(Test Bank) Kuby Immunology

Punt,Stranford,Jones,Owen, 8

Medicine

Test Bank

8th Edition

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Test Bank for Kuby Immunology, The downloadable file consists of 174 pages, and the total size of the file is 377.32 KB. Purchase now only for highly discounted price.

Author(s): Punt, Stranford, Jones, Owen

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1.Two of the main, early theories proposed to explain how antigen- specific antibodies develop were the instructional theory and the selective theory. How did the two differ? Which was ultimately shown to be CORRECT? 2.Often, serendipity plays a role in significant scientific discoveries. In your own words, explain how serendipity led Pasteur to discover a cholera vacc ine. 3.Despite its having been eradicated on a glo bal scale, smallpox is presently considered a potential bioterrorism threat. Why? Use evidence to support your answer. 4.Prior to 1999, it was claimed that a thimerosal additive in vacc ines was contributing to the rising incidence of autism. If the claims were true, what resultant trend might you expect to observe in the rate of autism once thimerosal was removed from vacc ines? 5.Given the discovery and development of effective antibiotics, make an argument for the continued use of vacc ines against bacterial pathogens. Use evidence to support your answer. 6.You have a friend unfamiliar with immunology, and he asks you the following question: 揥hy do I need the flu shot every year, but don't need an annual chickenpox vacc ine??As a student of immunology, how would you explain this discrepancy to your friend? Use evidence to support your answer. 7.Provide one benefit and one drawback o f generating random recognition receptors during the development of B cells. 8.A portion of our immune systems' white blood cells is constantly circulating throughout the body via circulation and lymphatics. What is the benefit of such circulation? Page 1Test Bank for Kuby Immunology 8e Jenni Punt, Sharon Stranford, Patricia Jones, Judith Owen (All Chapters Answer at the end of each Chapter)9.Complete the following table by comparing and contrasting innate and adaptive immune responses. 10.What are the hallmarks of inflammation? Describe the physical characteristics of someone experiencing an inflammatory response. 11.Upon receiving immune serum as a treatment for a venomous snake bite, would the recipient be immune from future bites of the same species? 12.Provide one common feature of and two differences between B-cell receptors and PRRs. 13.Given that an important function of the immune system is to both recognize and dispose of cancerous cells, postulate why tumors can be established in a human host. 14.The hygiene hypothesis posits that there is a connection between environmental conditions and certain inappropriate immune responses. If you were a supporter of the hygiene hypothesis, what recommendations would you make to keep people healthier? 15.Which is the BEST definition of 搃mmunity? A)The state of having been exposed to a pathogen repeatedly B)The state of being resistant to reinfection with a pathogen C)When an individual has never been exposed to a pathogen D)When the immune system is activated E)When physical barriers are not enough to prevent infection Page 2Innate ImmunityAdaptive Immunity Is mediated by what cells? What do they recognize? How are the receptors encoded? Why can't they control all infections alone? What do they do in response to antigen?16.What happens to a pathogen as it becomes attenuated? A)It becomes more dangerous to the host. B)It gets smaller. C)It has weakened virulence. D)It becomes older. E)All of the answers are correct. 17.Which of the following advances can be credited to progress made in our understanding of immunology? A)Smallpox eradication B)Treatment of asthma C)Ability to transplant human organs D)Cancer treatment E)All of the answers are correct. 18.Which of the following is the BEST example of herd immunity? A)A child infected with measles travels from Germany to the United States. Several babies contract the disease, but the outbreak is largely contained due to vaccinations. B)Certain populations of cattle are less susceptible to infection with encephalitis because of their genetic makeup. C)Once a certain threshold of individuals has been infected with a novel human pathogen, it is unlikely that any more will be. D)Geese and chickens are infected with different strains of influenza because they express different receptors on their cell surface. E)When infection spreads through a population, certain individuals generate stronger immune responses than others. 