Ecology is the study of how organisms interact with one another and with their physical environment of matter and energy. Ecology means “house” or “place to live,” and logos, meaning “study of”) is the study of how organisms interact with their living (biotic) environment of other organisms and with their nonliving (abiotic) environment. Major components of an ecosystem To enhance their understanding of nature, scientists classify matter into levels of organization from atoms to the biosphere. Ecologists focus on organisms, populations, communities, ecosystems, and the biosphere. What keeps us and other organisms alive Life is sustained by the flow of energy from the sun through the biosphere, the cycling of nutrients within the biosphere, and gravity . It has four major components: Atmosphere Troposhere Stratosphere Geosphere Answer the following questions: What is Ecology What keeps us and other organisms alive What are the major components of an ecosystem, give four examples for each one.