A-LevelBiologyBiodiversity and conservationOct/Nov 2015Paper 1 Q401 Mark
Anaerobic bacteria are found in large numbers in waterlogged soils. Which effect does this have on soil fertility and why?
Adecreased bacteria convert nitrate to ammonia
Bdecreased bacteria convert nitrate to nitrogen gas
Cincreased bacteria cause decomposition
Dincreased bacteria cause nitrogen fixation
✓ Correct Answer
The correct answer is B: decreased bacteria convert nitrate to nitrogen gas
📋 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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