Which cells secrete immunoglobulins and are derived from B lymphocytes?

• A. Lymphocytes
• B. Mast cells
• C. Plasma cells
• D. Elastic fibers

Answer: (C)

Antibody production is done by plasma cells, specialized descendants of B lymphocytes. When B cells encounter an antigen and receive help from helper T cells, they differentiate into plasma cells that synthesize and secrete large amounts of immunoglobulins into the blood and body fluids. These antibodies are the molecules that recognize pathogens and mark them for attack by other parts of the immune system. Plasma cells are packed with rough endoplasmic reticulum to support this high-volume protein synthesis. Lymphocytes is a broad category that includes B and T cells, but only the B-cell lineage becomes plasma cells that produce antibodies. Mast cells, though involved in inflammatory and allergic responses, arise from a different lineage and do not secrete immunoglobulins. Elastic fibers are extracellular matrix components, not cells.