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

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 cells can kill individual virus-infected cells in a contact dependent fashion
CD8 T cell receptor recognizes epitopes that are also commonly recognized by B cells

ANSWER DOWNLOAD EXAMIANS APP

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

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
Both (a) and (b)

ANSWER DOWNLOAD EXAMIANS APP

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

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 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

ANSWER DOWNLOAD EXAMIANS APP

Immune System
Polymorphonuclear leukocytes (or PMNs)

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

ANSWER DOWNLOAD EXAMIANS APP