Which type of lymphocyte develops in the bone marrow and later produces antibodies?

• A. T Lymphocyte
• B. B Lymphocyte
• C. Macrophage
• D. Neutrophil

Answer: (B)

The lymphocyte that develops in the bone marrow and later produces antibodies is the B lymphocyte. B cells mature in the bone marrow, and when they encounter their specific antigen, they can become activated and differentiate into plasma cells that secrete large amounts of antibodies. These antibodies circulate, neutralize pathogens, and mark invaders for destruction by other immune cells, forming the humoral immune response.

In contrast, T lymphocytes develop in the thymus and primarily mediate cell‑mediated immunity, helping regulate responses or killing infected cells rather than producing antibodies. Macrophages and neutrophils are phagocytes involved in innate immunity, not antibody production.