Which term describes the condition where cells experience an influx of water, causing them to swell?

The term that describes the condition where cells experience an influx of water, causing them to swell, is "hypotonic." In a hypotonic solution, the concentration of solutes outside the cell is lower than that inside the cell. This difference in solute concentration leads to water moving into the cell by osmosis, as water naturally flows from an area of lower solute concentration to an area of higher solute concentration. As water enters the cell, it causes the cell to swell and potentially become turgid.

In contrast, a hypertonic solution has a higher concentration of solutes outside the cell, leading to water moving out of the cell, potentially causing it to shrink. An isotonic solution has equal concentrations of solutes inside and outside the cell, resulting in no net movement of water and maintaining cell size. The term "stable" does not specifically describe a water movement condition in cells but rather suggests a balanced or steady state, which does not directly relate to the influx of water. Thus, the correct choice clearly indicates the swelling of cells due to the influx of water characteristic of a hypotonic situation.