Biology Module 2: Principles of Ecology

biogeochemical

Cycle by which chemicals circulate through an ecosystem using living and nonliving parts.

nitrogen fixation

Process of converting atmospheric nitrogen gas into ammonia

biome

a group of ecosystems with similar climates and organisms

biological community

all the different populations that live together in an area

autotroph

an organism that captures energy from sunlight or chemicals and converts it into food, also called a producer

decomposers

break down organic matter releasing nutrients that can be reused

ecosystem

collection of all the organisms that live in a particular place, together with their physical environment

biotic

living factors in the environment.

abiotic

nonliving factors in the environment

heterotroph

organism that obtains energy from the foods it consumes; also called a consumer

biosphere

part of Earth in which life exists including land, water, and air or atmosphere

Denitrification

process by which bacteria convert nitrates in soil into nitrogen gas

Symbiosis

relationship in which two species live closely together

ecology

scientific study of interactions among organisms and between organisms and their physical environment

trophic level

step in the movement of energy through an ecosystem; step in a food chain or web