Human Heredity: Principles and Issues (MindTap Course List)
11th Edition
ISBN: 9781305251052
Author: Michael Cummings
Publisher: Cengage Learning
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Chapter 5, Problem 7QP
Sunflowers with flowers 10 cm in diameter are crossed with a plant that has 20-cm flowers. The F1 plants have flowers 15 cm in diameter. In the F2 generation, 4 flowers are 10 cm in diameter and 4 are 20 cm in diameter. Between these are 5
- a. Assuming that the alleles that contribute to flower diameter act additively, how many genes control flower size in this strain of sunflowers?
- b. How much does each additive allele contribute to flower diameter?
- c. What size flower makes up the largest phenotypic class?
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Answer
You are studying three linked genes in snapdragons. The flower color locus is in the center. There are 8.3 cM between the
flower color locus and the plant height locus. There are 12.4 cM between the flower color locus and the leaf type locus. The
coefficient of coincidence is 0.8. Pure-breeding tall, red-flowered plants with fuzzy leaves were crossed to pure-breeding
dwarf, blue-flowered plants with smooth leaves. The F1 were testcrossed. Calculate the proportion of the testcross progeny
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In cucumbers, speckled fruit color (u') is dominant to uniform fruit color
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genes are linked at a map distance of 20.4 m.u.
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spines.
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small spines. What percentage of the offspring of this cross are expected
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39.8%
10.2%
79.6%
20.4%
Chapter 5 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
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