DP Biology (last assessment 2024)
Question 23M.1.HL.TZ2.16
Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.HL.TZ2.16 |
Level | HL | Paper | 1 | Time zone | TZ2 |
Command term | Question number | 16 | Adapted from | N/A |
16.
[Maximum mark: 1]
23M.1.HL.TZ2.16
How do methanogenic archaeans living in peat bogs obtain energy to survive?
A. They oxidize methane produced by peat to produce carbon dioxide and water.
B. They synthesize methane from carbon dioxide released by decomposing peat.
C. They convert organic compounds in fully decomposed vegetation into methane.
D. They produce methane while converting peat to coal.
[1]
Markscheme
B
Examiners report
Comments that methanogenesis is not included in the guide are invalid as the process is included in 4.3 which states that methane is produced from organic matter in anaerobic conditions by methanogenic archaeans. This question was difficult for the students and discriminated badly as many of the stronger students opted for the incorrect response C.