Chapter 21 Multiple Choice

55) What is the role of interferon in defense against disease? A) protects cells that have not yet been infected by viruses B) protects cells that have not yet been infected by bacteria C) activates the complement mechanism D) activates the inflammatory process

54) Which of the following is not a method by which antibodies work? A) neutralizing antigen B) direct cell lysis C) enhancing phagocytosis D) agglutinating and precipitating antigen

52) Antibody functions include all of the following except ________. A) binding and inactivating chemical toxins released by bacteria or other microorganisms B) cross-linking cell-bound antigens on red blood cells when blood types are properly matched C) linking soluble antigens together so that they fall out of solution D) targeting foreign cells so that complement proteins can cause cellular lysis

53) Which statement is true about T cells? A) They usually directly recognize antigens, which then activates a subpopulation of killer cells. B) Their proliferation is enhanced by interleukins 1 and 2. C) Once activated, they cannot secrete cytokines. D) They will develop into cytotoxic T cells if antigen is complexed with class II MHC proteins.

51) Which of the following is not a complement activation pathway? A) classical pathway B) alternative pathway C) lectin pathway D) lactate pathway

49) Which of the following is not an autoimmune disease? A) multiple sclerosis B) type II diabetes C) systemic lupus erythematosus D) glomerulonephritis

50) Which of the following is not a mechanism for the development of autoimmune disorders? A) exposure of previously "hidden" self-antigens to the adaptive immune system B) a second exposure to an allergen C) mutation followed by the appearance of membrane proteins not previously present D) cross-reaction of antibodies formed against foreign antigens with self-antigens

43) Natural killer (NK) cells ________. A) are also called cytotoxic T cells B) are a type of phagocyte C) are cells of the adaptive immune system D) can kill cancer cells before the immune system is activated

44) Select the correct statement about antigens. A) "Self-antigens" is another name for incomplete antigens. B) The largest type of antigen is called a hapten. C) Only small antigens exhibit reactivity. D) One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.

45) Clonal selection of B cells ________. A) occurs during fetal development B) results in the formation of plasma cells C) cannot occur in the presence of antigens D) only occurs in the secondary immune response

46) The primary immune response ________. A) occurs more rapidly and is stronger than the secondary response B) occurs when memory cells are stimulated C) is another name for immunological memory D) has a lag period while B cells proliferate and differentiate into plasma cells

47) Select the correct statement about the function of antibodies. A) Antibodies may directly destroy "invaders." B) Neutralization is the process by which antibodies cause invading cells to clump together. C) Complement fixation is the main mechanism by which antibodies provide protection. D) The most potent agglutinating agent is IgG.

48) Which of the following cells is the most critical cell in immunity? A) B cell B) helper T cell C) cytotoxic T cell D) APC

14) Which of the following does not respond to cell-mediated immunity? A) intracellular pathogens that reside within host cells B) some cancer cells C) foreign tissue transplants D) pathogens in the lumen of the stomach

42) Delayed hypersensitivities ________. A) are mediated by B cells B) include allergic contact dermatitis C) include anaphylactic shock, a systemic vasodilation that results in inadequate blood delivery to all tissues D) do not involve T cells

15) Which of the following cells predominate at the sites of chronic infections? A) Basophils B) Eosinophils C) Macrophages D) B cells

6) Interferons ________. A) are virus-specific, so that an interferon produced against one virus could not protect cells against another virus B) act by increasing the rate of cell division C) interfere with viral replication within cells D) are routinely used in nasal sprays for the common cold Answer: C

39) Helper T cells ________. A) bind tightly to target cells and release a lymphotoxin called perforin B) often function to decrease the immune response C) release B7 proteins D) function in the adaptive immune system activation

41) Which of the following is true of immediate hypersensitivities? A) They are also called type IV hypersensitivities. B) They are adaptive immune responses to disease organisms. C) They include allergic contact dermatitis. D) They involve IgE antibodies and the release of histamine from mast cells and basophils

17) Which of the following determine(s) what specific foreign substances our adaptive immune system will be able to recognize and resist? A) The type of antigen B) Memory cell production C) Enzymes present at the time of the invasion D) Our genes

40) Select the correct statement about immunodeficiency. A) Severe combined immunodeficiency (SCID) disease is an acquired condition. B) The causative agent in acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins. C) Hodgkin's disease is a hereditary immunodeficiency found in children. D) The most common form of immunodeficiency is graft-versus-host (GVH) disease.

