Science

2. the introduction of harmful materials into the environment
4. respiration A chemical process in which oxygen is used to make energy from carbohydrates (sugars)
5. the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
9. an animal which feeds on dead organic material, especially plant detritus.
10. the process of turning from liquid into vapor.
12. cells contain membrane-bound organelles and are the basis for both unicellular and multicellular organisms

1. the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
3. web consists of all the food chains in a single ecosystem
6. Fixation the chemical process by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle.
7. energy energy contained within a system that is responsible for its temperature.
8. the force by which a planet or other body draws objects toward its center.
11. A process in which glucose (sugar) is partially broken down by cells in enzyme reactions that do not need oxygen.