Nutrient cycles
Across
- 3. Performed by a living organism
- 4. Formation of clouds, lightning, flow of water
- 6. Chemical substances an organisms needs to live
- 11. Large deposits of CO2 are burned to make these
- 13. a type of bacteria that makes it so animals can use nitrogen
- 15. An effect caused by too much CO2 in the air
- 18. Animals use carbon dioxide in this process
- 19. Occurs when acidic water falls to the ground
- 20. main deposit of phosphorus
Down
- 1. An important chemical that makes up DNA
- 2. using fossil fuels, clearing land, fertilizers
- 5. Amount of living tissue within a trophic level
- 7. Volcanic eruptions, plate tectonics, etc.
- 8. basins collect the phosphorus in the soil
- 9. The main regulator of carbon dioxide
- 10. The percent of nitrogen in the atmosphere
- 12. Caused by too much phosphorus in the water
- 14. mixture of floating algae
- 16. used in the process of photosynthesis
- 17. A smaller source of carbon dioxide