Phenylketonuria (PKU) is an inherited metabolic disorder caused by a mutation in the PAH gene. For the PAH gene, approximately one allele in every 70 in a certain population is the mutated PKU allele. Explain why only one person in 4900 in this population is born with PKU.
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.