A-LevelBiologyNucleic acids and protein synthesisOct/Nov 2025Paper 2 Q313 Marks
The gene LCT codes for the enzyme lactase. In babies, lactase synthesis is necessary for digesting lactose, the sugar found in milk. Another gene, MCM6, has introns that have a regulatory role in the expression of gene LCT. Gene MCM6 codes for a protein that has no involvement in lactase synthesis. As children get older, the MCM6 introns are responsible for a decrease in lactase synthesis. This decrease in lactase synthesis is known as lactase non-persistence.
📋 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