Genetic Analysis: An Integrated Approach (3rd Edition)
3rd Edition
ISBN: 9780134605173
Author: Mark F. Sanders, John L. Bowman
Publisher: PEARSON
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Textbook Question
Chapter 20, Problem 31P
Albinism, an autosomal recessive trait characterized by an absence of skin pigmentation, is found in
a. the recessive allele at the locus
b. the dominant allele at the locus
c. heterozygotes in the population
d. For albinism only, what is the frequency of mating between heterozygotes?
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Albinos produce very little of the pigment melanin in their skin and hair. Albinism is inherited as a homozygous recessive trait. In North America, about 1 in 20,000 people are albinos.
a. What is the frequency of the dominant allele for albinism?b. What is the frequency of albinos?c. What is the frequency of heterozygotes?
Cystic fibrosis (CF) is a recessive autosomal disorder. In certain populations of Northern European descent, the number of people born with this disorder is about 1 in 2500. Assuming Hardy- Weinberg equilibrium for this trait:
A. What are the frequencies for the normal and CF alleles?
B. What are the genotype frequencies of homozygous normal, heterozygous, and homozygous affected individuals?
C. Assuming random mating, what is the probability that two phenotypically unaffected heterozygous carriers will choose each other as mates?
1)A population of 500 individuals has 231 homozygous dominant individuals, 218 heterozygotes, and 51 homozygous recessive individuals. Determine the frequency of the recessive genotype and frequency of the recessive allele, respectively.
a.
Frequency of Recessive Genotype
Frequency of Recessive Alleles
0.32
0.10
b.
Frequency of Recessive Genotype
Frequency of Recessive Alleles
0.10
0.32
c.
Frequency of Recessive Genotype
Frequency of Recessive Alleles
0.90
0.10
d.
Frequency of Recessive Genotype
Frequency of Recessive Alleles
0.68
0.32
2)A rabbit warren has 300 individuals. The coat colour of rabbits is expressed through incomplete dominance. The coat colour can be dark brown, light brown, or white.There are 81 dark brown rabbits, 150 light brown rabbits, and 69 white rabbits. Assume that all of the conditions are met for a population in Hardy–Weinberg equilibrium.What is the light brown genotype frequency,…
Chapter 20 Solutions
Genetic Analysis: An Integrated Approach (3rd Edition)
Ch. 20 - 20.1 Compare and contrast the terms in each of the...Ch. 20 - In a population, what is the consequence of...Ch. 20 - 20.3 Identify and describe the evolutionary forces...Ch. 20 - Describe how natural selection can produce...Ch. 20 - Thinking creatively about evolutionary mechanisms,...Ch. 20 - 20.6 Genetic drift, an evolutionary process...Ch. 20 - Over the course of many generations in a small...Ch. 20 - Catastrophic events such as loss of habitat,...Ch. 20 - 20.9 George Udny Yule was wrong in suggesting that...Ch. 20 - 20.10 The ability to taste the bitter compound...
Ch. 20 - Figure 20.6 illustrates the effect of an ethanol ...Ch. 20 - 20.12 Biologists have proposed that the use of...Ch. 20 - 20.13 Two populations of deer, one of them large...Ch. 20 - 20.14 Directional selection presents an apparent...Ch. 20 - 20.15 What is inbreeding depression? Why is...Ch. 20 - 20.16 Certain animal species, such as the...Ch. 20 - Genetic Analysis 20.1 predicts the number of...Ch. 20 - 20.18 In a population of rabbits, and . The...Ch. 20 - Sickle cell disease (SCD) is found in numerous...Ch. 20 - 20.20 Epidemiologic data on the population in the...Ch. 20 - The frequency of tasters and nontasters of PTC...Ch. 20 - Tay-Sachs disease is an autosomal recessive...Ch. 20 - 20.23 Cystic fibrosis (CF) is the most common...Ch. 20 - 20.24 In the mouse, Mus musculus, survival in...Ch. 20 - 20.25 In a population of flowers growing in a...Ch. 20 - Assume that the flower population described in the...Ch. 20 - 20.27 ABO blood type is examined in a Taiwanese...Ch. 20 - 20.28 A total ofmembers of a Central American...Ch. 20 - 20.29 A sample offield mice contains individuals...Ch. 20 - Prob. 30PCh. 20 - Albinism, an autosomal recessive trait...Ch. 20 - 20.32 The frequency of an autosomal recessive...Ch. 20 - 20.33 Evaluate the following pedigree, and answer...Ch. 20 - Evaluate the following pedigree, and answer the...Ch. 20 - The following is a partial pedigree of the British...Ch. 20 - Draw a separate hypothetical pedigree identifying...Ch. 20 - Prob. 37PCh. 20 - 20.38 Achromatopsia is a rare autosomal recessive...Ch. 20 - 20.39 New allopolyploid plant species can arise by...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Consider the disease phenylketonuria (PKU), which is an autosomal recessive defect in the enzyme phenylalanine hydroxylase. The absence of the enzyme prevents phenylalanine from being metabolized causing unusually high levels of phenylalanine in the body leading to severe mental retardation. The selection coefficient for the recessive homozygous individuals is 0.7 and the frequency of the recessive allele in the population is 1.0 x 10-2. If PKU is maintained by mutation-selection balance what is the predicted mutation rate? The actual mutation rate is 1 X 10-4. What other mechanism might be affecting the allele frequency?arrow_forwardin sheep, black wool is determined by a Dominant Allele (B) and white wool by a Recessive Allele (b). In a population of 200 sheep, 128 of them exhibit the dominant trait of having black wool and the rest have the recessive trait of white wool. Calculate the frequencies of both the (B) and (b) alleles. Calculate the frequencies of homozygous dominant vs.heterozygous sheep, as well as the homozygous recessives individuals.arrow_forwardAlbinism in humans is a relatively rare recessive condition. Let the allele for normal pigmentation be A and the allele for albinism be a. Therefore, individuals with the genotypes AA and Aa are normally pigmented individuals and aa are albinos. Suppose that in the US the frequency of albinos is 1 in 10,000. Estimate the allele frequencies and the frequencies of AA, Aa and aa genotypes in the population. Show all your work, and clearly state your logic and any assumptions you make in estimating the frequencies.arrow_forward
- Albinism is due to a recessive allele of an autosomal gene. Let a represent the albino allele and A represent the normal non-albino allele. If one out of every 10,000 people were albino and assuming that the population is in Hardy-Weinberg equilibrium, A. what would be the phenotype frequencies of albino and non-albino ? B. what would be the allele frequencies of a and of A? C. what fraction of people can be expected to be of the genotype Aa? D. what fraction of people can be expected to be of the genotype AA?arrow_forwardIn a population of 200 mice, 98 are the homozygous dominant for brown fur (BB), 84 are heterozygous (Bb), and 18 are homozygous recessive for white fur (bb). a. The genotypes frequencies of this population arearrow_forwardHelp me pleasearrow_forward
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