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Which of the following is NOT a characteristic of Natural Killer (NK) cells?
-NK cells attack transplanted organs.
-NK cells attack infected or cancerous cells.
– NK cells recognize abnormal or cancer cells by a specific antigen on their cell membrane.
– NK cells induce the target cell to undergo "apoptosis" (cell suicide).
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NK cells recognize abnormal or cancer cells by a specific antigen on their cell membrane
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Which of the following innate internal defenses work by interfering with viral replication?
-complement proteins
-T lymphocytes
-interferons
-phagocytes
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interferons
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How do phagocytes recognize foreign cells or bacteria?
-Phagocytes recognize a specific antigen on the cell surface.
-The phagocytes recognize molecules on pathogens not normally found on body cells.
-The phagocytes look for the absence of "self" proteins.
-All the foreign cells or bacteria are marked with opsonins that the phagocytes recognize.
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The phagocytes recognize molecules on pathogens not normally found on body cells
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Which of the innate defense mechanisms can lyse bacteria and mark cells for phagocytosis?
-interferons
-complement proteins
-cytokines
-natural killer (NK) cells
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complement proteins
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Which of the following can act as opsonins on bacteria, thus enhancing phagocytosis?
-interferons
-antibodies and complement proteins
-T cells
-natural killer (NK) cells
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antibodies and complement proteins
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What constitutes the body’s first line of defense against disease?
-antimicrobial proteins and various phagocytic cells
-the adaptive defense system
-intact skin and mucous membranes
-inflammation
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intact skin and mucous membranes
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How do interferons protect against infection in healthy cells?
-Interferons block viral reproduction in healthy cells through the production of antiviral proteins.
-Interferons perform complement activation.
-Interferons perform opsonization to coat microorganisms.
-Interferons promote fever, or an abnormally high body temperature.
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Interferons block viral reproduction in healthy cells through the production of antiviral proteins
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What is the specific target of interferons?
-infected cells
-antibodies
-specific viruses
-nearby healthy cells
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nearby healthy cells
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Which of the following is an effect of complement activation?
-tissue repair
-opsonization
-T cell activation
-fever
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opsonization
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What types of antigen are recognized by T cells?
-free antigens
-processed fragments of protein antigens displayed on surfaces of body cells
-bacterial antigens only
-cancer antigens only
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processed fragments of protein antigens displayed on surfaces of body cells
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Which of the following is not characteristic of the adaptive immune system?
-It is antigen-specific.
-It has memory.
-It is specific for a given organ.
-It is systemic.
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It is specific for a given organ
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How does a lymphocyte become immunocompetent?
-An antigen binds to a particular lymphocyte that has a receptor for it.
-Lymphocytes must be able to recognize their one specific antigen by binding to it.
-Lymphocytes must be relatively unresponsive to self-antigens so that they do not attack the body’s own cells.
-Lymphocytes rapidly proliferate to form an army of cells exactly like themselves and bearing the same antigen-specific receptors.
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Lymphocytes must be able to recognize their one specific antigen by binding to it
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Which of the following statements does NOT describe the adaptive immune response?
-It is systemic.
-It is specific.
-It has memory.
-It occurs immediately after the body is challenged by foreign material.
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It occurs immediately after the body is challenged by foreign material
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Which of the following exemplifies passive immunity?
-vaccine
-infection
-antitoxin
-vaccine booster shots
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antitoxin
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Which of the following best illustrates artificially acquired active humoral immunity?
-antivenoms
-infection
-vaccines
-antibodies received in breast milk
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Vaccines
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Select the correct statement about the function of antibodies.
-Complement fixation is the main mechanism by which antibodies provide protection.
-The most potent agglutinating agent is IgG.
-Neutralization is the process by which antibodies cause invading cells to clump together.
-Antibodies may directly destroy "invaders."
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Complement fixation is the main mechanism by which antibodies provide protection.
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What type of cell is the precursor to the helper T cell?
-memory T cell
-CD8 cell
-regulatory T cell
-CD4 cell
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CD4 cell
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What type of cell is a precursor to the cytotoxic T cell?
-activated T cell
-CD4 cell
-CD8 cell
-regulatory T cell
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CD8 cell
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