Mrs. Wilges Biology Module 2

ecology

scientific study of interactions among organisms have with their environments

biosphere

the portion of Earth that supports life, extends from the atmosphere to the bottom of the oceans

biotic factors

the living factors in an organisms that inhabit an environment

abiotic factors

the nonliving factors in an organism's environment; temperature, moisture, light, and soil

population

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

biological community

collection of several interacting populations that inhabit a common environment

ecosystem

interactions among populations in a community, the community's physical surroundings, or abiotic factors

biome

a large group of ecosystems that share the same climate and have similar types of communities

habitat

where an organism lives out its life

niche

a role or position that an organism has in its environment. includes all biotic and abiotic interactions as a animal meets its needs for survival and reproduction

predation

one organism consuming another organism for food

symbiosis

permanent close association between two or more organisms of different species

mutualism

a symbiotic relationship in which both species benefit

commensalism

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

parasitism

a symbiotic relationship in which one organism benefits at the expense of the other species

autotroph

organism that use energy from the sun or energy stored in chemical compounds to manufacture their own nutrients

heterotroph

organism that cannot make their own food and must feed on other organisms for energy and nutrients

herbivore

a heterotroph that only eats plants

carnivore

heterotrophs that prey on other heterotrophs

omnivore

organisms that eat both plants and animals

detrivore

organisms that eat fragments of dead matter and return nutrients to the soil, air, and water making nutrients available to other organisms

trophic level

organisms in each step of a food chain or food web

food chain

a simple model that shows how matter and energy move through an ecosystem

food web

model representing the many interconnected food chains and pathways in which energy flows through a group of organisms

biomass

total mass of living matter at each trophic level

matter

anything that takes up space and has mass

nutrient

a chemical substance that an organism must obtain from its environment to sustain life and life processes

biogeochemical cycle

the exchange of matter through the biosphere

nitrogen fixation

the process of converting nitrogen into a useable form for plants

denitrification

conversion of fixed nitrogen back into nitrogen gas

limiting factor

any abiotic or biotic factor that restricts the numbers, reproduction, or distribution of organisms

tolerance

the ability of any organism to survive when subjected to abiotic factors or biotic factors