Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Chapter 16, Problem 10P
Bacteriophage λ, after infecting a cell, can integrate into the chromosome of the cell if the repressor protein, cI, binds to and shuts down phage transcription immediately. (A strain containing a bacteriophage DNA integrated into the chromosome is called a lysogen.) The alternative fate is the production of many more viruses and lysis of the cell. In a mating, a donor strain that is a lysogen was crossed with a lysogenic recipient cell, and no phages were produced. However, when the lysogen donor strain transferred its DNA to a nonlysogenic recipient cell, the recipient cell burst, releasing a new generation of phages.
| a. Why did the mating with a nonlysogenic recipient result in phage growth and release, but the infection of a lysogenic recipient did not? |
| b. Explain how this phenomenon relates to the PaJaMo experiment in Fig. 16.6. |
| c. Explain how this phenomenon relates to hybrid dysgenesis, described in Problem 29 of Chapter 13. |
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Bacteriophage λ, after infecting a cell, can integrateinto the chromosome of the cell if the repressor protein, cI, binds to and shuts down phage transcriptionimmediately. (A strain containing a bacteriophageDNA integrated into the chromosome is called a lysogen.) The alternative fate is the production of manymore viruses and lysis of the cell. In a mating, a donor strain that is a lysogen was crossed with a lysogenic recipient cell, and no phages were produced.However, when the lysogen donor strain transferredits DNA to a nonlysogenic recipient cell, the recipientcell burst, releasing a new generation of phages. a. Why did the mating with a nonlysogenic recipientresult in phage growth and release, but the infectionof a lysogenic recipient did not?
In E. coli, the genes for histidine (his), arginine (arg), tyrosine (tyr), and valine (val) synthesis are closely linked. A wild-type strain is used as a donor for transducing viruses. Various recipient strains were treated with these viruses. Wild-type recombinant colonies were then counted, with the results shown in the following table.
Genotype of recipient
Number of wild-type colonies
Genotype of recipient
Number of wild-type colonies
his- arg+ val+ tyr+
254
his+ arg- val- tyr+
132
his+ arg+ val- tyr-
36
his+ arg- val+ tyr+
240
his- arg- val+ tyr+
28
his- arg+ val- tyr+
102
his- arg+ val+ tyr-
100
his+ arg- val+ tyr-
2
What is the cotransduction coefficient of histidine and valine? For consistency, standardize on histidine.
0.38 (wrong)
0.537
0.402
None of these
In Hershey-Chase experiment, bacteriophages protein coats were tagged with radioactive isotope S-32. These phages were used to infect E. coli cells and the cells were further centrifuged to form pellets.
Why was the radioactivity level of S-32 found greater outside the cells compared to the E. coli cell pellets? Explain briefly.
If the experiment is repeated in the same manner but this time the phage protein coats are labelled with isotope X and the phage DNA with isotope Y, which isotope’s radioactivity will be found in greater amounts in the E. coli cell pellets after centrifugation? Explain briefly.
Chapter 16 Solutions
Genetics: From Genes to Genomes
Ch. 16 - For each of the terms in the left column, choose...Ch. 16 - The following statement occurs early in this...Ch. 16 - One of the main lessons of this chapter is that...Ch. 16 - All mutations that abolish function of the Rho...Ch. 16 - The figure at the beginning of this chapter shows...Ch. 16 - The promoter of an operon is the site to which RNA...Ch. 16 - You are studying an operon containing three genes...Ch. 16 - You have isolated a protein that binds to DNA in...Ch. 16 - You have isolated two different mutants reg1 and...Ch. 16 - Bacteriophage , after infecting a cell, can...
Ch. 16 - Mutants were isolated in which the constitutive...Ch. 16 - Suppose you have six strains of E. coli. One is...Ch. 16 - The previous problem raises some interesting...Ch. 16 - For each of the E. coli strains containing the lac...Ch. 16 - For each of the following growth conditions, what...Ch. 16 - For each of the following mutant E. coli strains,...Ch. 16 - Maltose utilization in E. coli requires the...Ch. 16 - Seven E. coli mutants were isolated. The activity...Ch. 16 - Cells containing missense mutations in the crp...Ch. 16 - Six strains of E.coli mutants 16 that had one of...Ch. 16 - a. The original constitutive operator mutations in...Ch. 16 - In an effort to determine the location of an...Ch. 16 - Prob. 23PCh. 16 - The footprinting experiment described in Fig....Ch. 16 - Why is the trp attenuation mechanism unique to...Ch. 16 - a. How many ribosomes are required at a minimum...Ch. 16 - The following is a sequence of the leader region...Ch. 16 - For each of the E. coli strains that follow,...Ch. 16 - Prob. 29PCh. 16 - For each element in the list that follows,...Ch. 16 - Among the structurally simplest riboswitches are...Ch. 16 - Great variation exists in the mechanisms by which...Ch. 16 - Many genes whose expression is turned on by DNA...Ch. 16 - In 2005, Frederick Blattner and his colleagues...Ch. 16 - The E.coli MalT protein is a positive regulator of...Ch. 16 - Prob. 36PCh. 16 - Prob. 37PCh. 16 - Prob. 38PCh. 16 - Prob. 39PCh. 16 - Prob. 40PCh. 16 - Prob. 41PCh. 16 - The researchers who investigated bioluminescence...Ch. 16 - Prob. 43PCh. 16 - Quorum sensing controls the expression of...Ch. 16 - Scientists are currently screening a chemical...
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