Key Concept: Carbon moves through ecosystems by photosynthesis, respiration, decomposition, and combustion.
Section A: Key Processes
1. Describe the role of photosynthesis in the carbon cycle. [2]
2. Describe the role of respiration in the carbon cycle. [2]
3. Describe the role of decomposition in the carbon cycle. [2]
4. Describe the role of combustion in the carbon cycle. [2]
Section B: Sequence
5. Put these stages into a correct sequence for a carbon atom: photosynthesis, feeding, respiration, decomposition. [4]
Total marks: 12
Mark Scheme
1. Removes $CO_2$ from air and fixes it into glucose/biomass [2]
2. Releases $CO_2$ from organisms to the atmosphere [2]
3. Decomposers break down dead material and release $CO_2$ [2]
4. Burning fuels/biomass releases $CO_2$ into the air [2]
5. Photosynthesis -> feeding -> respiration -> decomposition (any logical cycle) [4]