| A | B |
|---|
| ecology | the scientific study of interactions among organisms and between organisms and their environment |
| population | a group of individuals that belong to the same species and live in the same area |
| community | an assemblage of different populations that live together in a defined area |
| ecosystem | a collection of all organisms that live in a particular place, together with their nonliving environment |
| producer | uses energy from the sun to make its own food |
| consumer | relies on other organisms for their energy and food supply |
| carnivore | obtains energy by only eating animals |
| herbivore | obtain energy by only eating plants |
| omnivore | eats both plants and animals |
| decomposer | breaks down organic matter |
| food chain | a series of steps in which organisms transfer energy by eating and being eaten |
| food web | links all food chains in an ecosystem together |
| trophic level | each step in a food chain or food web |
| ecological pyramid | shows the relative amounts of energy or matter contained within each trophic level |
| evaporation | the process by which water changes from liquid to an atmospheric gas |
| transpiration | when water enters the atmosphere by evaporating from the leaves of plants |
| nitrogen fixation | converting nitrogen gas into ammonia |
| denitrification | soil bacteria convert nitrates into nitrogen gas |
| biogeochemical cycle | connects all the biological, geological, and chemical aspects of the biosphere |
| biomass | the total amount of living tissue within a given trophic level |
