Differentiation between tracheoles and bronchioles.

Explanation

### Step-by-Step Solution

1. **Definition**:
- **Tracheoles**: Tracheoles are the finest unbranched extensions of the trachea found in insects. They are part of the tracheal respiratory system.
- **Bronchioles**: Bronchioles are the smaller branches of the bronchi in mammalian lungs. They are part of the mammalian respiratory system.

2. **Structure**:
- **Tracheoles**: They are thin-walled and do not have cartilage. They are filled with tracheolar fluid which helps in gas exchange.
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