front 1 Which of the following statements concerning antigen-presenting cells is true? | back 1 They are involved in activating T cells. |
front 2 What is the correct sequence of events for activation of a B cell by a T-dependent antigen? | back 2 (1) Immunoglobulin receptors on the B cell recognize and bind the antigen. (2) An antigen fragment in complex with MHC class 2 is displayed on the B cell's surface. (3) The MHC-antigen complex binds a receptor on a TH cell. (4) The TH cell secretes cytokines that activate the B cell. |
front 3 If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first? | back 3 IgM |
front 4 Which type of cell directly attacks infected cells? | back 4 Cytotoxic T-cells |
front 5 Immune cells that secrete cytokines and activate other immune cells are: | back 5 Helper T-cells |
front 6 HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? | back 6 Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body. |
front 7 How do helper T-cells and cytotoxic T-cells work together? | back 7 Helper T-cells produce cytokines to activate other cells of the immune system. |
front 8 Which of the following statements concerning cellular immunity is FALSE? | back 8 Cellular immunity involves cells that recognize antigens and make specific antibodies against them. |
front 9 An individual may be exposed to a pathogen and become infected without actually getting sick. This is known as a subclinical infection. Even in subclinical infections, the individual's adaptive immune system can generate memory for the pathogen. What type of adaptive immunity is this? | back 9 naturally acquired active immunity |
front 10 Where are MHC molecules located on a cell? | back 10 On the surface of the cell |
front 11 What is a feature of the small fragments presented by MHC-I proteins? | back 11 They are small peptides, roughly 8-10 amino acids long. |
front 12 Which organelle assists directly with the presentation of MHC-I antigens? | back 12 The endoplasmic reticulum |
front 13 When does MHC-II loading occur? | back 13 During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens |
front 14 Which of the cells listed below can present antigens on Class II MHC proteins? | back 14 Macrophages |
front 15 What is apoptosis? | back 15 The process of programmed cell death. |
front 16 What is the function of the CD8 receptor? | back 16 Bind to MHC molecules |
front 17 What is the fate of activated cytotoxic T-cells? | back 17 They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells. |
front 18 Which molecule triggers apoptosis? | back 18 Granzyme |
front 19 Which event happens first during cytotoxic T-cell activation? | back 19 CD8 binds to MHC molecules of infected cells |
front 20 Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell? | back 20 TCR |
front 21 TH2 cells produce cytokines that activate | back 21 B cells. |
front 22 Which proteins on the antigen-presenting cell are recognized by the helper T-cell? | back 22 MHC proteins |
front 23 When do helper T-cells develop into TH1 or TH2 cells? | back 23 After proliferation into a clonal population |
front 24 Natural killer cells are activated by | back 24 TH1 cells. |
front 25 What type of immunity results from vaccination? | back 25 artificially acquired active immunity |
front 26 Newborns' immunity due to the transfer of antibodies across the placenta is an example of | back 26 naturally acquired passive immunity. |
front 27 Which of the following statements is NOT a possible outcome of antigen-antibody reaction? | back 27 clonal deletion |
front 28 When an antibody binds to a toxin, the resulting action is referred to as | back 28 neutralization. |
front 29 The specificity of an antibody is due to | back 29 the variable portions of the H and L chains. |
front 30 Which of the following is NOT a characteristic of B cells? | back 30 They recognize antigens associated with MHC I. |
front 31 Plasma cells are activated by a(n) | back 31 antigen |
front 32 The antibodies found in mucus, saliva, and tears are | back 32 IgA. |
front 33 The antibodies found on the surface of B cells, and which always exist as monomers, are | back 33 IgD. |
front 34 In addition to IgG, the antibodies that can fix complement are | back 34 IgM. |
front 35 The most abundant class of antibodies in serum is | back 35 IgG. |
front 36 Memory cells do not require B cell receptors. | back 36 False |
front 37 Plasma cells will eventually differentiate into memory cells. | back 37 False |
front 38 The variable region of the antibody is solely responsible the significant diversity of antigen targets. | back 38 False |
front 39 Only dendritic cells produce interleukins. | back 39 False |
front 40 Cytokines are protein-based chemical messengers that allow for communication between cells of the immune system. | back 40 True |
front 41 IL-2, produced by TH cells, | back 41 Stimulates TH cell mutation |
front 42 Which of the following statements about natural killer cells is FALSE? | back 42 They are stimulated by an antigen. |
front 43 The following events occur in cellular immunity. What is the third step? | back 43 TH cells proliferate. |
front 44 Which of the following destroys virus-infected cells? | back 44 CTL |
front 45 Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens? | back 45 capsule |
front 46 In the figure, what can attach to a host cell? | back 46 e |
front 47 Which of the following statements is FALSE? | back 47 The constant region of a heavy chain is the same for all antibodies. |
front 48 In the figure, the arrow at time (c) indicates | back 48 the secondary response. |
front 49 Which of the following is the best definition of antigen? | back 49 a chemical that elicits an antibody response and can combine with these antibodies |
front 50 The following events elicit an antibody response. What is the third step? | back 50 TH cell recognizes antigen-digest and MHC II. |
front 51 In the figure, which areas are similar for all IgG antibodies? | back 51 c and d |