When kept in water, raisin swells in size. Name and explain the phenomenon involved with the help of a diagram. Give thre applications of the phenomenon.

Explanation

This phenomenon is called endo osmosis, i.e., movement of water inside the raisin and shown with the help of diagram as. The process of osmosis is of immense biological as well as industrial important. It is evident from the following examples:

(a) Movement of water from soil into plant roots and subsequently into upper portion of the plant is partly due to osmosis.
(b) Preservation of metal against bacterial action by addition salt.
(c) Preservation of fruits against bacterial action by adding sugar. Bacterium in canned fruit loses water through the process of osmosis and becomes in active.