| A | B |
|---|
| Producer | an organism that makes its own food |
| Consumer | organisms that get their energy from eating other organisms |
| Herbivores | consumers that only eat producers (plant-eaters) |
| Carnivores | consumers that only eat other consumers (meat-eaters) |
| Omnivores | eaters of all, both producers and consumers |
| Decomposers | consumers that get their food by breaking down dead organisms (fungi, bacteria) |
| Cellular Respiration | the process of breaking down food to yield energy |
| Food Chain | a sequence in which energy is transferred from one organism to the next as each organism eats another |
| Food Web | shows all of the feeding relationships in an ecosystem |
| Trophic Level | each step in the transfer of energy through an ecosystem |
| Water Cycle | water is never destroyed, it moves between the atmosphere and the earth |
| Precipitation | rain, sleet, or snow |
| Nitrogen-Fixing Bacteria | only organisms that can use nitrogen gas directly from the earth's atmosphere |
| Succession | a regular pattern of changes over time in types of species in a community |
| Climax Community | final, stable community that forms if the land is left undisturbed |
| Secondary Succession | when succession occurs where an ecosystem has previously existed |
| Pioneers | first organisms to colonize any newly available area |
| Primary Succession | when succession occurs where no ecosystem has existed before |
