nhuy tran

3. living things within an ecosystem
5. begins on rock formations, such as volcanoes or mountains, or in a place with no organisms or soil
8. species an organism that helps define an entire ecosystem
10. the concentration of individuals within a species in a specific geographic locale
11. a method that determines how dependent humans are on natural resources
13. an area classified according to the species that live in that location
17. the position of an organism in the food chain
19. living organism which gets its nourishment by eating another living organism
21. a graph that measures the proportion of individuals in a given species that are alive at different ages.
22. The act of leaving a habitat or place with the intent of moving to a different habitat or place.
23. the natural home or environment of a plant, animal, or other organism
25. an organism that feeds on and breaks down dead plant or animal matter.

1. an animal establishes a home in a habitat because it has resources it can utilize or because the habitat is ideal for them.
2. Mosses, lichen, and low-growing grasses
4. long-term, typical atmospheric conditions in an area, such as temperature and rainfall
6. a resource of which there is an endless supply because it can be replenished.
7. anything that constrains a population's size and slows or stops it from growing.
9. the rise or increase in the contaminated substances caused by the intoxicating environment
12. the introduction of harmful materials into the environment
14. consists of all the food chains in a single ecosystem
15. a graphical representation of the energy found within the trophic levels of an ecosystem.
16. organisms that acquire their energy from sunlight and materials from nonliving sources.
18. organisms that consume other organisms for energy.
20. a relationship in which both species are mutually benefited.
24. the study of organisms and how they interact with the environment around them