1. 1.Ecosystem: living and nonliving things interacting in an environment. 2.Population: a group of the same kinds of organisms living in a certain place 3.Adaptation: a trait that an animal possess in order to live in a certain environment. 4.Abiotic Factor: A non-living things in an environment in which living things interact with 5.Biotic Factor: the living organisms in an environment.

2. 6. Abiotic Factors: Sun, Water, Soil, Temperature Biotic Factors: fish, grass, algae 7. Food Web: a diagram that show how energy flows through a community of organisms – many overlapping food chains. 8. Producer 9. Consumer 10. Decomposer 11. Trees/Grass 12. Mouse, Cricket, Deer 13. Snake, Hawk, Owl, Frog

3. 14. The population of snakes and hawks would decrease if the mice were eliminated because there is less energy available in the food web. 15. The population of crickets would increase if the frogs were eliminated because there are less predators eating them. 16. Sun 17. Water + Carbon Dioxide ---------Sunlight-----------------Oxygen + Glucose

4. 18. Nitrogen Fixation 19. Carbon Dioxide 20. Helps to build new cells and DNA. 21. Water is important to living things because it helps to transport materials and remove waste. 22. Eating other organisms. 23. 90% 24. Level 3: second level consumers 25. The raccoon is an omnivore.

5. 26. 167 27. Week 5 or 6 28. Biotic Factor: predator, less food Abiotic Factor: Change in habitat/Temperature 29. The population of plants decreased by 70 30. The population of plants decreased by 20 31. When wolves were reintroduced, the population of plants dropped by 20. When wolves were not present, the plant population dropped by 70. 32. The population of plants did not change as much when wolves were present because the deer were not overgrazing 33. It is important to have a well balanced ecosystem because it helps to keep the flow of energy balanced.

6. Organisms Starting Population Ending Population Change in Population Plants10030-70 Deer150140-10 Organisms Starting Population Ending Population Change in Population Plants10080 -20 Deer150122 -28 Wolves2528 +3 Deer Population Wolves in Yellow Stone Park Table B Deer Population Prior to Wolves in Yellow Stone Park Table A