Insect tracheal system opesn to the outside through

Options

A. spiral valve
B. Pecten
C. Spiracles
D. Taenidia

Answer

**Step-by-Step Solution:**

1. **Understanding the Tracheal System:**
The tracheal system is a specialized respiratory system found in insects and some other invertebrates. It allows for the direct exchange of gases (oxygen and carbon dioxide) between the atmosphere and the tissues without the involvement of blood.

2. **Function of the Tracheal System:**
Insects utilize a network of tubes called tracheae that transport air directly to their tissues. This system is efficient for their small size and allows for rapid gas exchange.

3. **External Openings of the Tracheal System:**
The tracheal system opens to the outside environment through specific structures. These openings are crucial for the intake of oxygen and the release of carbon dioxide.

4. **Identifying the Openings:**
The external openings of the tracheal system in insects are known as spiracles. Spiracles are small pores located on the surface of the insect's body that lead to the tracheae.

5. **Conclusion:**
Therefore, the insect tracheal system opens to the outside through spiracles.

**Final Answer:**
The insect tracheal system opens to the outside through **spiracles**.

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