By the end of this topic you should be able to:

In this topic, you will find out how lots of substances move in and out of cells.

Diffusion is the movement of particles from a high concentration to a low concentration. It is responsible for the movement of oxygen into the blood from the alveoli in the lungs, for carbon dioxide leaving respiring cells and plants wilting.
Pay attention to the diagrams on page 21.

COMPLETE - B1 1.4 Interactive screen: Factors affecting diffusion (Kerboodle)

WATCH - Diffusion | Revision Monkey (YouTube)

EXPLORE - Agar cube diffusion (Twig) - [Not available on sample course]