Question

Nitrogenous waste is excreted in the form of pellet or paste by:

• A. Ornithorhynchus
• B. Salamandra
• C. Hippocampus
• D. Pavo

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Based on the main nitrogenous waste product, animals are classified as ammonotelic (Ammonia), ureotelic (Urea), or uricotelic (Uric acid).
Detailed Explanation:
- Uricotelic animals excrete nitrogenous waste as uric acid in the form of a pellet or paste with minimum loss of water. This is an adaptation for terrestrial life, especially for animals that need to conserve water.
- Uricotelic groups include: Reptiles, Birds, Land snails, and Insects.
- Let's check the options:
1. {Ornithorhynchus} (Platypus) - Mammal (Ureotelic).
2. {Salamandra} (Salamander) - Amphibian (Ureotelic/Ammonotelic).
3. {Hippocampus} (Sea horse) - Fish (Ammonotelic).
4. {Pavo} (Peacock) - Bird (Uricotelic).
Step 2: Final Answer:
{Pavo} (Peacock) is a bird and thus excretes waste in pellet/paste form.