Carbon is constantly cycled around the biosphere through processes like combustion, respiration, and being stored in marine organisms and limestone rocks. Combustion and respiration both release carbon dioxide gas. While both animals and plants respire, only respiration releases carbon dioxide. Scientists think increased carbon dioxide in the atmosphere from human activities will cause global warming.

1. To understand how carbon is constantly cycled around

4. True or false?

5. True

6. False – combustion releases carbon dioxide gas

7. False – more is found in marine organisms and limestone rock deposits

8. True

9. False – both animals and plants respire

10. False – they respire and release carbon dioxide

11. True

12. False – scientists think it will cause global warming

13. True

14. True