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What is the expected value of H (heterozygosity) in a population for a locus with two alleles, if one allele has a frequency of:
0.9? _________
0.5? _________
0.1? _________
What is the value of pi for a population of 1000 haploid individuals consisting of 500 individuals with sequence 1 and 500 with sequence 2, below.
AGTACTCAGC AGCTCTAGCG CTATCGCATC TAGACGCTCA GCTACCTGCA
AGTACTCACC AGCTCCAGCG CTACCGCATC TTGACGCTGA GCTACCTGCA
a. For 3 loci each with two alleles, how many haploid genotypes are possible?
b. How many diploid genotypes are possible?
c. You cross an ABC haploid genotype with an abc haploid genotype and obtain 25 each of the following haploid progeny: ABC, ABc, abC, abc
What can you say about linkage between A, B, and C loci?
Are A and B loci in linkage equilibrium with each other?
Are A and C loci in linkage equilibrium with each other?
d. How does your interpretation differ if you obtain 20 each of the above 4 genotypes and 5 each of AbC, Abc, aBC, aBc?
Are A and B loci in linkage equilibrium with each other?
Are A and C loci in linkage equilibrium with each other?
. In a bacterial population of 10,000,000 cells, two alleles, A and a, are present at a locus, at a frequency of 0.5 each. At another locus, all cells have genotype B until a mutation (Bïƒ* b) occurs, giving one copy of b. This mutation occurs in an individual with allele a at the first locus. All alleles are neutral.
a. What is the probability that a will be fixed?____
What is the probability that A will be fixed?______
b. What is the probability that B will be fixed? ____
What is the probability that b will be fixed?_ __
c. How long on average will it take for b to be fixed?
d. If b is not neutral but strongly beneficial rather than neutral, it has a higher chance of being fixed in the population. Could this affect the fixation of a? Please explain briefly.
A bacterium has a genome size of 1,000,000 base pairs, and the mutation rate is 1 base change/1,000,000 sites/cell replication. Replications (generations) occur at a rate of once per day.
a. How many changes will differ between two strains that are grown separately for 1 year? Assume that all the changes are neutral. (Remember that two strains are evolving from the ancestral state).
b. Why is the assumption that all changes are neutral unlikely to be true? In light of this, do you expect the number of observed changes to be greater or less than your estimate above? Explain briefly.
0.9? _________
0.5? _________
0.1? _________
What is the value of pi for a population of 1000 haploid individuals consisting of 500 individuals with sequence 1 and 500 with sequence 2, below.
AGTACTCAGC AGCTCTAGCG CTATCGCATC TAGACGCTCA GCTACCTGCA
AGTACTCACC AGCTCCAGCG CTACCGCATC TTGACGCTGA GCTACCTGCA
a. For 3 loci each with two alleles, how many haploid genotypes are possible?
b. How many diploid genotypes are possible?
c. You cross an ABC haploid genotype with an abc haploid genotype and obtain 25 each of the following haploid progeny: ABC, ABc, abC, abc
What can you say about linkage between A, B, and C loci?
Are A and B loci in linkage equilibrium with each other?
Are A and C loci in linkage equilibrium with each other?
d. How does your interpretation differ if you obtain 20 each of the above 4 genotypes and 5 each of AbC, Abc, aBC, aBc?
Are A and B loci in linkage equilibrium with each other?
Are A and C loci in linkage equilibrium with each other?
. In a bacterial population of 10,000,000 cells, two alleles, A and a, are present at a locus, at a frequency of 0.5 each. At another locus, all cells have genotype B until a mutation (Bïƒ* b) occurs, giving one copy of b. This mutation occurs in an individual with allele a at the first locus. All alleles are neutral.
a. What is the probability that a will be fixed?____
What is the probability that A will be fixed?______
b. What is the probability that B will be fixed? ____
What is the probability that b will be fixed?_ __
c. How long on average will it take for b to be fixed?
d. If b is not neutral but strongly beneficial rather than neutral, it has a higher chance of being fixed in the population. Could this affect the fixation of a? Please explain briefly.
A bacterium has a genome size of 1,000,000 base pairs, and the mutation rate is 1 base change/1,000,000 sites/cell replication. Replications (generations) occur at a rate of once per day.
a. How many changes will differ between two strains that are grown separately for 1 year? Assume that all the changes are neutral. (Remember that two strains are evolving from the ancestral state).
b. Why is the assumption that all changes are neutral unlikely to be true? In light of this, do you expect the number of observed changes to be greater or less than your estimate above? Explain briefly.