Question

Osmotic potential is depicted as
a. (-)
b. (+)
c. (x)
d. None of the above

Answer 1

Osmotic potential is potential of water molecules that help in the movement of water molecules from their higher concentration towards the lower concentration. The pure water has no solutes dissolved in it, hence, it has zero water potential.

Complete answer:
The pure water has zero potential as there will be no net movement of water towards it. But when some amount of solute is added to the water to make a solution, it becomes deficient in water and its osmotic potential becomes negative. When such a solution is kept in contact with the water, it will absorb the water to make its potential near to zero. Hypotonic solution has high osmotic potential while hypertonic solution has low osmotic potential that is why water will move from hypotonic solution to hypertonic solution.

Negative (-) osmotic or water potential means that the solution is deficient in the amount of water dissolved in it. When the salt is added to water its osmotic potential becomes negative. Thus if the water potential of any solution is negative, water will flow towards it.

Positive (+) and cross (x) osmotic potential is hypothetical; it has no significance.

Hence, the correct answer is option (A), because the osmotic potential of any solution is always negative.

Note: The movement of water molecules across the plasma membrane is called osmosis. Water moves from the area of its higher concentration towards the area of its lower concentration. In other words the water moves from low solute concentration towards the high solute concentration.