Deck 7: Genetic Transfer and Mapping in Bacteria

Question 1

Which of the following is true regarding bacterial genetics?

A) Bacteria are usually diploid organisms.
B) Bacteria primarily reproduce sexually.
C) The patterns of inheritance in bacteria are studied using different mechanisms than eukaryotes.
D) Bacteria generally have linear chromosomes.

Answer 1

C

Question 2

Mechanism of genetic transfer that uses competent cells.

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Answer 2

A

Question 3

The process of conjugation may introduce new alleles into the recipient strain, altering its genotype.

Answer 3

True

Question 4

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

A) origin of transfer
B) relaxase
C) nucleoprotein
D) T DNA

Question 5

Interrupted mating is defined as ________.

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 blender

Question 6

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

Question 7

The protein complex that initiates the process of conjugation following contact between two bacteria is called the ________.

A) origin of transfer
B) T DNA
C) relaxosome
D) nucleoprotein

Question 8

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

A) seconds
B) map units
C) centimorgans
D) recombination units
E) minutes

Question 9

Which mechanism of genetic transfer utilizes a sex pilus?

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 10

Which of the following is true regarding conjugation?

A) The bacteria must be in physical contact.
B) Most bacterial species have the ability to conjugate.
C) Strains called donor strains can transfer genetic information.
D) Donor strains can convert non-donor strains into donor strains.
E) All of the answers are correct.

Question 11

Which of the following is correct concerning F factors?

A) It may integrate into the host chromosome.
B) It stands for fertility factor.
C) It allows conjugation to occur.
D) F+ bacteria act as donor strains in conjugation.
E) All of the answers are correct.

Question 12

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

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 13

Which of the following mechanisms refer to when a bacteria assimilates genetic material (DNA) directly from the environment?

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 14

The process of interrupted mating may be used to do which of the following?

A) Inhibit transduction
B) Convert the recipient cell to F+
C) Determine the relative position of bacterial genes
D) Alter the genotype of the donor cell

Question 15

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

A) relaxosome
B) relaxase
C) F' factor
D) nucleoprotein
E) pili protein

Question 16

In conjugation the DNA that will be transferred from the donor cell to the recipient cell is

A) single-stranded.
B) double-stranded.
C) triple-stranded.
D) a mixture of single and double stranded.

Question 17

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

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 18

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

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 19

A histidine, methionine auxotroph ________.

A) can synthesize only histidine and methionine
B) can only use histidine and methionine as nutrition sources
C) cannot synthesize histidine and methionine
D) is killed by histidine and methionine
E) lacks proteins with histidine or methionine

Question 20

Which of the following represents a mechanism of genetic transfer in bacteria?

A) Transformation
B) Transduction
C) Conjugation
D) All of the answers are correct

Question 21

What is the maximum size of the E. coli chromosome capable of being carried by a P1 phage?

A) 10%-20%
B) 30%
C) 0.5%-1%
D) 2%-2.5%

Question 22

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

A) vertical gene transfer
B) conjugation
C) sexual reproduction
D) binary fission
E) horizontal gene transfer

Question 23

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

A) heteroduplex
B) plasmids
C) relaxosome

Question 24

Cotransduction establishes the general order of genes on a bacterial chromosome, while conjugation is more specific and thus may be used to establish precise distances.

Question 25

An episome is a segment of bacterial DNA that can exist as a plasmid or be integrated into the bacterial chromosome.

Question 26

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

A) cotransduction
B) transformation
C) conjugation
D) none of the answers are correct

Question 27

Competence factors do which of the following?

A) Allow the formation of a sex pilus.
B) Promote bacteriophages binding for transduction.
C) Allow DNA in the environment to bind to the cell surface.
D) Inhibit genetic transfer between donor and recipient cells.

Question 28

A phage that can carry a larger piece of a bacterial chromosome would have what type of effect on cotransduction frequencies?

A) Raise the cotransduction frequency.
B) Lower the cotransduction frequency.
C) Have no effect on the cotransduction frequency.

Question 29

A cell with an F factor integrated into the bacterial chromosome is called ________.

A) Hfr
B) F+
C) Conjugative plasmid

Question 30

A structure called a(n) ________ allows the transfer of genetic information during conjugation.

