Question

The factor that controls entry of water into the cell is

• A. O.P.
• B. I.P.
• C. W.P.
• D. T.P.

Answer 1

The correct option is A O.P.

The osmotic pressure of a solution is equivalent to the pressure which must be exerted upon it to prevent the flow of solvent into it through the semipermeable membrane. The phenomenon of osmosis important in the absorption of water by plants. Leaves become turgid and expand due to their osmotic pressure.

The pressure that an imbibant (the solid particles which adsorb water or any other liquid) develops when submerged in pure imbibing liquid is called imbibition pressure. It is the initial step in the germination of seeds.

The actual pressure exerted by the protoplasm against the cell wall due to the entry of water into it is called turgor pressure which is always less then osmotic pressure unless the cell is in distilled water. The cell wall is rigid and elastic and it exerts an equal and opposite pressure against the expanding protoplasm This pressure is called wall pressure and is equal and opposite to turgor pressure.

Thus, the correct answer is option A.