1. (4 Points) In a sample of 500 tiger lilies, 3 genotypes occurred in the following numbers. Calculate
a) the genotypic, and b) the allelic frequencies. Show your work, i.e., show how you got your answer.
Genotype AA Aa aa
Numbers 320 90 90
a) Correct way to calculate Genotypic frequencies (2 points):
b) Correct way to calculate Allelic frequencies (2 points):
2. (3 points) In a large population of ruby-throated hummingbirds, it was observed that the frequency of allele H was 0.4 and the frequency of allele h was 0.6. Calculate the expected genotype frequencies if the population is in Hardy-Weinberg equilibrium. Show your work, i.e., show how you got your answer.
3. (7 points) In a sample of 100 Hawaiians, it was found that 35, 20, and 45 individuals had blood groups MM, MN, and NN, respectively. Calculate a) the allelic frequencies (2 points), and b) the expected Hardy-Weinberg genotypic frequencies, showing your work (2 points). c) How many individuals of each genotype are expected to occur in a population of 100 individuals if the population is in Hardy-Weinberg equilibrium (1 point)? d) Is this population in Hardy-Weinberg equilibrium? Explain why or why not (2 points).
a) Allelic frequencies (2 points):
b) Expected genotypic frequencies if the population is in H-W equilibrium (2 points):
c) Expected number of individuals of each genotype in a population of 100 individuals if the population is in H-W equilibrium (1 point):
d) Is the population in H-W equilibrium? Explain why or why not (2 points, assume statistical significance of your results) (2 points).
4. (5 points) In Lop-eared rabbits, about 1 in 1000 has curly hair rather than straight hair; curly hair is due to a recessive gene. a) What is the proportion of curly alleles in the population (2 points)? b) What are the frequencies of individuals with homozygous straight hair, heterozygous straight hair, and curly hair in this population (3 points)? Show your work and assume that you know that the population is in Hardy-Weinberg equilibrium.
a) Proportion of recessive alleles, giving p and q; explain your answer (2 points):
b) Frequencies of individuals with homozygous straight hair (SS), heterozygous straight hair (Ss), and homozygous curly hair; explain your answer (2 points):
5. (6 points) In a population of bark beetles in Minnesota, the following genotypes are observed:
AA (feeds under bark) = 0.60, Aa (feeds on top of bark) = 0.10, aa (feeds on leaves) = 0.30
a) What are the allelic frequencies (1 point) and expected genotypic frequencies (1 point)? Show your work (1 point). b) Explain whether or not the population is in H-W equilibrium (1 point) (NOTE: You do not need to analyze this statistically. Make a judgment based on the proportions). c) List several (at least 2) biologically valid reasons for why the observed population may or may not be in equilibrium (2 points).
a) Allelic frequencies (1 point), expected genotypic frequencies (1 point); show your work (1 point):
Allelic frequencies:
Expected genotypic frequencies:
b) Explain whether the population is in H-W equilibrium (1 point):
c) Give at least two biologically valid reasons for why the observed population may or may not be (indicate which) in equilibrium (2 points):
