Question 1

The enzyme that allows the reforming of a circular plasmid following conjugation is called _________.

Accepted Answer

A)  relaxosome
B)  relaxase
C)  F' factor
D)  nucleoprotein
E)   pili proteinF) C) and D)
G) A) and B)

Question 2

The use of bacteriophages to map bacterial genes is called ___________.

Accepted Answer

A)   generalized transduction
B)   cotransduction
C)   transformation
D)   conjugation
E)   none of the answers are correctF) None of the above
G) A) and E)

Question 3

Which of the following mechanisms of genetic transfer was first observed by Lederberg and Tatum (1946)  in Escherichia coli?

Accepted Answer

A)   Transformation
B)   Transduction
C)   Conjugation
D)   All of the answers are correctE) All of the above
F) A) and B)

Question 4

Which of the following uses a bacteriophage as an intermediary for the genetic information?

Accepted Answer

A)   Transformation
B)   Transduction
C)   Conjugation
D)   All of the answers are correctE) B) and D)
F) C) and D)

Question 5

Interrupted mating is defined as ____________.

Accepted Answer

A)   the inability of a bacteriophage to transfer genetic material
B)   a mechanism of transformation
C)   a process of asexual reproduction in bacteria
D)   a process by which conjugation is stopped using a blenderE) A) and B)
F) A) and C)

Question 6

The units of genetic distance derived from bacterial conjugation studies are called _____.

Accepted Answer

A)   seconds
B)   map units
C)   centimorgans
D)   recombination units
E)   minutesF) C) and D)
G) A) and E)

Question 7

During conjugation, one strand of the F factor DNA remains in the donor cell and one strand is transferred to the recipient cell.

Accepted Answer

A) True 
 B)False

Question 8

An Hfr strain is produced when

Accepted Answer

A)   an F episome integrates into the E. coli chormosome.
B)   an F episome leaves the E. coli chromosome.
C)   an F episome is transferred to a new cell.
D)   an F episome leaves the host chromosome and removes some of the host chromosome.E) All of the above
F) A) and D)

Question 9

The transfer of genetic material from two unrelated species is called ________.

Accepted Answer

A)   Vertical gene transfer
B)   Conjugation
C)   Sexual reproduction
D)   Binary fission
E)   Horizontal gene transferF) C) and D)
G) None of the above

Question 10

What strategy did Benzer use to perform intragenic mapping?

Accepted Answer

A)   Infection of a cell with two different viruses that had mutations in the same gene could not result in a wild type virus by recombination
B)   Infection of a cell with two different viruses that had mutations in the same gene would result in a wild type virus by transduction
C)   Infection of a cell with two different viruses that had mutations in different genes could result in a wild type virus by recombination
D)   Infection of a cell with two different viruses that had mutations in the same gene could result in a wild type virus by recombinationE) A) and C)
F) All of the above

Question 11

In formation of plaques by bacteriophages which of the following statements is true?

Accepted Answer

A)   A plaque is the result of several different viruses initially infecting a single cell
B)   The plaque is the result of a single virus that has replicated in many bacterial cells in a localized area
C)   A plaque results when a single virus infects one cell and then does not infect any other cell
D)   Plaques are the areas where cells have not been infected at allE) B) and C)
F) B) and D)

Question 12

The results below are from an interrupted conjugation experiment performed with an Hfr strain. Which genes could also be mapped with generalized transduction?

Accepted Answer

A)   argR and argG only
B)   All three could be mapped to each other using generalized transduction
C)   argR could be mapped to recA and argG could be mapped to recA but argR and argG are too close to each other to be mapped using generalized transduction
D)   Only argG could be mapped with recA since argR is farther away from recA there would be little recombination that would include all three genes together and so argR could not be reliably mapped using generalized transduction.E) C) and D)
F) A) and B)

Question 13

In a conjugation experiment not all of the cells receiving two genes will demonstrate an altered phenotype for both genes. What is the most likely explanation of this phenomenon?

Accepted Answer

A)   One gene is toxic to the cell
B)   Transferred genes must undergo recombination for genotypic conversion of the recipient cell and there is a possibility that only one gene will be recombined into the recipients chromosome
C)   The transferred DNA is rapidly degraded by the recipient cell and one gene can be degraded before it is recombined into the host chromosome
D)   It is not physically possible to recombine more than one gene into a single host genome per conjugation eventE) None of the above
F) A) and B)

Question 14

In the experiment performed by Benzer for intragenic mapping which of the following is the most critical control?

