Assertion(A): `CO_(2)` diffuses only from tissue to alveoli and not in reverse direction.
Reason(R): `CO_(2)` is 10 times more soluble than`O_(2)`

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A and R are false

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "CO₂ diffuses only from tissue to alveoli and not in the reverse direction."
- In the human respiratory system, carbon dioxide (CO₂) is produced in the tissues as a byproduct of cellular respiration. The concentration of CO₂ is higher in the tissues compared to the alveoli in the lungs. Therefore, CO₂ will naturally diffuse from an area of higher concentration (tissues) to an area of lower concentration (alveoli). This part of the assertion is true.

2. **Understanding the Reason (R)**:
- The reason states that "CO₂ is 10 times more soluble than O₂."
- It is indeed true that CO₂ is more soluble in blood than O₂. This property allows CO₂ to be transported more efficiently in the bloodstream. However, the reason provided does not explain why CO₂ diffuses from tissues to alveoli. The diffusion of gases is primarily driven by concentration gradients, not solely by solubility.

3. **Evaluating the Relationship**:
- While both the assertion and the reason are true statements, the reason does not correctly explain the assertion. The assertion is based on the concentration gradient of CO₂, while the reason discusses solubility, which is not the primary factor for the direction of diffusion in this context.

4. **Conclusion**:
- Based on the analysis, the correct answer is: "Both assertion and reason are true, but the reason is not the correct explanation of the assertion."

### Final Answer:
Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

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