Part A
In humans, individuals may or may not have a widowâs peak. This trait is controlled by genes at a single locus, with the allele for having a widowâs peak dominant to the allele for not having one. A population of humans is sampled; 59 have a widowâs peak and 44 do not. 25 of the people with a widowâs peak are homozygous dominant. What are the frequencies of the dominant and recessive alleles observed in this sample?
p = _____
q = _____
Part B
In a species of corn, individuals have either narrow or wide corn cobs. This trait is controlled by genes at a single locus, with the narrow cob allele dominant to the wide cob allele. A farmer counts 74 narrow cob and 113 wide cob plants in a field. Of the narrow cob plants, 28 are homozygous dominant. What are the frequencies of the dominant and recessive alleles observed in this sample?
p = _____
q = _____
Part C
In a population of peas, the frequency of the dominant allele for a purple flower is 0.61 and the frequency of the recessive allele for a white flower is 0.39. What would the genotypic frequencies be if the population is in equilibrium?
_____ = Frequency of homozygous dominant individuals
_____ = Frequency of heterozygous individuals
_____ = Frequency of homozygous recessive individuals
How many individuals would you expect of each genotype in a population of 500 peas?
_____ = Number of homozygous dominant individuals
_____ = Number of heterozygous individuals
_____ = Number of homozygous recessive individuals
Part D
In mice, a mahogany coat color allele is dominant over the tan coat color allele. In a population of mice, the frequency of the allele for mahogany coat color is 0.19 and the frequency of the allele for tan coat color is 0.81. What would the genotypic frequencies be if the population is in equilibrium?
_____ = Frequency of homozygous dominant individuals
_____ = Frequency of heterozygous individuals
_____ = Frequency of homozygous recessive individuals
How many individuals would you expect of each genotype in a population of 100 mice?
_____ = Number of homozygous dominant individuals
_____ = Number of heterozygous individuals
_____ = Number of homozygous recessive individuals
Part E
In humans, the free earlobe allele is dominant over the attached ear lobe allele. In a population of humans, the frequency of the allele for free earlobes is 0.42 and the frequency of the allele for attached earlobes is 0.58. What would the genotypic frequencies be if the population is in equilibrium?
_____ = Frequency of homozygous dominant individuals
_____ = Frequency of heterozygous individuals
_____ = Frequency of homozygous recessive individuals
How many individuals would you expect of each genotype in a population of 25 humans?
_____ = Number of homozygous dominant individuals
_____ = Number of heterozygous individuals
_____ = Number of homozygous recessive individuals
