GENETIC ANALYSIS: AN INTEG. APP. W/MAS
2nd Edition
ISBN: 9781323142790
Author: Sanders
Publisher: Pearson Custom Publishing
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Chapter 6, Problem 24P
The phage P1 is used as a generalized transducing phage in an experiment combining a donor strain of E. coli of genotype leu+phe+ala+ and a recipient strain that is leu-phe-ala-. In separate experiments, transductants are selected for leu+ (experiment A), for phe+ (experiment B), and for ala+ (experiment C). Following selection, transductant genotypes for the unselected markers are identified.
a. What compound or compounds are added to the minimal medium to select for transductants in experiments A, B, and C?
b. Selection experiment results below show the frequency of each genotype.
c. Determine the order of genes on the donor chromosome.
d. Diagram the crossover events that form each of the transductants in experiment A.
e. In experiment B, why are there no transductants with the genotype leu- ala+?
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By conducting conjugation experiments between Hfr and recipientstrains, Wollman and Jacob mapped the order of many bacterialgenes. Throughout the course of their studies, they identified severaldifferent Hfr strains in which the F-factor DNA had been integratedat different places along the bacterial chromosome. A sample of theirexperimental results is shown in the following table:What information do you know based on the question and your understanding of the topic?
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In one experiment, the researchers mixed cells of Hfr strain AB‑312, which were xyl+ mtl+ mal+ met+ and sensitive to phage T6, with F− strain AB‑531, which was xyl− mtl− mal− met− and resistant to phage T6. The cells were allowed to undergo conjugation. At regular intervals, the researchers removed a sample of cells and interrupted conjugation by killing the Hfr cells with phage T6. The F− cells, which were resistant to phage T6, survived and were then tested for the presence of genes transferred from the Hfr strain. The results of this experiment are shown in the graph.
On the basis of these data, give the order of the xyl, mtl, mal, and met genes on the bacterial chromosome and the minimum distances between them in minutes. The origin of transfer is represented by the red triangle. The distances between genes are not…
Chapter 6 Solutions
GENETIC ANALYSIS: AN INTEG. APP. W/MAS
Ch. 6 - For bacteria that are F+, Hfr, F', and F-, perform...Ch. 6 - The flow diagram identifies relationships between...Ch. 6 - Conjugation between an Hfr cell and an F-cell does...Ch. 6 - Bacteria transfer genes by conjugation,...Ch. 6 - Explain the importance of the following features...Ch. 6 - Prob. 6PCh. 6 - Describe what is meant by the term site-specific...Ch. 6 - What is a prophage, and how is a prophage formed?Ch. 6 - How is the frequency of cotransduction related to...Ch. 6 - Describe the differences between genetic...
Ch. 6 - Among the mechanisms of gene transfer in bacteria,...Ch. 6 - What is lateral gene transfer? How might it take...Ch. 6 - Lateral gene transfer is thought to have played a...Ch. 6 - Prob. 14PCh. 6 - Prob. 15PCh. 6 - 16. Suppose you have an lysis mutant that maps to...Ch. 6 - Five Hfr strains from the same bacterial species...Ch. 6 - An interrupted mating study is carried out on Hfr...Ch. 6 - An Hfr strain with the genotype cys+leu+met+strS...Ch. 6 - A triple-auxotrophic strain of E. coli having the...Ch. 6 - Penicillin was first used in the 1940 s to treat...Ch. 6 - An attribute of growth behavior of eight...Ch. 6 - Synthesis of the amino acid histidine is a...Ch. 6 - The phage P1 is used as a generalized transducing...Ch. 6 - Prob. 25PCh. 6 - Five rII partial-deletion mutants are mapped and...Ch. 6 - A 2013 CDC report identified the practice of...Ch. 6 - Hfr strains that differ in integrated F factor...
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