Question

Endosmosis of water occur when water potential of the cell sap is
A) Higher
B) Equal
C) Lower
D) None of the above

Answer 1

Hint: Osmosis can be defined as the passage of water molecules through semipermeable membranes.

Complete answer:
Cell wall and cell membrane is present around the plant cell. The cell wall is freely permeable water and other substances present in solutions. The solute potential of the cell is contributed by the vacuolar sap and a large central vacuole.
Osmosis is usually the term used to refer to the diffusion of water across a differentially or selectively permeable membrane. Osmosis is the results of the driving force and the rate of osmosis depends on both the pressure gradient and concentration gradient.

>Option A:-If the water potential of the cell sap is high then exosmosis occurs, if the water potential of the cell sap is same then no osmosis takes place and if the water potential of the cell sap is low then endosmosis takes place. Therefore, this is the incorrect option.
>Option B:-If the external solution is the same as the osmotic pressure of the cytoplasm then it is called isotonic solution. In this case, no osmosis occurs. Therefore, this is the incorrect option.
>Option C:-Endosmosis is the inward movement of water through a semipermeable membrane when the solution around it is less concentrated. Due to this the cell swells up and this solution is known as a hypotonic solution. Therefore, this is the correct option.
>Option D:-As one of the options is correct, therefore, this is the incorrect option.

Hence option ‘C’ is the correct answer.

Note:On the basis of the cell the osmosis can be divided into inward or outward depending on the range of solutions around it. Endosmosis and exosmosis are the two types of osmosis.