A) F factor
B) plasmid
C) sex pilus
D) transformation bridge

Question 31

During conjugation, one gene (A) is found to transfer to the recipient bacteria 26 minutes following the start of conjugation, while a second gene (M) is found to transfer 37 minutes following the start of conjugation. A third gene (T) transfers 45 minutes following the start of conjugation. Based on this information, which of the following is true?

A) The genetic distance between genes A and M is 11 minutes.
B) The genetic distance between genes A and T is 19 minutes.
C) The genetic distance between genes M and T is 8 minutes.
D) The order of the genes is A M T.
E) All of the answers are correct.

Question 32

A minute is the basic unit of map distance in bacteria.

Question 33

What is the equation that would be used to determine the distance between two genes with a cotransduction frequency of 0.68, in a P1 transduction?

A) 0.68=(1 - d/2)3
B) d=.683 - 1
C) d=(1-.68)2

Question 34

What is the order of the genes in this experiment?

A) abc
B) bac
C) acb

Question 35

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

A) F+ x F-
B) F' x F-
C) Hfr x F-

Question 36

Who was the first to discover the process of natural transformation?

A) Morgan
B) Sturtevant
C) Griffith
D) Avery

Question 37

Competent cells are those used in studies of conjugation.

Question 38

Based on the following data, what two genes are farthest apart?

A) a-b
B) b-c
C) a-c

Question 39

Acquired antibiotic resistance between two different species is an example of vertical gene transfer.

Question 40

Which of the following conditions must be correct for transformation to occur?

A) Temperature
B) Ionic conditions
C) Correct nutrient balance
D) All of the answers are correct

Question 41

An Hfr strain is produced when

A) an F episome integrates into the E. coli chromosome.
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.

Question 42

What are the mechanisms by which bacteria preferentially take up DNA from individuals of the same species? Check all that apply.

A) A specific sequence in the species DNA allows for uptake of DNA fragments that carry that sequence.
B) Proteins that are secreted by the bacteria must reach a threshold level that is correlated to the number of individuals of the same species being present.
C) Some species require a specific calcium level for uptake and the levels of calcium are correlated with the number of bacteria in localized area.

Question 43

In the experiment performed by Lederberg and Tatum bacteria of different genotypes had to be mixed together to obtain genetic transfer. However, Davis performed the experiment in a slightly different manner by separating cells with a filter incapable of allowing bacteria to pass. What possibility did the experiment by Davis exclude that could have occurred by the protocol used by Lederberg and Tatum?

A) Transformation
B) Conjugation
C) Transduction

Question 44

What is the correct order for the steps in transduction?

A) (1) Phage infects cell. (2) Phage transported DNA recombines with chromosome of new cell. (3) Host DNA digested into fragments. (4) Some phage accidentally carry host DNA fragment. (5) Phage infects new cell.
B) (1) Phage infects cell. (2) Phage transported DNA recombines with chromosome of new cell. (3) Host DNA digested into fragments. (4) Phage infects new cell. (5) Some phage accidentally carry host DNA fragment.
C) (1) Phage infects cell. (2) Host DNA digested into fragments. (3) Some phage accidentally carry host DNA fragment. (4) Phage infects new cell. (5) Phage transported DNA recombines with chromosome of new cell.
D) (1) Phage infects cell. (2) Phage transported DNA recombines with chromosome of new cell. (3) Some phage accidentally carry host DNA fragment. (4) Phage infects new cell. (5) Host DNA digested into fragments.

Question 45

In the Lederberg and Tatum experiment what is the purpose of performing the experiment with the strains without adding them together?

A) It serves as a control to calculate the rate of reversion mutations.
B) There is no experimental purpose to performing that part of the experiment.
C) It tests that the strains were made correctly.
D) It tests to make sure the media was made correctly.

Question 46

Although there are several different types of plasmids they all

A) can confer some kind of selective growth advantage depending on environmental conditions.
B) can induce a mating phenotype.
C) result in horizontal transfer.
D) make cells resistant to antibiotics

Question 47

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

A) Only argR and argG could be mapped to each other using transduction.
B) All three could be mapped to each other using 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 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 transduction.