1. What did Robert Paine do with the purple star fish? 2. What was Professor Fred Smith thinking about when he asked “Why is that tree green?”
3. Why is the world truly green?
4. What animal did Robert Paine discover is at the top of the food chain?
5. On the rock shoreline, how was biodiversity affected by the removal of starfish?
6. What term did Paine coin to describe a species that could regulate the composition of an entire community?
7. What organism did Paine suspect was reducing the population of kelp?
8. What human activity caused sea otters to be on the brink of extinction?
9. What happens when you remove sea otters from the ecosystem?
10. What controls the distribution of resources in a trophic cascade?
11. Which organism was truly responsible for the sustainability of the kelp forest ecosystem?
12. What did Tim Tinker hypothesize was affecting the abundance of sea otters?
13. After WWII, what species’ population was reduced by human activity?
14. What trophic level do orcas belong in, supporting Paine’s theory?
15. The removal of what type of species has profound effects on the number and variety of other species, and the ecosystem as a whole?

Analysis Questions (After Video)

16. What are trophic cascades?

17. Describe how keystone species keep an ecosystem in check.