AP BIOLOGY

Detailed explanation-1: -All adaptive immune responses develop in steps, consisting of: antigen recognition; activation of specific lymphocytes to proliferate and differentiate into effector and memory cells; elimination of the antigen; and decline of the response, with memory cells being the long-lived survivors.

Detailed explanation-2: -Adaptive immune responses are carried out by white blood cells called lymphocytes. There are two broad classes of such responses-antibody responses and cell-mediated immune responses, and they are carried out by different classes of lymphocytes, called B cells and T cells, respectively.

Detailed explanation-3: -Type I: reaction mediated by IgE antibodies. Type II: cytotoxic reaction mediated by IgG or IgM antibodies. Type III: reaction mediated by immune complexes. Type IV: delayed reaction mediated by cellular response.

Detailed explanation-4: -Humans have three types of immunity-innate, adaptive, and passive: Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection.