Question

Exclusion of the thymus,the primary lymphoid organs in mammals, results in severe immunodeficiency. This due to the absence of the following in the peripheral circulation

• A. All leucocytes
• B. Mature T and B cells
• C. Mature T cells
• D. Mature B cells

Answer 1

The correct option is C Mature T cells

Thymus a primary lymphoid organ is situated in the chest below the thyroid glad. It is the site for the maturation of T cells. In this, the T lymphocytes mature and become competent. So a complete and congenital removal of thymus leads to the absence of T cells and so causes severe immunodeficiency as these T cells help in the cell-mediated immune response. Thus, the correct answer is option C.