Question

Activation of a B cell by an antigen results in its proliferation and differentiation into ________, which secrete the antibodies that attack the antigen.

A) cytotoxic T cells
B) T cells
C) plasma cells
D) memory cells
E) helper T cells

Answer 1

Activation of B cells by an antigen, with the help of helper T cells and cytokines, leads to the proliferation of the cells and their differentiation into plasma cells, which produce antibodies, and memory B cells, which provide quicker responses to future encounters with the antigen.

Step-by-step explanation:

Activation of a B cell by an antigen results in its proliferation and differentiation into plasma cells, which secrete the antibodies that attack the antigen. This process, aided by the interaction with helper T cells, encompass the activation of B cells. Upon encountering an antigen, B cells internalize and process it, presenting fragments on their surface using MHC II molecules. A helper T cell recognizes the displayed antigen and releases cytokines that signal the B cell to proliferate and differentiate. Through a process known as clonal selection, the activated B cell produces thousands of identical (clonal) cells.

These cells become either plasma cells or memory B cells. The plasma cells are the antibody factories of the immune response, secreting large quantities of antibodies to combat the antigen. Meanwhile, memory B cells remain inactive until they are needed for a more rapid response during a subsequent encounter with the same antigen.