20 terms

Schlecker Bio Chapter 2

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autotroph
organism that use energy from the sun or energy stored in chemical compounds to manfacture their own nutrients.
heterotroph
organism that cannot make its own food and must feed on other organisms for energy and nutrients.
decomposers
organisms, such as fungi and bacteria, that break down and absorb nutrients from dead organisms.
food chain
simple model that shows how matter and energy move through an ecosystem.
trophic level
organism that represents a feeding step in the movement of energy and materials through an ecosystem.
food web
model that shows all the possible feeding relationships at each trophic level in a community.
ecology
scientific sudy of interactions between organisms and their environments.
biosphere
portion of Earth that supports life; extends from high in the atmospphere to the bottom of the oceans.
abiotic factor
nonliving parts of an organism's environment; air currents, temperature, moisture, light, and soil are examples.
biotic factor
all the living organisms that inhabit an environment.
population
group of organisms all of the same species, which interbreed and live in the same place at the same time.
biological community
a community made up of interacting populations in a certain area at a certain time.
ecosystem
interactions among populations in a community; the community's physical surroundings or abiotic factors.
habitat
place where an organism livesout its life.
niche
role or position a species has in its its needs for survival and reproduction.
symbiosis
permanent, close association between two or more organisms of different species.
commensalism
symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited.
mutualism
a symbiotic relationship in which both species benefit.
parasitism
symbiotic relationship in which one organism benefits at the expense of another, usually another species.
biomass
the total mass or weight of all living matter in a given area.