PowerPoints are fully editable! Texas Environmental Systems TEKS: 6A, 6C, 6E and 6DUnit 1: The Biosphere Notes PowerPoint includes the following topics... Spheres of Earth (Bio, Hydro, Cryo, Atmo)Niches (Fundamental and Realized)Tolerance (Specialists and Generalists)Energy in Ecosystems (Autotrophs and Heterotrophs)Trophic Levels (Producers, primary, secondary, tertiary, quarternary) Food webs/food chainsTransfer of Energy (1st and 2nd laws of thermodynamics)Symbiotic relationships (Mutualism,