| A | B |
|---|
| producer | an organism that can make its own food |
| consumer | an organism that obtains energy by feeding on other organisms |
| herbivore | a consumer that eats only plants |
| carnivore | a consumer that eats only animals |
| omnivore | a consumer that eats both plants and animals |
| scavenger | a carnivore that feeds on the bodies of dead organisms |
| decomposer | an organism that breaks down wastes and dead organisms |
| food chain | a series of events in which one organism eats another and obtains energy |
| food web | the pattern of overlapping food chains in an ecosystem |
| energy pyramid | a diagram that shows the amount of energy that moves from one feeding level to another in a food web |
| water cycle | the continuous process by which water moves from Earth's surface to the atmosphere and back |
| condensation | the process by which a gas changes to a liquid |
| nitrogen fixation | the process of changing free nitrogen gas into a usable form |
| evaporation | the process by which molecules of a liquid absorb energy and change into a gas |
| precipitation | rain, snow, sleet, or hail |
| biogeography | the study of where organisms live |
| continental drift | the very slow motion of the continents |
| exotic species | species that are carried to a new location by people |
| dispersal | the movement of organisms from one place to another |
| climate | the typical weather pattern in an area over a long period of time |
| biome | a group of land ecosystems with similar climates and organisms |
| desert | an area that receives less than 25 cm of precipitation per year |
| deciduous tree | a tree that sheds its leaves and grows new ones each year |
| coniferous tree | a tree that produces its seeds in cones and that has needle-shaped leaves |
| permafrost | soil that is frozen all year |
| canopy | a leafy roof formed by tall trees in a forest |
| grassland | an area populated by grasses and other nonwoody plants. Most get 25 - 75 cm of rain each year |
| tundra | an extremely cold, dry biome |
| understory | a layer of shorter plants that grow in the shade of a forest canopy |
| savanna | a grassland close to the equator that receives as much as 120 cm of rain per year |
| estuary | a habitat in which the fresh water of a river meets the salt water of the ocean |
| neritic zone | the region of shallow ocean water over the continental shelf |
| intertidal zone | the area between the highest high-tide line and the lowest low-tide line |
