A Level Biology Practice Exam

Which of the following cells are involved in the production of antibodies?

1. B memory cells

2. T helper cells

3. B lymphocytes

4. Killer T cells

The correct answer is: B lymphocytes

The production of antibodies is primarily the role of B lymphocytes, also known as B cells. When these cells encounter a specific antigen, they undergo activation and differentiation into plasma cells. Plasma cells are specialized B cells that secrete large quantities of antibodies into the bloodstream. These antibodies bind to antigens, marking them for destruction or neutralizing their effects, which is crucial for the immune response. While B memory cells and T helper cells play important roles in the immune system—B memory cells help in faster responses upon re-exposure to the same antigen and T helper cells assist in activating B cells along with other immune responses—neither of these directly produces antibodies. Killer T cells, on the other hand, target and destroy infected host cells rather than producing antibodies. Thus, B lymphocytes are the direct source of antibody production in the immune response.