The height of the seed head in wheat at maturity is determined by several genes. In one variety, the head is just 9 inches above the ground; in another, it is 33 inches above the ground. Plants from the 9-inch variety were crossed to plants from the 33-inch variety. Among the F1, the seed head was 21 inches above the ground. After self-fertilization, the F1 plants produced an F2 population in which 9-inch and 33-inch plants each appeared with a frequency of 1/256. (a) How many genes are involved in the determination of seed head height in these strains of wheat? (b) How much does each allele of these genes contribute to seed head height? (c) If a 21-inch F2 plant were crossed to a 9-inch plant, how often would you expect 18-inch wheat to occur in the progeny?

The height of the seed head in wheat at maturity is determined by several genes. In one variety, the head is just 9 inches above the ground; in another, it is 33 inches above the ground. Plants from the 9-inch variety were crossed to plants from the 33-inch variety. Among the F1, the seed head was 21 inches above the ground. After self-fertilization, the F1 plants produced an F2 population in which 9-inch and 33-inch plants each appeared with a frequency of 1/256. (a) How many genes are involved in the determination of seed head height in these strains of wheat? (b) How much does each allele of these genes contribute to seed head height? (c) If a 21-inch F2 plant were crossed to a 9-inch plant, how often would you expect 18-inch wheat to occur in the progeny?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter5: The Inheritance Of Complex Traits

Section: Chapter Questions

Problem 7QP: Sunflowers with flowers 10 cm in diameter are crossed with a plant that has 20-cm flowers. The F1...

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Two true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high.So What would be the size and genotype of the F1 from a cross between a true-breeding 11 cm plant and a true-breeding 47 cm plant?
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