(a) Name the phenomenon which helps fresh water unicellular organisms (e.g., Amoeba) continuosuly gain water in their bodies. Also name the mechanisms by which these organisma throw out exces of water from their bodies.
(b) Give at least two examples in plants where similar phenomenon in used to gain water.

Explanation

(1) jAmoeba is a freshwater unicellular organism. It continuously gain water it body due to osmosis. It contains contractile vacuoles to throw out excess of water from its body.
2 (i) Absorption of water by the plant root hairs occurs due to osmois.
(ii) In plants, cells, tissues and soft organs such as leaves, buds, young shoots, flowers, fruits maintain turgidity due to osmotic absorption of water.