Ecology Vocabulary
Name
Date
Period
Find listed below the eligible Keystone Ecology
vocabulary as identified at Pennsylvania’s Standards
Aligned System or SAS website. A basic knowledge of
this vocabulary is vital to achieve success not only on
the Keystone Biology Exam but also in your biology
class. Which by the way, I think is much more important
than one standardized test. But then again if you need
the test to graduate that makes it pretty darn important
as well!
Review, review, review this vocabulary.
Creating flash cards for each term would be an
excellent idea. I have notecards available just for that
very purpose. And don’t wait until May to start!!!
10% rule/law- only about 10 percent of the energy available within one trophic level is
transferred to organisms at the next trophic level.
Abiotic- physical or nonliving factor that shapes an ecosystem (water, soil, etc.)
Aquatic ecosystem- ecosystems determined primarily by the depth, flow, temperature,
and chemistry of the overlying water and are often grouped according to the abiotic
factors that affect them. Can be freshwater, saltwater or mixed.
Autotroph- organism that can capture energy from sunlight or chemicals and use it to
produce its own food from inorganic compounds; also called producers.
Biodiversity- biologic diversity; the sum total of the variety of organisms in the biosphere
and is one of the Earth’s greatest natural resources. When biodiversity is lost, potential
sources of material with significant value to the biosphere and to humankind may be lost
with it.
Biome- group of ecosystems that have the same climate and dominant communities.
Biosphere- part of Earth in which life exists including land, water, and air or atmosphere.
Biotic- living or biological influences on organisms within and ecosystem.
Biotic potential- The potential growth a population of living things can expect if it were
living under ideal environmental circumstances. It is when the population just keeps on
growing and growing; the rate at which a species reproduces with unlimited conditions
.
Carbon cycle- the series of processes by which carbon compounds are interconverted
in the environment, chiefly involving the incorporation of carbon dioxide into living tissue
by photosynthesis and its return to the atmosphere through respiration, the decay of
dead organisms, and the burning of fossil fuels.
Carnivore- organism that obtains energy by eating animals
Carrying capacity- largest number of individuals of a population that a given
environment can support
Chemosynthesis- process by which some organisms, such as certain bacteria, use
chemical energy to produce carbohydrates
Commensalism- symbiotic relationship in which one member of the association benefits
and the other is neither helped nor harmed (barnacle living on a whale, orchid living on
a tree)
Community- assemblage of different populations that live together in a defined area
Competition- when organisms of the same or different species attempt to use an
ecological resource in the same place at the same time
Consumer- organism that relies on other organisms for its energy and food supply; also
called a heterotroph
Decomposer- organism that breaks down and obtains energy from dead organic matter
Density dependent- limiting factor that depends on population size
Density independent- limiting factor that affects all populations in similar ways, regardless
of population size
Ecological pyramid- diagram that shows the relative amounts of energy or matter within
each trophic level in a food chain or food web
Ecosystem- collection of all the organisms that live in a particular place, together with
their nonliving environment
Energy- the chemical potentials produced and consumed by the myriad and interwoven
reactions that take place within the compartments of living matter as it carries out life
functions
Evolution- change in a kind of organism over time; process by which modern organism
have descended from ancient organisms
Extinction- disappearance of a species from all parts of its geographical range
Food chain- series of steps in an ecosystem in which organisms transfer energy by eating
and being eaten
Food web- network of complex interactions formed by the feeding relationships among
the various organisms in an ecosystem
Fundamental niche- The fundamental niche is the potential niche, in other words the
niche that would prevail in the absence of competition and other factors that might
constrain its acquisition and use of the resources
Herbivore- organism that obtains energy by eating only plants
Heterotroph- organism that obtains energy from the foods it consumes; also called a
consumer
Limiting factors-factor that causes the growth of a population to decrease
Mutualism- symbiotic relationship in which both species benefit from the relationship
Nitrogen cycle- process by which different forms of nitrogen cycle through the biosphere
Nonnative species- not living or growing naturally in a particular place or region; plants
or animals originating in a part of the world other than where they are growing
Omnivore- organism that obtains energy by eating both plants and animals
Organism- individual living thing
Oxygen cycle- process by which oxygen cycles through the biosphere
Parasitism- symbiotic relationship in which one organism lives in or on another organism
(the host) and consequently harms it
Photosynthesis- process by which plants and some other organisms use light energy to
convert water and carbon dioxide into oxygen and high-energy carbohydrates such as
sugars and starches
Population- group of individuals of the same species that live in the same area
Predation- interaction in which one organism captures and feeds on another organism
Producer- organism that can capture energy from sunlight or chemicals and use it to
produce food from inorganic compounds; also called autotrophs
Realized niche- the actual niche an organism occupies as a result of competition for its
resources, problems in acquiring those resources. The realized niche is always smaller than
the fundamental niche
Succession- the series of predictable changes in response to natural and human
disturbances in a community over time
Symbiosis- relationship in which two species live closely together
Terrestrial ecosystem- an ecosystem found only on land defined by a unique set of
abiotic factors particularly climate and a characteristic assemblage of plants and
animals
Trophic level- step in a food chain or food web
Water cycle- process by which water cycles through the biosphere