Question

The figure given below shows the epidermal cells of an onion bulb. This cell was then transferred to a drop of sugar solution.

(i) Draw a well-labelled diagram of the epidermal cell as it would appear after immersion in a strong sugar solution.

(ii) What scientific term is used for the changes as shown in (i)?

(iii) What should be done to restore the cell back to its original condition?

(iv) Give the scientific term for the recovery of the cell as a result of the step taken in (iii) above.

Answer 1

(i) Diagram of the epidermal cell after immersion in a strong sugar solution:

1. The strong sugar solution is a hypertonic solution.
2. If the epidermal cell is immersed in a hypertonic solution, water molecules will move out of the cell as the concentration of surrounding is high.
3. As a result, the protoplasm of the cell will show shrinkage.

(ii) Scientific term that is used for the changes shown in (i):

1. Shrinkage of protoplasm is known as ‘plasmolysis'.
2. The cell with shrunken protoplasm is called a ‘plasmolyzed cell’.

(iii) Ways to restore the cell back to its original condition:

To restore the cell back to its original condition we can-

1. Place the cell in a hypotonic solution.
2. Place the cell in plain water (neutral solution).

Thus, water from the surrounding will enter the cell and the cell will swell back to its original state.

(iv) Scientific term for the recovery of the cell:

1. It is the opposite process of plasmolysis.
2. For this reason, it is called ‘deplasmolysis'.
3. In this process, water from the surroundings enters the cell, and the cell swells.