Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Chapter 21, Problem 25P
In a population of infinite size, three loci A, B, and C have two alleles each. Alleles A1, B1, and C1 are found in 1% of the population at a particular moment in time, and each has beneficial effects on the organisms’ fitnesses as compared to the other allele of that locus (A2, B2, and C2, respectively). The relative fitnesses of the three possible genotypes at each of these loci is:
The frequencies of alleles A, B, and C over thousands of generations is shown in the following graph:
| a. | Which line (blue, red, or green) corresponds to A1? B1? C1? |
| b. | Why does the allele represented by the red line go to fixation more quickly than that represented by the green line? |
| c. | Why does the allele represented by the blue line go to fixation more slowly than the alleles represented by either the red or green lines? |
| d. | Suppose the population only had 1000 individuals. Discuss how this change in |
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Students have asked these similar questions
An autosomal locus has alleles A and a.
The allele frequencies in a population at Hardy Weinberg equilibrium are
p = Freq(A) = 0.5
q = Freq(a) = 0.5
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Enter a single number between 0 and 1, for example, 0.33
Among a population of lizards inhabiting an arid habitat, the skin color is controlled by two alleles—B (brown skin color) that is dominant over b (green skin color). The green lizards comprise only 4 percent of the population whereas the brown lizards comprise the rest. Over a long period of time, increased rainfall in the area leads to transformation of the habitat, with growth of shrubs and small trees. The brown and green lizard numbers almost reverse with the green lizards approaching 81 percent of the total population. Calculate the allele frequency for the green skin color before and after the climate change occurred. Why did the brown lizard, which initially had greater relative fitness than the green lizard, reduce in number drastically?
A.
2, 9; because relative fitness is dependent on environmental conditions
B.
0.2, 0.9; because relative fitness is dependent on environmental conditions
C.
0.2, 0.9; because the green lizard population acquired new…
Consider an autosomal locus with alleles A and a. If the the allele
frequencies are as follows
Freq(A) = 0.4,
Freq(a) = 0.6.
, then what is the predicted frequency of heterozygous Aa individuals,
assuming the population is in Hardy-Weinberg equilibrium?
Freq(Aa) = ?
Enter a number between 0 and 1, inclusive, for example 0.33
Chapter 21 Solutions
Genetics: From Genes to Genomes
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