Which set of animals is ureotelic?

Options

A. Aquatic amphibians and insects
B. Bony fishes and insects
C. Bony fishes and mammals
D. Mammals and terrestrial amphibians

Answer

To determine which set of animals is ureotelic, we need to understand what ureotelic means. Ureotelic organisms are those that excrete urea as their primary nitrogenous waste product. Let's analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understanding Ureotelism**:
- Ureotelic organisms excrete urea. This is a key characteristic that we will use to evaluate the options.

2. **Evaluating Option A: Aquatic Amphibians and Insects**:
- Aquatic amphibians primarily excrete ammonia, making them ammonotelic.
- Insects excrete uric acid, classifying them as uricotelic.
- **Conclusion**: This option is incorrect as neither group is ureotelic.

3. **Evaluating Option B: Bony Fishes and Insects**:
- Bony fishes also excrete ammonia, so they are ammonotelic.
- Insects, as noted, are uricotelic.
- **Conclusion**: This option is incorrect as neither group is ureotelic.

4. **Evaluating Option C: Bony Fishes and Mammals**:
- Bony fishes are ammonotelic (excreting ammonia).
- Mammals are ureotelic (excreting urea).
- **Conclusion**: This option is incorrect because it includes bony fishes, which are not ureotelic.

5. **Evaluating Option D: Mammals and Terrestrial Amphibians**:
- Mammals are ureotelic (excreting urea).
- Terrestrial amphibians (like frogs) also excrete urea, making them ureotelic as well.
- **Conclusion**: This option is correct as both groups are ureotelic.

### Final Answer:
The correct set of animals that is ureotelic is **Mammals and Terrestrial Amphibians (Option D)**.