| A | B |
|---|
| producers | organisms that produce their own food through photosynthesis |
| population | individuals of the same kind living in the same environment |
| food web | shows the relationship among many different food chains in a single ecosystem |
| consumers | living things that must eat to get energy |
| habitat | place in an ecosystem where each population lives |
| extinct | species become this after the last individual in the population dies |
| exotic | nonnative organisms |
| competition | contest between organisms for limited resources |
| energy pyramid | shows amount of energy available to pass from one level of a food chain to the next |
| learned behaviors | behaviors animals are taught or acquire after birth |
| decomposer | consumer that breaks down tissues of decaying organisms |
| community | all the populations of organisms living together in an environment |
| ecosystem | community of organisms and their physical environment |
| threatened | likely to become endangered if it is not protected |
| individual | single organism in an environment |
| instinct | behavior an organism inherits |
| food chain | show how consumers in an ecosystem are connnected to one another according to what they eat |
| endangered | having a population so small it is likely to disappear unless steps are taken to save it |
| symbiosis | long-term relationship between different kinds of organisms |
| niche | role of a population of organisms within a particular habitat |
