Across
- 2. involving or requiring free oxygen.
- 4. using up a resource.
- 9. colourless unstable toxic gas formed from oxygen.
- 12. permeation of a liquid into something by filtration.
- 13. fuel a natural fuel such as coal or gas.
- 14. process of oxidizing or being oxidized.
- 16. the action or process of precipitating a substance from a solution.
- 17. the draining away of water from the surface of an area of land
- 19. fixing they contain symbiotic bacteria called rhizobia within nodules in their root systems
Down
- 1. person or thing eating something else.
- 2. not derived from living organisms.
- 3. organism that decomposes organic material.
- 5. when a plant absorbs water in its roots
- 6. cycle the process by which oxygen released into the atmosphere by photosynthetic organisms
- 7. process of burning something.
- 8. process of turning from liquid to vapor.
- 10. rain made sufficiently by acid from the atmosphere.
- 11. total mass of organism in a given area or volume
- 15. a large natural or artificial lake used as a source of water supply.
- 18. a leguminous plant.