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 9, Problem 15PDQ
The maternal-effect mutation bicoid (bcd) is recessive. In the absence of the bicoid protein product, embryogenesis is not completed. Consider a cross between a female heterozygous for the bicoid alleles (bcd+/bcd−) and a male homozygous for the mutation (bcd−/bcd−).
- (a) How is it possible for a male homozygous for the mutation to exist?
- (b) Predict the outcome (normal vs. failed embryogenesis) in the F1 and F2 generations of the cross described.
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The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product, embryogenesis isnot completed. Consider a cross between a female heterozygousfor the bicoid mutation (bcd+/ bcd-) and a homozygousmale(bcd-/ bcd-).
How is it possible for a male homozygous for the mutationto exist?
In Drosophila, the X-linked recessive mutation vermilion (v) causes bright red eyes, in contrast to the brick-red eyes of wild type. A separate autosomal recessive mutation, suppressor of vermilion (su-v), causes flies homozygous or hemizygous for v to have wildtype eyes. In the absence of vermilion alleles, su-v has no effect on eye color. Determine the F1 and F2 phenotypic ratios from a cross between a female with wild-type alleles at the vermilion locus, but who is homozygous for su-v, with a vermilion male who has wildtype alleles at the su-v locus
IN DROSOPHILA, AN X-LINKED
RECESSIVE MUTATION, Xm CAUSES
MINIATURE WINGS. LIST
THE F₂ PHENOTYPIC RATIOS IF:
A MINIATURE-WINGED FEMALE IS
CROSSED WITH A NORMAL MALE AND
A MINIATURE-WINGED MALE IS
●
●
CROSSED WITH A NORMAL FEMALE.
WHAT WOULD THE PHENOTYPIC RATIO
FROM (A) BE IF THE MINIATURE-
WINGED GENE WERE AUTOSOMAL?
ASSUME IN ALL CASES THAT THE P1
INDIVIDUALS ARE TRUE-BREEDING.
Chapter 9 Solutions
Concepts of Genetics (11th Edition)
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Ch. 9 - A plant may have green, white, or green-and-white...Ch. 9 - In diploid yeast strains, sporulation and...Ch. 9 - Predict the results of a cross between ascospores...Ch. 9 - In Lymnaea, what results would you expect in a...Ch. 9 - In a cross of Lymnaea, the snail contributing the...Ch. 9 - In Drosophila subobscura, the presence of a...Ch. 9 - A male mouse from a true-breeding strain of...Ch. 9 - Consider the case where a mutation occurs that...Ch. 9 - What is the endosymbiotic theory, and why is this...Ch. 9 - In an earlier Problems and Discussion section (see...Ch. 9 - The specification of the anteriorposterior axis in...Ch. 9 - The maternal-effect mutation bicoid (bcd) is...Ch. 9 - (a) In humans the mitochondrial genome encodes a...Ch. 9 - Mutations in mitochondrial DNA appear to be...Ch. 9 - Researchers examined a family with an interesting...Ch. 9 - Payne, B. A. et al. (2013) present evidence that a...
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