LIFE SCIENCE

Detailed explanation-1: -They detect cells infected by viruses or tumorous cells and destroy them (cytotoxic T cells). Some T helper cells become memory T cells after the infection has been defeated. They can “remember” which germs were defeated and are then ready to activate the adapted immune system quickly if there is another infection.

Detailed explanation-2: -Memory T and B cells remain, however, and maintain a heightened ability to mount a response to a recurrence of infection with the same pathogen. The antibody and memory T cells remaining in an immunized individual also prevent the activation of naive B and T cells by the same antigen.

Detailed explanation-3: -Memory immune responses Because our memory cells are “experienced, ‘’ we will respond to a second (or subsequent) encounter more quickly. Whereas in a primary encounter, antibodies are not generated for several days, during a memory response antibodies appear in just a few days.

Detailed explanation-4: -Adaptive immunity also involves a memory to provide the host with long-term protection from reinfection with the same type of pathogen; on re-exposure, this memory will facilitate an efficient and quick response.