Final answer:
Lymphoid hemopoiesis mainly occurs in the bone marrow, where B cells undergo nearly all their development, and in the thymus gland, where T cells mature.
Step-by-step explanation:
Lymphoid hemopoiesis is the process by which lymphocytes, a class of leukocytes involved in immunity, are produced from lymphoid stem cells and subsequently mature. The majority of this process occurs in the bone marrow, for B cells, and in the thymus gland, for T cells. While other lymphatic tissues like the spleen and lymph nodes are involved in the maturation and function of lymphocytes, they are not the primary sites for lymphoid hemopoiesis.
The bone marrow contains the hematopoietic stem cells (HSC) that differentiate into various types of blood cells and lymphocytes. B cells nearly complete their development in the bone marrow, acquiring the ability to recognize antigens. In contrast, the immature T cells, known as thymocytes, leave the bone marrow and mature primarily in the thymus gland, thus playing a crucial role in cell-mediated immunity.