Question

Specific humoral defense in teleost is mediated by

• A. Macrophages
• B. Antibody
• C. T cells
• D. Interferon

Hint:

Immunity Keywords:
1. Humoral + Specific = Antibody (IgM).
2. Cellular + Specific = T-cells.
3. Humoral + Non-specific = Complement, Lysozyme, Interferon.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the primary component responsible for "specific humoral defense" in bony fishes (teleosts).
Detailed Explanation:

• Humoral vs. Cellular Immunity:
• Humoral Immunity: Involves components found in "humors" (body fluids like serum). It is mediated by molecules secreted by cells.

• Cellular Immunity: Involves direct cell-to-cell contact and killing (e.g., T-cells).

• Antibodies: In teleost fish, the primary humoral defense is mediated by antibodies (specifically IgM, and also IgD and IgT/IgZ). These are produced by B-lymphocytes. Antibodies specifically bind to antigens to neutralize them or mark them for destruction.

• Analysis of other options:
• Macrophages (A): Part of the innate, non-specific cellular defense.

• T cells (C): Mediate specific cellular (not humoral) immunity.

• Interferon (D): Part of the non-specific (innate) humoral response, primarily against viruses.

Step 3: Final Answer:
Specific humoral defense is mediated by antibodies.