Assertion :- Water potential of a cell is affected by both solute and pressure potential.
Reason:- Addition of solute and water both leads to increase in free energy of solution.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false

Answer

**Step-by-Step Solution:**

1. **Understanding Water Potential:**
Water potential (Ψ) is a measure of the potential energy of water in a system and is influenced by two main factors: solute potential (Ψs) and pressure potential (Ψp). The formula for water potential is:
\[ Ψ = Ψs + Ψp \]
- **Hint:** Remember that water potential is a combination of solute and pressure potentials.

2. **Assertion Analysis:**
The assertion states that the water potential of a cell is affected by both solute and pressure potential. This is true because:
- Solute potential decreases when solutes are added, reducing the water potential.
- Pressure potential can increase or decrease depending on the turgor pressure within the cell.
- **Hint:** Think about how adding solutes affects the movement of water and the overall potential.

3. **Reason Analysis:**
The reason given states that the addition of solute and water both leads to an increase in the free energy of the solution. This is incorrect because:
- Adding solute to water actually decreases the free energy of the solution since solutes occupy space and reduce the number of free water molecules available to do work.
- Adding pure water increases the free energy, but the assertion specifically refers to the addition of solutes.
- **Hint:** Consider how solutes interact with water molecules and how this affects their energy.

4. **Conclusion:**
Based on the analysis:
- The assertion is true: Water potential is indeed affected by both solute and pressure potentials.
- The reason is false: Adding solutes does not increase the free energy of the solution.
- Therefore, the correct answer is that the assertion is true, but the reason is false.

**Final Answer:**
Assertion is true, but the reason is false.

---