Question

Explain the carbon cycle or biogeochemical cycle.

Answer 1

The carbon cycle is a biogeochemical cycle by which carbon is exchanged among the biosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone.

Steps in the carbon cycle:

1. Carbon enters the atmosphere as CO₂ from respiration and combustion.
2. CO₂ is absorbed by producers to make carbohydrates in photosynthesis.
3. Animals feed on the plant passing the carbon compounds along the food chain. Most of the carbon they consume is exhaled as CO₂, formed during respiration. The animals and plants eventually die.
4. The dead organisms are eaten by decomposers and the carbon in their bodies is returned to the atmosphere as CO₂. The plant and animal material may then be available as fossil fuels in the future for combustion.