biology

5. organism that breaks down dead organic material
7. species' average population size in a particular habitat
8. An interaction between individuals of different species that results in positive (beneficial) effects
9. living organism that shapes its environment
10. Makes their own food
11. non-living part of an ecosystem
12. An organism that generally obtains food by feeding on other organisms

1. The branch of biology that deals with the relations of organisms
2. self-regulating process by which an organism tends to maintain stability
3. inborn impulse or motivation to action typically performed in response to specific external stimuli
4. relationship between individuals of two species in which one species obtains food or other benefits from the other without either harming or benefiting the latter
6. organism that lives on or in a host organism