Environmental science

2. the sometimes swampy coniferous forest of high northern latitudes,
5. a close, prolonged association between two or more different biological species
7. a tree that sheds its leaves seasonally, usually in the fall
8. used by organisms to carry out complex tasks
10. an animal that is caught and killed by another for food
11. a biogeochemical process through which nitrogen is converted
12. an animal that lives by killing and eating other animals
15. The mass in an isolated system can neither be created nor be destroyed but can be transformed from one form to another
18. everything that takes up space and has mass
19. energy is neither created nor destroyed
21. dry environments with scarce vegetation, harsh temperatures

1. the process in which carbon atoms continually travel from the atmosphere to the Earth and then back
2. a treeless plain especially of arctic regions having a permanently frozen layer below the surface
3. when organisms interact with each other to gain access to a limited resource, such as food, water, or space
4. an area classified according to the species that live in that location
6. a tree or shrub that produces cones and has needle-like or scale-like leaves instead of flowers
9. a symbiotic relationship between two species where both organisms benefit from their interaction
10. relationship between two species of plants or animals in which one benefits at the expense of the other, sometimes without killing the host organism
13. a long-term ecological relationship between two species where one species benefits while the other is neither harmed nor helped.
14. a diagram that shows the flow of energy through an ecosystem
16. the tidal mouth of a large river, where the tide meets the stream
17. areas where water covers the soil
20. the continuous movement of water within the Earth and atmosphere