During respiration in cockroach air enters in tracheal system through

Options

A. Trachea
B. Spiracles
C. Tracheoles
D. Blood

Answer

To answer the question "During respiration in cockroach, air enters in tracheal system through," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Respiratory System of Cockroaches**:
- Cockroaches have a unique respiratory system that is different from mammals. They do not have lungs; instead, they have a network of tubes called the tracheal system.

2. **Identifying the Entry Point for Air**:
- The tracheal system allows for the direct exchange of gases. Air enters this system through specific openings on the body surface.

3. **Defining Spiracles**:
- The openings through which air enters the tracheal system are called **spiracles**. These are small pores located on the sides of the cockroach's body.

4. **Function of Spiracles**:
- Spiracles open to the outside environment and allow air to flow into the tracheal system. Once inside, oxygen is transported to the cells, and carbon dioxide is expelled back out through the spiracles.

5. **Conclusion**:
- Therefore, the correct answer to the question is that air enters the tracheal system of cockroaches through **spiracles**.

### Final Answer:
**Spiracles**

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