BIO -- carbon cycle (20 marks)

Removal of CO2 from air:
1.producers:remove CO2 from air and fix it as carbohydrates to proteins and fats
2.consumers: they digest the organic compounds of plant tissues and change them into animal tissue
3.fossil fuels: they are lLOCKED-UP carbon

Return of CO2 to air:
1.producer and consumer :carry out respiration
2.Decomposor : break down the dead organisms and release CO2 to air
3. combustion

sunlight: provide energy for photosynthesis

2007-06-21 11:32:21 補充：
Source: Basic Principles in Biology book1

All things in the carbon cycle are important.
I think the most important are the producer and the decomposer.
Producers,mainly plant and algae, chang carbon dioxide to organic substance such as
cardohydrates.
Decomposers include bacteria and fungi change the organic materials back to crabon dioxide.