CBSE Class 9 Answered

Osmosis is the movement of water through a semipermeable membrane, from a solution with a low solute concentration to a solution with a higher solute concentration, until there is an equal concentration of water on both sides of the membrane.

For exampleIf blood cells (or other cells) are placed in contact with an isotonic solution, they will neither shrink nor swell. If the solution is hypertonic, the cells will lose water and shrink . If the solution is hypotonic the cells will swell; the osmotic pressure that is developed may even be great enough to rupture the cell membrane.

Osmosis has a number of life-preserving functions: it assists plants in receiving water, it helps in the preservation of fruit and meat, and is even used in kidney dialysis. In addition, osmosis can be reversed to remove salt and other impurities from water