Question

If a cell A with DPD 4 bars is connected to cell B, C and D, whose osmotic pressure (OP) and turgor pressure (TP) are respectively 4 and 4, 10 and 5, 7 and 3 bars, the flow of water will be

• A. B to A, C and D
• B. A and D to B and C
• C. C to A, B and D
• D. A to B, C and D

Answer 1

The correct option is A B to A, C and D

DPD (Diffusion pressure deficit) is the value by which diffusion pressure of solution is lower than that of pure solvent. Osmotic pressure (OP) of solution is always higher than the pure solvent. Turgor pressure (TP) is the pressure of water that pushes the plasma membrane against the cell wall of a plant cell. TP of plasmolysed cell is always zero. Hence, DPD = OP - TP

In the given example, DPD of cell A is 4 bars. OP of cell B, C and D 4, 10 and 7 bars and TP of cell B, C and D 4, 5 and 3 bars. Hence, DPD of cell B, C and D will be 0, 5 and 4. Thus, the flow of water will be B to A, C and D.

Thus, the correct answer is option A.