Learners' Outcomes

1. Define the process of diffusion as the net movement of molecules from a region of high concentration to a region of low concentration.
2. Define the process of osmosis as the net movement of water molecules from a region of higher water potential, to a region of lower potential across a selectively permeable membrane.
3. Explain that osmosis is a subset of diffusion and that osmosis is restricted to the net movement of water molecules whilst diffusion involves the movement of any type of molecules. In addition, be aware that a selectively permeable membrane is involved in osmosis whilst a membrane need not necessarily be present for diffusion.
4. Explain how animal and plant cells behave differently in solutions of varying water potential.
5. Appreciate the importance of diffusion and osmosis to living systems and list examples of both processes.