Name the primary and secondary lymphoid organs.
Primary lymphoid organs: Bone marrow and Thymus.
Secondary lymphoid organs: Spleen, Lymph nodes, Tonsils, Peyer's patches of small intestine, and Appendix.
Explanation
According to the NCERT textbook, primary lymphoid organs (bone marrow and thymus) are where immature lymphocytes differentiate into antigen-sensitive lymphocytes and undergo maturation. Secondary lymphoid organs (spleen, lymph nodes, tonsils, Peyer's patches, and appendix) provide sites for interaction of lymphocytes with antigens, where they proliferate to become effector cells.
Solution Steps
Step 1: Identify primary lymphoid organs from context - bone marrow and thymus (where differentiation and maturation of lymphocytes occurs).
Step 2: Identify secondary lymphoid organs from context - spleen, lymph nodes, tonsils, Peyer's patches of small intestine, and appendix (where lymphocytes interact with antigens).