AP BIOLOGY

Detailed explanation-1: -T lymphocytes develop from a common lymphoid progenitor in the bone marrow that also gives rise to B lymphocytes, but those progeny destined to give rise to T cells leave the bone marrow and migrate to the thymus (see Fig. 7.2). This is the reason they are called thymus-dependent (T) lymphocytes or T cells.

Detailed explanation-2: -T lymphocytes originate from bone marrow progenitors that migrate to the thymus for maturation, selection, and subsequent export to the periphery.

Detailed explanation-3: -Organs and Tissues The bone marrow is extremely important to the immune system because all the body’s blood cells (including T and B lymphocytes) originate in the bone marrow. B lymphocytes remain in the marrow to mature, while T lymphocytes travel to the thymus.

Detailed explanation-4: -It has been known for a long time that T-cell precursors generated in the bone marrow migrate to the thymus, where T-cell development occurs.