Huntington's disease is an inherited neurodegenerative disorder caused by a dominant allele.
Arrange the terms DNA nucleotide, gene, and chromosome in order of size, starting with the largest.
Approximately 1 in 12,000 people in a certain population have Huntington's disease. In a city with a population of 1,800,000, calculate how many people are expected to have Huntington's disease.
A man who is heterozygous for Huntington's disease (Hh\text{Hh}Hh) and a woman who is also heterozygous (Hh\text{Hh}Hh) are expecting a baby. State the probability that their baby will inherit Huntington's disease.
97 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.