Question

Assertion : Primary lymphoid organs are the places where immature lymphocytes differentiate into antigen-sensitive lymphocytes.
Reason : Primary lymphoid organs provide micro-environment for the development and maturation of lymphocytes.

• A. Both assertion and reason are true and reason is the correct explanation of the assertion
• B. Both the assertion and reason are true but the reason is not the correct explanation of the assertion
• C. Assertion is true but the reason is false
• D. Both the assertion and reason are false

Answer 1

The correct option is A Both assertion and reason are true and reason is the correct explanation of the assertion

Lymphoid organs provide the microenvironment for the functional maturity (primary lymphoid organs) and activation (secondary lymphoid organs) of lymphocytes.

The primary lymphoid organ provides a microenvironment for the development and maturation of lymphocytes. Examples include bone marrow and thymus.

B cells mature into B lymphocytes in the bone marrow, while T cells migrate to, and mature in, the thymus. Following maturation, the lymphocytes enter into the circulation and into the secondary lymphoid organs (like the spleen and lymph nodes) where they survey for invading pathogens.

So both assertion and the reason are true and the reason is the correct explanation of the assertion.