O-LevelBiologyRespiration5090/12 · May/June 2020 · Q261 Mark

The diagram shows some apparatus set up to produce alcohol by fermentation. [Figure 26.1] What is the purpose of the oil layer?

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Ato keep the alcohol in the solution

Bto prevent aerobic respiration

Cto produce carbon dioxide

Dto provide nutrients for the yeast

✓ Correct answer

B: to prevent aerobic respiration

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Topic: Respiration, O-Level Biology (syllabus 5090). Multiple choice, 1 mark.
Source: O-Level Biology, May/June 2020 Paper 1 Variant 2, question 26.

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