Accepted Answer

A)   Perform the experiment with each different virus alone to determine the rate of reversion mutation
B)   Re-type the strain of E. coli
C)   Test the agar to make sure it can support E. coli and viral growth
D)   Perform at least five dilutions to make sure the dilutions were performed correctlyE) All of the above
F) A) and C)

Question 15

Which of the following matings would have the highest frequency of chromosomal gene transfer?

Accepted Answer

A)   F+ x F-
B)   F' x F-
C)   Hfr x F-D) A) and C)
E) A) and B)

Question 16

In an experiment with an Hfr cell if the uvrA gene is transferred 1 minute and the pyrB gene is transferred at 2.5 minutes then where is the oriT of the Hfr cell located? Use the map of the

Accepted Answer

A)   70 minutes
B)   90 minutes
C)   100 mintues
D)   97.5 minutesE) B) and D)
F) B) and C)

Question 17

Small circular pieces of DNA that are not associated with the bacterial chromosome are called _______.

Accepted Answer

A)   heteroduplex
B)   plasmids
C)   relaxosomeD) B) and C)
E) A) and B)

Question 18

The site on a plasmid that is digested, producing a single strand of DNA, to allow conjugation to occur is called the ____________.

Accepted Answer

A)   origin of transfer
B)   relaxase
C)   nucleoprotein
D)   T DNAE) A) and D)
F) A) and C)

Question 19

Which of the following mechanisms of genetic transfer utilizes a physical connection between two bacteria?

Accepted Answer

A)   Transformation
B)   Transduction
C)   Conjugation
D)   All of the answers are correctE) B) and C)
F) A) and B)

Question 20

Which of the following is inhibited by DNAse?

Accepted Answer

A)   Transformation
B)   Conjugation
C)   Transduction
D)   None of the answers are correctE) None of the above
F) All of the above

Exam 7: Genetic Transfer and Mapping in Bacteria and Bacteriophages

In formation of plaques by bacteriophages which of the following statements is true?

Correct AnswerverifiedShow Answer

The results below are from an interrupted conjugation experiment performed with an Hfr strain. Which genes could also be mapped with generalized transduction?

Correct AnswerverifiedShow Answer

During conjugation, one strand of the F factor DNA remains in the donor cell and one strand is transferred to the recipient cell.

Correct AnswerverifiedShow Answer

An Hfr strain is produced when

Correct AnswerverifiedShow Answer

The enzyme that allows the reforming of a circular plasmid following conjugation is called _________.

Correct AnswerverifiedShow Answer

In a conjugation experiment not all of the cells receiving two genes will demonstrate an altered phenotype for both genes. What is the most likely explanation of this phenomenon?

Correct AnswerverifiedShow Answer

In the experiment performed by Benzer for intragenic mapping which of the following is the most critical control?

Correct AnswerverifiedShow Answer

Small circular pieces of DNA that are not associated with the bacterial chromosome are called _______.

Correct AnswerverifiedShow Answer

Which of the following uses a bacteriophage as an intermediary for the genetic information?

Correct AnswerverifiedShow Answer

Which of the following mechanisms of genetic transfer was first observed by Lederberg and Tatum (1946) in Escherichia coli?

Correct AnswerverifiedShow Answer

Which of the following matings would have the highest frequency of chromosomal gene transfer?

Correct AnswerverifiedShow Answer

The units of genetic distance derived from bacterial conjugation studies are called _____.

Correct AnswerverifiedShow Answer

What strategy did Benzer use to perform intragenic mapping?

Correct AnswerverifiedShow Answer

Which of the following is inhibited by DNAse?

Correct AnswerverifiedShow Answer

The use of bacteriophages to map bacterial genes is called ___________.

Correct AnswerverifiedShow Answer

In an experiment with an Hfr cell if the uvrA gene is transferred 1 minute and the pyrB gene is transferred at 2.5 minutes then where is the oriT of the Hfr cell located? Use the map of the

Correct AnswerverifiedShow Answer

Which of the following mechanisms of genetic transfer utilizes a physical connection between two bacteria?

Correct AnswerverifiedShow Answer

Interrupted mating is defined as ____________.

Correct AnswerverifiedShow Answer

The transfer of genetic material from two unrelated species is called ________.

Correct AnswerverifiedShow Answer

The site on a plasmid that is digested, producing a single strand of DNA, to allow conjugation to occur is called the ____________.

Correct AnswerverifiedShow Answer

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