B4 - Diffusion
Difusion is when something travels from an area of high concentration to an area of low concentration (used kinetic energy) The particles move aong a concentration gradient.
The diffusion of water particles from an area of high concentration to an area of low concentration along a concentration gradient through a semepermiable membrane.
Diffusion in plants
oxygen diffuses in and carbon dioxide diffuses out through the stoma.
Diffusion in animals
oxygen diffuses in and carbondioxide diffuses out of the blood in the lungs. In the intestine the villi give a massive surface area for the maximum amount of diffusion.