study of interactions between organisms and their environment

two organisms that are so similar they can interbreed in nature and produce fertile offspring

members of a species in a defined area that routinely interbreed

populations of different organisms (biotic factors) living in a defined area

all the organisms (biotic factors) in a particular location, including their non-living environment (abiotic factors)

group of ecosystems that have the same climate and dominant communities

part of Earth that living organisms inhabit

(smallest to largest)

living factors or organisms that affect an ecosystem

non-living factor that affects an ecosystem

organism that makes its own food using sunlight or chemicals; also called producer

organism that makes its own food using sunlight or chemicals; also called autotroph

organism that relies on other organisms for food; also called consumer

consumer that eats plants

consumer that eats animals or meat

consumer that eats both plants and animals

organism that breaks down and absorbs nutrients from dead organisms

organism that feeds on plant and animal remains and other dead matter

organism that relies on other organisms for food; also called heterotroph

series of steps in which organisms transfer energy by eating and being eaten

network of all the food chains in an ecosystem

step in a food chain, food web, or ecological pyramid

-producer is always at the first level

the ultimate source of energy for most ecosystems on Earth

diagram that shows the energy available to each trophic level in an ecosystem; 10% is passed on to upper levels, the rest is lost as heat

total amount of living tissue within a given trophic level

primary producer; autotroph

primary consumer; herbivore or omnivore

secondary consumer; carnivore or omnivore

the amount of energy passed from one trophic level to the next

anything that an organism needs to live, ex. food, water, space

the type of environment in which an organism or group normally lives or occurs

full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

relationship in which two species live closely together

symbiotic relationship in which one organism hunts, captures, and feeds on another organism; also called predator and prey relationship

symbiotic relationship in which both organisms benefit

symbiotic relationship in which one organism benefits and the other organism is not affected

symbiotic relationship in which one organism benefits and the other organism is harmed

number of individuals per unit area

circulation of water in the environment through precipitation, evaporation, transpiration, and condensation

circulation of carbon from the atmosphere into organisms and back again; includes the cycling of carbon between cellular respiration and photosynthesis

process in which an organism captures the energy from the sun, carbon dioxide, and water to make glucose; plants, bacteria, and protists

process in which an organism uses oxygen to convert chemical energy stored glucose molecules to produce ATP and carbon dioxide; plants, animals, protists, and bacteria

The cycling of nitrogen in the environment in which nitrogen goes from a gas, to organic compounds in the soil, to proteins in a plant, and then is again released into the atmosphere as a gas.

bacteria that convert nitrogen in the air into forms that can be used by plants and animals

bacteria that convert nitrate back into nitrogen gas