A cell will swell up if
(a) the concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium
(b) the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell
(c) the concentration of water molecules is same in the cell and in the surrounding medium
(d) concentration of water molecules does not matter.

AcademicBiologyNCERTClass 9

Correct Answer: (b) the concentration of water molecules in the surrounding medium is higher than water molecules concentration in the cell

Explanation:

Concentration gradient is the unequal distribution of solutes in a solution when they diffuse from areas of higher concentration to areas of lower concentration in passive transport.  

Plasmolysis is the process that takes place when the plant cell losses cytoplasmic water due to osmosis and shrinks in size.

It occurs when the plant\'s cell is placed in a hypertonic solution or solution having a higher concentration of salts. Cytoplasm loses its water to the hypertonic solution to achieve equilibrium and shrinks.

When a plasmolyzed cell (or the cells whose cytoplasm got shrunk) is placed in water, the cell absorbs water from the surroundings due to varied concentration gradients and tries to regain its original size and shape. Thus, the plant cell becomes turgid.

Osmosis is the process of movement of water from a region of higher water concentration to a region of lower water concentration. Osmosis involves the movement of water molecules, while diffusion involves the movement of solute particles across a concentration gradient.

Also, osmosis involves the presence of a semi-permeable membrane to allow the selective movement of only water molecules and not solute particles.

raja
Updated on 10-Oct-2022 13:28:28

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