17.1 Multiple Choice Questions

14) Plasma cells are activated by a(n) A) antigen. B) T cell. C) B cell. D) memory cell. E) APC.

Answer: A

18) In addition to IgG, the antibodies that can fix complement are A) IgM. B) IgA. C) IgD. D) IgE. E) None of the answers is correct.

Answer: A

20) The most abundant class of antibodies in serum is A) IgG. B) IgM. C) IgA. D) IgD. E) IgE.

Answer: A

29) In Figure 17.2, which areas are different for all IgM antibodies? A) a and b B) a and c C) b and c D) c and d

Answer: A

30) In Figure 17.2, which areas represent antigen-binding sites? A) a and b B) a and c C) b and c D) c and d E) b and d

Answer: A

32) Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens? A) capsule B) flagellum C) pili D) ribosome E) plasmid

Answer: A

34) Which of the following destroys virus-infected cells? A) CTL B) Treg C) TH D) dendritic cells E) B cells

Answer: A

36) Cytokines released by TH1 cells A) activate CD8+ cells to CTLs. B) convert TH1 cells to TH2 cells. C) convert TH2 cells to TH1 cells. D) kill parasites. E) convert B cells to T cells.

Answer: A

39) Thymic selection A) destroys T cells that do not recognize self-molecules of MHC. B) destroys B cells that make antibodies against self. C) destroys MHC molecules. D) destroys CD4+ cells that attack self. E) activates B cells.

Answer: A

43) ADCC is a process that is most effective in destroying A) eukaryotic pathogens. B) virus-infected host cells. C) extracellular viruses. D) bacterial pathogens. E) bacterial toxins

Answer: A

6) Which of the following statements is NOT a possible outcome of antigen-antibody reaction? A) clonal deletion B) activation of complement C) opsonization D) ADCC E) agglutination

Answer: A

9) CD4+ T cells are activated by A) interaction between CD4+ and MHC II. B) interaction between TCRs and MHC II. C) cytokines released by dendritic cells. D) cytokines released by B cells. E) complement.

Answer: A

19) Large antibodies that agglutinate antigens are A) IgG. B) IgM. C) IgA. D) IgD. E) IgE.

Answer: B

23) In Figure 17.1, the arrow at time (c) indicates A) the time of exposure to the same antigen as at time (a). B) the secondary response. C) the primary response. D) exposure to a new antigen. E) the T-cell response.

Answer: B

25) Which of the following is the best definition of antigen? A) something foreign in the body B) a chemical that elicits an antibody response and can combine with these antibodies C) a chemical that combines with antibodies D) a pathogen E) a protein that combines with antibodies

Answer: B

3) What type of immunity results from recovery from mumps? A) innate immunity B) naturally acquired active immunity C) naturally acquired passive immunity D) artificially acquired active immunity E) artificially acquired passive immunity

Answer: B

41) An antibody's Fc region can be bound by A) antibodies. B) macrophages. C) T helper cells. D) B cells. E) CTLs.

Answer: B

44) IL-2, produced by TH cells, A) activates macrophages. B) stimulates TH cell maturation. C) causes phagocytosis. D) activates antigen-presenting cells. E) activates TC cells to CTLs.

Answer: B

10) Which of the following recognizes antigens displayed on host cells with MHC II? A) TC cell B) B cell C) TH cell D) natural killer cell E) basophil

Answer: C

21) In Figure 17.1, which letter on the graph indicates the patient's secondary response to an antigen? A) a B) b C) c D) d E) e

Answer: C

33) The presence of which of the following indicates a current infection rather than a previous infection or vaccination? A) IgA B) IgG C) IgM D) IgD E) IgE

Answer: C

38) At a minimum, the human immune system is capable of recognizing approximately how many different antigens? A) 105 B) 1010 C) 1015 D) 1020 E) 1025

Answer: C

42) A Treg cell deficiency could result in A) increased number of viral infections. B) increased number of bacterial infections. C) autoimmunity. D) increased severity of bacterial infections. E) transplant rejection

Answer: C

5) Newborns' immunity due to the transfer of antibodies across the placenta is an example of A) innate immunity. B) naturally acquired active immunity. C) naturally acquired passive immunity. D) artificially acquired active immunity. E) artificially acquired passive immunity.

Answer: C

1) What type of immunity results from vaccination? A) innate immunity B) naturally acquired active immunity C) naturally acquired passive immunity D) artificially acquired active immunity E) artificially acquired passive immunity

Answer: D

13) Which of the following is NOT a characteristic of cellular immunity? A) The cells originate in bone marrow. B) Cells are processed in the thymus gland. C) It can inhibit the immune response. D) B cells make antibodies. E) T cells react with antigens.

