APES Miller 17th ed. Chapter 3 Questions Ecosystems: What are they and how do they work? 1. What are the 3 reasons we should care about tropical rain forests? 2. Identify and write out the 2 chemical equations used by autotrophs and heterotrophs to gain energy for chemical functions. 3. Use the dead tree in Fig 3-10 to describe the processes of detritus feeders and decomposers. 4. What are the chemical outputs of anaerobic respiration and fermentation? 5. Use the laws of thermodynamics to describe the flow arrows in Fig 3-11 and explain why these flows are one way. Describe where you think the heat goes? 6. Use Fig 3-15 of NPP by ecosystem to explain why some systems are more productive than other systems. (Hint: Which of these systems have the most interaction of the 4 spheres of Earth life support?) 7. Water expands as it freezes. Explain why this is important to aquatic life. (See Science Focus). 8. Rank the 5 human impacts on the carbon cycle. Explain why your top pick needs to be addressed first. 9. Describe how bacteria change the chemical form of N in each step of the nitrogen cycle: nitrogen fixation, nitrification, ammonification, and denitrification. How does N move through the spheres? 10. What are the 5 ways we interfere with the nitrogen cycle? 11. Describe ways S enters the atmosphere? In what forms? Describe 3 ways we affect the S cycle?