Microbiology Chapter 19 Flashcards
All of the following are true of hypersensitivity EXCEPT
A) it requires previous exposure to an antigen.
B) it is synonymous with "allergy."
C) it occurs when an individual is exposed to an allergen for the first time.
D) it is due to an altered immune response.
E) it occurs in the presence of an antigen.
The chemical mediators of anaphylaxis are
A) antigen-antibody complexes.
B) found in basophils and mast cells.
C) the proteins of the complement system.
Which of the following may result from systemic anaphylaxis?
C) hay fever
Which antibodies will be in the serum of a person with blood type B,
A) anti-A, anti-Rh
C) anti-B, anti-Rh
D) anti-A, anti-B, anti-Rh
Which of the following types of transplant is least compatible?
E) All of these types of tranplant are equally compatible.
All of the following are used to determine relatedness between a
donor and a recipient for transplants EXCEPT
A) HLA antigens.
B) ABO blood group antigens.
C) MHC antigens.
D) HLA and MHC antigens.
E) HLA, MHC, and ABO blood group antigens.
Graft-versus-host disease will most likely be a complication of a(n)
a)bone marrow transplant
b)RH incompatibility between mother and fetus
c) blood transfusion
e) corneal transplant
A positive tuberculin skin test is an example of a)autoimmunity
b)acute contact dermatitis
d)delayed cell immunity
A healthy immune system destroys cancer cells with
A) tumor-specific antigens.
B) CD+ T cells.
D) CTLs and activated macrophages.
E) activated macrophages.
The symptoms of an immune complex reaction are due to
B) complement fixation.
D) antibodies against self.
E) destruction of the antigen.
Rheumatoid arthritis is due to deposition of
A) IgG and IgA complexes in joints.
B) IgA antibodies in joints.
C) complement in joints.
D) IgD and IgE complexes in joints.
E) complexes of IgM and IgG and also complement in joints.
Allergic contact dermatitis is due to
A) sensitized T cells.
B) IgE antibodies.
C) IgG antibodies.
D) activated macrophages.
E) IgM antibodies.
Attachment of HIV to the target cell depends on
A) gp120 combining with the chemokine receptor CCR5.
B) gp120 combining with the CD4+ receptor.
C) CXCR4 binding to the CD4+ receptor.
D) gp120 binding to the CD4+ plasma membrane.
E) gp41 binding to the CD4+ receptor.
All of the following pertain to serological tests EXCEPT
A) reactions can be detected by uptake of trypan blue by damaged cells.
B) they are used to test for specific HLAs on lymphocytes.
C) they can detect antibodies but not antigens.
D) they can be used to diagnose various diseases.
E) they are used to detect compatible tissues for transplantation.
The process of desensitization to prevent allergies involves the injection of increasing amounts of a
Which of the following statements about type I reactions is FALSE?
A) Antibodies bind to mast cells and basophils.
B) The symptoms are due to histamine.
C) The symptoms occur soon after exposure to an antigen.
D) They involve helper T cells.
E) They involve IgE antibodies.
Which of the following statements about type IV reactions is FALSE?
A) Reactions are primarily due to T cell proliferation.
B) Reactions are not apparent for a day or more.
C) Cytokines initiate tissue damage.
D) Hemolytic disease of the newborn is an example.
E) Allergic contact dermatitis is an example.
Hemolytic disease of the newborn can result from an
A) Rh- mother with an Rh+ fetus.
B) Rh- mother and an A fetus.
C) AB mother with a B fetus.
D) AB mother with an O fetus.
E) Rh+ mother with an Rh- fetus.
All of the following are false regarding Herceptin EXCEPT
A) it acts as an immunotoxin to target and kill cancer cells.
B) it is used to treat some breast cancer patients.
C) it is a vaccine to prevent the development of cancer.
D) it is an endotoxin that stimulates TNF by macrophages.
E) it neutralizes the growth factor EGF.
Which of the following utilizes a combination of monoclonal antitumor
antibody and immunotoxin?
A) immune complex
C) immunologic surveillance
D) immunologic enhancement
All of the following are reasons why an HIV vaccination has not been
A) small and inexpensive animals for vaccine research are not available.
B) use of a weakened virus would potentially transmit the infection.
C) HIV has a high mutation rate so one vaccination would not be effective to treat the world-wide pandemic.