18) Regulatory T cells ________. A) release cytokines that increase the activity of cytotoxic T cells and activated B cells B) decrease their activity as antigenic stimulus decreases C) may function in preventing autoimmune reactions D) aid B cells in antibody production

37) Select the correct statement about active and passive immunity. A) Immunological memory is established by passive immunization. B) A vaccination is an example of the introduction of passive immunity into the body. C) The antibodies utilized in active immunity are acquired from another organism. D) Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.

19) Select the correct definition about tissue grafts. A) Isografts are between identical twins. B) Allografts are between different species. C) Xenografts are between individuals of the same species. D) Autografts are between two genetically identical individuals.

38) Cytotoxic T cells ________. A) are the only T cells that can directly attack and kill other cells B) require the double recognition signal of I MHC plus II MHC on the target cell in order to function C) function mainly to stimulate the proliferation of other T cell populations D) self-destruct once the antigen has been neutralized

20) Which of the statements below does not describe antigens? A) Antigens exhibit immunogenicity and reactivity. B) Antigens only come from microbes. C) The parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants. D) Antigens can include proteins, nucleic acids, lipoproteins, glycoproteins, and certain large polysaccharides.

35) Immunocompetence ________. A) occurs in one specific organ of the adaptive immune system B) is the ability of individual cells to recognize a specific antigen by binding to it C) prevents intercellular communication so that only specific cell types respond to the invader D) requires exposure to an antige

21) Activated T cells and macrophages release ________ to mobilize immune cells and attract other leukocytes into the area. A) Cytokines B) Perforins C) Interleukin 1 proteins D) Interleukin 2 proteins

22) Which of the following is a part of the second line of defense against microorganisms? A) keratin B) cilia C) gastric juice D) phagocytes

23) Which of the following is characteristic of complete antigens? A) small molecules B) reactivity with an antibody C) contain many repeating chemical units D) inhibit production of antibodies

31) Innate immune system defenses include ________. A) B cells B) T cells C) plasma cells D) phagocytosis

24) B cells respond to the initial antigen challenge by ________. A) reducing its size B) immediately producing antigen-specific antibodies C) forming of a large number of cells that are unlike the original B cell D) producing progeny cells that include plasma cells and memory cells

25) T-cell activation requires ________. A) antigen binding and co-stimulation B) antigen binding and antibody production C) antibody production and co-stimulation D) antigen binding, antibody production, and co-stimulation

30) Which of the following would be classified as a delayed hypersensitivity reaction? A) immune complex hypersensitivity B) anaphylaxis C) cytotoxic hypersensitivity D) allergic contact dermatitis

32) Which of the following statements is incorrect or false? A) Haptens lack immunogenicity unless attached to protein carriers. B) Class 1 MHC molecules are built into the plasma membranes of all body cells. C) Class II MHC molecules appear only on the surface of antigen-presenting cells, thymic cells, and T cells that have been activated by exposure to antigens. D) MHC proteins are the cell's identity markers.

26) Cancer cells and virus-infected body cells can be killed before activation of adaptive immunity by ________. A) natural killer cells B) T lymphocytes C) B lymphocytes D) pinocytosis

29) Monoclonal antibodies are used for the diagnosis of all of the following except ________. A) juvenile diabetes B) hepatitis C) rabies D) pregnancy

27) Complement proteins and antibodies coat a microorganism and provide binding sites, enabling macrophages and neutrophils to phagocytize the organism. This phenomenon is termed ________. A) diapedesis B) agglutination C) opsonization D) chemotaxis

28) Which of the following is not characteristic of the adaptive immune system? A) It is antigen-specific. B) It is systemic. C) It has memory. D) It is specific for a given organ.