least toxic form of excretory product is

Options

A. ammonia
B. urea
C. uric acid
D. carbon dioxide

Answer

To determine the least toxic form of excretory product, let's analyze the options provided:

1. **Understanding Excretory Products**: Excretory products are substances eliminated from the body as waste. The toxicity of these substances varies, and their forms can influence how they are excreted.

2. **Analyzing the Options**:
- **Option A: Ammonia**: Ammonia is highly toxic and requires a large amount of water to be safely excreted. It is primarily excreted by aquatic animals.
- **Option B: Urea**: Urea is less toxic than ammonia and is excreted by mammals and amphibians. It requires less water than ammonia but is still considered toxic.
- **Option C: Uric Acid**: Uric acid is the least toxic of the three. It is excreted as a paste with minimal water loss, making it advantageous for organisms in arid environments. This process is known as uricotelism.
- **Option D: Carbon Dioxide**: While carbon dioxide is a waste product of respiration, it is not classified as an excretory product in the same context as the others.

3. **Conclusion**: Based on the analysis, uric acid is the least toxic form of excretory product. It is excreted in a way that conserves water, making it suitable for organisms that need to minimize water loss.

Therefore, the correct answer is **Option C: Uric Acid**.