The thymus is the primary lymphoid organ for the development of which cells?

The thymus is the primary lymphoid organ for the development of which cells?

• A. T cells
• B. B cells
• C. NK cells
• D. Macrophages

Answer: (A)

T cells mature in the thymus. Progenitors come from the bone marrow and migrate to the thymus to rearrange their T cell receptor genes and undergo positive and negative selection, ensuring they recognize self-MHC and are not strongly self-reactive. B cells primarily develop in the bone marrow, NK cells arise mainly from lymphoid progenitors and mature outside the thymus, and macrophages come from myeloid precursors in the bone marrow, so the thymus is specifically the site for T cell development.

T cells mature in the thymus. Progenitors come from the bone marrow and migrate to the thymus to rearrange their T cell receptor genes and undergo positive and negative selection, ensuring they recognize self-MHC and are not strongly self-reactive. B cells primarily develop in the bone marrow, NK cells arise mainly from lymphoid progenitors and mature outside the thymus, and macrophages come from myeloid precursors in the bone marrow, so the thymus is specifically the site for T cell development.