| A | B |
|---|
| ecosystem | all living things in a certain area as well aas their physical surroundings |
| biotic factor | living components of an ecosystem |
| abiotic factors | temperature, rainfall, soil |
| organism | an individual living thing |
| population | group of same species living in the same area at a given time |
| community | all the different species in an ecosystem |
| natural selection | survival of the fittests |
| competition | 2 or more organisms attempting to use the same limited resource |
| habitat | place where an organism lives |
| consumers | organisms that cannot make their own food |
| producers | organisms that can photosynthesize |
| succession | regular pattern of changes over time in the type of species in a community |
| climax community | final stable community that forms when land is left undisturbed |
| primary succession | occurs in areas where no ecosystem has existed previously |
| secondary succession | a pattern of change in an area where an ecosystem has previously been |
| pioneers | first organisms to colonize any newly available area and start the succession process |
| biomes | regions that have distinctive climates |
| rain forests | biome with constant temperatures and average rainfall of over 250 cm per year |
| deciduous forests | biome that has trees with leaves that fall in autumn |
| tundra | frozen desert |
| desert | receives less than 10 cm of rain per year |
| grassland | needs fire to remain healthy |
| taiga | characterized by many conifers |
| wetland | covered with water at least part of the year |
| permafrost | permanently frozen land in the tundra |
| littoral zone | shallow water zone near the shore |
| benthic zone | inhabited by decomposers |
| marshes | wetland with nonwoody plants |
| swamps | wetland with woody plants |
| estuaries | mix of salt and fresh water |
