2. An energy pyramid shows the amount of energy contained in the bodies of organisms at each __________ level.

3. In an ecosystem, ________ diminishes at each successive trophic level.

4. A path of energy through the energy levels of an ecosystem is called a ____ _____.

5. The primary productivity of an ecosystem is a measure of the amount of organic material that the ___________ organisms in the ecosystem produce.

6. The interrelated food chains in an ecosystem are called a ___________ ______.

7. An organism that eats a primary consumer is called a _______ consumer.

8. Animals known as ______ eat only primary producers.

9. The niche of a deer in a forest is that of a herbivore. The niche of a cougar that eats the deer is that of a _____.

10. A fish called a cleaner wrasse eats the tiny parasites that cling to and feed upon much larger fish. Therefore, the cleaner wrasse has a ____ relationship to the larger fish.

11. The symbiotic relationship in which one organism benefits and the other neither benefits nor suffers harm is called ____.

12. The struggle among organisms for the same limited natural resources is called ____.

13. Colored bands on the body of a harmless king snake that resemble the bands on a poisonous coral snake is an example of ____.

14. The term _____ is used for a close relationship between two dissimilar organisms in which one organism usually benefits.

15. A symbiotic relationship in which one organism benefits and another is often harmed but not killed is called _____.

16. In a parasitic relationship, the organism that provides benefits to another organism at its own expense is called the _____.

17. The _______ _________ is the population size that can be sustained by an environment.

18. The way in which members of a population are arranged i a given area is referred to as _____.

19. A _____ describes the habitat, feeding habits, other aspects of an organism's biology, and its interactions with other organisms and the environment.

20. An ecosystem consists of the living and ____ environment.

Score =