Carbon is released into the atmosphere only during the burning of fossil fuels
Explanation:
During the process of fuel burning, carbon is released in the atmosphere. The human invented power plants, factories, cars and other vehicles releases carbon in the form of carbon di-oxide in atmosphere.
However, the cellular respiration is similar to that of fuel burning as it is too a combustion process. But the carbon produced in this process fuels the inner cellular activities rather than releasing it in the atmosphere.
The oldest layers are on the bottom thats why they are the oldest. Super position is what it is called if thats what your asking.
The answer will be Phosphate groups, adenosine purine base.
