Final answer:
Small lymphocytes are primarily responsible for antibody production, and they play a vital role in humoral and cell-mediated immune responses.
Step-by-step explanation:
Small lymphocytes are primarily responsible for antibody production. They play a crucial role in the adaptive immune system, with different types of lymphocytes performing distinct functions. B cells, a type of lymphocyte, mature in the bone marrow and are involved in humoral immunity where they differentiate into plasma cells that produce antibodies. On the other hand, T cells are involved in the cell-mediated immune response, where cytotoxic T cells (Tc cells) directly destroy infected cells.
It's important to distinguish between the roles of various immune cells, such as macrophages, which are phagocytic, and lymphocytes, which, depending on their subtype, may be responsible for the production of antibodies or cell-mediated cytotoxicity.