Assertion (A): Marine fishes excrete nitrogenous waste primarily as ammonia. Reason (R): Marine fishes are hyperosmotic to their…

Question

Assertion (A): Marine fishes excrete nitrogenous waste primarily as ammonia.

Reason (R): Marine fishes are hyperosmotic to their environment, leading to high water retention.

1. A. Both A and R are correct, and R explains A.
2. B. Both A and R are correct, but R does not explain A.
3. C. A is correct, but R is incorrect. (Correct answer)
4. D. A is incorrect, but R is correct.

Correct Answer

Option C — A is correct, but R is incorrect.

Detailed Solution & Explanation

The correct answer is A is correct, but R is incorrect..

Key Points

• Marine teleost fish (bony fish) are ammoniotelic - they do excrete ammonia (A is correct).
• However, marine teleosts are HYPOSMOTIC to seawater (not hyperosmotic) - they lose water and must drink seawater. R is incorrect.