The Primary Lymphoid Tissues Include

Question

The primary lymphoid tissues include
A) the bone marrow.
B) the thymus.
C) the bone marrow and thymus.
D) the lymph nodes and tonsils.
E) the bone marrow, thymus, spleen and lymph nodes.

Accepted Answer

The primary lymphoid tissues are the sites where lymphocytes mature and develop their antigen-specific receptors. These tissues include the bone marrow, where B-cells mature, and the thymus, where T-cells mature. Therefore, the best choice is C, as it includes both the bone marrow and thymus as primary lymphoid tissues. The other answer choices include secondary lymphoid tissues such as lymph nodes, tonsils, and spleen.