| A | B |
|---|
| ecology | the study of the interactions of organisms with one another and with their physical environment |
| community | the organisms that live in a particular place |
| habitat | the physical location an organism lives |
| ecosystem | the self-sustaining collection of organisms and the environment |
| diversity | the measureof the number of species |
| producers | take in energy from their surroundings and store it |
| consumers | obtain energy by consuming other organisms |
| decomposers | obtain energy by consuming organic waste and dead bodies |
| trophic levels | the level of an organism in flow of energy throug the food chain |
| autotrophs | plants and other organisms that make their own food |
| herbivores | on the second trophic level; plant eaters |
| carnivores | on the third trophic level or above; flesh eaters |
| omnivores | eat both plant and animal |
| heterotrophs | organisms that cannot make their own food; above the first trophic level |
| food chain | the pathway of energy transfered through from one animal to the next in an ecosystem |
| food web | all the food chains within an ecosystem |
| ecological pyramid | a picture showing the amount of energy at each trophic level |
| nitrogen fixation | the conversion of nitrogen gas to ammonia |
| greenhouse effects | the ability of gases such as carbon dioxide to retain the sun's heat, and in doing so warm the atmosphere |
| biomes | a wide area of land in which communities live |
| symbiosis | species interactions between two or more species |
| parasitism | the parasite obtains nutrients from the host and in doing so harms the host |
| mutualism | a symbiotic relationship in which one organism benefits |
| commensalism | one organism benefits and the other is not obviously affected |
| predator-prey | the relationship in which one organism hunts the other for food |
