A mutation in the coding DNA of a gene changes one amino acid in an enzyme.
Tests show that the enzyme still works at the same rate as before.
Which statement suggests why?
The changed amino acid did not alter the shape of the active site.
The mutation was in non-coding DNA, so the enzyme was not changed.
The changed amino acid made the active site fit the substrate better.
The mutation switched the gene off, so the old enzyme was still used.
186 exam-style questions on OCR GCSE Biology 5.1 Inheritance, covering 5.1.1 The genome, 5.1.2 Environment and phenotype, 5.1.3 Variants and mutations, 5.1.4 How genetic variants influence phenotype, 5.1.5 Asexual and sexual reproduction, 5.1.6 Haploid and diploid, 5.1.7 Meiotic cell division, 5.1.8 Single gene inheritance, 5.1.9 Predicting single gene crosses, 5.1.10 Sex determination, 5.1.11 Multiple gene inheritance, and 5.1.12 Development of our understanding of genetics. Each one has a worked solution and a mark scheme showing where the marks go.