A-LevelBiologyCell structureOct/Nov 2014Paper 1 Q21 Mark
Which steps are needed to find the actual width of a xylem vessel viewed in transverse section using a ×10 objective lens? 1 Convert from mm to µm by multiplying by 10⁻³. 2 Calibrate the eyepiece graticule using a stage micrometer on ×4 objective lens. 3 Measure the width of the xylem vessel using an eyepiece graticule. 4 Multiply the number of eyepiece graticule units by the calibration of the eyepiece graticule.
A1, 2, 3 and 4
B2, 3 and 4 only
C1 and 2 only
D3 and 4 only
✓ Correct Answer
The correct answer is D. This question tests the candidate's understanding of cell structure within the Biologysyllabus. The examiner's mark scheme requires...
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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...
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