During embryo development, patterns of protein concentration appear in response to morphogen gradients. These patterns provide spatial and chemical information that directs the fate of the underlying ...

Diffusion is the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration. This is due to the random movement of the molecules.

If a crystal of a coloured soluble chemical, eg potassium manganate(VII), is placed in water, the particles spread out and mix with the water particles. As well as diffusion occurring between ...