Question

Study the following table showing the components of water potential of three mesophyll cells A, B and C.

Cell	Osmotic potential (Mpa)	Pressure potential (Mpa)
A B C	-0.6 -0.5 -0.9	0.2 0.3 0.4

If the above cells are in direct contact with each other, than the water moves at the lowest rate between the two mesophyll cells.

• A. C$\to$B
• B. B$\to$C
• C. B$\to$A
• D. A$\to$C

Answer 1

The correct option is D A$\to$C

Osmosis is the movement of water from regions of higher potential to the regions of lower potential. Net diffusion of water occurs from regions of less negative potential to one or more negative potential and continues until the potential becomes equal. Osmotic potential is solute potential which decreases when water is added to the solution. Pressure potential represents the hydrostatic pressure exerted on the water in a cell. Pressure potential is positive in case of the turgid cell.

In the given question, the net potential in A cell is -0.6 + o.2 =. -0.4, In cell B is -0.5. + o.3 = -0.2 and In cell C is - 0.9 + 0.4 = - 0.5.

Cell A and C have the least potential difference of 0.1, and A has more pressure than C, therefore the water moves at the lowest rate from A to C.

Thus, the correct answer is option D.