IMMUNOLOGY

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: -During the secondary immune response, the immune system can eliminate the antigen, which has been encountered by the individual during the primary invasion, more rapidly and efficiently. Both T and B memory cells contribute to the secondary response.

Detailed explanation-3: -Once B-cells are activated, they become plasma cells that produce antibodies in response to an antigen. Or they become memory cells that remember the antigen so your immune system can quickly identify and fight it in the future.

Detailed explanation-4: -T lymphocytes are cells that are programmed to recognize, respond to and remember antigens. T lymphocytes (or T cells) contribute to the immune defenses in two major ways. Some direct and regulate the immune responses.

Detailed explanation-5: -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.