Which term is used to describe a more concentrated solution outside a cell than inside?

The term used to describe a solution that is more concentrated outside a cell than inside is "hypertonic." In a hypertonic environment, the concentration of solutes (such as salts or sugars) is greater outside the cell than inside. This creates a gradient where water moves out of the cell to balance the solute concentrations, leading to the cell potentially losing water and shrinking in size—a process known as crenation in animal cells or plasmolysis in plant cells.

Understanding the concept of hypertonicity is essential in biology because it highlights key physiological processes, such as osmosis, which is the movement of water across a semi-permeable membrane. The terms hypotonic and isotonic describe opposite scenarios: a hypotonic solution has a lower concentration of solutes outside the cell, leading to water moving into the cell, while an isotonic solution has equal concentrations of solutes inside and outside the cell, resulting in no net movement of water. The term "concentrated," while it can imply a higher solute concentration, is not specific enough to indicate the comparative nature of solute concentrations inside and outside the cell, and thus is not used in this context.