organsim:
an individual animal, plant, or single-celled life form.
"fish and other organisms have been destroyed over large areas of the creek"
population:
In biology, a population is a number of all the organisms of the same group or species who live in a particular geographical area and are capable of interbreeding.
communtiy:
a group of people living in the same place or having a particular characteristic in common.
"the scientific community"
ecosystem:
a biological community of interacting organisms and their physical environment.
"the marine ecosystem of the northern Gulf had suffered irreparable damage"
biome:
a large naturally occurring community of flora and fauna occupying a major habitat, e.g. forest or tundra.
biosphere:
the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms.