AP BIOLOGY

Detailed explanation-1: -B lymphocytes are the cells of the immune system that make antibodies to invading pathogens like viruses. They form memory cells that remember the same pathogen for faster antibody production in future infections.

Detailed explanation-2: -Memory B cells are generated during primary responses to T-dependent vaccines. They do not produce antibodies, i.e., do not protect, unless re-exposure to antigen drives their differentiation into antibody producing plasma cells.

Detailed explanation-3: -B cells have B cell receptors (BCRs) on their surface, which they use to bind to a specific protein. Once the B cells bind to this protein, called an antigen, they release antibodies that stick to the antigen and prevent it from harming the body. Then, the B cells secrete cytokines to attract other immune cells.

Detailed explanation-4: -Each B cell produces a single species of antibody, each with a unique antigen-binding site. When a naïve or memory B cell is activated by antigen (with the aid of a helper T cell), it proliferates and differentiates into an antibody-secreting effector cell.

Detailed explanation-5: -There are two main types of T-cells: Helper T-cells stimulate B-cells to make antibodies and help killer cells develop. Killer T-cells directly kill cells that have already been infected by a foreign invader.