Immune System
Natural killer cells are involved in

tumour rejection
non-specific killing of virus transformed target cells
all of these
allograft rejection

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

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 that recognize high concentrations of antigens (self) in the absence of other signals undergo apoptosis in the bone marrow
B cells can undergo class switching and produce a different antibody type

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

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

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

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