Question

Assertion: Secondary immume response is stronger and faster than primary response.

Reason: Memory cell formed during primary response auickly recognize the antigen.

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

Answer 1

Answer: (A)

Assertion and reason are true and reason is the correct explanation of assertion.

Answer 2

The assertion states that the secondary immune response is stronger and faster than the primary response. This is a fundamental characteristic of adaptive immunity. When the body encounters an antigen for the first time (primary response), it takes time to develop an immune response, and the response is relatively weaker. However, during this primary response, specific memory B and T cells are formed.

The reason states that memory cells formed during the primary response quickly recognize the antigen. This is also true. These memory cells are long-lived and circulate in the body. Upon subsequent exposure to the same antigen (secondary response), these memory cells are rapidly activated. They quickly proliferate and differentiate into effector cells (e.g., plasma cells producing antibodies, or cytotoxic T cells), leading to a much quicker, stronger, and more prolonged immune response compared to the primary response.

Therefore, the presence and rapid activation of memory cells that quickly recognize the antigen are precisely why the secondary immune response is stronger and faster. The reason correctly explains the assertion.