Question

what happened to the cell to cause it to swell?

due to the hypotonic solution, water is entering the cell.
due to the isotonic solution, water is entering the cell.
due to the hypertonic solution, water is leaving the cell.
due to the hypertonic solution, water is entering the cell.

Explanation:

Analyze the cellular change

Using the Tonicity Effects knowledge point
When a cell swells, it is gaining volume because water is moving across the semipermeable plasma membrane into the intracellular space.

Determine the direction of water movement

Using the Osmosis Principles knowledge point
Water moves via osmosis from an area of lower solute concentration (higher water potential) to an area of higher solute concentration (lower water potential) to reach equilibrium. Therefore, for water to enter the cell and cause it to swell, the net movement of water must be directed inward.

Identify the solution type

Using the Tonicity Effects and Osmosis Principles knowledge points
A solution that has a lower solute concentration compared to the inside of the cell is defined as a hypotonic solution. Placing a cell in a hypotonic environment causes water to diffuse into the cell, leading to swelling (and potential lysis in animal cells).

Answer:

• (A) Due to the hypotonic solution, water is entering the cell. (Correct answer)
• (B) Due to the isotonic solution, water is entering the cell.
• (C) Due to the hypertonic solution, water is leaving the cell.
• (D) Due to the hypertonic solution, water is entering the cell.