19.Which of the following diseases does NOT currently have an effective vaccine? A)Chicken pox B)Polio C)HIV D)Smallpox E)Diptheria Page 320.Examine Figure 1-8. Which cells are MOST likely responsible for the intense response to Antigen A following a second exposure? A)B cells B)T cells C)Memory T cells D)Memory B cells E)Both memory T cells and memory B cells are responsible. 21.Effectors of the humoral immune system are known as A)antibodies. B)immunoglobulin. C)complement. D)B cells. E)All of the answers are correct. 22.Which of the following cell types are lymphocytes? A)Macrophages B)Mast cells C)Neutrophils D)Erythrocytes E)T cells 23.Which of the following is TRUE about antigens? A)They are always derived from pathogens. B)They are always proteins. C)They are recognized by T cells or B cells. D)They must be microbial in origin. E)They usually cause cellular damage. Page 424.Which of the following is a fungal pathogen? A)Vibrio cholera B)Leishmania major C)Poliovirus D)Candida albicans E)Bordetella pertussis 25.True or False? Overall, the human immune system views microbes as pathogens. A)True B)False 26.Which of the following factors has been shown as potentially impacting immune homeostasis in favor of inflammation? A)Diet B)Stress C)Microbiome composition D)All of the answers are correct. E)None of the answers are correct. 27.Many of the ideas raised by Ehrlich's conception of selective theory were true. Which of the following ideas (if any) were later shown to be FALSE? A)Interaction between a cell-bound receptor and pathogen could induce the cell to proliferate. B)The specificity of receptors was determined in the host prior to exposure to a foreign antigen. C)The antigen selected the appropriate receptor in a specific manner. D)The binding of a receptor to an infectious agent was like the fit between a lock and a key. E)All the ideas listed were shown to be true. 28.Which of the following cell types is MOST commonly associated with recognizing antigens found inside of cells? A)Macrophages B)B cells C)T H cells D)CTLs E)Antibodies Page 529.Which of the following classes of cell surface receptors are directly encoded in the germ line? A)TCR B)BCR C)PRR D)Antibodies E)All of the answers are correct. 30.What is the central mechanism for establishing self-tolerance? A)Self-reactive T cells and B cells are killed during development. B)Individuals that have immune systems that respond to self- antigens do not survive to reproduce. C)Immune cells that react to self-antigens are turned off when they recognize self-tissues. D)Certain immune suppressive cytokines are maintained in tissues to dampen auto reactive immune responses. E)Peripheral tissues have mechanisms to kill T or B cells that respond to them. 31.Which of the following BEST describes chemokines? A)Membrane receptors that detect the presence of soluble messengers in the environment B)Soluble proteins that recruit specific cells to an area C)Chemical messengers that induce cell differentiation D)Transcription factors that induce the expression of genes involved in cell adhesion E)Adhesion molecules that bind to the inside of blood vessels 32.Which of the following statements BEST differentiates innate and adaptive immune responses? A)Innate responses are stronger during the primary and less important during the secondary response, whereas adaptive responses are less robust during primary responses and stronger during secondary responses. B)Innate responses are weaker during the primary and more robust during the secondary response, whereas adaptive responses are stronger during the primary and weaker during secondary responses. C)Innate responses are slower and weaker than adaptive responses. D)Adaptive responses are slower and weaker than innate responses. E)Adaptive responses are required for effective immune responses, whereas innate responses are not required. Page 633.True or False? The innate and adaptive immune responses work largely independently of one another. A)True B)False 34.How do memory cells develop? A)Upon reinfection, memory centers in the brain send signals to the bone marrow to induce T-cell and B-cell differentiation. B)T cells and B cells from the primary response persist and become reactivated. C)Innate cells are trained to activate new T cells and B cells more quickly with secondary infection. D)T cells and B cells from the primary infection slowly mutate their receptors over time, priming themselves for the secondary response. E)Innate cells modify their cell surface receptors to prepare for reinfection. 