O-LevelBiologyRespiration5090/11 · Oct/Nov 2010 · Q71 Mark

A freshly picked leaf is placed in a sealed test-tube with some hydrogen carbonate indicator solution. The tube is kept in the light during the day. The indicator changes colour as shown. [Diagram with table] Which colour will the hydrogen carbonate indicator be at midday and at midnight?

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Apurple yellow

Bred purple

Cyellow purple

Dyellow red

✓ Correct answer

A: purple yellow

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Topic: Respiration, O-Level Biology (syllabus 5090). Multiple choice, 1 mark.
Source: O-Level Biology, Oct/Nov 2010 Paper 1 Variant 1, question 7.

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