A-LevelBiologySelection and evolutionFeb/Mar 2020Paper 4 Q411 Marks
The rainbow trout, Oncorhynchus mykiss, is a fish that is bred in commercial fish farms. Rainbow trout that have a blue-silver colour are sold at a higher price than rainbow trout that have a brown colour. The number of fish with each of the different colours was recorded in a breeding population in one fish farm. • population total = 2936 • number of blue-silver fish = 1437 • number of brown fish = 1499
📋 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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