D) vaccines are not effective against viral infections.
E) there is no known organism that can provide a model of natural immunity.
Treatment with certain drugs to reduce transplant rejection can cause
C) immunologic enhancement.
E) immunologic surveillance.
Which of the following statements about human embryonic stem cells is
A) They are undifferentiated.
B) They are pluripotent.
C) They express few MHC I antigens.
D) They are typically obtained from the blastocyst stage of embryonic development.
E) They express no MHC II antigens.
In immune complex reaction shown in Figure 19.1, what is the
structure labeled "a"?
C) mast cell
In immune complex reaction shown in Figure 19.1, what is the end
result of the reaction
A) IgG is directed against cell membrane antigens.
B) Complement is activated.
C) Endothelial cells are damaged.
D) Neutrophils are attracted and release enzymes.
E) Antibodies destroy neutrophils.
HIV spikes attach to CD4+ receptors found on
B) dendritic cells.
C) T helper cells.
D) T helper cells and macrophages.
E) T helper cells, macrophages, and dendritic cells.
Which of the following is the least likely vaccine against HIV?
C) attenuated virus
D) protein core
E) All of these vaccines are equally likely.
Which of the following is a possible outcome of an HIV infection?
A) The disease does not progress to AIDS.
B) Infection may initially be asymptomatic.
C) There may be persistent yeast infections .
D) Virions may remain latent.
E) All of the answers are correct.
Which of the following regions has the greatest distribution of HIV
infection and AIDS in the world?
A) North America
B) South and Southeast Asia
C) Eastern Europe and Central Asia
D) sub-Saharan Africa
E) Latin America
Chemotherapy to inhibit the progression of HIV infection utilizes all
of the following mechanisms EXCEPT
A) blockage of viral attachment.
B) destruction of viral ribosomes.
C) termination of viral DNA.
D) inhibition of viral proteases.
E) prohibition of viral integration into host cell DNA.
During asymptomatic phase I of HIV disease, HIV infection is
A) testing for seroconversion.
B) counting CD8+ T cells. C) counting CD4+ T cells.
D) measuring antibodies against HIV.
E) measuring viral RNA.
All of the following regarding "privileged sites" are true
A) they do not have lymphatic vessels.
B) they include corneal and brain tissue.
C) they include any tissue transplanted from a pig.
D) they are rarely rejected.
E) they explain how animals tolerate pregnancies without rejecting the fetus.
All of the following are considered examples of type I
A) penicillin allergic reactions.
C) pollen allergies.
D) transplant rejections.
E) dust allergies.
All of the following lead to drug-induced thrombocytopenic purpura.
Which occurs first?
A) Antibodies against haptens are formed.
B) Antibodies and complement react with platelets.
C) Platelets are destroyed.
D) Drug binds to platelets.
E) Purpura occurs on the skin.
Immunodeficiencies are a result of all of the following EXCEPT
B) HIV infection.
C) Hodgkin's disease.
D) DiGeorge syndrome.
E) autoimmune diseases.
Which of the following describes a cytotoxic autoimmune reaction?
A) Antibodies are not made.
B) Mediate by T cells.
C) Immune complexes form.
D) Cells are killed.
E) Antibodies react to cell-surface antigens.
Symptoms of delayed cell-mediated reactions are due to
A) IgE antibodies.
B) IgG antibodies.
Desensitization involves injection of
C) IgG antibodies.
E) IgE antibodies.
The following events occur if human cells expressing HLA-I are mixed
with anti-HLA-I, complement, and trypan blue. What step indicates the
cells are HLA-I?
A) Trypan blue enters the cells.
B) Enzyme is released from neutrophils.
C) Cells are damaged by complement.
D) Anti-HLA antibodies bind to HLAs on lymphocytes.
E) None of the answers are correct; the T cells are missing.
In rheumatoid arthritis, IgM, IgG, and complement deposit in joints.
This is an example of
A) acquired immunodeficiency.
B) immune complex autoimmunity.
C) cytotoxic autoimmunity.
D) cell-mediated autoimmunity.
The initial symptom of HIV infection is
A) significant weight loss
C) high viral load.
D) appearance of thrush.
E) loss of T cells.
The number of T cells drops to below 200 cells/microliter in which
phase of HIV infection?
A) phase 1
B) phase 2
C) phase 3
D) initial phase
E) asymptomatic phase