Micro Exam 3 (mastering) – Flashcards
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You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________. A) increased metabolic rate B) constriction of blood vessels C) shivering D) dilation of blood vessels
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D) dilation of blood vessels
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Which of the following statements concerning phagocytosis is true? A) Phagocytes ingest microorganisms by using protein transporters that are specific for the bacteria. B) Phagocytes cannot ingest microorganisms unless they are coated with antibodies. C) Adherence always requires opsonization. D) Bacteria are digested when the phagosome fuses with a lysosome.
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D) Bacteria are digested when the phagosome fuses with a lysosome.
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Which of the following statements about beta interferon is true? A) It acts as a signal that induces uninfected cells to produce antiviral proteins. B) It is a protein that specifically degrades viral RNA. C) It is produced only in response to infection with the hepatitis B virus. D) It induces neutrophils and macrophages to kill bacteria.
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A) It acts as a signal that induces uninfected cells to produce antiviral proteins.
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Which of the following statements about innate immunity is true? A) The innate immune response does not have a mechanism for detecting invading microorganisms. It is activated only in response to tissue damage or a signal from an infected cell. B) It involves the activity of B and T cells. C) Innate immunity is present at birth. D) Innate immunity involves specific recognition of microorganisms via a memory response.
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C) Innate immunity is present at birth.
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Which of the following is an event that ultimately results in activation of complement C3 by splitting it into C3a and C3b?
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Interaction of mannose-binding lectin with mannose molecules on a bacterium
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Activation of C3 results in __________. A) enhancement of phagocytosis via opsonization B) release of histamine and other pro-inflammatory chemicals C) formation of a membrane attack complex (MAC), which causes cytolysis of bacteria D) all of these
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D) All of these
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Which of the following statements concerning immunological memory is true? A) The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure. B) Antibodies produced in response to a secondary infection are mostly IgM. C) The memory response involves only B cells. D) The memory response is usually faster but not as strong.
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A) The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure.
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If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first?
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IgM
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Consider a helminthic infection in which an individual is colonized by a parasitic worm. The worm is too big to be engulfed by a phagocytic cell. How does the immune system respond?
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The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it.
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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?
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naturally acquired active immunity
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Macrophages arise from which of the following? A) monocytes B) lymphocytes C) basophils D) eosinophils E) neutrophils
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A) monocytes
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Innate immunity... A) is nonspecific and present at birth. B) provides increased susceptibility to disease. C) involves a memory component. D) is slower than adaptive immunity in responding to pathogens. E) involves T cells and B cells.
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A) is nonspecific and present at birth.
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IL-2, produced by TH cells, stimulate what?
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TH cell maturation
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TLRs attach to all of the following EXCEPT A) AMPs. B) LPS. C) peptidoglycan. D) flagellin. E) PAMPs.
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A) AMPs.
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After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT A) complement. B) H2O2. C) HOCl. D) O2-. E) OH•.
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A) complement.
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All of the following protect the skin and mucous membranes from infection EXCEPT A) tears. B) saliva. C) multiple layers of cells. D) the "ciliary escalator." E) HCl.
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E) HCl.
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Which of the following statements about the classical pathway of complement activation is FALSE? A) The C1 protein complex is initiated by antigen-antibody complexes. B) Cleaved fragments of some of the proteins act to increase inflammation. C) C3b causes opsonization. D) C1 is the first protein activated in the classical pathway. E) C3 is not involved in the classical pathway.
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E) C3 is not involved in the classical pathway.
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What type of immunity results from vaccination?
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artificially acquired active immunity
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The presence of which of the following indicates a current infection rather than a previous infection or vaccination? A) IgD B) IgM C) IgA D) IgE E) IgG
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B) IgM
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An antibody's Fc region can be bound by A) B cells. B) antibodies. C) T helper cells. D) macrophages. E) CTLs.
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D) macrophages.
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Innate immunity includes all of the following EXCEPT A) phagocytosis. B) production of interferon. C) activation of complement. D) production of antibody. E) inflammation.
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D) production of antibody.
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Which of the following statements is NOT a possible outcome of antigen-antibody reaction? A) agglutination B) activation of complement C) ADCC D) opsonization E) clonal deletion
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E) clonal deletion
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Which non-specific defense mechanism is mismatched with its associated body structure or body fluid? A) keratin and tightly packed cells skin B) lysozyme tears and saliva C) mucociliary escalator intestines D) cerumen and sebum ear E) very acidic pH stomach
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C) mucociliary escalator intestines
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When an antibody binds to a toxin, the resulting action is referred to as
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neutralization.
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Which of the following is NOT a reason why monoclonal antibodies (Mabs) are useful? A) They are highly specific. B) They are uniform. C) They are always highly sensitive. D) They can be produced in large quantities.
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C) They are always highly sensitive.
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You are conducting a viral hemagglutination inhibition test. Which of the following indicates that a patient's serum has antibodies against influenza virus?
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Hemagglutination occurs in a mixture of influenza virus and erythrocytes but does not occur when the patient's serum is added.