35.Which of the following is the BEST example of a hypersensitivity reaction? A)T cells responding vigorously to the flu virus B)B cells failing to respond to HIV, allowing it to replicate out of control C)Inflammation of the airways in response to pollen D)Anemia as a result of iron deficiency E)T cells attacking the myelin sheath of nerves resulting in paralysis 36.HIV disease is a(an) A)autoimmune disease. B)hypersensitivity disease. C)immunodeficiency. D)genetic disorder. E)allergic reaction. Page 737.Predict the outcome of being immunosuppressed as it relates to the development of cancer. A)Immunosuppressed individuals are at lower risk of cancer because cytokines produced by the immune system induce cancer. B)Immunosuppressed individuals are at lower risk of cancer because they are more likely to contract infectious diseases. C)Immunosuppressed individuals are at higher risk of cancer because the immune system recognizes and destroys cancerous cells. D)Immunosuppressed individuals are at higher risk of cancer because they bear a higher load of microbes that damage host tissues. E)None of the answers are correct. 38.What occurs when someone receives a tissue transplant from an unrelated individual? A)The host's lymphocytes enter the tissues and become suppressed. B)The host's lymphocytes enter the tissues and become activated. C)The host's lymphocytes that react to the tissue graft are deleted in the thymus. D)The donor's lymphocytes suppress the host's lymphocytes, allowing for graft survival. E)The donor's lymphocytes destroy the host's immune system. 39.Which of the following is TRUE? A)Vaccines cause autism. B)Vaccines cause obesity. C)Vaccines cause cancer. D)Vaccines cause diabetes. E)None of the answers are correct. 40.Conditions in which the immune system attacks self-antigens are known as A)autoimmunity. B)immune deficiency. C)hypersensitivities. D)neuroplasias. E)None of the answers are correct. Page 8Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.B 16.C 17.E 18.A 19.C 20.E 21.E 22.E 23.C 24.D 25.B 26.D 27.E 28.D 29.C 30.A 31.B 32.A 33.B 34.B 35.C 36.C 37.C 38.B 39.E 40.A Page 91.Imagine that you are a thymocyte that has just entered the thymus. Assuming you will survive positive and negative selection, what changes will you experience before developing in a na 飗e CD4+ T cell? 2.Name three parts of the human body where you would expect to find secondary lymphoid tissues. 3.In your own words, explain how an NKT cell displays properties of both innate and adaptive immunity. 4.Plasma cells can secrete thousands of antibodies per second. Based on this observation, name two organelles that you might expect to find in abundance within an active plasma cell. 5.What important role do antibodies play in the isolation of HSCs from the bone marrow? 6.A graduate student observes a strain of mice that are impaired in their ability to combat parasitic worms. Given this observation, which arm of hematopoiesis is MOST likely deficient in this strain? 7.In addition to the bone marrow, HSCs have been observed to occur within the blood. How has this observation improved the procedures used to transplant HSCs from donors to recipients that are bone marrow deficient? 8.Can you think of two cellular activities occurring within a swelling lymph node that has been exposed to antigen from a pathogen? 9.Beyond structural differences, name functional differences between a lymph node and the spleen. 10.You have discovered a potentially new leukocyte that appears to share a common progenitor with CD8+ T cells, lack antigen-specific receptors, do not participate in antigen presentation, and have a capacity for ADCC. Using knowledge of hematopoiesis, which cell type MOST closely resembles the potentially new leukocyte? Page 111.All blood cells in an adult human can trace their ancestry to which compartment within the body? A)Thymus B)Bone marrow C)Lymph node D)Peyer's patch E)None of the answers are correct. 12.If a human were unable to produce lymphoid progenitor cells, predict which part of the immune system would be MOST greatly impacted? A)Innate immunity B)Adaptive immunity C)Both innate and adaptive would be equally impacted D)Neither innate nor adaptive immunity would be impacted E)None of the answers would be impacted. 13.A pluripotent stem cell can do which of the following? A)Differentiate into a finite number of different cell types B)Differentiate into any type of cell found in the adult C)Divide an infinite number of times D)All of the answers are correct. E)None of the answers are correct. 14.Which of the following is the pluripotent stem cell that gives rise to all blood cells? A)CLP B)CMP C)CEP D)HSC E)None of the answers are correct. 15.From which of the following stem cells are NK cells derived? A)CLP B)CMP C)CEP D)Both CLP and CMP are correct. E)None of the answers are correct. 16.Which cell can differentiate into the GREATEST variety of cells during hematopoiesis? A)B-cell progenitor B)Basophil progenitor C)T-cell progenitor D)Eosinophil progenitor E)Myeloid progenitor Page 217.Using a light microscope, you observe a human blood smear. Among the abundance of erythrocytes, you note a leukocyte that appears to contain a multilobed nucleus. What is the MOST likely identity of the observed leukocyte? A)T lymphocyte B)B lymphocyte C)Neutrophil D)Eosinophil E)Both Neutrophil and eosinophil are equally likely. 