Skip to main content
A-LevelBiologyCell structureFeb/Mar 2018Paper 1 Q21 Mark

A student was asked to use the scale bar shown to calculate the magnification of a cell on a photomicrograph. [Figure showing a scale bar: 2 μm] Which method could the student use to calculate the magnification of the cell?

Adivide the diameter of the cell by the length of the scale bar, both measured in the same units of length
Bmeasure the diameter of the cell in millimetres, multiply by 2000 and divide by the length of the scale bar measured in millimetres
Cmeasure the length of the scale bar in millimetres, convert to micrometres and divide by 2
Dmeasure the length of the scale bar in millimetres, convert to micrometres and multiply by 2

✓ Correct Answer

The correct answer is C: measure the length of the scale bar in millimetres, convert to micrometres and divide by 2

📋 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.

🔒

Unlock the Examiner's Analysis

Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.

Sign Up Free to Unlock →

Join thousands of Cambridge students already using Oracle Prep

About This A-Level Biology Question

Topic

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

Source

This question appeared in the Cambridge A-Level Biology Feb/Mar 2018 examination, Paper 1 Variant 2.

Practice on Oracle Prep

Oracle Prep provides AI-powered practice for all Cambridge O-Level and A-Level subjects. Our platform includes topic predictions with 87.7% accuracy, AI essay grading, and a comprehensive question bank spanning 25 years of past papers across 29 subjects.

Related Biology Questions

© 2026 Oracle Prep — The AI-Powered Cambridge Exam Engine