What is the consequence of surgical removal of the thymus in a newborn?

Deficient T-lymphocyte production

The correct answer is (d) Deficient T-lymphocyte production.

The thymus is a primary lymphoid organ responsible for the maturation of T-lymphocytes, also known as T-cells. T-cells play a vital role in cell-mediated immune responses, including the recognition and destruction of infected cells and activation of other immune cells.

If the thymus is surgically removed in a newborn, it can result in a condition called thymectomy. Thymectomy leads to the absence or reduced production of T-lymphocytes, which significantly impairs the immune system's ability to mount an effective cellular immune response.

The removal of the thymus does not directly impact the production of allergens (a), interferons (b), or B-lymphocytes (c).

Allergens are substances that trigger allergic reactions in susceptible individuals and are not produced by the thymus. Interferons are signaling proteins produced by various cells in response to viral infections, and their production is not solely dependent on the thymus. B-lymphocytes, which are responsible for antibody production, primarily mature in the bone marrow and not the thymus.

Therefore, the surgical removal of the thymus in a newborn will result in the failure to produce T-lymphocytes, leading to deficient cellular immune responses.