Which cells produce antibodies?

• A. T-Lymphocytes
• B. B-Lymphocytes
• C. Neutrophils
• D. Erythrocytes

Answer: (B)

Antibodies are produced by B-lymphocytes that mature into plasma cells. When a B cell recognizes a specific antigen and receives signals (often from helper T cells), it differentiates into plasma cells that secrete antibodies. These antibodies circulate in blood and lymph, bind to the antigen, neutralize pathogens, and mark them for attack by other parts of the immune system. Some B cells become memory cells for faster responses next time. This humoral aspect of immunity is distinct from what T cells, neutrophils, or erythrocytes do: T cells coordinate cellular responses, neutrophils are frontline phagocytes, and red blood cells carry oxygen.