STUDY GUIDE FOR BIOLOGY CHAPTER 2 ECOLOGY What does ecology study? Know biotic factors vs. abiotic factors. Know examples of autotrophs. Terms to know: Biological community, biogeochemical cycle, nutrients, biome, population, ecosystem, habitat, commensalism, competition, parasitism, mutualism, predation, nitrogen fixation (what does the fixing?) What is a waste product of photosynthesis (good thing for us)? Be able to compare and contrast: carnivore, detritivore, herbivore, and omnivore Why do ecologists use models? What substance is formed from decomposing matter? Make sure you understand the three pyramids.