Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Neutrophils are highly phagocytic in nature
Reason (R) : They release toxic major basic proteins to kill the foreign body
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Always associate "Major Basic Protein" (MBP) with eosinophils and their anti-parasitic immune responses, never with neutrophils.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Leukocytes (white blood cells) are divided into granulocytes and agranulocytes, each possessing unique granules, enzymes, and functional roles in the host's immune defense.
Detailed Explanation:
Let us analyze the statements:
- Assertion (A) analysis: Neutrophils are the first line of cellular defense during acute infections. They are highly active phagocytes, capable of engulfing, ingesting, and destroying invading microorganisms. Thus, Assertion (A) is true.
- Reason (R) analysis: Major Basic Protein (MBP) is a highly toxic, specialized protein stored in the preformed granules of eosinophils, not neutrophils. Eosinophils release MBP to kill large, non-phagocytosable extracellular parasites like helminths. Neutrophils destroy engulfed pathogens using myeloperoxidase, reactive oxygen species, and defensins. Thus, Reason (R) is false.

Step 2: Final Answer:
Since (A) is true and (R) is false, the correct choice is Option (C).