Science·Organisms & Life Processes·conceptual
How Diffusion Works
Explain diffusion as the net movement of particles from a region of higher concentration to lower concentration, and describe its role in moving materials (oxygen, carbon dioxide, glucose) in and between cells
Suggested ages 12–13
Evidence of understanding
- Defines diffusion using particle theory
- Explains the direction of diffusion of oxygen and carbon dioxide at the alveoli
- Explains how cells get glucose from the blood using diffusion
- Identifies factors that affect the rate of diffusion (concentration gradient, surface area, distance)
Assessment prompt
If How Diffusion Works was asked why oxygen moves from the lungs into the blood without the body needing to pump it, could they explain what diffusion is and why it always moves in one particular direction?
Standards alignment
KS3.Sci.Bio.GasExchange.3GB · uk-nc-2013
Role of diffusion
The national curriculum in England: Key stages 1 and 2 framework document · KS3