front 1 Innate immunity_____. A) Depends on an infected animal's previous exposure to the same pathogen B) is based on recognition of antigens that are specific to different pathogens C) is found only in vertebrate animals D) is activated immediately upon infection | back 1 Answer: D |
front 2 Engulfing-phagocytic cells of innate immunity of vertebrates include_____. I) neutrophils II) macrophages III) dentritic cells IV) natural killer cells A) I and IV B) II and IV C) I, II, and III D) I and III | back 2 Answer: C |
front 3 the cells and signaling molecules involved in the initial stages of the inflammatory responses are ____. A) dendritic cells and interferons B) lymphocytes and interferons C) mast cells and histamines D) phagocytes and chemokines | back 3 Answer: C |
front 4 Inflammatory responses typically include____. A) inhibiting the release of white blood cells from bone marrow B) release of substances to decrease the blood supply to an inflamed area C) reduce permeability of blood vessels to conserve plasma D) increased activity of phagocytes in an inflamed area | back 4 Answer: D |
front 5 Mammals have Toll-like receptors (TLRs) that can recognize a kind of macromolecule that is absent from vertebrates but present in or on certain groups of pathogens, such as viral _____. A) glycoproteins B) phospholipids C) double-stranded DNA D) double-stranded RNA | back 5 Answer: D |
front 6 Septic shock, a systemic response including high fever and low blood pressure, is a response to ____. A) the presence of natural killer cells B) specific forms of viruses C) increased production of neutrophils D) certain bacterial infections | back 6 Answer: D |
front 7 The cells involved in innate immunity, whose absence increases the chances of developing malignant tumors, are ____. A) cytotoxic T cells B) B cells C) natural killer cells D) macrophages | back 7 Answer: C |
front 8 You and a friend were in line for a movie when you noticed the woman in front of you sneezing and coughing. Both of you were equally exposed to the woman's virus, but over the next few days, only your friend acquired flu-like symptoms and was ill for almost a week before recovering. Which one of the following is a logical explanation for this? A) your friend has an autoimmune disorder B) your friend had allergies C) your friend had antibodies to that virus D) you had an adaptive immunity to that virus | back 8 Answer: D |
front 9 A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. What response is occurring? A) lytic response B) autoimmune response C) adaptive immune response D) inflammatory response | back 9 Answer: D |
front 10 Acidity in human sweat is an example of ____. A) acquired immunity B) cell-mediated immune response C) adaptive immunity D) innate immunity | back 10 Answer: D |
front 11 The eyes and the respiratory tract are both protected against infections by _____. A) interferons produced by immune cells B) the secretion of complement proteins C) the release of slightly alkaline secretions D) the secretion of lysozyme onto their surfaces | back 11 Answer: D |
front 12 The complement system is ____. A) a group of antimicrobial proteins that act together in a cascade fashion B) a set of proteins involved in innate but not acquired immunity C) a group of proteins that include interferons and interleukins D) a set of proteins that act individually to attack and lyse microbes | back 12 Answer: A |
front 13 Bacteria entering the body through a small cut in the skin _____. A) stimulate apoptosis of nearby body cells B) activate a group of proteins called complement C) stimulate release of interferons D) inactivate the erythrocytes | back 13 Answer: B |
front 14 Mucus occurs in both the respiratory and digestive tracts. What is its main immunological function? A) destruction of pathogens because it is acidic B) increasing oxygen absorption C) physically trapping pathogens D) sweeping away debris | back 14 Answer: C |
front 15 An antigen____. A) is a protein attacked by an invading microorganism B) is a foreign molecule that evokes a specific response by a lymphocyte C)is a protein molecule that helps defend the body against disease D) induces development of white blood cells in the bone marrow E) could be an invading bacterium | back 15 Answer: B |
front 16 The fact that there are about a million different antigen receptors possible in human B cells is based on _____. A) having one million different immunoglobulin genes B) temporary changes in the ways that RNA is spliced in the B cells C) constant changes in the splicing pattern of receptor genes after the differentiation of the B cell D) recombination of the segments of the receptor DNA that make up the functional receptor genes of differentiated B cells E) the capacity of memory cells to produce antibodies | back 16 Answer: D |
