A) If the IgG is bound to the phagocyte BEFORE opsonization, it would most likely be ingested by the phagocyte before it could bind to a pathogen (it would be "naked," so to speak) .
B) Binding of IgG by phagocytes would block the antigen binding sites on the IgG molecules, preventing them from binding to the microbes.
C) Binding of IgG by phagocytes changes their conformation-and by changing their protein conformation, their antigen binding sites are changed and they can no longer recognize their specific antigenic epitopes.
D) Binding of antibody by phagocytes results in immediate release of protein-destroying enzymes to the outside of the cell. Since antibodies are proteins, they would be destroyed by these enzymes (and would then be unable to bind to their specific antigenic epitopes) .
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A) Progesterone, a lipid hormone.
B) Serum albumin, a large protein.
C) Glucose, a simple sugar.
D) Linoleic acid, a fatty acid.
E) These are all equally immunogenic.
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A) antibodies are modified, at the time of antigen exposure, to specifically react with the antigen.
B) self-reactive T cells are killed in the thymus.
C) B cells producing autoantibodies are eliminated in the thymus.
D) each B cell is already programmed to produce a specific antibody.
E) self-reactive T cells are killed in the thymus AND B cells producing autoantibodies are eliminated in the thymus.
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A) are parts of the antibody molecule.
B) are T cell receptors.
C) are parts of an antigen recognized by an antibody.
D) are B cell receptors.
E) are parts of an antibody recognized by an antigen.
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A) produce MHC class I molecules.
B) produce MHC class II molecules.
C) produce antibodies.
D) activate cytotoxic T cells.
E) activate regulatory T cells.
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A) IgA
B) IgD
C) IgG
D) IgE
E) IgM
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A) antigenic determinants.
B) an autoimmune response.
C) monomers.
D) allergens.
E) antibody determinants.
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A) only on the heavy chains.
B) only on the light chains.
C) on one of the light chains.
D) on all four chains.
E) at the hinge region only.
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A) Macrophages
B) Dendritic cells
C) B cells
D) Macrophages, dendritic cells, AND B cells
E) Macrophages AND dendritic cells
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A) imply that each individual lymphocyte produces a single antibody.
B) describe how a single lymphocyte proliferates in a population of effector cells.
C) depend on an antibody recognizing a specific epitope.
D) explain how an antigen stimulates the production of matching antibodies.
E) All of the answer choices are correct.
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A) When a person is exposed to an antigen, B cells get activated by TH cells, proliferating and differentiating to form populations of plasma cells and memory cells.
B) Plasma cells produce antibodies which are specific proteins that bind to the antigens, tagging them for elimination by other immune cells such as macrophages and neutrophils.
C) On first exposure to an antigen, a person makes IgM followed by IgG. On second exposure to that same antigen, memory cells produce large amounts of IgG.
D) If a woman experiences a primary exposure to a particular while pregnant, she makes IgM in response. This antibody crosses the placenta and protects her fetus from that pathogen.
E) If a woman experiences a secondary exposure to a particular pathogen while pregnant, she makes IgG that crosses the placenta and protects the fetus from that antigen.
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A) IgA
B) IgD
C) IgM
D) IgE
E) IgG
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A) TC cells induce apoptosis in infected "self" cells.
B) TC produce antibodies AND TC destroy cancerous "self" cells.
C) TC destroy cancerous "self" cells AND TC cells induce apoptosis in infected "self" cells.
D) TC cells activate B cells AND TC cells induce apoptosis in infected "self" cells.
E) TC cells activate B cells and macrophages AND TC cells produce antibodies AND TC destroy cancerous "self" cells
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A) Koch.
B) von Behring.
C) Jenner.
D) Roux.
E) Pasteur.
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A) play the same role in each type of cell.
B) bind to free antigen.
C) have two binding sites for antigen.
D) have variable and constant regions.
E) play the same role in each type of cell AND bind to free antigen.
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A) T helper cells.
B) natural killer cells.
C) T cytotoxic cells.
D) macrophages.
E) plasma cells.
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A) After activation, T lymphocytes divide and proliferate to form a population of helper T cells and a population of cytotoxic T cells; activated T cells secrete cytokines that exert an effect on other cells.
B) After activation, B lymphocytes divide and proliferate to form a population of plasma cells and a population of memory cells; plasma cells produce antibodies that tag microbial invaders for elimination by phagocytes.
C) Once activated, helper T cells form a population of TH effector cells and a population of TH memory cells; TH effector cells produce cytokines that activate B cells and macrophages.
D) Once activated, cytotoxic T cells form a population of TC effector cells and a population of TC memory cells; TC effector cells produce cytokines that induce apoptosis in virally infected self cells.
E) Effector B cells and T cells express traits that help eliminate invaders in a primary response. Memory B cells and T cells are responsible for the effectiveness of the secondary response.
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