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Carrying Capacity

the amount of organisms an ecosystem can support


when a species reaches stability, balance

Exponential Growth

a j-curved graph that shows when a population increases rapidly

Density Independent

limiting factors that affect the population, regardless of the size(abiotic)

Density Dependent

limiting factors that affect the population depending on the size (biotic)


compete for space, food, water and shelter


the action of eating prey


a group of the same types of organisms


a group of organisms of one species that interbreed and live in the same place at the same time


collection of interacting populations


interaction among the populations in a community and the community's physical surroundings (biotic and abiotic factors)

Growth Rate

the rate a species grows

Zero Population Growth

same amount of births, immigration and deaths, emmigration


species moving into an ecosystem


species moving out of an ecosystem


symbiotic relationship in which one organism benefits at the expense of the others


symbiotic relationship in which both species benefit


symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited


branch of biology developed from natural history; scientific study of interactions among organisms and their environments


organisms that cannot make their own food and must feed on other organisms


organisms that use energy (from the sun or that is stored in chemical compounds) to manufacture their own nutrients


an organism that uses photosynthesis (and thus, energy from the sun) to obtain its energy


an organism that eats producers or other consumers to obtain its energy


heterotrophs that feed only on plants


heterotrophs that eat both plant and animal material


heterotrophs that feed only on other animals

Top Carnivore

carnivore on top of the food chain; highest


organisms that break down and absorb nutrients from dead organisms; break down the complex compounds of dead and decaying plants and animals into simpler molecules that can be more easily absorbed


Renewable organic matter

Food Chain

a simple model that scientists use to show how matter and energy move through an ecosystem

Food Web

expresses all possible feeding relationships at each trophic level in a community; more realistic than a food chain as most organisms depend on more than one species for food


______ are needed for organisms to survive, this are cycled through out the soil.


the capacity to do work


non-living parts of an organism's environment


all living organisms of an organism's environment

Trophic Level

a feeding step representing the passage on energy and materials in a food chain; each level/step represents an organism in the food chain

Carbon Cycle

the cycle in which carbon is passed all throughout the ecosystems so that organisms can use it

Nitrogen Cycle

the cycle in which nitrogen is passed all throughout the ecosystems so that organisms can use it

Phosphorus Cycle

the cycle in which phosphurus is passed all throughout the ecosystems so that organisms can use it

Nitrogen Fixation

how nitrogen is converted into a compund so that it can be used by organisms. This occurs by lightning and bacteria fixing it into the soil

Cellular Respiration

The process in which oxygen is used by organisms and then converted to carbon dioxide and released into the air


the process plants use to create glucose and oxygen from converting sunlight (energy), carbon dioxide and water

Greenhouse Effect

the effect that keeps the earth warm by allowing some sunlight heat rays to stay inside the atmosphere

Global Warming

the raise of temperature in the biosphere caused by the excess effects of the greenhouse effect.


an individual living thing


species being eaten


species that feeds on animals

Birth Rate

number of births

Death Rate

number of deaths

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