1. Hardy-Weinberg Worksheet

2. A population consists of 9% white sheep and 91% black sheep
A population consists of 9% white sheep and 91% black sheep. What is the frequency of the black-wool allele if the black-wool allele is dominant and the white-wool allele is recessive? Calculate your answer to the nearest tenth.
q = 0.09 white sheep (homozygous recessives)
p2 + 2pq = 0.91 black sheep (homozygous dominants and heterozygotes)
Calculate the square root of 0.09 ….0.3 or 30%
p = 1-q = 0.7

3. Calculate the percentage of the M allele to the nearest whole number.
A blood group consists of two alleles, M and N. The following data were obtained for a population:
Calculate the percentage of the M allele to the nearest whole number.
Blood Types
Number of Individuals M
169 MN
182 N 49

4. Add all individuals to find population size: 169 + 182 + 49 = 400
Blood Types
Number of Individuals M
169 MN
182 N 49
Add all individuals to find population size: = 400
p2 = 169/400 = ; p = 0.65

5. In a certain population of birds, the allele for a crown on the head (C) is dominant to the allele for no crown on the head (c). A particularly cold an d long winter favored the birds with no crown. When spring came, researchers determined that the population was currently in Hardy-Weinberg equilibrium and that the occurance of the birds with no crown was up to 24%. What will the frequency of the no-crown allele be in 10 years? Give your answer to the nearest hundredth.
0.49
24% = q2 therefore q=0.489

6. A population of butterflies found in Madagascar is polymorphic
A population of butterflies found in Madagascar is polymorphic. There are two varieties of the coloring. The trait for a yellow stripe on the wing is dominant over having no stripe. In recent years the island was struck by several powerful storms and the butterfly population was drastically reduced. Now the population is in Hardy-Weinberg equilibrium, and the trait for having no stripe on the wing is 21% of the population. What will the frequency of the allele for no stripe be next year?
0.46
0.21 = q2 therefore q=0.46

7. A population in Hardy-Weinberg equilibrium consists of 300 sheep, some black and some white. If the allele frequency for the recessive allele is 0.3, how many black sheep are there in the population?
Given that q=0.3 and p + q = 1, then p=0.7
The frequency of white individuals is q2 = (0.3)2 = 0.09
The frequency of black individuals must be = 0.91 = p2 + 2pq
0.91 x 300 sheep = 273 sheep.

8. AP exam 1989
Calculate, showing all work, the frequencies of the alleles and the frequencies of the genotypes in a population of 100,000 rabbits of which 25,000 are white and 75,000 are agouti. (In rabbits the white color is due to a recessive allele, w, and the agouti is due to a dominant allele, W.)

9. q2 = 25,000/100,000 = 0.25 therefore q=0.5
Since p + q = 1, p also equals 0.5
Homozygous dominant p2 = 0.25;
Homozygous recessive q2 = 0.25
Heterozygous dominant 2pq = 0.5

10. 2008 B Exam
For a particular genetic locus of a population, the frequency of the recessive allele (a) is 0.4 and the frequency of the dominant allele is What is the frequency of each genotype (AA, Aa, aa) in this population? What is the frequency of dominant phenotype?