Nitrogenous waste products are eliminated mainly as

Options

A. urea in both frog and tadpole
B. uric acid in frog and urea in tadpole
C. urea in frog and ammonia in tadpole
D. urea in tadpole and ammonia in frog

Answer

To solve the question regarding the elimination of nitrogenous waste products, we will analyze the options provided and the characteristics of the organisms mentioned.

### Step-by-Step Solution:

1. **Understanding Nitrogenous Waste**: Nitrogenous waste products are the byproducts of protein metabolism. The primary forms of nitrogenous waste are ammonia, urea, and uric acid.

2. **Identifying the Organisms**: The question mentions frogs and tadpoles. Frogs are adult amphibians, while tadpoles are their larval form.

3. **Excretion in Tadpoles**: Tadpoles are aquatic and primarily excrete ammonia. This is because they live in water, which allows for the dilution and easy elimination of ammonia, making them ammonotelic.

4. **Excretion in Frogs**: Adult frogs are ureotelic, meaning they primarily excrete urea. They have adaptations that allow them to conserve water, especially when on land, and thus produce urea instead of ammonia.

5. **Evaluating the Options**:
- **Option 1**: Urea in both frog and tadpole - Incorrect, as tadpoles excrete ammonia.
- **Option 2**: Uric acid in frog and urea in tadpole - Incorrect, as frogs excrete urea, not uric acid.
- **Option 3**: Urine in urea in frog and ammonia in tadpole - Incorrect, as this option is not clearly stated.
- **Option 4**: Urea in tadpole and ammonia in frog - Incorrect, as tadpoles excrete ammonia, and frogs excrete urea.

6. **Correct Answer**: The correct answer is that frogs excrete urea and tadpoles excrete ammonia. Thus, the correct option is: **Urea in frog and ammonia in tadpole**.

### Final Answer:
Nitrogenous waste products are eliminated mainly as **urea in frogs and ammonia in tadpoles**.

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