There is generally a fixed number of carbon atoms on earth, which are being recycled, and have been since life began.
Carbon dioxide from the air is taken in by plants for __________ and converted into __________. The plant will use some of this sugar for __________ releasing __________ back into the atmosphere.
The plant could either be eaten by animals, or die and be eaten by decomposers such as microorganisms, fungi or insects. In any case, these organisms __________ returning carbon atoms to the atmosphere.
Animals themeselves will either be eaten by another animal or die and be __________ in the same way.
Alternatively the plant could be burnt producing carbon dioxide through the process of __________