Question

Carbon dioxide enters the atmosphere mainly from the decay of vegetation, but it also comes from volcanic eruptions, the exhalations of animal life, from the burning of fossil fuels (such as coal, oil, and natural gas), and from

Answer 1

And also from decomposition of organisms.

When organisms die, decomposers such as bacteria digest on the dead organism. As bacteria also requires respiration for energy, they release carbon dioxide as well, just like other animals.

Therefore, the decomposition of dead organisms also produces carbon dioxide into the atmosphere, which is an important process in the carbon cycle.