front 1 what is the term used for the ability of some microbes to alter their surface molecules and evade destruction by the hosts antibodies | back 1 antigenic variation |
front 2 which statement is false | back 2 coagulase destroys blood clots |
front 3 are exotoxins more potent than endotoxins | back 3 yes |
front 4 are endotoxins gram positive or gram negative | back 4 gram negative |
front 5 the visible signs of viral infections | back 5 cytopathic effects |
front 6 baceterial iron binding proteins | back 6 siderophores |
front 7 is staphylococcal enterotoxin produced by staphylococcus aureus growing in the host intestines | back 7 no |
front 8 which of the following statements about M protein in false | back 8 it is readily digested by phagocytes |
front 9 polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use? | back 9 mucous membranes only |
front 10 all of the following bacteria release endotoxin except | back 10 clostridium botulinum |
front 11 endotoxins in sterile injectable drugs could cause | back 11 septic shock symptoms |
front 12 in general LD50 for exotoxins is much greater than the LD50 for endotoxins | back 12 false |
front 13 the M protein enhances the virulence of streptoccus by preventing phagocytosis | back 13 true |
front 14 In AB exotoxins, ,the A component binds to the host cell receptor so that the B component can enter the cell | back 14 false |
front 15 most symptoms of endotoxins can be treated with administration of anti-endotoxin antibodies | back 15 false |
front 16 infections with some viruses may induce chromosomal changes that alter the growth properties of host cells | back 16 true |
front 17 many pathogens use the same portal for entry an exit from the body | back 17 true |
front 18 Which of the following statements concerning antigen-presenting cells is true?
| back 18 They are involved in activating T cells. |
front 19 What is the correct sequence of events for activation of a B cell by a T-dependent antigen? | back 19 (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 20 If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first? | back 20 IgM |
front 21 Which type of cell directly attacks infected cells? | back 21 Cytotoxic T-cells |
front 22 Immune cells that secrete cytokines and activate other immune cells are: | back 22 Helper T-cells |
front 23 HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? | back 23 Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body |
front 24 How do helper T-cells and cytotoxic T-cells work together? | back 24 Helper T-cells produce cytokines to activate other cells of the immune system. |
front 25 Which of the following statements concerning cellular immunity is FALSE? | back 25 Cellular immunity involves cells that recognize antigens and make specific antibodies against them. |
front 26 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 26 naturally acquired active immunity |
front 27 Where are MHC molecules located on a cell? | back 27 On the surface of the cell |
front 28 What is a feature of the small fragments presented by MHC-I proteins? | back 28 They are small peptides, roughly 8-10 amino acids long. |
front 29 Which organelle assists directly with the presentation of MHC-I antigens? | back 29 The endoplasmic reticulum |
front 30 When does MHC-II loading occur? | back 30 During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens |
front 31 Which of the cells listed below can present antigens on Class II MHC proteins? | back 31 Macrophages |
front 32 What is apoptosis? | back 32 The process of programmed cell death. |
front 33 What is the function of the CD8 receptor? | back 33 Bind to MHC molecules |
front 34 What is the fate of activated cytotoxic T-cells? | back 34 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 35 Which molecule triggers apoptosis? | back 35 Granzyme |
front 36 Which event happens first during cytotoxic T-cell activation? | back 36 CD8 binds to MHC molecules of infected cells |
front 37 Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell? | back 37 TCR |
front 38 TH2 cells produce cytokines that activate | back 38 B cells. |
front 39 Which proteins on the antigen-presenting cell are recognized by the helper T-cell? | back 39 MHC proteins |
front 40 When do helper T-cells develop into TH1 or TH2 cells? | back 40 After proliferation into a clonal population |
front 41 Natural killer cells are activated by | back 41 TH1 cells. |
front 42 What type of immunity results from vaccination? | back 42 artificially acquired active immunity |
front 43 Newborns' immunity due to the transfer of antibodies across the placenta is an example of | back 43 naturally acquired passive immunity. |
front 44 Which of the following statements is NOT a possible outcome of antigen-antibody reaction? | back 44 clonal deletion |
front 45 When an antibody binds to a toxin, the resulting action is referred to as | back 45 neutralization. |
front 46 The specificity of an antibody is due to | back 46 the variable portions of the H and L chains. |
front 47 Which of the following is NOT a characteristic of B cells? | back 47 They recognize antigens associated with MHC I. |
front 48 Plasma cells are activated by a(n) | back 48 antigen. |
front 49 The antibodies found in mucus, saliva, and tears are | back 49 IgA. |
front 50 The antibodies found on the surface of B cells, and which always exist as monomers, are | back 50 IgD. |
front 51 In addition to IgG, the antibodies that can fix complement are | back 51 IgM |
front 52 The most abundant class of antibodies in serum is | back 52 IgG. |
front 53 Memory cells do not require B cell receptors. | back 53 False |
front 54 Plasma cells will eventually differentiate into memory cells. | back 54 False |
front 55 The variable region of the antibody is solely responsible the significant diversity of antigen targets. | back 55 False |
front 56 Only dendritic cells produce interleukins. | back 56 False |
front 57 Cytokines are protein-based chemical messengers that allow for communication between cells of the immune system. | back 57 True |
front 58 IL-2, produced by TH cells, | back 58 stimulates TH cell maturation |
front 59 Which of the following statements about natural killer cells is FALSE? | back 59 They are stimulated by an antigen. |
front 60 The following events occur in cellular immunity. What is the third step?
| back 60 TH cells proliferate. |
front 61 Which of the following destroys virus-infected cells? | back 61 CTL |
front 62 Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens? | back 62 capsule |
front 63 In the figure, what can attach to a host cell?
| back 63 e |
front 64 Which of the following statements is FALSE? | back 64 The constant region of a heavy chain is the same for all antibodies. |
front 65 In the figure, the arrow at time (c) indicates | back 65 the secondary response. |
front 66 Which of the following is the best definition of antigen? | back 66 a chemical that elicits an antibody response and can combine with these antibodies |
front 67 The following events elicit an antibody response. What is the third step? | back 67 TH cell recognizes antigen-digest and MHC II. |
front 68 In the figure, which areas are similar for all IgG antibodies? | back 68 c and d |
front 69 Which of the following is not a mechanism used by pathogens to avoid phagocytosis?
| back 69 destroying the pseudopods to prevent ingestion by the phagocyte |
front 70 the dermis is composed of connective tissue and provides protection from the external environment | back 70 true |
front 71 the inflammatory response can only be trigged by an infection | back 71 false |
front 72 histamine and kinins cause increased blood flow and capillary permeability | back 72 true |
front 73 ingestion of certain lactic acid bacteria has been show to be beneficial for function and health of the intestinal tract | back 73 true |
front 74 which of the following cells is not an APC | back 74 natural killer cells |
front 75 which of the following is not a characteristic of cellular immunity | back 75 it can inhibit the immune response |
front 76 the antibodies that can bind to large parasites are | back 76 IgE |
front 77 What are the large antibodies that agglutinate antigens | back 77 IgM |
front 78 an antibody's Fc region can be bound by | back 78 macrophages |
front 79 cytokine storms negatively impact human health | back 79 true |
front 80 which of the following is found normally in serum | back 80 complement |
front 81 which of the following is not a membrane disrupting toxin | back 81 ab toxin |