Biology - Unit 7 Energy and Ecosystems

limiting factor

anything that constrains a population's size and slows or stops it from growing

logistic growth model/carrying capacity

the number of organisms that an ecosystem can sustainably support

biotic factor

the living components (organisms) that shape up the environment

abiotic factor

a non-living part of an ecosystem that shapes its environment

trophic cascade (top-down, bottom-up)

powerful indirect interactions that can control entire ecosystems

green world hypothesis

proposes that predators are the primary regulators of ecosystems

decomposer

An organism, often a bacterium, fungus, or invertebrate that feeds on and breaks down dead plant or animal matter, making organic nutrients available to the ecosystem

decomposition

the process in which a living or organic substance is broken down into simpler organic or inorganic matter

ecosystem

a community of living organisms (plants, animals and microbes) in a particular area

energy flow

the flow of energy through living things within an ecosystem

food chain

a linear sequence of organisms through which nutrients and energy pass as one organism eats another

food web

a complex network of interconnecting and overlapping food chains showing feeding relationships within a community

herbivore

an organism that mostly feeds on plants

predation

a biological interaction where one organism, the predator, kills and eats another organism, its prey

consumer

an organism that cannot produce its own food and must eat other plants and/or animals to get energy

producer

organisms that make their own food

10% rule

when energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on

keystone species

an organism that helps define an entire ecosystem

autotroph

an organism that can produce its own food using light, water, carbon dioxide, or other chemicals

heterotroph

an organism that eats other plants or animals for energy and nutrients