During respiration in cockroach air enters in tracheal system through

Options

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

Answer

To solve the question "During respiration in cockroach, air enters in tracheal system through," we will analyze the options provided and understand the respiratory system of the cockroach.

### Step-by-Step Solution:

1. **Understanding the Respiratory System of Cockroach**:
- The cockroach has a unique respiratory system that consists of a network of tubes called tracheae. These tubes are responsible for transporting air directly to the tissues.

2. **Identifying the Entry Points for Air**:
- The air does not enter through the trachea itself, but rather through small openings on the body surface. These openings are known as spiracles.

3. **Exploring the Options**:
- **Option A: Trachea** - This is the main tube of the respiratory system but does not serve as the entry point for air.
- **Option B: Spiracles** - These are the external openings through which air enters the tracheal system. This is the correct option.
- **Option C: Tracheals** - These are smaller branches of the tracheae that distribute air to various parts of the body but do not function as entry points.
- **Option D: Blood** - Blood is not involved in the direct entry of air into the respiratory system of cockroaches.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Option B: Spiracles**.

### Final Answer:
**Air enters the tracheal system of the cockroach through spiracles.**