AP BIOLOGY

Detailed explanation-1: -Passive immunity provides immediate protection, but the body does not develop memory; therefore, the patient is at risk of being infected by the same pathogen later.

Detailed explanation-2: -In addition to “fighting off” these pathogens, active immunity is important because it lasts a long time in the form of immunologic memory. Immunologic memory consists of B and T cells that can recognize a particular pathogen (see “Adaptive immune system").

Detailed explanation-3: -Rapid and blunt, the innate immune system is the first line of defense. It recognizes a limited number of molecular patterns in disease-causing microbes, or pathogens. Convention says that the innate immune system retains no memory of previous infections.

Detailed explanation-4: -Passive Immunity. Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. A newborn baby acquires passive immunity from its mother through the placenta.

Detailed explanation-5: -Humoral Immunity. The B cell is stimulated when it encounters an antigen that binds to its membrane-bound immunoglubulin receptor. B cell activation, augmented by T helper cells, leads to differentiation of B cells into plasma cells (antibody producers) and memory B cells.