Question

What happens during endosmosis? Choose the correct answer from the following.
A. Water molecules diffuse from lower water potential to higher water potential
B. Water molecules diffuse from higher water potential to lower water potential
C. Water molecules move from a solution towards pure water
D. Water molecules move from cell towards its exterior

Answer 1

Hint: The flow of liquid into the cell is known as endosmosis. The movement of liquid occurs along the concentration gradient without the use of chemical energy (ATP). In osmosis, the semipermeable membrane of the cell is involved.

Complete answer:
Tonicity is referred to as the amount of solute in different solutions outside the cell. Plant cells have a rigid cell wall. When a plant cell is placed in a hypotonic solution, e.g. pure water, then the process of diffusion (osmosis) starts and the cell swells up. Due to osmosis, the pressure inside the cell increases until the internal pressure is equal to the external pressure. The hydrostatic pressure then prevents further water intake. The plant cell at this stage is turgid, i.e. swollen and hard. The inward flow of solvent through the semipermeable of a cell is called endosmosis. It is commonly observed in raisins. In this process, there is no requirement of energy in the form of ATP.

Hence, the correct answer is option B.

Additional information: Exosmosis is another phenomenon opposite to endosmosis. In exosmosis, the movement of water outside the cells when a cell is placed in a hypertonic solution. The cell becomes flaccid by the movement of water outside.

Note: When we put a plant cell in pure water then, water enters into the cell because of osmosis making the cell expand in size. Water will move from a region of higher concentration towards a region of lower concentration.