Cell A and cell B are adjacent plant cells. In cell A `Psi_(s)=-20` bars and `Psi_(p) =8` bars. In cell B, `Psi_(s)=-12` bars and `Psi_(p)=2` bars . Then,

Options

A. Water moves from cell a to cell b
B. There is no movement of water between cell a and cell b
C. Water moves from cell b to cell a
D. Equal amount of water is simultaneously exchanged between cell a and cell b.

Answer

To solve the problem regarding the movement of water between two adjacent plant cells (Cell A and Cell B), we need to calculate the water potential (Ψ_w) for both cells and then determine the direction of water movement based on these values.

### Step-by-Step Solution:

1. **Identify Given Values:**
- For Cell A:
- Solute potential (Ψ_s) = -20 bars
- Pressure potential (Ψ_p) = 8 bars
- For Cell B:
- Solute potential (Ψ_s) = -12 bars
- Pressure potential (Ψ_p) = 2 bars

2. **Calculate Water Potential for Cell A:**
- The formula for water potential (Ψ_w) is:
\[ Ψ_w = Ψ_s + Ψ_p \]
- For Cell A:
\[ Ψ_w = -20 \, \text{bars} + 8 \, \text{bars} = -12 \, \text{bars} \]

3. **Calculate Water Potential for Cell B:**
- For Cell B:
\[ Ψ_w = -12 \, \text{bars} + 2 \, \text{bars} = -10 \, \text{bars} \]

4. **Compare Water Potentials:**
- Water potential for Cell A (Ψ_w) = -12 bars
- Water potential for Cell B (Ψ_w) = -10 bars
- Since -12 bars < -10 bars, Cell A has a lower water potential than Cell B.

5. **Determine Direction of Water Movement:**
- Water moves from an area of higher water potential to an area of lower water potential.
- Therefore, water will move from Cell B (higher water potential) to Cell A (lower water potential).

### Conclusion:
Water moves from Cell B to Cell A.

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