Date | May 2021 | Marks available | 1 | Reference code | 21M.1.HL.TZ2.31 |
Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
Command term | Question number | 31 | Adapted from | N/A |
Question
The Hill reaction occurs when isolated chloroplasts are exposed to sunlight in the presence of DCPIP. DCPIP replaces NADP as the final electron acceptor for the light-dependent reactions of photosynthesis. What are products of the Hill reaction?
A. H2O and ATP
B. ATP and CO2
C. O2 and ATP
D. C6H12O6 and O2
Markscheme
C
Examiners report
Some G2 responses mentioned that the Hill reaction does not appear in the Understandings in the guide, only in the Aims in the right-hand column in Section 8.3 (Photosynthesis). It was assumed most teachers would have mentioned the Hill reaction when covering this part of the guide, and for those who were unfamiliar with the name Hill the question included an explanation of the reaction. Statistically, the question performed well.