Least toxic nitrogenous waste among the following is

Options

A. Urea
B. Uric acid
C. Ammonia
D. More than one option is correct

Answer

To determine the least toxic nitrogenous waste among urea, uric acid, and ammonia, we will analyze each type of nitrogenous waste based on its toxicity and energy requirements for excretion.

### Step-by-Step Solution:

1. **Understanding Nitrogenous Wastes**:
- Nitrogenous wastes are products of protein metabolism and must be excreted from the body to prevent toxicity. The main types are ammonia, urea, and uric acid.

2. **Analyzing Ammonia**:
- Ammonia is highly toxic and requires a large amount of water for its excretion. It is the most toxic form of nitrogenous waste and is primarily excreted by aquatic animals (ammonotelic organisms).

3. **Analyzing Urea**:
- Urea is less toxic than ammonia and requires less water for excretion. It is produced in the liver through the urea cycle and is excreted by mammals (ureotelic organisms). While it is less toxic than ammonia, it is still more toxic than uric acid.

4. **Analyzing Uric Acid**:
- Uric acid is the least toxic of the three nitrogenous wastes. It is excreted as a paste with minimal water loss, making it advantageous for organisms in arid environments. Uric acid requires the most energy for its synthesis compared to ammonia and urea.

5. **Conclusion**:
- Among the three nitrogenous wastes (ammonia, urea, and uric acid), uric acid is identified as the least toxic nitrogenous waste.

### Final Answer:
The least toxic nitrogenous waste among the following is **uric acid**.

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