Final answer:
During their residence in the thymus, pre-T cells develop into thymocytes, which proliferate rapidly as any other cells in the body. The thymus is the primary lymphoid organ where T lymphocytes proliferate and mature.
Step-by-step explanation:
During their residence in the thymus, pre-T cells develop into thymocytes, cells that proliferate as rapidly as any in the body. Thymocytes undergo a series of developmental stages within the thymus that ensure both function and tolerance before they leave and become functional components of the adaptive immune response. The thymus is the primary lymphoid organ where T lymphocytes proliferate and mature.