Although the adaptive immune system has two arms, it has been said, 'no T cells, no immunity.' Explain.

Mark the following statements as true or false. If a statement is false, correct is to make a true statement.

The secondary immune response is mediated by plasma cells.

How does a cytotoxic T cell destroy another cell displaying antigens bound to class I MHC proteins?

Mr. White developed neutropenia as a consequence of cancer chemotherapy, which destroyed much of his bone marrow. What other components of the immune system would be harmed by bone marrow destruction? Would you expect his hematocrit to be elevated or decreased? What effects would you expect to see from this change in hematocrit?

Blocking the antigen receptors on the surface of lymphocytes would interfere with

(a) Phagocytosis of the antigen

(b) That lymphocyte's ability to produce antibodies

(c) Antigen recognition

(d) The ability of the lymphocyte to present antigen

(e) Opsonization of the antigen