Question

The letter T in T-lymphocytes refers to-
A. Thyroid
B. Thymus
C. Thalamus
D. Tonsil

Answer 1

Hint: T-lymphocyte or T cells are a type of lymphocyte that plays a major part in the adaptive immune system. They produce cytokines and also act as a fighter for foreign particles.

Complete answer:
T- lymphocytes originate in the Bone Marrow and mature in the Thymus region, hence named T- lymphocyte. The mature T-cells are mostly found in the lymph nodes. The receptors present on them are called T-cell receptors that help them to distinguish from other lymphocytes and these cells are differentiated into many subsets like, Tc (Cytotoxic T cells which kills target cells bearing specific antigen), Th (Helper T cells which are required for all the adaptive immune responses), memory cells and suppressor cells. These lymphocytes are involved in cell-mediated immune response and have a longer life span.
T-cells are derived from the Haematopoietic stem cells and their progenitor migrate and colonize the Thymus where their maturation occurs.
The other main type of lymphocyte is B lymphocyte which originates and matures in the Bone marrow hence the name. It is involved in humoral immunity and helps to eliminate the free foreign invaders.

Hence, the correct answer is option (B)

Note: T lymphocytes play a major role in the regulation of antigen-specific immune responses. They provide immunity against most viruses by lysing virus-infected cells and pathogens. They also help to activate B cells and help them in antibody production.