Multiple choice

The excretory substance is ammonia in

  1. camel

  2. cartilagenous fishes

  3. whale

  4. fresh water fishes

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freshwater fish are ammonotelic, meaning they excrete ammonia as their primary nitrogenous waste. Ammonia is highly toxic but water-soluble, and freshwater fish have ample water to dilute and excrete it.