Question

Study the following and select the correct statement about B-lymphocytes.

• A. Encounter with the antigens results in division of immature B-cells
• B. Memory B-cells do not express the same antibody as their parent B-cell
• C. Effector cells are short-lived
• D. Antibodies play the major role in cell-mediated immunity

Answer 1

The correct option is C Effector cells are short-lived

B-lymphocytes are a type of white blood cells in the immune system. They mature in the bursa of Fabricius (in birds) or bone marrow (in mammals).

A mature B-cell displays membrane-bound antibodies which serve as receptors for the antigen. Once a mature B-cell encounters an antigen that binds to its membrane-bound antibody, it causes the cell to divide rapidly and differentiates into plasma cells and memory cells. Hence option a is incorrect.

The plasma cells (effector cells) are short-lived and are responsible for the secretion of soluble antibodies which play a major role in humoral immunity. So option d is incorrect and option c is correct.

Memory cells express the same antibody as their parent B-cells and help in the secondary immune responses (immune response during subsequent encounters with the same antigen). So option b is incorrect.

Figure : Formation of plasma cells and memory cells