Question

Cell A has osmotic potential of –18 bars and pressure potential of 8 bars, whereas cell B has osmotic potential of –14 bars and pressure potential 2 bars. The direction of flow of water will be

• A. from cell B to cell A
• B. from cell A to cell B
• C. no flow of water
• D. in both the directions

Answer 1

The correct option is B from cell A to cell B

Cell A:
Osmotic potential = -18 bars
$\Rightarrow$ Osmotic Pressure (OP) = 18 bars
Pressure potential = 8 bars
$\Rightarrow$ Turgor Pressure (TP) = 8 bars

Therefore, DPD (diffusion pressure deficit) = OP - TP = 18 - 8 = 10 bars.

Cell B:
Osmotic potential = -14 bars
$\Rightarrow$ Osmotic Pressure (OP) = 14 bars
$\Rightarrow$ Turgor Pressure (TP) = 2 bars

Therefore, DPD = OP - TP = 14 - 2 = 12 bars.

Hence, water will move from lower DPD to higher DPD, i.e., from A to B.