Nutrient Cycle
Across
- 2. Too much CO2 in the atmosphere can cause the _____ effect
- 6. This is essential to life on earth
- 10. Animal _____ is returned to the soil in a part of the nitrogen cycle
- 12. The water cycle consists of precipitation, evaporation, and this
- 13. volcanic eruptions, rock formations, and plate tectonics
- 15. the process by which plants use CO2 to make sugar and oxygen
- 18. Our ____ is 78% nitrogen gas
- 19. Phosphorus makes up this important chemical
Down
- 1. nutrient whose supply limits productivity
- 3. activities performed by living organisms
- 4. Animals in plants use this found in the atmosphere
- 5. ____ is found in rocks and minerals
- 7. chemical substances that an organism needs to sustain life
- 8. This can run off into water ways
- 9. The water cycle is powered by the ____
- 11. formation of clouds, lightning, flow of water
- 14. This is another source of CO2
- 15. Higher organisms use nitrogen to make their _____
- 16. Decayed plants and animals can be burned as fossils fuels to make ____, coal, and natural gas
- 17. mining and burning of fossil fuels, clearing of land, and use of fertilizer