Answer: D

16) The antibodies found on the surface of B cells, and which always exist as monomers, are A) IgG. B) IgM. C) IgA. D) IgD. E) IgE.

Answer: D

24) Which of the following statements is FALSE? A) The variable region of a heavy chain binds with antigen. B) The variable region of a light chain binds with antigen. C) The Fc region attaches to a host cell. D) The constant region of a heavy chain is the same for all antibodies. E) All of the answers are correct.

Answer: D

26) Which of the following WBCs are NOT lymphocytes? A) cytotoxic T cells B) helper T cells C) NK cells D) M cells E) B cells

Answer: D

27) The following events elicit an antibody response. What is the third step? A) Antigen-digest goes to surface of APC. B) APC phagocytizes antigen. C) B cell is activated. D) TH cell recognizes antigen-digest and MHC II. E) TH cell produces cytokines.

Answer: D

28) In Figure 17.2, which areas are similar for all IgG antibodies? A) a and b B) a and c C) b and c D) c and d E) b and d

Answer: D

4) Which of the following is the best definition of epitope? A) specific regions on antigens that interact with T-cell receptors B) specific regions on antigens that interact with MHC class molecules C) specific regions on antigens that interact with haptens D) specific regions on antigens that interact with antibodies E) specific regions on antigens that interact with perforins

Answer: D

40) Which of the following statements about natural killer cells is FALSE? A) They destroy virus-infected cells. B) They destroy tumor cells. C) They destroy cells lacking MHC I. D) They are stimulated by an antigen. E) None of the answers are correct; all of these statements are true.

Answer: D

45) Which of the following statements about IL-12 is FALSE? A) It activates macrophages. B) It inhibits some tumor cells. C) It activates the TH1 pathway. D) It causes autoimmune diseases. E) It causes TH cells to respond to HIV.

Answer: D

7) Which of the following cells is NOT an APC? A) dentritic cells B) macrophages C) immature B cells D) natural killer cells E) None of the answers is correct; all of these are APCs.

Answer: D

11) The specificity of an antibody is due to A) its valence. B) the H chains. C) the L chains. D) the constant portions of the H and L chains. E) the variable portions of the H and L chains.

Answer: E

12) Which of the following is NOT a characteristic of B cells? A) They originate in bone marrow. B) They have antibodies on their surfaces. C) They are responsible for the memory response. D) They are responsible for antibody formation. E) They recognize antigens associated with MHC I.

Answer: E

17) The antibodies that can bind to large parasites are A) IgG. B) IgM. C) IgA. D) IgD. E) IgE.

Answer: E

2) What type of immunity results from transfer of antibodies from one individual to a susceptible individual by means of injection? A) innate immunity B) naturally acquired active immunity C) naturally acquired passive immunity D) artificially acquired active immunity E) artificially acquired passive immunity

Answer: E

22) In Figure 17.1, which letter on the graph indicates the highest antibody titer during the patient's response to a second antigen? A) a B) b C) c D) d E) e

Answer: E

31) In Figure 17.2, what can attach to a host cell? A) a and c B) b and c C) b D) a and d E) e

Answer: E

35) The following events occur in cellular immunity. What is the third step? A) Antibodies are produced. B) Dendritic cell takes up antigen. C) Antigen enters M cell. D) TH cell produces cytokines. E) TH cells proliferate.

Answer: E

37) Which one of the following causes transmembrane channels in target cells? A) granzymes B) hapten C) IL-1 D) IL-2 E) perforin

Answer: E

8) When an antibody binds to a toxin, the resulting action is referred to as A) agglutination. B) opsonization. C) ADCC. D) apoptosis. E) neutralization.

Answer: E

Apoptosis results in significant leakage of cellular contents.

FALSE

Memory cells do not require B cell receptors

FALSE

Only dendritic cells produce interleukins.

FALSE

Plasma cells will eventually differentiate into memory cells.

FALSE

The production of interferons at an infection site is critical for chemotaxis.

FALSE

Cytokine storms negatively impact human health.

TRUE

Cytokines are protein-based chemical messengers that allow for communication between cells of the immune system.

TRUE

The implementation of vaccinations occurred prior to experimental support for the germ theory of disease.

TRUE

15) The antibodies found in mucus, saliva, and tears are A) IgG. B) IgM. C) IgA. D) IgD. E) IgE.

Answer: C

The variable region of the antibody is solely responsible the significant diversity of antigen targets

FALSE

When haptens attach to carrier molecules, an epitope forms on hapten which then can be bound to antibody.

FALSE