QUESTIONS+on+CYCLES

__**ANSWER the questions following each picture (-do not need to write out question-you may just list the Figure and the # of the question) Review the animations again as needed:**__

1. Explain how decomposers supply phosphorous to soil, groundwater, oceans, lakes, ponds and rivers. 2. Compare to the other cycles you viewed- what part of the environment does NOT include P going through it as all the others do? 3. Name 2 essential molecules found in living things that P is needed for.
 * FIGURE 1: Phosphorus Cycle**

4.What is the role of photosynthesis in the carbon cycle? 5. What process puts C back into the atmosphere and what form is it in? 6. How does C get into animals?
 * Figure 2: Carbon Cycle**

7.Which process returns nitrogen to the food web from the atmosphere? 8. Which organisms(general group) are key players in the processing of N throughout the cycle? 9. What form must N be in for plants to be able to use it? 10. What kind of plants have an important mutual relationship that involves them in this cycle?
 * Figure 3: Nitrogen Cycle **

11. To other animals, this was a source of energy. How might __plants__ have used it to survive? 12. How might the water in this animal continue to cycle through the ecosystem? 13. EXTRA: What mineral will rodents obtain from this skull?
 * Figure 4**

14. Explain how the O2 and CO2 cycles are related. 15. What is the role of transpiration? 16. Which molecules/elements are placed into the atmosphere by combustion?
 * Figure 5: Oxygen/Carbon Dioxide/Water cycles **

**Figure 6: Sulfur Cycle** 17. What pollutant involves sulfur as a component? (see animation for help) 18. How does sulfur get cycled back to the atmosphere from soil and ocean sediments?

19. Which cycles involve bacteria? 20. Why are these called biogeochemical cycles? 21. How do these cycles demonstrate the biological principle of homeostasis?
 * General: **