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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Textbook Question
Chapter 4, Problem 41ESP
Students taking a genetics exam were expected to answer the following question by converting data to a “meaningful ratio” and then solving the problem. The instructor assumed that the final ratio would reflect two gene pairs, and most correct answers did. Here is the exam question:
“Flowers may be white, orange, or brown. When plants with white flowers are crossed with plants with brown flowers, all the F1 flowers are white. For F2 flowers, the following data were obtained:
Convert the F2 data to a meaningful ratio that allows you to explain the inheritance of color. Determine the number of genes involved and the genotypes that yield each
- (a) Solve the problem for two gene pairs. What is the final F2 ratio?
- (b) A number of students failed to reduce the ratio for two gene pairs as described above and solved the problem using three gene pairs. When examined carefully, their solution was deemed a valid response by the instructor. Solve the problem using three gene pairs.
- (c) We now have a dilemma. The data are consistent with two alternative mechanisms of inheritance. Propose an experiment that executes crosses involving the original parents that would distinguish between the two solutions proposed by the students. Explain how this experiment would resolve the dilemma.
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Students have asked these similar questions
A cross was made between a Red and Long flowered (RRLL) plant and a blue and dwarf flowered (rrll) plant. The resulting F1 plants were testcrossed to blue and dwarf plants.
140 red and long
28 red and dwarf
32 blue and long
145 blue and dwarf
After showing your Punnett square for the testcross, use the Chi Square test to determine if the genes are assorting independently. If they are linked, calculate the distance between the two genes. Show your work.
E. W. Lindstrom crossed two corn plants with green seedlings and obtained the following progeny: 3583 green seedlings, 853 virescentwhite seedlings, and 260 yellow seedlings .
Q. Give the genotypes for the green, virescent-white, and yellow progeny.
A cross was performed using Drosophila melanogaster involving a female known to be heterozygous for both ebony body and sepia eyes and a male known to be homozygous wild type male.
The resulting progeny were allowed to mate with one another to produce the data set. Three repetitions of the experiment were conducted. The following data were produced from the crosses. Test these data to determine if they are significantly different from the expected phenotypic ratio. Use the 5% level of significance. Your answer should include the hypothesized cross in genotypes, the Chi-squared value, the critical value and whether you reject or do not reject for each experiment.
Wild eye Wild body – 112, Wild eye Ebony body – 40, Sepia eye Wild body – 35, Sepia eye Ebony body – 11
Chapter 4 Solutions
Concepts of Genetics (12th Edition)
Ch. 4 - In the guinea pig, one locus involved in the...Ch. 4 - In some plants a red flower pigment, cyanidin, is...Ch. 4 - Below are three pedigrees. For each trait,...Ch. 4 - Researching their family histories, a deaf couple...Ch. 4 - Researching their family histories, a deaf couple...Ch. 4 - HOW DO WE KNOW? In this chapter, we focused on...Ch. 4 - CONCEPT QUESTION Review the Chapter Concepts list...Ch. 4 - In shorthorn cattle, coat color may be red, white,...Ch. 4 - In foxes, two alleles of a single gene, P and p,...Ch. 4 - In mice, a short-tailed mutant was discovered....
Ch. 4 - List all possible genotypes for the A, B, AB, and...Ch. 4 - With regard to the ABO blood types in humans,...Ch. 4 - In a disputed parentage case, the child is blood...Ch. 4 - The A and B antigens in humans may be found in...Ch. 4 - In chickens, a condition referred to as creeper...Ch. 4 - In rabbits, a series of multiple alleles controls...Ch. 4 - Three gene pairs located on separate autosomes...Ch. 4 - As in Problem 12, flower color may be red, white,...Ch. 4 - Horses can be cremello (a light cream color),...Ch. 4 - With reference to the eye color phenotypes...Ch. 4 - Pigment in mouse fur is only produced when the C...Ch. 4 - In rats, the following genotypes of two...Ch. 4 - Given the inheritance pattern of coat color in...Ch. 4 - In a species of the cat family, eye color can be...Ch. 4 - In a plant, a tall variety was crossed with a...Ch. 4 - In a unique species of plants, flowers may be...Ch. 4 - Five human matings (15), identified by both...Ch. 4 - A husband and wife have normal vision, although...Ch. 4 - In humans, the ABO blood type is under the control...Ch. 4 - In Drosophila, an X-linked recessive mutation,...Ch. 4 - Another recessive mutation in Drosophila, ebony...Ch. 4 - In Drosophila, the X-linked recessive mutation...Ch. 4 - While vermilion is X-linked in Drosophila and...Ch. 4 - In a cross in Drosophila involving the X-linked...Ch. 4 - Consider the three pedigrees below, all involving...Ch. 4 - In goats, the development of the beard is due to a...Ch. 4 - Predict the F1 and F2 results of crossing a male...Ch. 4 - Two mothers give birth to sons at the same time at...Ch. 4 - Discuss the topic of phenotypic expression and the...Ch. 4 - Prob. 35PDQCh. 4 - Labrador retrievers may be black, brown...Ch. 4 - A true-breeding purple-leafed plant isolated from...Ch. 4 - In Dexter and Kerry cattle, animals may be polled...Ch. 4 - A geneticist from an alien planet that prohibits...Ch. 4 - The following pedigree is characteristic of an...Ch. 4 - Students taking a genetics exam were expected to...Ch. 4 - In four oclock plants, many flower colors are...Ch. 4 - Below is a partial pedigree of hemophilia in the...
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