Question

The primary lymphoid organs include:

• A. Bone marrow and tonsil
• B. Tonsil and lymph node
• C. Thymus and bone marrow
• D. Thymus and tonsil

Answer 1

Answer:

C. Thymus and bone marrow

• In the immune system, lymphoid organs are classified based on their function. Primary (central) lymphoid organs are the sites where lymphocytes (white blood cells) are generated and matured. Bone Marrow: This is the site where all blood cells are produced (haematopoiesis). It is specifically where B-lymphocytes (B-cells) mature. Thymus: This is a gland located behind the breastbone. Progenitor cells migrate from the bone marrow to the thymus to develop into T-lymphocytes (T-cells).