A mutation changes one base in a gene that codes for an enzyme. What is the most likely effect of this mutation on the enzyme?
The active site changes shape, so the substrate no longer fits into it
The active site changes shape, so the substrate fits into it more tightly
The enzyme is denatured, because the temperature inside the cell has risen
There is no effect on the enzyme, because most mutations do not alter the phenotype
76 exam-style questions on AQA GCSE Biology 6.1 Reproduction, covering 6.1.1 Sexual and asexual reproduction, 6.1.2 Meiosis, 6.1.3 Advantages and disadvantages of sexual and asexual reproduction, 6.1.4 DNA and the genome, 6.1.5 DNA structure, 6.1.6 Genetic inheritance, 6.1.7 Inherited disorders, and 6.1.8 Sex determination. Each one has a worked solution and a mark scheme showing where the marks go.