Diffusion and Osmosis

Today we're going to start looking at diffusion and osmosis in cells, which is the start of the year 11 course. Answer the following in your books:

1. How can you define diffusion?
2. Explain WHY diffusion occurs in some conditions, but not others:
3. Where in the body does diffusion occur?
4. What part of the CELL allows diffusion to occur?
5. What things affect the rate of diffusion?
6. How would you explain a concentration gradient?
7. What is osmosis?
8. How could you make cells in a solution get smaller, or larger?
9. What do isotonic, hypotonic and hyper tonic mean?
10. Explain how osmosis can kill cells:
11. Name two organelles and explain what they do in the cell:
12. Watch this video, and then explain the difference between osmosis and diffusion in your own words:                         

Extension - In what ways are our lungs adapted to help gases diffuse into and out of the blood more quickly?