Thin tubes that carry oxygen from the air to all the parts in cockroach constitute

Options

A. Tacheal system
B. Haemolymph
C. Lungs
D. Gills

Explanation

To solve the question regarding the thin tubes that carry oxygen from the air to all parts of a cockroach, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify the system in cockroaches that is responsible for transporting oxygen throughout their body.

2. **Identify the Options**: The options provided are:
- a) Tracheal system
- b) Hemolymph
- c) Lungs
- d) Gills

3. **Analyze Each Option**:
- **Tracheal System**: This is a network of tubes (tracheae) that directly carries oxygen from the environment to the tissues of the cockroach. It is specifically adapted for gas exchange in insects.
- **Hemolymph**: This is the fluid equivalent to blood in insects, but it does not carry oxygen in the same way that blood does in vertebrates.
- **Lungs**: Cockroaches do not have lungs; they rely on their tracheal system for respiration.
- **Gills**: Gills are used for respiration in aquatic organisms, not in terrestrial insects like cockroaches.

4. **Conclusion**: Since the tracheal system is specifically designed for transporting oxygen in cockroaches, it is the correct answer.

5. **Final Answer**: The thin tubes that carry oxygen from the air to all the parts in a cockroach constitute the **tracheal system**.