Teeth are absent in the jaws of

Options

A. Amphibians
B. Fishes
C. Birds
D. Mammals

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which group of animals has jaws that are devoid of teeth.

2. **Analyzing the Options**: The options provided are amphibians, fishes, birds, and mammals. We need to evaluate each group to determine which one lacks teeth in their jaws.

3. **Examining Each Group**:
- **Amphibians**: Most amphibians, like frogs and salamanders, have teeth.
- **Fishes**: Many fish species have teeth, although some may not.
- **Mammals**: Mammals generally possess teeth, with some exceptions like certain species of whales.
- **Birds**: Birds, classified as Aves, are known for having beaked jaws that are toothless.

4. **Identifying Characteristics of Birds**: Birds are characterized by:
- Feathers
- Toothless beaks
- Laying hard-shelled eggs
- A high metabolic rate
- A four-chambered heart
- A lightweight skeleton

5. **Reason for Absence of Teeth in Birds**: The absence of teeth in birds is an adaptation for flight. Teeth would add weight to their jaws, making flight less efficient. Instead, birds have developed beaks that are lighter and serve various feeding functions.

6. **Conclusion**: Based on the analysis, the correct answer is that teeth are absent in the jaws of birds.

**Final Answer**: Teeth are absent in the jaws of **birds**.

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