Final answer:
Most lymphocytes in the human body are B cells or T cells, with B cells comprising 10 to 20 percent of them. B cells produce antibodies and mature in the bone marrow, playing a critical role in the humoral immune response.
Step-by-step explanation:
Most lymphocytes belong to the subset B cells or T cells. Lymphocytes are a type of white blood cell and are crucial in the body's adaptive immune responses. In human circulating blood, lymphocytes are approximately 80 to 90 percent T cells and 10 to 20 percent B cells. T cells are involved in the cell-mediated immune response, whereas B cells are part of the humoral immune response and are responsible for producing antibodies. They are named based on the locations in which they mature: "B" for bone marrow and "T" for thymus.
B cells function by producing antibodies, which are proteins that bind specifically to antigens on the surface of pathogens. Once B cells are activated by antigens, they differentiate into plasma cells that secrete antibodies to fight off infections. B cells mature in red bone marrow, and the human body contains approximately 10¹² lymphocytes.