Uric acid is the excretory product of which of the following?

Options

A. Frog, human
B. Bird, snake
C. Amoeba, starfish
D. None of these

Explanation

To determine which organisms excrete uric acid, we can analyze the options provided and understand the excretory products of each group.

### Step-by-Step Solution:

1. **Understanding Excretory Products**: Different organisms have different ways of excreting waste. The primary types of nitrogenous waste are ammonia, urea, and uric acid.

2. **Identifying Uric Acid Producers**: Uric acid is typically produced by organisms that need to conserve water. This is common in terrestrial animals that have adaptations to prevent water loss.

3. **Analyzing the Options**:
- **Frog**: Frogs excrete urea, not uric acid.
- **Mammals**: Most mammals, including humans, excrete urea.
- **Birds**: Birds excrete uric acid, which is often in a paste form to conserve water.
- **Snakes**: Like birds, snakes also excrete uric acid.
- **Amoeba and Starfish**: These organisms typically excrete ammonia due to their aquatic environments.

4. **Conclusion**: From the analysis, we find that birds and snakes are the organisms that excrete uric acid.

5. **Final Answer**: Uric acid is the excretory product of birds and snakes.