18.From which of the following stem cells are DCs derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. 19.From which of the following stem cells are platelets derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. 20.From which of the following stem cells are eosinophils derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. 21.From which of the following stem cells are helper T cells (T H) derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. Page 322.From which of the following stem cells are monocytes derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. 23.From which of the following stem cells are RBCs derived? A)CLP B)CMP C)CEP D)Both CLP and CMP. E)None of the answers are correct. 24.What level of gene expression is regulated by such factors as Notch1, GATA-2 and Bmi-1 ? A)Replication B)Transcription C)RNA processing D)Translation E)None of the answers are correct. 25.Which lineage of immune cells constitutes the first line of defense against an infection? A)Lymphoid B)Erythroid C)Myeloid D)All of the answers are correct. E)None of the answers are correct. 26.You have consumed a salad contaminated with Salmonella enterica , which typically causes a self-limiting, gastrointestinal disease in humans. Based on this information, which immune organ is MOST likely to first recognize and mount a response against the pathogen? A)Spleen B)SALT C)Thymus D)GALT E)Lymph node Page 427.Which properties listed below are shared by both na 飗e B cells and mature T cells? A)Are derived from lymphoid progenitor cells B)Are considered lymphocytes C)Contain membrane-bound antigen receptors D)All of the answers are correct. E)None of the answers are correct. 28.Which of the following is NOT descended from the common lymphoid progenitor? A)T cells B)NK cells C)B cells D)Eosinophils E)All of the answers are descended from the common lymphoid progenitor. 29.Which of the following granulocytes contains histamine within its granules? A)Neutrophils B)Eosinophils C)Basophils D)Both Eosinophils and Basophils E)All of the answers are correct. 30.Which of the following is NOT true about monocytes? A)They comprise between 5%-10% of circulating leukocytes. B)They have the ability to differentiate into macrophages or dendritic cells. C)They can be subdivided into inflammatory monocytes and patrolling monocytes. D)They can give rise to platelets. E)All of the answers are true. 31.Which of the following cell types is responsible for the secretion of immunoglobulins? A)T H1 B)T H2 C)T H17 D)T FH E)Plasma cell Page 532.Which of the following cell types is responsible for regulating responses against intracellular pathogens? A)T H1 B)T H2 C)T H17 D)T FH E)Plasma cell 33.Which of the following cell types is responsible for activating B cells in germinal centers? A)T H1 B)T H2 C)T H17 D)T FH E)Plasma cell 34.Which of the following cell types is responsible for regulating responses against predominantly extracellular pathogens? A)T H1 B)T H2 C)T H17 D)T FH E)Plasma cell 35.Which of the following cell types secretes IL-17 and may play a role in antifungal responses? A)T H1 B)T H2 C)T H17 D)T FH E)Plasma cell 36.Which of the following effector T lymphocyte populations is produced via the activation of a na 飗e T cell through antigen presented in MHC Class I? A)CTL B)T H1 C)T H2 D)T H17 E)None of the answers are correct. Page 637.Which of the following types of effector T lymphocytes is capable of inhibiting an immune response to an antigen recognized with its T-cell receptor (TCR)? A)T H1 B)T REG C)T H2 D)T H17 E)None of the answers are correct. 38.Which of the following descendants of the CLP act in the innate immune response? A)T cells B)NK cells C)B cells D)Plasma cells E)All of the answers are correct. 39.Which of the following is NOT considered primary lymphoid tissue? A)Draining lymph node B)Thymus C)Peyer's patch D)Neither draining lymph node nor Peyer's patch are primary lymphoid tissue. E)None of the answers are primary lymphoid tissue. 40.In mammals, T-cell development occurs in the _____, whereas B-cell development occurs predominantly in the _____. A)thymus; bursa of Fabricius B)bone marrow; mesenteric lymph nodes C)bone marrow; thymus D)thymus; bone marrow E)None of the answers are correct. 