What is the primary characteristic of a hypotonic solution in relation to cells?

A hypotonic solution is characterized by having a lower concentration of solutes compared to the inside of the cells. When cells are placed in a hypotonic solution, water moves into the cells via osmosis because water always moves from areas of low solute concentration to areas of higher solute concentration.

As water enters the cells, they swell in size. If the influx of water is excessive, the cells can become distorted, leading to a condition where they may take on a ghostly appearance and may even burst, resulting in cell lysis. This process occurs because the cell membrane cannot withstand the increasing pressure from the water inside.

In the context of the other options, cells shrinking would occur in a hypertonic solution, where they lose water to the surrounding environment. Maintaining the same size and shape would happen in an isotonic solution, where the solute concentration inside and outside the cell is equal, resulting in no net movement of water. The bursting of cells due to excessive water intake is an extreme consequence that can occur if the hypotonic environment persists and may not represent the early stages of cellular response in a hypotonic solution where swelling is the first observable characteristic. Thus, the primary characteristic of a hypotonic solution is indeed the swelling of cells