least toxic nitrogeneous waste material is

Answer

To determine the least toxic nitrogenous waste material, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Types of Nitrogenous Waste**:
- There are three primary types of nitrogenous wastes produced by organisms: ammonia, urea, and uric acid.

2. **Evaluate Toxicity Levels**:
- **Ammonia**: This is the most toxic form of nitrogenous waste. It is primarily excreted by aquatic organisms such as fish and amphibians. Due to its high toxicity, it requires a large amount of water to be safely excreted.
- **Urea**: This is less toxic than ammonia and is excreted by terrestrial animals, including humans and mammals. Urea requires less water for excretion compared to ammonia.
- **Uric Acid**: This is the least toxic of the three nitrogenous wastes. It is excreted by organisms such as birds and reptiles. Uric acid requires the least amount of water for excretion.

3. **Conclusion**:
- Based on the evaluation of toxicity levels, the least toxic nitrogenous waste material is **uric acid**.

### Final Answer:
The least toxic nitrogenous waste material is **uric acid**.

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