CIE iGCSE Co-Ordinated Science B18.3 Carbon cycle Exam Style Questions Paper 2
Question
The diagram shows part of the carbon cycle.
Which process, due to human activities, has increased the concentration of carbon dioxide in the atmosphere?
▶️Answer/Explanation
Ans: D
Question
The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration?
▶️Answer/Explanation
Answer: C
Explanation: Respiration is the process by which animals release carbon dioxide (CO₂) into the atmosphere. Therefore, the arrow labelled “animals” represents respiration in the carbon cycle.
Question
The diagram shows some of the processes in the carbon cycle.
Which process is respiration?
▶️Answer/Explanation
Answer: C
Explanation: Respiration is the process where organisms release carbon dioxide into the atmosphere. Option C shows animals producing carbon dioxide, which is the result of respiration.
Question
The diagram shows the carbon cycle. Which process represents decomposition?
▶️Answer/Explanation
Answer: C
Explanation: Decomposition is the process where dead organisms are broken down by decomposers, returning carbon to the soil and atmosphere. In the diagram, this is represented by the process labeled C.