Ecology

5. The variety of life on Earth
8. Recycles dead organisms and waste
9. All the members of one species living in an area
11. fixation Bactria take nitrogen from the air and change it into a form that can be used by plants
12. The process in which plants use water, sunlight, and carbon dioxide to make sugar and oxygen
14. Eats dead animals
15. One species benefits, the other is neither helped nor harmed in some way
18. Living or once living or made by something that was alive
19. All the different populations living in an area
20. Must eat something for energy
21. Eats both plants and meat

1. Both species benefit from the relationship
2. Being dependent on others for some needs, being mutually dependent on each other
3. An environmental factor that is not alive, has never lived, and was never part of something living
4. Eats plants
6. One living thing
7. Animals use sugar to make carbon dioxide
10. Makes its own food
12. One species benefits, the other is harmed in some way
13. How an ecosystem changes over time
16. All of the living and nonliving things that interact in an area
17. a close relationship between species that benefits at least one of the species
19. Eats meat