| A | B |
|---|
| producer | organism that can make its own food |
| consumer | organism that obtains energy by feeding on other organisms |
| herbivores | consumers that eat only plants |
| carnivores | consumers that eat only animals |
| omnivore | consumer that eats both plants and animals |
| scavenger | carnivore that feeds on th bodies of dead organisms |
| decomposer | organisms that break down wastes and dead organisms and return the raw materials to the environment |
| food chain | series of events in which one organism eats another and obtains energy |
| food web | consists of the many overlapping food chians in an ecosystem |
| energy pyramid | shows the amount of energy that moves from one feeding level to another in a food web |
| water cycle | continuous process by which water moves from earth's surface to the atmosphere and back |
| evaporation | process by which molecules of liquid water absorb energy and change to the gas state |
| condensation | process by which gas changes to a liquid |
| precipitation | rain, snow, sleet or hail |
| carbon and oxygen cycle | producers use carbon from the carbon dioxide to produce other carbon-containing molecules |
| nitrogen cycle | nitrogen moves from the air to the soil, into living things and back into the air |
| nitrogen fixation | process of changing free nitrogen gas into a usable form of nitrogen |
| nodules | bumps on plants where bacteria live; usually on plants such as legumes. |
| sucession | series of predictable changes that occur in a community over time |
| pioneer species | first species to populate in an area |
| primary succession | series of changes that occur in an area where no ecosystem previously existed |
| secondary succession | series of changes that occur after a disturbance in an existing ecosystem |
