Immune System

2) How Do people contract salmonella poisoning? A) The microbe can survive the acidic environment of the stomach and resist lysosomal degradation in macrophages. B) The chemotactic messengers released by the salmonella bacterium do not attract sufficient neutrophils to entirely destroy the infection. C) There is a delay in selection of the population of eosinophils that recognize and are responsible for fighting these bacterial infections. D) The bacterium releases chemical messengers that make it resistant to phagocytosis. E) The combination of foods eaten at the meal reduces the pH of the stomach sufficiently so that the bacterium was not destroyed.

A

24) Which of the following cell types are responsible for initiating a secondary immune response? A) memory cells B) macrophages C) stem cells D) B cells E) T cells

A

28) In which of the following situations will helper T cells be activated? A) when an antigen is displayed by a dendritic cell B) when a cytotoxic T cell releases cytokines C) when natural killer (NK) cells come in contact with a tumor cell D) in the bone marrow during the self-tolerance test E) when B cells respond to T-independent antigens

A

34) These cells are involved in cell-mediated immunity and destroy virally infected cells: A) cytotoxic T cells B) natural killer cells C) helper T cells D) macrophages E) B cells

A

41) Both lysozyme and cytotoxic T cells A) kill cells through chemical interactions. B) kill cells by inducing apoptosis. C) kill cells by generating a membrane attack complex. D) are part of innate immunity. E) are involved in cell-mediated immune responses.

A

71) Some pathogens can undergo rapid changes resulting in antigenic variation. Which of the following is such a pathogen? A) the influenza virus, which expresses alternative envelope proteins B) the strep bacteria, which can be communicated from patient to patient with high efficiency C) human papilloma virus, that can remain latent for several years D) the causative agent of an autoimmune disease such as rheumatoid arthritis E) multiple sclerosis, that attacks the myelinated cells of the nervous system

A

1) Which of the following is not a component of an insectʹs defense against infection? A) enzyme activation of microbe-killing chemicals B) activation of natural killer cells C) phagocytosis by hemocytes D) production of antimicrobial peptides E) a protective exoskeleton

B

54) Which of the following would be most beneficial in treating an individual who has been bitten by a poisonous snake that has a fast-acting toxin? A) vaccination with a weakened form of the toxin B) injection of antibodies to the toxin C) injection of interleukin-1 D) injection of interleukin-2 E) injection of interferon

B

6) Inflammatory responses may include which of the following? A) clotting proteins migrating away from the site of infection B) increased activity of phagocytes in an inflamed area C) reduced permeability of blood vessels to conserve plasma D) release of substances to decrease the blood supply to an inflamed area E) inhibiting the release of white blood cells from bone marrow

B

60) A transfusion of type A blood given to a person who has type O blood would result in which of the following? A) the recipientʹs B antigens reacting with the donated anti-B antibodies B) the recipientʹs anti-A antibodies clumping the donated red blood cells C) the recipientʹs anti-A and anti-O antibodies reacting with the donated red blood cells if the donor was a heterozygote (Ai) for blood type D) no reaction because type O is a universal donor E) no reaction because the O-type individual does not have antibodies

B

72) Some viruses can undergo latency, the ability to remain inactive for some period of time. Which of the following is an example? A) influenza, a particular strain of which returns every 10-20 years B) herpes simplex viruses (oral or genital) whose reproduction is triggered by physiological or emotional stress in the host C) Kaposiʹs sarcoma, which causes a skin cancer in people with AIDS, but rarely in those not infected by HIV D) the virus that causes a form of the common cold, which recurs in patients many times in their lives E) myasthenia gravis, an autoimmune disease that blocks muscle contraction from time to time

B

8) An invertebrate, such as an insect, has innate immunity that can be nonspecific about which pathogens are prevented from harming its metabolism. Which of the following is most likely to function this way in the insectʹs intestine? A) complement B) lysozyme C) mucus D) neutrophils E) dendritic cells

B

19) Clonal selection is an explanation for how A) a single type of stem cell can produce both red blood cells and white blood cells. B) V, J, and C gene segments are rearranged. C) an antigen can provoke production of high levels of specific antibodies. D) HIV can disrupt the immune system. E) macrophages can recognize specific T cells and B cells.

C

20) A person exposed to a new cold virus would not feel better for one to two weeks because A) specific B cells and T cells must be selected prior to a protective response. B) it takes up to two weeks to stimulate immunologic memory cells. C) no memory cells can be called upon, so adequate response is slow. D) antigen receptors are not the same as for a flu virus to which she has previously been exposed. E) V-J gene rearrangement must occur prior to a response.

C

25) Which of the following differentiates T cells and B cells? A) T cells but not B cells are stimulated to increase the rate of their cell cycles. B) Only B cells are produced from stem cells of the bone marrow. C) T cells but not B cells can directly attack and destroy invading pathogens. D) T cells but not B cells have surface markers. E) Only B cells take part in cell-mediated immunity.

C

38) Which of the following is the last line of defense against an extracellular pathogen? A) lysozyme production B) phagocytosis by neutrophils C) antibody production by plasma cells D) histamine release by basophils E) lysis by natural killer cells

C

5) Which statement best describes the difference in responses of effector B cells (plasma cells) and cytotoxic T cells? A) B cells confer active immunity; cytotoxic T cells confer passive immunity. B) B cells kill viruses directly; cytotoxic T cells kill virus-infected cells. C) B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells. D) B cells accomplish the cell-mediated response; cytotoxic T cells accomplish the humoral response. E) B cells respond the first time the invader is present; cytotoxic T cells respond subsequent times.

