E) The cell's inside is more negative than the outside.

____ 37) Where are neurotransmitter receptors located?A) the nuclear membraneB) the nodes of RanvierC) the postsynaptic membraneD) synaptic vesicle membranesE) the myelin sheath

____ 38) Temporal summation always involvesA) both inhibitory and excitatory inputs.B) synapses at more than one site.C) inputs that are not simultaneous.D) electrical synapses.E) multiple inputs at a single synapse.

____ 39) Why are action potentials usually conducted in one direction?A) The nodes of Ranvier conduct potentials in one direction.B) The brief refractory period prevents reopening of voltage–gated Na+ channels.C) The axon hillock has a higher membrane potential than the terminals of the axon.D) Ions can flow along the axon in only one direction.E) Voltage–gated channels for both Na+ and K+ open in only one direction.

____ 40) Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?A) Voltage–gated calcium channels in the membrane open.B) Synaptic vesicles fuse with the membrane.C) The postsynaptic cell produces an action potential.D) Ligand–gated channels open, allowing neurotransmitters to enter the synaptic cleft.E) An EPSP or IPSP is generated in the postsynaptic cell.