Bird differs from bat in the absence of

Options

A. Homeothermy
B. Four chambered heart
C. Tracheae
D. Diaphragm

Answer

To solve the question "Bird differs from bat in the absence of", we will analyze the options provided and identify the key differences between birds and bats.

### Step-by-Step Solution:

1. **Identify the Organisms**:
- We are comparing birds and bats. Birds are avian species, while bats are mammals.

2. **Examine the Options**:
- The options given are:
- Homeothermy
- Four-chambered heart
- Trachea
- Diaphragm

3. **Analyze Common Features**:
- Both birds and bats have:
- **Homeothermy**: They are both warm-blooded.
- **Four-chambered heart**: Both have a heart structure that efficiently separates oxygenated and deoxygenated blood.
- **Trachea**: Both possess a trachea for respiration.

4. **Identify Unique Features**:
- The key feature that differentiates birds from bats is the **diaphragm**.
- Bats, being mammals, have a well-developed diaphragm which aids in respiration.
- Birds do not have a diaphragm; instead, they have a different respiratory system that involves air sacs.

5. **Conclude the Answer**:
- Therefore, the correct answer is that birds differ from bats in the absence of a **diaphragm**.

### Final Answer:
Birds differ from bats in the absence of **diaphragm**.

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