A well developed echo-apparatus (a kind of radar) is present in flying mammals belong to order

Options

A. Primate
B. Insectivore
C. Rodentia
D. Chiroptera

Answer

### Step-by-Step Solution:

1. **Understanding the Echo-apparatus**:
- The echo-apparatus is a biological mechanism that allows certain animals to navigate and detect objects around them by emitting sound waves and interpreting the echoes that bounce back. This is particularly useful in low visibility environments.

2. **Identifying the Functionality**:
- This apparatus works by producing ultrasonic sound waves. When these sound waves hit an object, they bounce back, and the animal can determine the distance and size of the object based on the time it takes for the echo to return.

3. **Recognizing the Importance of Vision**:
- Animals that possess a well-developed echo-apparatus typically have rudimentary eyes, meaning their eyesight is not well developed or is less effective, making echolocation a vital alternative for navigation.

4. **Examining Various Orders of Mammals**:
- The question asks about flying mammals. We can analyze different orders:
- **Primates**: Includes lemurs, monkeys, apes, and humans. They have well-developed eyes and do not rely on echolocation.
- **Insectivores**: Includes hedgehogs, shrews, and moles. They have effective eyesight and are mostly nocturnal.
- **Rodentia**: Includes rats, hamsters, and mice. They also have good vision and can see well at night.
- **Chiroptera**: This order includes bats, which are known for their ability to use echolocation to navigate in the dark.

5. **Conclusion**:
- Based on the analysis, the order that contains flying mammals with a well-developed echo-apparatus is **Chiroptera**.

### Final Answer:
The well-developed echo-apparatus is present in flying mammals belonging to the order **Chiroptera**.

---