PATHOLOGY

Detailed explanation-1: -In secondary responses, on antigen rechallenge, memory B cells are activated and have at least two fates: they either differentiate into long-lived plasma cells or enter GCs to undergo rounds of population expansion, SHM and selection (Fig.

Detailed explanation-2: -When the memory B cells encounter their complementary antigen, they rapidly differentiate into plasma cells that secrete antibodies as well as more memory B cells. This is called the secondary immune response, and it is much more rapid and a stronger reaction than the primary response.