Question

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

Answer 1

The correct option is B

The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell

The correct option is (B)

Explanation of the correct option :

1. If the medium surrounding the cell has a higher water concentration than the cell, meaning that the outside solution is very dilute, the cell will gain water by osmosis. It is known as hypotonic solution.
2. This allows the osmotic entry of water into the cell and thus the cell swells.

Explanation of the incorrect option :

Option (A) When a cell is placed in a solution which has higher salt concentration ( hypertonic solution)than the cell itself , then it causes the loss of water from the cell and thus the cell shrinks.

Option (C) When the concentration of water molecules is same in the cell and in the surrounding medium , then there will be no changes in the cell.

Option (D) Concentration of water molecules does matter and determines the entry or loss of water .

Final answer :

A cell will swell up if the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell.