organism- an individual animal, plant, or single-celled life form.
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
ecosystem- a biological community of interacting organisms and their physical environment.
biome-a large naturally occurring community of flora and fauna occupying a major habitat
biosphere-the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms
