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.