Question

A candidate in order to study the process of osmosis has taken 3 potato cubes and put them in 3 different beakers containing 3 different solutions. After 24 hours, in the first beaker the potato cube increased in size, in the second beaker the potato cube decreased in size and in the third beaker there was no change in the size of the potato cube. The following diagram shows the result of the same experiment:

(i) Give the technical terms of the solutions used in beakers, 1, 2, and 3. 

(ii) In beaker 3 the size of the potato cube remains the same. Explain the reason in brief. 

(iii) Write the specific feature of the cell sap of root hairs which helps in absorption of water. 

(iv) What is osmosis ? 

(v) How does a cell wall and a cell membrane differ in their permeability ?

Answer 1

(i) 

(1) Hypotonic solution. 

(2) Hypertonic solution. 

(3) Isotonic solution. 

(ii) In beaker 3, the concentration of potato cube and the medium is same. So there is no osmosis taking place therefore the size of cube remains same. 

(iii) The concentration of cell sap is higher in the root hair as compared to soil water due to endosmoses is takes place facilitating absorption of water. 

(iv) Osmosis is a process of flow of solvent molecules from lower concentration to higher concentration through a semipermeable membrane. 

(v) Cell wall is freely permeable and cell membrane is semi-permeable.