Explain how tonicity relates to the direction of water movement across a membrane.

A concentration gradient affects the direction that solutes diffuse. Describe how molecules move with respect to concentration.

The movement of water is called osmosis. Osmosis is the diffusion of water, and it too moves to reach equilibrium.   The relationship between solute concentration and water are opposite. An area with high concentration of solute has less water "concentration", and an area of low solute concentration has a higher water "concentration".   Select the options that describe the movement of water if there is a gradient across a membrane.   Hint: There are two correct answers. One with the solute perspective and one with a water perspective.   Select all that apply: Water moves from an area of high solute concentration to an area of low solute concentration.   Water moves from an area of low solute concentration to an area of high solute concentration.   Water moves from an area of high water "concentration" to an area of low water "concentration".   Water moves from an area of low water "concentration" to an area of high water "concentration".