front 17 Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by a(n)_____. A) reverse transcriptase B) recombinase C) epitopase D) RNA polymerase | back 17 Answer: B |
front 18 Clonal selection and differentiation of B cells activated by antigen exposure leads to the production of _____. A) short-lived plasma cells that secrete antibodies for the antigen B) large quantities of the antigen initially recognized C) vast numbers of B cells with random antigen-recognition receptors D) long-lived erythrocytes that can later secrete antibodies for the antigen | back 18 Answer: A |
front 19 A newborn who is accidentally given a drug that destroys the thymus would most likely _____. A) have a reduced number of B cells and be unable to form antibodies B) be unable to differentiate and mature T cells C) be unable to genetically rearrange antigen receptors D) lack innate immunity | back 19 Answer: B |
front 20 Clonal selection is an explanation for how _____. A) macrophages can recognize specific T cells and B cells B) an antigen can provoke production of high levels of specific antibodies C) V, J, and C gene segments are rearranged D) HIV (human immunodeficiency virus) can disrupt the immune system | back 20 Answer: B |
front 21 An immunoglobulin (Ig) molecule, of whatever class, with regions symbolized as C or V, H or L, has a light chain made up of _____. A) two C regions and two V regions B) one H region and one L region C) three H regions and one L region D) one C region and one V region | back 21 Answer: D |
front 22 Immunological memory accounts for _____. A) the observation that some strains of the pathogen that causes dengue fever cause more severe disease than others B) the ability of a helper T cell to signal B cells via cytokines C) the human body's ability to distinguish self from non-self D) the ancient observation that someone who had recovered from the plague could safely care for those newly diseased | back 22 Answer: D |
front 23 Use the following information to answer the question(s) below. A) class II MHC molecules B) a complement C) class I MHC molecules D) antibodies | back 23 Answer: C |
front 24 Vaccination increases the number of _____. A) macrophages specific for a pathogen B) lymphocytes with receptors that can bind to the pathogen C) epitopes that the immune system can recognize D) major histocompatability (MHC) molecules that can present an antigen | back 24 Answer: B |
front 25 If a patient is missing B and T cells, what would be absent from the immune response? A) memory B) cytokines C) lysozymes D) defense against bacteria | back 25 Answer: A |
front 26 Lymphocytes mature in the _____. A) only I and III B) only II and III C) I, II, and III D) only I and II | back 26 Answer: B |
front 27 Which of the following statements are fundamental to the
clonal-selection theory of how the adaptive immune system
functions? A) Only II, III, and IV B) only II and IV C) only I and III D) only I, II, and IV | back 27 Answer: D |
front 28 What major advantage is conveyed by having a system of adaptive immunity? A) It results in effector cells with specificity for a large number of antigens. B) It allows for the destruction of antibodies. C) It enables a rapid defense against an antigen that has been previously encountered. D) It enables an animal to counter most pathogens almost instantly the first time they are encountered. | back 28 Answer: C |
front 29 Which of the following is a difference between B cells and T cells? A) T cells are produced in the thymus and B cells are produced in the bone marrow. B) B cells are activated by free-floating antigens in the blood or lymph. T cells are activated by membrane-bound antigens. C) One has a major role in antibody production, while the other has a major role in cytotoxicity. D) One binds a receptor called BCR (B-cell receptor), while the other recognizes a receptor called TCR (T-cell receptor). | back 29 Answer: C |
front 30 A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over twenty years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell? A) thyroid cells B) macrophage C) memory cell D) plasma cell | back 30 Answer: C |
front 31 Which of the following statements about epitopes are correct? A) only II, III, and IV C) only I and III D) only I, II, and III | back 31 Answer: D |
front 32 Which of the following pairs of proteins shares the most overall similarity in structure? A) B-cell receptors and T-cell receptors B) B-cell receptors and antibodies C) T-cell receptors and antibodies D) antibodies and antigens | back 32 Answer: B |
