Across
- 5. A type of rock that contains carbon.
- 9. When water evaporates, it ends up here.
- 11. Process that occurs in plants that transforms carbon dioxide and water into glucose and oxygen.
- 12. 78% by volume of Earth’s atmosphere is made up of ______ gas.
- 14. What human activity is most known for causing an imbalance in the nitrogen cycle by increasing the levels of nitrogen drastically?
- 17. this is the biological oxidation of ammonium slats to nitrites and the further oxidation of nitrites to nitrates.
- 19. When this substance is burned, it makes carbon enter the Earth's atmosphere as CO2, therefore supporting the progression of global warming.
- 20. Examples of biogeochemical ______ are oceans, the atmosphere, plants, animals and soil.
Down
- 1. The ______ of the Earth is estimated to replace 90% of all used oxygen.
- 2. This is a type of fertilizer that causes damage to the environment (notably bodies of water).
- 3. What is the consequence of nitrogen pollution (excess nitrogen) in a lake or stream.
- 4. Weathering and erosion of rocks gradually releases this element and an ion which is soluble in water.
- 6. What is the process where the originally bound nitrogen of microbial, plant and animal remains is recycled after their death.
- 7. What cycle is a set of processes where an element passes from one environment to the next and eventually returns to its original environment.
- 8. This element plays a part in every biogeochemical cycle.
- 10. ______ activity returns carbon into the atmosphere after having been trapped in rocks.
- 13. The nitrogen cycle is important because nitrogen plays a part in DNA, ______ and chlorophyll in plants.
- 15. All forms of life are based on this element.
- 16. What is the layer around the world that contains all living organisms?
- 18. What are organisms such as insects, fungi and bacteria that convert CO2 into carbon called?