Question

A cell is placed in a water solution with the same salt concentration as the cell. The cell is placed in a _____.

Answer 1

Isotonic solution. Since it has the same salt concentration as the cell the solution is neither hypotonic or hypertonic.

Answer 2

The right answer is an isotonic solution.

An isotonic solution is a system in which the osmotic concentration is the same as the solute concentration of a cell. In this case, the cell does not swell or shrink because there is no gradient of water concentration across the cell membrane.

The water molecules diffuse across the plasma membrane in both directions, and the rate of water diffusion is the same in each direction of this cell without gaining or losing water.