CIE iGCSE Co-Ordinated Science B18.3 Carbon cycle Exam Style Questions Paper 1
Question
What does not contribute to the carbon cycle?
A. combustion
B. deforestation
C. transpiration
D. photosynthesis
▶️Answer/Explanation
Answer: C
Explanation: Transpiration is the process by which water is lost from plants through evaporation and does not directly involve the carbon cycle. Combustion, deforestation, and photosynthesis all play roles in the carbon cycle.
Question
The diagram shows a simplified carbon cycle.
Which labelled arrow represents respiration?
A) CO2 → green plants
B) green plants → animals
C) animals → CO2
D) fossil fuels → CO2
▶Answer/Explanation
Answer: C
Explanation: Respiration in animals releases carbon dioxide (CO2) into the atmosphere. Therefore, the arrow from animals to CO2 represents respiration.
Question
The diagram shows part of the carbon cycle.
What are processes X, Y and Z?
▶️Answer/Explanation
Ans :C
Question
The diagram shows part of the carbon cycle.
Which arrow represents plant respiration?
▶️Answer/Explanation
Ans : B
Question
A student draws four different attempts at part of the carbon cycle.
Which diagram is correct?
▶️Answer/Explanation
Ans : A
Question
The graph shows the change in atmospheric carbon dioxide levels over time.
A reduction of which process could cause the change in carbon dioxide shown?
(A) combustion
(B) decomposition
(C) photosynthesis
(D) respiration
▶️Answer/Explanation
Ans : C
Question
Which process is not part of the carbon cycle?
(A) combustion
(B) fossilisation
(C) transpiration
(D) photosynthesis
▶Answer/Explanation
Ans : C
Question
The diagram shows gas exchange by two groups of organisms during the hours of darkness.
Which letters represent gases that are part of the carbon cycle?
(A) P and Q (B) P and R (C) P and S (D) Q and S
▶️Answer/Explanation
Ans: B
Question
The diagram shows part of the carbon cycle.
Which process does X represent?
(A) combustion
(B) decomposition
(C) photosynthesis
(D) respiration
▶️Answer/Explanation
Ans: C
Question
In the carbon cycle, which process decreases the level of carbon dioxide in the atmosphere?
A. combustion
B. decomposition
C. photosynthesis
D. respiration
▶️Answer/Explanation
Answer: C
Explanation: Photosynthesis is the process by which plants and other photosynthetic organisms convert carbon dioxide from the atmosphere into organic compounds, such as glucose. This process reduces the level of carbon dioxide in the atmosphere.