A-LevelBiologyBiological moleculesOct/Nov 2022Paper 1 Q61 Mark

The table shows the observations recorded from tests for biological molecules on four samples, A, B, C and D. Which conclusion is correct?

Q: What topic does this question test?

This question tests Biological molecules in A-Level Biology (syllabus code 9700). It is worth 1 mark.

ABenedict's solution: blue, biuret reagent: blue, iodine solution: blue-black, conclusion: contains starch only

BBenedict's solution: blue, biuret reagent: purple, iodine solution: orange, conclusion: contains reducing sugar only

CBenedict's solution: green, biuret reagent: blue, iodine solution: orange, conclusion: contains reducing sugar and protein

DBenedict's solution: red, biuret reagent: blue, iodine solution: blue-black, conclusion: contains starch and protein

✓ Correct Answer

The correct answer is A: Benedict's solution: blue, biuret reagent: blue, iodine solution: blue-black, conclusion: contains starch only

📋 Examiner Report & Trap Analysis

Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...

🎯 Mark Scheme Breakdown

Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.

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About This A-Level Biology Question

Topic

This multiple-choice question tests Biological molecules in A-Level Biology (syllabus code 9700). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Biology Oct/Nov 2022 examination, Paper 1 Variant 2.

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