41.As thymocytes develop, they are classified on the basis of the state of their T-cell receptors and which of the following? A)Which class of MHC they express on their surface B)The state of the immunoglobulin heavy and light chains on their surface C)The presence of coreceptor proteins CD4 and CD8 on their surface D)The expression of the transcription factor, FoxP3 E)None of the answers are correct. Page 742.Upon entering the thymus, thymocytes are classified as double _____ with regard to coreceptors; before exiting as single-positive, na 飗e T cells, they pass through a period in which they are double _____. A)positive; negative B)negative; positive C)Both 損ositive; negative?and 搉egative; positive?are correct. D)Neither 損ositive; negative?nor 搉egative; positive?are correct. E)Coreceptor expression state does not change in the thymus. 43.Contraction of which of the following types of muscles is responsible for propulsion of lymph through the lymphatic system? A)Cardiac B)Skeletal C)Smooth D)Both skeletal and smooth are correct. E)None of the answers are correct. 44.Na飗e lymphocytes enter secondary lymphoid tissues via which of the following structures? A)Afferent lymphatics B)Efferent lymphatics C)HEVs D)Marginal sinus E)None of the answers are correct. 45.Which of the following does NOT appear to utilize the FRCC system as its primary means for trafficking through the lymph node? A)B cells B)T cells C)Free antigen that entered via an afferent lymphatic D)Cytokines and chemokines E)None of the answers utilizes the FRCC system. Page 8Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.B 12.B 13.A 14.D 15.A 16.E 17.E 18.D 19.C 20.B 21.A 22.B 23.C 24.B 25.C 26.D 27.E 28.D 29.C 30.D 31.E 32.A 33.D 34.B 35.C 36.A 37.B 38.B 39.D 40.D 41.C 42.B 43.D 44.C 45.A Page 91.Which of the following types of bonds would be LEAST likely in a receptor-ligand interaction? A)Ionic bond B)Covalent bond C)Hydrogen bond D)Hydrophobic interaction E)All of the answers are equally likely. 2.The end results of signal transduction are varied but can include A)Induction of cell division. B)Cellular differentiation. C)Altered metabolism. D)Altered protein secretion patterns. E)All of the answers are correct. 3.K a, the association constant, is a measure of which of the following? A)The concentration of unbound ligand B)The concentration of unbound receptor C)The affinity of receptor for ligand D)The size of the receptor relative to the ligand E)The number of ligands for each receptor 4.Which of the provided disassociation constants is MOST likely to be observed from an antibody binding an antigen during an immune response involving memory B cells? A)10-3 M B)10-5 M C)10-2 M D)10-10 M E)Antibody-antigen interactions cannot be measured. 5.Receptors that are multivalent tend to bind to their ligands more strongly than receptors with a single binding site. What is the term used to describe this phenomenon? A)Avidity B)Valency C)Affinity D)Magnetism E)None of the answers are correct. Page 16.Which of the following BEST describes how cytokines are released from activated T cells? A)Cytokines are released near where T-cell receptors are clustered. B)T cells release cytokines on the side of the cell opposite the MTOC to more efficiently distribute the response around the cell. C)T cells release cytokines evenly around the cell. D)Cytokines are released in short bursts from preformed vesicles full of cytokines. E)Cytokines are released in whatever direction the MTOC happens to be facing upon TCR ligation. 7.Receptors that dimerize upon ligand binding often contain _____ in their cytoplasmic domains. A)tyrosine kinases B)hydrophobic regions C)proteases D)metal-binding regions E)large immunoglobulin folds 8.Portions of the cytoplasmic domains of many immune receptors are targets for phosphorylation. These domains are known as A)Grb domains. B)ITAMs. C)leucine zipper motifs. D)SOS domains. E)None of the answers are correct. 9.You note a population of T cells that contain primarily high-affinity IL-2R on their cell surfaces. Based on that observation, what can you predict about the activation state of the cells? A)They have not been exposed to antigen. B)T cells do not express IL-2R, so we cannot determine their activation state using these data. C)This cell population has been exposed to IL-2 and is active. D)They have been exposed to antigen but not IL-2. E)None of the answers are correct. 10.Lipid rafts are highly ordered regions of the cell membrane that are enriched in A)unsaturated fats. B)cholesterol. C)metabolic proteins. D)clathrin. E)tubulin. Page 211.Which of the following are well-established ways that tyrosine phosphorylation directly affects signaling pathways? A)Inducing kinase activity B)Recruiting enzymes through SH2 domains C)Opening calcium channels D)Both inducing kinase activity and recruiting enzymes through SH2 domains E)Both recruiting enzymes through SH2 domains and opening calcium channels 12.Which of the following is the CORRECT relationship? A)PIP 2 = PIP 3 ?DAG B)PIP 2 = IP 3 + DAG C)PLC = PIP 2 + PIP 3 D)DAG = PIP 2 + PIP 3 E)PIP 3 = IP 3 + PIP 2 13.Which transcription factor becomes translocated to the nucleus downstream of calmodulin activation? A)NF- kB B)NFAT C)STAT1 D)STAT2 E)STAT3 14.G proteins A)bind GTP. B)dephosphrylate ITAMs. C)are transcription factors. D)downmodulate immune responses. E)are adhesion molecules. 