GCSE Biology Unit 3

Gas and Solute Exchange

• Substances move osmosis, diffusion and active transport.
• Life processes need gases or other dissolved substances before they can happen.
• Waste substances also need to move out of the cells so that the organism can get rid of them. 
• These substances move to where they need to be by diffusion, osmosis and active transport.
• Diffusion - This is where particles move from an area of high concentration to an area of low concentration. E.g. different gases can simply diffused through one another, like when a…