The domestic cat, $Felis\ catus$, is a widely kept pet. In $F.\ catus$, fur length is controlled by two alleles, H and h: • the allele for short hair, H, is dominant • the allele for long hair, h, is recessive. A survey of the domestic cat population in a city found: • there were 15000 cats in the population • 6.8% of these cats had long hair. Calculate the percentage of cats in the city that were heterozygous for hair length. Use the Hardy-Weinberg equations in your calculation: $p + q = 1$ $p^{2} + 2pq + q^{2} = 1$ Show your working.
State two reasons why the domestic cat population does not satisfy the conditions required to use the Hardy-Weinberg principle.
A small domestic-cat population, including some tailless individuals, was introduced to an island named the Isle of Man in the 1700s. After several generations, and without artificial selection by humans, a large proportion of the population was tailless. Suggest why the tailless phenotype became common in the small cat population on the Isle of Man.
Cheetahs, $\textit{Acinonyx jubatus}$, are predatory mammals. Their fur has evolved black spots, which act as camouflage in their habitats. Describe how the spotted fur phenotype of $A.\;jubatus$ may have evolved through natural selection from a non-spotted ancestor.