1. Ecology

2. Levels of Organization

3. Biotic and Abiotic Factors Biotic factors are the living organisms in an ecosystem Abiotic factors are the nonliving conditions or materials in the ecosystem Examples of Biotic FactorsExamples of Abiotic Factors Bison population Hawk population Snake population Prairie dog population Grass population Stream (water) Rocks Air (oxygen, carbon dioxide) Light Temperature

4. Energy Pyramids Only 10% of the energy stored in each trophic level is passed on to the level above