Question

Explain the carbon cycle with the help of a simplified model.

Answer 1

Photosynthesis and respiration are key processes involved in carbon cycle.

In photosynthesis, carbon-dioxide and water produce carbohydrate and oxygen while respiration oxidizes food to give carbon-dioxide and water. In oceans, carbon-dioxide dissolves readily in water. In rock it gets stored as calcium carbonate. Carbon can either be liberated to atmosphere through respiration or can be passed to animal when being eaten or remain in plant even after death. After death of plant or animal, decomposition takes place and carbon dioxide gets released into the atmosphere. They can also be buried inside the earth and converted to coal or natural gas. Natural gas and coal are fuels and on combustion they release carbon dioxide back into the atmosphere. Excess of carbon-dioxide can cause global warming.