ELT-PSSA review

2. The vertical layers that make up the soil
4. The process by which water changes from a liquid to a gas
7. The introduction of harmful materials into the environment
8. A device used for identifying organisms based on observable traits.
11. Method, an empirical method for acquiring knowledge that has characterized the development of science
13. The capacity to do work or produce heat
14. an organism that obtains energy and nutrients by feeding on other organisms or organic matter
15. Any form of water that falls from the atmosphere to the Earth's surface

1. an assemblage of two or more populations of different species occupying the same geographical area at the same time
3. the process of interaction and integration among people, companies, and governments worldwide
5. the capacity to maintain something at a certain rate or level
6. are organisms, mainly plants and algae, that produce their own food through photosynthesis, forming the base of a food web.
9. The biogeochemical cycle that describes the transformation and movement of nitrogen through the environment
10. A natural resource that can be replenished naturally over a relatively short period of time
12. The continuous circulation of water in the Earth-Atmosphere system