Give scientific reasons for the following.
(i) Animal cells rupture when placed in distilled water.
(ii) Plant cells get plasmolysed when placed in hypertonic solution.
(i) Animal cells do not possess cellulose cell wall. When placed in distilled water, they absorb water due to endosmosis and swell. Excessive endosmosis results in the increased turgor pressure which ruptures the animal cells.
(ii) Plant cells have rigid cellulose cell wall. When placed in hypertonic solution, they lose water due to exosmosis resulting the shrinking of their protoplast. Ultimately the protoplasm separates from the cell wall and assumes spherical shape. This condition ii called plasmolysis.