Across
- 3. In the Phosphorus Cycle, phosphorus moves between the soil and this
- 4. Higher organisms use nitrogen to make this
- 10. This can directly use nitrogen in our atmosphere
- 11. Phosphorus is contained in these
- 13. This effect is caused by too much CO2 in the atmosphere
- 14. Animals use this in the process of respiration to make more CO2
- 15. Animal waste is returned to this
- 16. A source of phosphorus in water comes from this
- 17. Plants use this in photosynthesis to make sugar and oxygen
- 18. Phosphorus in soils can be washed away into these
- 20. Animals and plants cannot directly use all the nitrogen found in this
Down
- 1. Products rich in nitrogen
- 2. The process plants use to make sugar and oxygen
- 5. Too much phosphorus in water leads to this
- 6. Our atmosphere is 78% of this
- 7. This is not found in the free state of nature
- 8. This is the main regulator of CO2 in the atmosphere because CO2 dissolves easily in it
- 9. An important chemical made up of Phosphorus
- 12. This is a natural source for CO2
- 19. These eat plants containing nitrogen