| A | B |
|---|
| ecology | study of interactions among organisms and their environment |
| biosphere | the combined portions of the planet in which all of life exists |
| species | a group of organisms that can breed and produce fertile offspring |
| populations | groups of individuals that belong to the same species that live in the same area |
| communities | different populations that live together in a defined area |
| ecosystem | a collection of all organisms that live together with their nonliving environment- biotic and abiotic |
| biome | a group of ecosystems that have the same climate and communities |
| autotroph | organisms that make their own food |
| heterotroph | organisms that have to consume food for energy |
| food chain | a series of steps in which organisms transfer energy |
| food web | links of food chains in an ecosystem |
| trophic level | each step in a food chain or food web |
| decomposer | organisms that break down organic matter |
| ecological pyramid | a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web |
| chemosynthesis | process where organisms use chemical energy to produce carbohydrates |
