Immune System
Which of the following(s) is/are the determinants of antigenicity?

All of these
Size of the antigen
Chemical nature
Foreignness

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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?

Both (a) and (b)
By rearrangements of the DNA encoding the variable regions of the heavy and light chains
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

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Immune System
Polymorphonuclear leukocytes (or PMNs)

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

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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 cells synthesize antibodies and put them on their cell surface
B one marrow stem cells migrate to the thymus and develop into B cells
B cells can undergo class switching and produce a different antibody type

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Immune System
T cell receptors (or TCR) on CD4+ T cells

recognize peptides not associated with MHC molecules
recognize peptides associated with MHC class II molecules
recognize peptides associated with MHC class I molecules
are secreted out into the environment to bind antigens

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