Challenging Your Thinking About Diffusion Name:

Your 9-year old cousin has just read about diffusion and now she has a few questions. Help her understand diffusion by answering her questions. Remember she is only nine so don't use middle school words like semi-permeable or Concentration.

1. When stuff diffuses does everything go in the same direction? Is it like a magnet where things are attracted to something?

2. Does stuff ever stop diffusing? when?

3. Can stuff ever move from where there is less of it to where there is more of it? How would that happen?

Okay, now your cousin has gone outside so you can answer questions like you are talking to an informed adult.

4. Draw some plant cells (think of how your onion cells looked) and water molecules and show how a plant will wilt if it does note get enough water due to the principle of osmosis.

5. Using the principle of osmosis, show what will happen to a freshwater fishs cells if it is placed in saltwater. Draw and label a before and after picture to show this.

6. Using the principle of osmosis, show what will happen to a saltwater fishs cells if it is placed in freshwater. Draw and label a before and after picture to show this.

7. Why will drinking salt water make you thirstier than not drinking any water at all?

8. Draw a diagram of a cell in a hyotonic solution.

9. Draw what will happen to that cell in a hypotonic solution.

10. Draw a diagram of a cell in a hypertonic solution.

11. Draw what will happen to that cell in a hypertonic solution.

12. Draw a cell in an isotonic solution.

13. Draw what will happen to that cell in an isotonic solution.

14. What organ in your body does the job of keeping your blood cells in isotonic solution? (hint: you have two of them but can survive with only one).