1. Ecology
Thinking Questions

2. Compare and contrast a population and a community.

3. Compare and contrast a population and a community.
A community consists of all the populations in an ecosystem and therefore has many different species in it. A population consists of all the members of one—and only one—species that live in an ecosystem

4. Compare and contrast a community and an ecosystem

5. Compare and contrast a community and an ecosystem
All the living organisms—the populations of all the species that live in an area—make up a community. An ecosystem includes the nonliving factors as well as the living organisms.

6. If corn is planted at one-foot intervals, what is the population density of a fully planted acre of corn? Note: One acre equals 43,560 square feet.

7. If corn is planted at one-foot intervals, what is the population density of a fully planted acre of corn? Note: One acre equals 43,560 square feet.
43,560 plants per acre

8. Raccoons live in an old, dead tree in the Rosarios' backyard
Raccoons live in an old, dead tree in the Rosarios' backyard. Every night, the raccoons rummage through the garbage cans in the neighborhood, knocking them over in search of discarded human food. Describe the habitat and the niche of these raccoons.

9. Describe the habitat and the niche of these raccoons.
The raccoons' habitat is the old, dead tree. The niche involves knocking over garbage cans and getting food that humans consider garbage.

10. The clown fish lives among the stinging tentacles of the sea anemone but never gets stung. The sea anemone protects the clown fish from predators, and the clown fish helps bring food to the carnivorous sea anemone. What kind of relationship is this?

11. What kind of relationship is this?
Mutualism – both organisms benefit

12. Explain why cooperation is a part of an organism's niche rather than its habitat.

13. Explain why cooperation is a part of an organism's niche rather than its habitat.
An organism's habitat is where it lives: its niche is how it survives. Cooperation is part of the way an organism survives and so is part of its niche

14. Explain how competition can limit population size.

15. Explain how competition can limit population size.
Competition occurs when two or more organisms seek the same resource at the same time. If a resource is in short supply, not every organism will be able to get all that it needs for growth or survival. Some organisms in the population may leave the area; others may not survive.

16. Why must a producer be at the base of every food chain?

17. Why must a producer be at the base of every food chain?
Producers are the only organisms that can make the energy-rich substances that are used for food. The second step in a food chain must be a consumer that eats the producer. Consumer eat producers or other consumers that have eaten producers.

18. What kind of succession occurs when lava covers the land?

19. What kind of succession occurs when lava covers the land?
Primary succession because the land area is newly created, without any soil

20. Compare a climax community to a pioneer species.

21. Compare a climax community to a pioneer species.
A climax community is complex and stable over time. A pioneer community is a new and changing environment.

22. What is the connection between climate and climax communities?

23. What is the connection between climate and climax communities?
Areas with similar climates produce similar climax communities.

24. What changes are shown in this diagram
What changes are shown in this diagram? What type of succession is demonstrated?

25. What changes are shown in this diagram?
The pond is beginning to fill in.
There is very little water left
No aquatic life is visible.
Secondary succession is shown.