Question

The cells of plants, fungi and bacteria can withstand hypotonic conditions without bursting. Give reasons.

Answer 1

Hint: The solution in which the concentration of solvent is greater than that of solute is known as hypotonic solution. When a cell is placed in a hypotonic solution, endosmosis takes place.

Complete Answer:
To solve this question, we must know about the distinct features of plants, fungi and bacteria cells.
- The cells of plants, bacteria and fungi are composed of cell walls which is a distinct feature which is absent in animal cells. The cell wall is a rigid structure which protects the cell from changing its shape.
- When these cells are placed in a hypotonic medium in which the concentration of water is greater than that of the cell, the endosmosis takes place. Due to the inward movement of the water, the cell swells. As these cells are surrounded by a cell wall which is a rigid structure, the cell is able to maintain its structure without bursting. The cell in this state becomes turgid.
- The cell wall is composed of cellulose and hemicelluloses and derivatives of oligosaccharides which are intact structures and cannot be digested easily. Apart from maintaining the rigid structure of the cell; the cell wall protects the cell from external environment, stress and mechanical shock.

Note: When an animal cell is placed in a hypotonic solution, it bursts. This is due to the absence of a cell wall. The outer membrane of the animal cell is the cell membrane which is not rigid. It is flexible and allows the movement of water molecules easily as it is semi permeable in nature.