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I have a new test for determining whether a patient is infected with the influenza virus. It is very specific but not very sensitive. What does this mean? A) False-positives and false-negatives will happen with high frequency. B) False-positives will be rare, but false-negatives may happen frequently. C) False-positives will happen frequently, but false-negatives will be rare. D) Both false-positives and false-negatives will be rare.
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B) False-positives will be rare, but false-negatives may happen frequently.
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What is an adjuvant?
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a chemical additive that increases the effectiveness of vaccines
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Which of the following is NOT an advantage of using live attenuated vaccines? A) They often do not require boosters. B) They often produce a more complete type of immunity that includes both humoral and cell-mediated components. C) They are usually safer than other types of vaccines. D) They are usually highly effective.
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C) They are usually safer than other types of vaccines.
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Consider a Kirby-Bauer disk-diffusion assay. If you put penicillin and streptomycin disks adjacent to one another, the zone of inhibition is greater than that obtained by either disk alone. This is an example of __________.
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synergism
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Why is it more difficult to treat viral infections than it is to treat bacterial infections? A) Viruses are very similar to human cells. B) Viruses have cell walls. C) Viruses use the host cell's processes to carry out their own reproduction. D) Viruses are smaller than human cells.
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C) Viruses use the host cell's processes to carry out their own reproduction.
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Why is methicillin-resistant Staphylococcus aureus (MRSA) methicillin resistant?
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It produces a modified version of the molecule that is targeted by the drug.
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Which of the following is an antiprotozoan drug that interferes with anaerobic metabolism? A) metronidazole B) chloroquine C) acyclovir D) erythromycin
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A) metronidazole
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If penicillin G is chosen as the best treatment for a given infection, what microorganisms are most likely the cause?
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gram-positive bacteria
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Antimicrobial peptides work by
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disrupting the plasma membrane.
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Protozoan and helminthic diseases are difficult to treat because
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their cells are structurally and functionally similar to human cells.
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A DNA plasmid encoding a protein antigen from West Nile virus is injected into muscle cells of a horse. This is an example of a(n) A) subunit vaccine. B) nucleic acid vaccine. C) live whole-agent vaccine. D) conjugated vaccine. E) attenuated whole-agent vaccine.
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B) nucleic acid vaccine.
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A hybridoma results from the fusion of a(an)
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B cell with a myeloma cell.
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Monoclonal antibodies are used in diagnostic tests and disease treatments because they
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are highly specific and they can be produced in large quantities.
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A reaction between an antibody and soluble antigen-forming lattices is called a(n)
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precipitation reaction.
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Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT A) it does not affect eukaryotic cells. B) it was the first antibiotic. C) it inhibits gram-positive cell wall synthesis. D) it has selective toxicity. E) it kills bacteria.
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B) it was the first antibiotic.
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In what way are semisynthetic penicillins and natural penicillins alike?
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Both are based on β-lactam.
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Purified protein from Bordetella pertussis is used in a(n) A) nucleic acid vaccine. B) conjugated vaccine. C) attenuated whole-agent vaccine. D) subunit vaccine. E) toxoid vaccine.
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D) subunit vaccine.
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Which of the following is a pregnancy test used to find the fetal hormone HCG in a woman's urine using anti-HCG and latex spheres? A) direct agglutination reaction B) indirect agglutination reaction C) immunofluorescence D) neutralization reaction E) precipitation reaction
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B) indirect agglutination reaction
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Which of the following correctly lists the current distribution of HIV infection and AIDS in order of DECREASING prevalence? A) sub-Saharan Africa, Australia / New Zealand, Western Europe, Latin America B) sub-Saharan Africa, Latin America, Western Europe, Australia / New Zealand C) Latin America, sub-Saharan Africa, Western Europe, Australia / New Zealand D) sub-Saharan Africa, Western Europe, Latin America, Australia / New Zealand
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B) sub-Saharan Africa, Latin America, Western Europe, Australia / New Zealand
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Which type of hypersensitivity is allergic contact dermatitis? A) type IV reaction B) type III reaction C) type II reaction D) type I reaction
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A) type IV reaction
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Which of the following is a characteristic of rheumatoid arthritis? A) T cytotoxic cells attack joint tissue. B) Antibodies coat acetylcholine receptors at neuromuscular junctions. C) Antibodies attach to receptors on thyroid gland cells. D) Immune complexes of IgM, IgG, and complement are involved.
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D) Immune complexes of IgM, IgG, and complement are involved.
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Assuming Rh compatibility is present, which of the following individuals would be able to receive donor blood from any of the four blood types (A, B, AB, and O)? A) B B) AB C) O D) A
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B) AB
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Which statement regarding cancer immunotherapy is FALSE? A) An immunotoxin is an antigen combined with a toxic agent. B) Cancer immunotherapy is preferable to radiation therapy because it does not involve causing damage to healthy cells. C) Monoclonal antibodies are a promising tool for cancer treatment delivery. D) Cancer vaccines may be either therapeutic or prophylactic.
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A) An immunotoxin is an antigen combined with a toxic agent.
