Protected tympanum can be traced in

Options

A. All birds
B. Duck only
C. Bats
D. Toads

Answer

### Step-by-Step Solution:

1. **Understanding Tympanum**:
- The tympanum is a structure that allows sound to enter the ear. It is often described as a small pore or hole.

2. **Occurrence in Animal Groups**:
- The tympanum is primarily found in amphibians, reptiles, and birds (Aves). It is not present in mammals, which have an external ear structure known as the pinna.

3. **Protection of Tympanum**:
- In birds, the tympanum is more protected compared to amphibians and reptiles. This is because in birds, the tympanum is covered with feathers (contour feathers), providing additional protection.

4. **Comparison with Other Groups**:
- In amphibians and reptiles, the tympanum is typically covered with a thin layer to protect it from environmental factors, such as water. However, it is less protected than in birds.

5. **Evaluating Options**:
- The question asks where the protected tympanum can be traced. The options include:
- All Birds (Aves)
- Duck only (which is a type of bird)
- Bats (which are mammals and do not have a tympanum)
- Toads (which have a tympanum that is either naked or covered with a thin layer)

6. **Conclusion**:
- The correct answer is "All Birds" since all birds possess a tympanum that is well-protected by feathers.

### Final Answer:
Protected tympanum can be traced in **All Birds (Aves)**.

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