Across
- 2. main constituent of the environment
- 4. introducing harmful materials into the environment
- 6. dense forest rich in biodiversity with heavy rainfall
- 7. a very large expanse of sea
- 9. occurs when a species population exceeds
- 10. found on land
- 11. protective gas layer from sun's UV-B radiation
- 12. found in sea
Down
- 1. derived of living matter
- 3. thin layer of gases covering the earth
- 5. process by which plants synthesize food from co2 and water
- 8. Plants grow in this