Background Information

     The Earth's surface is where life exists.  Living things are called organisms.  Each type of organism has certain needs that must be satisfied in order for it to stay alive.  Every organism tries to live in a place that will satisfy all of its needs.  The natural place where an organism lives, its home, is called its habitat.  Any organism that lived in a particular habitat before humans arrived is called a native .  Each type of habitat is affected by two factors:  the organisms that live there and the non-living characteristics that affect them.  The organisms include all of the plants, animals, and other creatures.  These are also called the biotic factors.  The non-living factors include things like sunlight, climate, soil and water.  These are also called abiotic factors.  All organisms in your area that look alike and can produce offspring are members of the same species.  All the members of the species that live in your area are called a population.  All of the different populations that live together in your area make up a community.