Question

If turgor pressure becomes equal to the wall pressure, then
A. Water leaves the cell
B. water enters the cell
C. No exchange of water takes place
D. Solute goes from the cell into water

Answer 1

Turgor pressure is the pressure applied by protoplasm to the cell wall and the wall pressure is the pressure applied by the cell wall to the protoplasm.

Complete answer:
First of all you should know what Turgor pressure and wall pressure is. Turgor pressure is the force which is exerted by the fluid in a cell that pushes the cell membrane against the cell wall and the wall pressure is opposite of turgor pressure which is the pressure exerted by the cell wall on the plant cell.
This wall pressure is applied because the cell wall is rigid and flexible and hence it exerts and equal and opposite wall pressure against the protoplasm and due to this the turgor pressure becomes equal to the wall pressure. If TP becomes equal to the WP then it means that there is no net movement of water into the cell which means that there is no exchange of water takes place and the equilibrium is also established.
If we look at options now, Option A is Water leaves the cell, it is not the correct option because when the TP becomes equal to WP then there is no exchange of water takes place and therefore this option is incorrect and it gets eliminated.
Moving to option B which is Water enters the cell, if water enters the cell then the turgor pressure and the wall pressure cannot be equal. Therefore, this option is incorrect and it gets eliminated.
Moving to option C which is No exchange of water takes place, this option is the correct one since when TP becomes equal to WP then there is no net movement of water. In other words, no exchange of water takes place. Therefore, this option is correct.
Last option is Solute goes from the cell into water, it is also an incorrect option because when solute goes from the cell into the water then the turgor pressure and wall pressure cannot equal, when they are equal then there is no exchange of water. Therefore, this option is incorrect and it gets eliminated.

Thus, the correct answer is Option C which is No exchange of water takes place.

Note:
Since the turgor pressure is the pressure applied by protoplasm to the cell wall and the wall pressure is the pressure applied by the cell wall to the protoplasm, this wall pressure is applied as an equal and opposite pressure and when they become equal then there is no exchange of water takes place.