Antibodies are secreted by
- A. plasma cells derived from B lymphocytes
- B. cytotoxic T lymphocytes
- C. macrophages in the lymph nodes
- D. neutrophils in the blood
Explanation
When a B lymphocyte meets its matching antigen it divides, and most of the daughter cells become plasma cells packed with rough endoplasmic reticulum for mass producing one type of antibody. T cells act directly on infected cells and secrete cytokines but never antibody, which is the usual confusion. Macrophages present antigen to lymphocytes rather than making antibody themselves.