Carbon Cycle
Living things are made up of carbon. Carbon is found naturally in the atmosphere, rocks, fossil fuels and dead organic matter.
Carbon enters the atmosphere as carbon dioxide during combustion of fossil fuels and respiration by living things. Carbon dioxide in the atmosphere is absorbed by plants during photosynthesis to make sugars. The carbon becomes part of the plants. Animals feed on the plants, passing the carbon compounds along the food chain. Some of the carbon in the animals and plants is exhaled as carbon dioxide during respiration.