Explain the difference between osmosis and diffusion.

Osmosis is the movement of water molecules from an area of high concentration to an area of low concentration, through a partially permeable membrane.Diffusion is the movement of molecules from an area of high concentration to an area of low concentration, down a concentration gradient.The key differences are therefore: Osmosis ONLY applies to water molecules - whereas diffusion can apply to all molecules.Osmosis always occurs through a partially permeable membrane AND along a concentration gradient - whereas diffusion only requires a concentration gradient (not necessarily across a membrane)