| Term | Definition |
| abiotic factors | the non-living, physical aspects of an ecosystem such as air, water, soil, heat, and light. |
| aerobic respiration | energy releasing biochemical reactions that use oxygen. |
| air | a mixture of gases; mostly nitrogen and oxygen. |
| anaerobic respiration | energy releasing biochemical reactions that do not need oxygen to occur. |
| atom | a tiny particle of matter. |
| biotic factors | the living things in an ecosystem. |
| carbohydrates | chemical compounds containing carbon, hydrogen, and oxygen. Sugar is a carbohydrate. Carbohydrates store energy in their chemical bonds. |
| carbon cycle | the movement of carbon atom through an ecosystem between living organisms as well as the non-living part of the environment. |
| carbon dioxide/oxygen cycle | he recycling of carbon dioxide and oxygen between organisms and the air. |
| carbon dioxide | a chemical compound made from one atom of the element carbon and two atoms of the element oxygen. The chemical formula for carbon dioxide is CO2 |
| cellular respiration | the process of releasing energy stored in carbohydrates. |
| chemical compound | a molecule composed of atoms of two or more different elements. |
| condensation | the formation of snow or rain from water vapor. |
| decomposers | break down food |
| dentrification | the process by which bacteria cause nitrogen gas to be released back into the environment |
| ecology | the study of the relationships and interactions of living things with one another and with their physical environment |
| ecosystem | where plants and animals live and interate in the envierment |
| element of matter- a basic type of matter, such | a basic type of matter, such as the elements carbon, sulfur, iron, and oxygen. Every element has a different atomic structure. |
| energy | the ability to do work. Light and heat are examples of energy. Energy has no mass (weight)and occupies no space. |
| extinction | can never be a live again |
| food chain | its what eats what |
| food producers | give energy throw f photosynthesis |
| habitat | a place where an animal lives |
| helem | a trace of element in air |
| humus | soil material created by decay of organic material such as dead leaves |
| krypton | trace element in air |