Population - all the inhabitants of a particular town, area, or country.

Community - a group of people living in the same place or having a particular characteristic in common.

Producer - Beginning of ecosystem that supports consumers

Autotroph - an organism that can form nutritional organic substances from simple inorganic substances such as carbon dioxide.

Consumer - An organism in the ecosystem that will either feed on other organisms or producers

Heterotroph - an organism deriving its nutritional requirements from complex organic substances.

Herbivore - an animal that eats only plants

Carnivore - an animal that feeds on flesh.

Omnivore - an animal or person that eats food of both plant and animal origin.

Decomposer - an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.

Biomass - the total mass of organisms in a given area or volume.

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

Food web - consists of all the food chains in a single ecosystem

Food chain - a hierarchical series of organisms each dependent on the next as a source of food

Trophic Level - each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.

Biotic Factor - Living Organisms

Abiotic Factor - non-Living organisms

Habitat - The environment in which animals and plants live in an ecosystem

Predators -animals that prey/hunt others

Prey - animals that are hunted

Carrying Capacity - the average population for organisms in an area

Symbiotic - involving interaction between two different organisms living in close physical association

Mutualism - symbiosis that is beneficial to both organisms involved

Commensalism - One organism benefits while the other is not benefited but is unharmed

Parasitism - one organism is benefited while the other isn’t and is harmed

Predation - the preying of one animal on others

Competition - the relationship between organisms that strive for the same resources in the same place

Photosynthesis - the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water