Concepts of Genetics (11th Edition)
11th Edition
ISBN: 9780321948915
Author: William S. Klug, Michael R. Cummings, Charlotte A. Spencer, Michael A. Palladino
Publisher: PEARSON
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Chapter 23, Problem 23ESP
Type A1B brachydactyly (short middle phalanges) is a genetically determined trait that maps to the short arm of chromosome 5 in humans. If you classify individuals as either having or not having brachydactyly, the trait appears to follow a singlelocus, incompletely dominant pattern of inheritance. However, if one examines the fingers and toes of affected individuals, one sees a range of expression from extremely short to only slightly short. What might cause such variation in the expression of brachydactyly?
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Anhidrotic ectodermal dysplasia is an X-linked recessive disorder in humans characterized by small teeth, no sweat glands, and sparse body hair. This trait is usually seen in men, but women who are heterozygous carriers of the trait often have irregular patches of skin with few or no sweat glands (see the illustration below). a. Explain why women who are heterozygous carriers of a recessive gene for anhidrotic ectodermal dysplasia have irregular patches of skin lacking sweat glands. b. Why does the distribution of the patches of skin lacking sweat glands differ among the females depicted in the illustration, even between the identical twins?
Ectrodactyly is a rare condition in which the fingers are absent and the hand is split. This condition is usually inherited as an autosomal dominant trait. Ademar Freire-Maia reported the appearance of ectrodactyly in a family in São Paulo, Brazil, whose pedigree is shown here. Is this pedigree consistent with autosomal dominant inheritance? If not, what mode of inheritance is most likely? Explain your reasoning.
Ectrodactyly is a rare condition in which the fingers are absent and the hand is split. This condition is usually inherited as an autosomal dominant trait. Ademar Freire-Maia reported the appearance of ectrodactyly in a family in São Paulo, Brazil, whose pedigree is shown here. Is this pedigree consistent with autosomal dominant inheritance? If not, what mode of inheritance is most likely? Explain your reasoning.
Chapter 23 Solutions
Concepts of Genetics (11th Edition)
Ch. 23 - A homozygous plant with 20-cm-diameter flowers is...Ch. 23 - The following table shows measurements for fiber...Ch. 23 - The following cable gives the percentage of twin...Ch. 23 - Prob. 1CSCh. 23 - Prob. 2CSCh. 23 - Prob. 3CSCh. 23 - HOW DO WE KNOW? In this chapter, we focused on a...Ch. 23 - CONCEPT QUESTION Review the Chapter Concepts list...Ch. 23 - Define the following: (a) polygenic, (b) additive...Ch. 23 - A dark-red strain and a white strain of wheat are...
Ch. 23 - Height in humans depends on the additive action of...Ch. 23 - An inbred strain of plants has a mean height of 24...Ch. 23 - Erma and Harvey were a compatible barnyard pair,...Ch. 23 - In the following table, average differences of...Ch. 23 - What kind of heritability estimates (broad sense...Ch. 23 - List as many human traits as you can that are...Ch. 23 - Corn plants from a test plot are measured, and the...Ch. 23 - The following variances were calculated for two...Ch. 23 - The mean and variance of plant height of two...Ch. 23 - Prob. 14PDQCh. 23 - Prob. 15PDQCh. 23 - In an assessment of learning in Drosophila, flies...Ch. 23 - Prob. 17PDQCh. 23 - Prob. 18PDQCh. 23 - In a population of 100 inbred, genotypically...Ch. 23 - Many traits of economic or medical significance...Ch. 23 - A 3-inch plant was crossed with a 15-inch plant,...Ch. 23 - In a cross between a strain of large guinea pigs...Ch. 23 - Type A1B brachydactyly (short middle phalanges) is...Ch. 23 - In a series of crosses between two true-breeding...Ch. 23 - Students in a genetics laboratory began an...Ch. 23 - Prob. 26ESPCh. 23 - Canine hip dysplasia is a quantitative trait that...Ch. 23 - Floral traits in plants often play key roles in...Ch. 23 - In 1988, Horst Wilkens investigated blind...
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