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Which of the following is true concerning systemic anaphylaxis? A) Anaphylactic shock results from an increase in blood pressure, which is caused by blood vessel constriction. B) Injected antigens combine with IgE antibodies on the surface of certain cells, causing them to release histamines and other inflammatory mediators. C) Asthma is a type of systemic anaphylaxis. D) Systemic anaphylaxis frequently occurs as a result of exposure to inhaled allergens.
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B) Injected antigens combine with IgE antibodies on the surface of certain cells, causing them to release histamines and other inflammatory mediators.
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Which of the following best describes graft-versus-host disease? A) Immune cells attack transplanted tissue in a privileged site. B) A tissue transplant is rejected because the host's T cytotoxic cells are activated and kill the transplanted tissue. C) Immune cells in transplanted bone marrow attack the cells of the host. D) The cells of a host reject transplanted bone marrow.
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C) Immune cells in transplanted bone marrow attack the cells of the host.
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Which statement regarding the infectiveness and pathogenicity of HIV is FALSE? A) During latent infections, the provirus directs the synthesis of many new viruses. B) The ability of the HIV to remain as a provirus shelters it from the immune system. C) Attachment of HIV to the target cell depends on the glycoprotein spike (gp120) combining with the CD4+ receptor. D) Some cells that do not carry the CD4 molecule can become infected with HIV.
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A) During latent infections, the provirus directs the synthesis of many new viruses.
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Which of the following is a xenograft? A) transplantation of a kidney from a woman to her older brother B) transplantation of tissue from one area on a person's body to anther C) the replacement of a human's heart valve with a pig's heart valve D) transplantation of a kidney from a woman to her twin sister.
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C) the replacement of a human's heart valve with a pig's heart valve
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Which of the following is FALSE concerning type II (cytotoxic) hypersensitivity reactions? A) They are responsible for transfusion reactions. B) Macrophage activity my lead to additional cellular damage. C) IgM and IgG antibodies bind to antigens on foreign cells. D) IgE binds to mast cells or basophils.
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D) IgE binds to mast cells or basophils.
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The level of HIV population in the blood is highest: A) When the patient has clinical AIDS B) When CD4+ levels are the highest C) When the patient is asymptomatic
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C) When the patient is asymptomatic.
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The progression from initial HIV infection to AIDS (in the US) usually takes: A) 5 years B) 10 years C) 20 years
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B) 10 years.
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Early indication of immune system failure is provided by: A) high levels of HIV virus in the blood B) Seroconversion of HIV C) Falling levels of CD4+ cells
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C) Falling levels of CD4+ cells.
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Immunodeficiencies are a result of all of the following EXCEPT A) HIV infection. B) autoimmune diseases. C) cyclosporine. D) Hodgkin's disease. E) DiGeorge syndrome.
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B) autoimmune diseases.
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All of the following pertain to serological tests EXCEPT A) they can be used to diagnose various diseases. B) reactions can be detected by uptake of trypan blue by damaged cells. C) they are used to detect compatible tissues for transplantation. D) they are used to test for specific HLAs on lymphocytes. E) they can detect antibodies but not antigens.
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E) they can detect antibodies but not antigens.
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Which of the following utilizes a combination of monoclonal antitumor antibody and immunotoxin? A) immunotherapy B) immune complex C) immunologic surveillance D) immunologic enhancement E) immunosuppression
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A) immunotherapy
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Graft-versus-host disease will most likely be a complication of a(n) A) bone marrow transplant. B) blood transfusion. C) Rh incompatibility between mother and fetus. D) skin graft. E) corneal transplant.
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A) bone marrow transplant.
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Which of the following is a possible outcome of an HIV infection? A) Virions may remain latent. B) The disease does not progress to AIDS. C) There may be persistent yeast infections . D) Infection may initially be asymptomatic. E) All of the answers are correct.
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E) All of the answers are correct.
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Which of the following types of transplant is least compatible? A) isograft B) xenotransplant C) allograft D) autograft E) All of these types of tranplants are equally compatible.
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B) xenotransplant
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Worldwide, the primary method of transmission of HIV is
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heterosexual intercourse
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Treatment with certain drugs to reduce transplant rejection can cause A) immunologic surveillance. B) autoimmunity. C) immunosuppression. D) immunologic enhancement. E) immunotherapy.
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C) immunosuppression.
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HIV spikes attach to CD4+ receptors found on
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T helper cells, macrophages, and dendritic cells.
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Which of the following statements about type IV reactions is FALSE? A) Cytokines initiate tissue damage. B) Allergic contact dermatitis is an example. C) Reactions are not apparent for a day or more. D) Reactions are primarily due to T cell proliferation. E) Hemolytic disease of the newborn is an example.
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E) Hemolytic disease of the newborn is an example.
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Which of the following are used to determine relatedness between a donor and a recipient for transplants? A) HLA antigens. B) ABO blood group antigens. C) MHC antigens. D) HLA and MHC antigens. E) HLA, MHC, and ABO blood group antigens.
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E) HLA, MHC, and ABO blood group antigens.
