1. What is the difference between a population, a community, and an ecosystem? 2. What is the difference between a niche and a habitat?

3. Why are the roles in different ecosystems the same but the species that fill them often different?

4. Why is a food web a better representation of the feeding relationships of organisms than a food chain?

5. Why does a predator kill its prey but a parasite rarely kills its host?

6. How can carbon cycle very quickly from the atmosphere and then back into the atmosphere?

7. Describe one way that carbon can be stored for a short time in the natural cycle.

8. Describe two ways that carbon can be stored for a very long time in the natural cycle.

9. Describe two ways that humans interfere with the natural carbon cycle.

10. Describe two important functions for carbon dioxide in the atmosphere.