Date | May 2019 | Marks available | 1 | Reference code | 19M.1.HL.TZ2.23 |
Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
Command term | Identify | Question number | 23 | Adapted from | N/A |
Question
The global carbon cycle involves sinks where carbon is stored, and fluxes where carbon is transferred. What are the largest sink and flux?
Markscheme
C
Examiners report
In Topic 4.3 candidates had to estimate carbon fluxes due to processes in the carbon cycle. Candidates should have known that respiration and combustion return carbon dioxide to the atmosphere while photosynthesis uses this carbon dioxide. The total amount for the carbon dioxide released to the atmosphere is equal or smaller than the carbon dioxide absorbed, therefore eliminating answers A and B. Unfortunately, many capable candidates chose these options, making this question a bad discriminator. The ocean is by far the largest sink.