C

51) Naturally acquired passive immunity would involve the A) injection of vaccine. B) ingestion of interferon. C) placental transfer of antibodies. D) absorption of pathogens through mucous membranes. E) injection of antibodies.

C

69) In the human disease known as lupus, there is an immune reaction against a patientʹs own DNA from broken or dying cells. This kind of response typifies which kind of irregularity? A) allergy B) immunodeficiency C) autoimmune disease D) antigenic variation E) cancer

C

73) Most newly emerging diseases, no matter how severe their effects on a population, human or otherwise, have which of the following in common? A) greater severity as there are more and more occurrences of the infection B) major pandemics, spreading the infection far and wide in the population C) a tendency to die out rather quickly, cease to reproduce, or cause a less severe effect on the host D) a destruction of the host immune system and eventual cancer E) no discoverable relationship with other pathogens in the same or related species

C

1) Both the eye and the respiratory tract are protected against infections by which of the following? A) the mucous membranes that cover their surface B) the secretion of complement proteins C) the release of slightly acidic secretions D) the secretion of lysozyme onto their surface E) interferons produced by immune cells

D

13) Histamines trigger dilation of nearby blood vessels, and increase in their permeability. Which of the signs of inflammation are therefore associated with histamine release? A) redness and heat only B) swelling only C) pain D) redness, heat, and swelling E) all of the signs of inflammation

D

16) What are antigens? A) proteins found in the blood that cause foreign blood cells to clump B) proteins embedded in B cell membranes C) proteins that consist of two light and two heavy polypeptide chains D) foreign molecules that trigger the generation of antibodies E) proteins released during an inflammatory response

D

2) Which of the following is a characteristic of the early stages of local inflammation? A) anaphylactic shock B) fever C) attack by cytotoxic T cells D) release of histamine E) antibody- and complement-mediated lysis of microbes

D

27) A patient can produce antibodies against some bacterial pathogens, but he does not produce antibodies against viral infections. This is probably due to a disorder in which cells of the immune system? A) B cells B) plasma cells C) natural killer cells D) T cells E) macrophages

D

46) Why can normal immune responses be described as polyclonal? A) Blood contains many different antibodies to many different antigens. B) Construction of a hybridoma requires multiple types of cells. C) Multiple immunoglobulins are produced from descendants of a single B cell. D) Diverse antibodies are produced for different epitopes of a specific antigen. E) Macrophages, T cells, and B cells all are involved in normal immune response.

D

49) Phagocytosis of microbes by macrophages is enhanced by which of the following? A) the binding of antibodies to the surface of microbes. B) antibody-mediated agglutination of microbes. C) the release of cytokines by activated B cells. D) A and B only E) A, B, and C

D

5) Which cells and which signaling molecules are responsible for initiating an inflammatory response? A) phagocytes: lysozymes B) phagocytes: chemokines C) dendritic cells: interferons D) mast cells: histamines E) lymphocytes: interferons

D

50) What is the primary function of humoral immunity? A) It primarily defends against fungi and protozoa. B) It is responsible for transplant tissue rejection. C) It protects the body against cells that become cancerous. D) It produces antibodies that circulate in body fluids. E) It primarily defends against bacteria and viruses that have already infected cells.

D

52) Which of the following is true of active but not passive immunity? A) acquisition and activation of antibodies. B) proliferation of lymphocytes in bone marrow. C) transfers antibodies from the mother across the placenta. D) requires direct exposure to a living or simulated pathogen. E) requires secretion of interleukins from macrophages.

D

53) Jenner successfully used cowpox virus as a vaccine against the virus that causes smallpox. Why was he successful even though he used viruses of different kinds? A) The immune system responds nonspecifically to antigens. B) The cowpox virus made antibodies in response to the presence of smallpox. C) Cowpox and smallpox are antibodies with similar immunizing properties. D) There are some antigenic determinants common to both pox viruses.

D

7) Which of the following results in long-term immunity? A) the passage of maternal antibodies to a developing fetus B) the inflammatory response to a splinter C) the administration of serum obtained from people immune to rabies D) the administration of the chicken pox vaccine E) the passage of maternal antibodies to a nursing infant

D

75) A patient reports severe symptoms of watery, itchy eyes and sneezing after being given a flower bouquet as a birthday gift. A reasonable initial treatment would involve the use of A) a vaccine. B) complement. C) sterile pollen. D) antihistamines. E) monoclonal antibodies.

D

Immunodeficiencies may be genetic in origin. Two examples of these are Brutonʹs agammaglobulinemia, an X-linked disorder, and DiGeorge syndrome, caused by a deletion from chromosome 22. Brutonʹs results in underdeveloped B cells, while DiGeorge syndrome results in a missing or seriously underdeveloped thymus. 65) A child is diagnosed with DiGeorge syndrome (DGS). With which of the following would the child have serious immunological problems? A) production of antibodies B) rate of mitosis in plasma cells C) response to infection by a bacterium such as streptococcus D) response to infection by a virus such as influenza E) response to allergens such as bee venom

D

7) A bacterium entering the body through a small cut in the skin will do which of the following? A) inactivate the erythrocytes B) stimulate apoptosis of nearby body cells C) stimulate release of interferons D) stimulate natural killer cell activity E) activate a group of proteins called complement

E

70) A patient undergoes a high level of mast cell degranulation, dilation of blood vessels, and acute drop in blood pressure. These symptoms could be caused by which of the following? A) an autoimmune disease B) a typical allergy that can be treated by antihistamines C) an organ transplant, such as a skin graft D) the effect of exhaustion on the immune system E) anaphylactic shock immediately following exposure to an allergen

E