front 33 To answer the following question, assume that the number of B cells producing a specific antibody is proportional to the concentration of that antibody. On day 16, assume that one out of every 105 B cells in the body is specific for antigen A and that the antibody concentration on day 16 is about 2 × 101.Calculate the frequency of B cells specific for antigen A on day 36 if the antibody concentration on day 36 is about 8 × 103. (For practice doing calculations with proportions, try this exercise. For practice doing calculations with numbers written in scientific notation, try this exercise.) A) 1 in 105 B) 1 in 400 C) 1 in 250 D) 1 in 20 | back 33 Answer: C |
front 34 The words “antigen” and “virus” are interchangeable. A) True B) false | back 34 Answer: B |
front 35 A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body.What might this mean? A) He was probably exposed sometime within the past two weeks, but we don’t have enough information to say more. B) He was probably exposed a few days ago and clonal selection has yet to produce plasma cells. C)He was probably exposed more than several months ago, antibody production has ceased, and antibodies are no longer detectable. | back 35 Answer: B |
front 36 Which is a true statement about memory cells? A) They produce antibodies. B) They engulf antigens bound by antibodies. C) The first time an antigen is encountered, memory cells become plasma cells. D) They have a longer lifespan than plasma cells. | back 36 Answer: D |
front 37 Which structure is not a component of the adaptive immune system? A) Thymus B) Lymphatic ducts C) Tissues D) Spleen | back 37 Answer: C |
front 38 True or false? B cells were originally isolated from the bursa in chickens, and their function is to produce antibodies; T cells were originally isolated from the thymus in mice, and their functions include killing host cells that are being infected with a virus. A) True B) False | back 38 Answer: A |
front 39 Which of the following statements about the clonal-selection theory of immune system function is false? A) An activated lymphocyte makes many copies of itself in response to an infection. B) Cloned cells persist after the pathogen is eliminated. C) Antigens are recognized by receptor proteins inside the lymphocyte. D) Each lymphocyte recognizes one antigen. | back 39 Answer: C |
front 40 What is the final step in the cell-mediated response to a viral infection? A) Antibodies coat viral particles. B) Cytotoxic T lymphocytes punch holes in the membranes of infected host cells. C) Macrophages digest viral particles. D) CD8+ T cells are activated. | back 40 Answer: B |
front 41 How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell? A) Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies. B) Helper T cells divide and produce plasma and memory cells. C) Helper T cells secrete antibodies against the viral antigen. D) The B cell recognizes the receptor-antigen complex and divides to produce plasma and memory cells. | back 41 Answer: A |
front 42 Which protein presents viral antigens on the outer surface of cells? A) antibody B) B cell receptor C) T cell receptor D) MHC protein | back 42 Answer: D |
front 43 How are cytotoxic T lymphocytes (CTLs) produced? A) Helper T cells divide and differentiate into cytotoxic T lymphocytes. B) Plasma cells secrete cytotoxic T lymphocytes. C) B cells divide and differentiate into cytotoxic T lymphocytes. D) CD8+ T cells divide and differentiate into cytotoxic T lymphocytes. | back 43 Answer: D |
front 44 Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium? A) Plasma cells B) cytotoxic T cell C) Macrophage D) B cell E) helper T cell | back 44 Answer: C |
front 45 _____ interact with the antigen-class II MHC complex presented by macrophages. A) helper T cells B) Bacterial cells C) Epithelial cells D) Cytotoxic T cells E) B cells | back 45 Answer: A |
front 46 B cells that have been stimulated by interleukin-2 develop into _____. A) antigens B) plasma cells C) cytotoxic T cells D) helper T cells E) macrophages | back 46 Answer: B |
front 47 The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response. A) antibodies ... antibody-mediated B) interleukin-2 ... humoral C) antibodies ... humoral D) perforin ... cell-mediated E) perforin ... humoral | back 47 Answer: D |
front 48 Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____. A) T cells ... B cells B) helper T cells ... plasma cells C) B cells ... macrophages D) macrophages ... B cells and T cells E) B cells ... plasma cells and memory cells | back 48 Answer: E |
front 49 Which of these cells is responsible for the rapidity of the secondary immune response? A) cytotoxic T cells B) cytokines C) macrophages D) memory cells E) plasma cells | back 49 Answer: D |
front 50 Which of these cells produce and secrete antibodies? A) plasma cells B) bacterial cells C) cytotoxic T cells D) macrophages E) helper T cells | back 50 Answer: A |