What is Osmosis?
Osmosis is a special type of diffusion, in which water or solvent moves from a weak solution to the concentrated solution when the two are separated by means of a semipermeable membrane. If the solution is separated from its pure solvent, the molecules of a solvent move to the solution.
Thus osmosis may be defined as “the diffusion of water or solvent from its pure state/dilute solution into a solution/stronger solution when the two are separated by a semipermeable membrane till a state of equilibrium is reached”.
Importance of Osmosis:
(1) It helps in the absorption of water by root hairs.
(2) It leads to the cell-to-cell movement of water.
(3) It induces turgidity in cells which help in stretching of stem and in keeping the leaves expanded.
(4) Osmosis provides mechanical support in non-woody plants like maize, banana and sugarcane by making the cells fully turgid.
(5) Growing tips of roots remain turgid because of osmosis and thus are able to penetrate into the soil.
(6) Osmosis regulates the opening and closing of stomata.
(7) Resistance of plants to drought and frost is brought about by osmosis.
(8) Movement of plant and plant parts is brought about by cell’s turgor due to osmosis, as for example, movement of leaflets of the sensitive plant, Mimosa pudica.