11 The carbon cycle

Carbon dioxide is removed from the environment by green plants and algae during photosynthesis

The carbon from the carbon dioxide is used to make carbohydrates, fats and proteins, which make up the body of plants and algae

When green plants and algae respire, some of this carbon becomes carbon dioxide and is released into the atmosphere

When green plants and algae are eaten by animals and these animals are eaten by other animals, some of the carbon becomes part of the fats and proteins that make up their bodies

When animals respire, some of this carbon becomes carbon dioxide and is released into the atmosphere

When plants, algae and animals die, some animals and micro organisms feed on their bodies

Carbon is released into the atmosphere as carbon dioxide when microorganisms respire

By the time the microorganisms and detritus feeders have broken down the waste products and dead bodies of the organisms in ecosystems and cycled the materials and plant nutrients, all the energy originally absorbed by green plants and algae has been transferred

Combustion of wood and fossil fuels releases carbon dioxide into the atmosphere