Concepts of Genetics (12th Edition)
12th Edition
ISBN: 9780134604718
Author: William S. Klug, Michael R. Cummings, Charlotte A. Spencer, Michael A. Palladino, Darrell Killian
Publisher: PEARSON
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Chapter 25, Problem 4PDQ
A dark-red strain and a white strain of wheat are crossed and produce an intermediate, medium-red F1. When the F1 plants are interbred, an F2 generation is produced in a ratio of 1 dark-red: 4 medium-dark-red: 6 medium-red: 4 light-red: 1 white. Further crosses reveal that the dark-red and white F2 plants are true breeding.
- (a) Based on the ratios in the F2 population, how many genes are involved in the production of color?
- (b) How many additive alleles are needed to produce each possible phenotype?
- (c) Assign symbols to these alleles, and list possible genotypes that give rise to the medium-red and light-red
phenotypes . - (d) Predict the outcome of the F1 and F2 generations in a cross between a true-breeding medium-red plant and a white plant.
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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.
a) How many i) genes and ii) how many alleles are involved in determining height in this plant?
b) What is the contribution of each dominant allele to the phenotype in cm?
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?
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.
What is the contribution of each dominant allele to the phenotype in cm?
Chapter 25 Solutions
Concepts of Genetics (12th Edition)
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