15.Which of the following is responsible for IL-2 expression in T cells? A)NF- kB B)NFAT C)AP-1 D)Both NF- kB and NFAT are responsible. E)All of the answers are responsible. Page 316.Immunoglobulin domains consist of A)a series of a helices bound together by hydrophobic interactions in their side chains. B) a helices alternating with parallel b-pleated sheets. C)antiparallel b-pleated sheets folded and stabilized by hydrophobic interactions. D)compact, parallel b sheets forming a barrel structure. E) a helices held together by leucine repeats. 17.On the gel below, which bands would you expect to bind antigen? A)Band A B)Band B C)Band C D)Band D E)Bands A, B, and C 18.Antibodies consist of A)two identical heavy chains and two identical light chains. B)an a chain, a b chain, a l chain, and a k chain. C)two a chains, an b chain, and a k chain. D)two b chains, an a chain, and a k chain. E)either an a chain or a b chain, a k chain, and a l chain. 19.Which of the following isotypes of antibodies is the largest? A)IgM B)IgG C)IgA D)IgE E)IgD Page 420.An antibody's idiotype refers to A)the kind of Fc region it contains. B)the sequence of its CDR. C)Ii's allelic form. D)whether it is membrane bound or secreted. E)which accessory molecules associate with it. 21.Carbohydrate chains attached to the C H2 domains of IgA, IgD, and IgG are believed to A)allow for closer contact between partner chains. B)confer stability to the molecule resulting in a higher desaturation temperature. C)prevent protease degradation. D)provide space for complement protein binding. E)increase binding affinity for antigen. 22.Whether an immunoglobulin is secreted or membrane bound is directly determined by A)the sequence of the DNA in the Ig locus. B)mRNA splicing. C)the kind of B cell that is producing it. D)DNA rearrangement. E)GPI anchors. 23.Receptors that bind the constant regions of antibodies are known as A)B-cell receptors. B)T-cell receptors. C)idiotype receptors. D)toll-like receptors. E)Fc receptors. 24.Large amounts of monoclonal antibodies in the serum of an individual might be an indicator of A)infection. B)T-cell deficiency. C)autoimmune disease. D)myeloma. E)stress. Page 525.Which of the following would be BEST for depleting an entire class of antibodies? A)Anti-idiotype antibody B)Anti-isotype antibodies C)Anti-CD19 D)Anti-CD4 E)Anti-CD8 26.Which of the following BEST describes why it is challenging for surface immunoglobulin to transduce a signal into the cell upon antigen binding? A)It takes twice as much antigen to stimulate the cells because each antibody has two antigen binding sites. B)The cytoplasmic domain of surface Ig only has three amino acids. C)Ig a is rapidly dephosphorylated. D)Ig is an inflexible molecule. E)All of the answers are correct. 27.Regions of TCRs and BCRs that are particularly variable in their amino acid sequences are known for A)binding to antigen. B)sticking to denatured proteins. C)spanning the plasma membrane. D)binding to adaptor proteins. E)becoming phosphorylated. 28.Which of the following contains the MOST ITAMs? A)CD3 g B)CD3 d C)CD3 z D)TCR a E)TCR b 29.CD4 binds to A)TCR a. B)TCR b. C)MHC class I. D)MHC class II. E)CD8. Page 630.The antigen specific component of the B-cell receptor is A)ITAM. B)CD19. C)Iga/b. D)CD21. E)Lyn. 31.In the research laboratory, you observe that B cells, cytotoxic T cells and mast cells begin to proliferate when exposed to IL-4. In this case, this effect of IL-4 may be described as A)synergy. B)antagonism. C)redundancy. D)pleiotrophy. E)both redundancy and pleiotrophy. 32.The biological outcomes of immune system recognition can include A)migration of leukocytes into infected tissues. B)clearance of a pathogen by an activated macrophage. C)promotion of optimal antigen presentation. D)induction of long-lived B and T cells. E)All of the answers are correct. 33.Name the two key elements to a meaningful receptor-ligand interaction as a means of cell-to-cell communication. 34.Explain the observation that receptor-ligand interactions are noncovalent despite the weak nature of such bonds versus covalent bonds. 35.In your own words, explain an advantage of a bivalent versus univalent approach to receptor-ligand binding. 36.Structural studies of a potentially new cell surface protein reveal a hydrophobic C-terminal region, several regions consisting of b sheets, predicted disulfide bonds, and a variable N-terminal area dominated by loops. Based on this information, what family of proteins might this protein belong to? What is a potential function of the hydrophobic C-terminal region? Page 7