Humber Admissions Practice Test

What does a hypertonic environment cause to a cell?

1. The cell to swell with water

2. The cell to maintain its normal shape

3. The cell to lose water and shrink

4. The cell to double in size

The correct answer is: The cell to lose water and shrink

In a hypertonic environment, the concentration of solutes outside the cell is greater than that inside the cell. As a result, water moves out of the cell in order to balance the solute concentrations on both sides of the cell membrane. This outward movement of water leads to a decrease in the cell's volume, causing it to shrink. This process is known as crenation in red blood cells. The other options describe scenarios that do not accurately reflect what occurs in a hypertonic situation. Water moving into the cell, which would cause it to swell, would pertain to a hypotonic environment instead. Maintaining normal shape typically describes an isotonic environment, where solute concentrations are equal both inside and outside the cell. Doubling in size is an exaggerated consequence that does not realistically occur in any of these osmosis-related contexts, especially not in a hypertonic environment.