| A | B |
|---|
| abiotic | the nonliving factors in an ecosystem are called |
| variation | a variety in charactertistics or organisms is called this |
| autotroph | an organism that can make its own food by using energy from the sun |
| trophic level | a level in a food chain |
| biological magnification | an increasing concentration of harmful chemicals in organisms through a food chain |
| tolerance | an organism's capacity to survive in unfavorable conditions |
| biomass | the total amount of living mass within a trophic level |
| symbiosis | a relationship in which tow species live closely together |
| biosphere | the region of the earth that supports life is |
| species | a group of organisms that can breed and produce fertile offspring |
| biotic factor | the living factor in an ecosystem |
| secondary consumer | second consumer in a food chain |
