*Energy flow (food chains & food webs, producers vs. consumers)*Biotic vs. abiotic factors*Symbioses (commensalism, mutualism, parasitism, competition, predation)*Cycling of Matter (carbon, nitrogen)*Biomes (desert, rain forest, ocean, coniferous forest, deciduous forest, grassland, tundra)*Changes in the environment & their effects (oil spills, water pollution, climate change, loss of species, introduced species)*Survivability of populations*Ecosystem equilibrium*Biodiversity*Interaction of ecosystems and impact on global environment