In a breed of dogs 1 pup in 900 is born albino. Albinism is due to a recessive g
ID: 64484 • Letter: I
Question
In a breed of dogs 1 pup in 900 is born albino. Albinism is due to a recessive gene at a coat pigment locus. Assume that the population is in Hardy-Weinberg equilibrium. a) What is the frequency of albino alleles in the population? Show your work and circle your final answer. b) What is the expected frequency of individuals with two normal alleles? Show your work and circle your final answer.. c) What is the expected frequency of individuals that are heterozygotes at this locus? Show your work and circle your final answer..
Explanation / Answer
The incidence of albino pups = 1 in 900.
Frequency of albino allele is calculated as follows:
No. of homozygous recessive alleles = 2 in 1800 (900 × 2 alleles = 1800 alleles)
The frequency of recessive allele is 0.033
The expected frequency of individuals with two normal alleles is frequency of p2
Since q = 0.033, p = 1-q (since the population is in Hardy-Weinberg equilibrium)
P = 1 – 0.033 = 0.967
Frequency of individuals with two normal alleles is homozygous dominant alleles = p2 = (0.967)2 = 0.935
The frequency of heterozygotes = 2pq = 2 × 0.033 × 0.967 = 0.064