(a) Fresh water unicellular organisms (e.g., Amoeba) continuously gain water in their bodies due to osmosis. These organisms have contractile vacuoles to throw out excess of water from their bodies.
(b) (i) Absorption of water by the plant roots from the soil through root hairs occurs due to osmosis.
(ii) In plants, cells, tissues and soft organs (leaves, young shoots, flowers) maintain turgidity due to osmotic absorption of water.