Immune System
Which is not an antigen-presenting cell (or APC)?

B cell
Dendritic cell
Polymorphonuclear leukocyte (or PMN)
All of these

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Immune System
Numerous antibodies can be prepared, against one antigen, each binds to unique epitopes. How is this antibody diversity generated?

By the combination of different heavy and light chains that form the antigen binding site
Both (a) and (b)
By rearrangements of the DNA encoding the variable regions of the heavy and light chains
Antibody proteins can physically change their shape to bind different epitopes

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Immune System
Which of the following is correct for CD8 T cells?

CD8 T cell receptor recognizes epitopes that are also commonly recognized by B cells
CD8 T cells can kill individual virus-infected cells in a contact dependent fashion
In the thymus, CD8 T cells undergo positive selection only, whereas CD4 T cells undergo negative selection only
CD8 T cells only recognize virus-infected cells

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Immune System
Which of the following statements is false regarding B cells?

B cells that recognize high concentrations of antigens (self) in the absence of other signals undergo apoptosis in the bone marrow
B one marrow stem cells migrate to the thymus and develop into B cells
B cells synthesize antibodies and put them on their cell surface
B cells can undergo class switching and produce a different antibody type

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Immune System
Polymorphonuclear leukocytes (or PMNs)

are a type of phagocyte that can engulf and kill bacteria
can be attracted to the site of an infection following activation of complement
are derived from bone marrow stem cells
All of these

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