Cockroach has no R.B.C. but respires due to :

Options

A. Gaseous exchange takes place directly through tissues
B. Haemoglobin combines with oxygen
C. Oxygen is taken by lungs
D. Oxygen is taken by book lungs

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks why a cockroach can respire even though it does not have red blood cells (RBCs).

2. **Identifying the Respiratory System of Cockroaches**: Cockroaches have a unique respiratory system that does not rely on hemoglobin or RBCs for gas exchange. Instead, they utilize a system of air tubes known as trachea.

3. **Structure of the Trachea**: The trachea in cockroaches consists of numerous shiny, transparent, and branched air tubes. These tubes are responsible for transporting air directly to the tissues.

4. **Gas Exchange Mechanism**: The trachea facilitates gas exchange through diffusion. The air enters the tracheal system through small openings called spiracles, which are located on the sides of the cockroach's body.

5. **Role of Spiracles**: Spiracles are slit-like apertures that allow atmospheric air to enter and exit the tracheal system. Cockroaches have ten pairs of spiracles that play a crucial role in respiration.

6. **Conclusion**: Since cockroaches do not have hemoglobin or lungs, and their gas exchange occurs directly through the trachea and spiracles, the correct answer to the question is that cockroaches respire by exchanging gases directly through their tissues.

### Final Answer:
Cockroach has no RBCs but respires due to gas exchange occurring directly through its tissues via a system of trachea and spiracles.

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