Answer:
The two processes that fuel the carbon cycle are photosynthesis and cellular respiration.
Photosynthesis is the process by which carbon obtained from carbon dioxide (atmosphere) is fixed into the biomass (glucose or food).
This food or carbon content is then passed to animals through the food chain and to fossil fuels through decomposition.
This food or carbon content is then used by cellular respiration which releases carbon dioxide back into the atmosphere.
In addition, the burning of fossil fuels also releases carbon dioxide back into the atmosphere.