Flashcards for AQA A Level Biology Alteration of the sequence of bases in DNA can alter the structure of proteins (A-level only), covering the key terms, definitions and processes you need to recall for Paper 1, Paper 2 and Paper 3. 33 cards drawn from Alteration of the sequence of bases in DNA can alter the structure of proteins (A-level only), matched to the AQA A Level Biology (7402) specification.