Q. Which of the following ways carbon is added to atmosphere in carbon biogeochemical cycle?
1. Respiration
2. Decomposition
3. Photosynthesis
Select the correct answer using the code given below:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: B

Carbon is present in the atmosphere, mainly in the form of carbon dioxide (CO2). Carbon cycle involves a continuous exchange of carbon between the atmosphere and organisms.  

  • Carbon from the atmosphere moves to green plants by the process of photosynthesis, and then to animals.  
  • By process of respiration and decomposition of dead organic matter it returns back to atmosphere. It is usually a short-term cycle. 

Source: NCERT