What is the key characteristic of a hypertonic solution?

A hypertonic solution is defined by its solute concentration relative to the contents of a cell. When a solution is hypertonic, it possesses a higher solute concentration compared to the solute concentration within the cell. This characteristic has significant physiological implications, particularly concerning osmosis.

In a hypertonic environment, water will move out of the cell to the area of higher solute concentration. This can lead to cell shrinkage or crenation, as the cell loses water in an attempt to equilibrate the solute concentrations across the cell membrane. Understanding this concept is essential in various biological processes and applications, including IV fluid administration and cellular biology.

The other options describe different types of solutions but do not accurately represent the defining feature of hypertonic solutions. A solution with lower solute concentration would be considered hypotonic, while a solution with equal solute concentration would be isotonic. The completely soluble aspect is not a defining characteristic of a hypertonic solution, but rather pertains to the solubility of specific substances. Thus, recognizing that a hypertonic solution contains a higher concentration of solutes than the cell is crucial for understanding osmotic behavior in biological systems.