Deck 9: Genetics in Bacteria

Question 1

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

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

Answer 1

D

Question 2

DNA may be transferred between bacteria via

A) conjugation.
B) transformation.
C) transduction.
D) fission.

Answer 2

A,B,C

Question 3

How do researchers interrupt the process of conjugation?

A) using tweezers
B) using a microscope
C) using a blender
D) using a special gene

Answer 3

C

Question 4

Bacterial cells that can participate in ________ are known as competent cells.

A) transformation
B) transduction
C) conjugation
D) fission

Question 5

After conjugation,the enzyme that rejoins the ends of the linear DNA into a circular plasmid is called ________.

A) relaxosome
B) relaxase
C) F factor
D) nucleoprotein

Question 6

In conjugation,the strand of DNA that is transferred from the donor cell to the recipient cell is single stranded.

Question 7

In experiments,interrupted mating may be used to 

A) inhibit transduction.
B) generate loss of function alleles.
C) determine the relative position of genes.
D) alter the genotype of the donor cell.

Question 8

DNA transfer via a physical connection between two bacteria is known as 

A) transformation.
B) transduction.
C) conjugation.
D) fission.

Question 9

Which correctly describe the process of conjugation?

A) The cells must be in physical contact.
B) It requires bacteriophage as an intermediary.
C) It involves a sex pilus.
D) Only competent cells can participate.
E) Donor strains can convert non-donor strains into donor strains.

Question 10

When a bacteria assimilates genetic material (DNA)directly from the environment,this is called

A) transformation.
B) transduction.
C) conjugation.
D) fission.

Question 11

After two cells make contact via the conjugation bridge,the protein complex that initiates DNA transfer is called the

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

Question 12

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

A) transformation
B) transduction
C) conjugation
D) fission

Question 13

This form of DNA transfer uses a sex pilus to transfer the genetic material.

A) transformation
B) transduction
C) conjugation
D) fission

Question 14

Which correctly describes F factors?

A) "F factor" is short for "fertility factor".
B) If present, that cell can act as a donor.
C) It consists of a single gene that is present on the chromosome.
D) All natural isolates of E. coli have it.
E) After it is transferred by conjugation, the recipient cell becomes F⁺.

Question 15

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

Question 16

This form of DNA transfer was first observed by Lederberg and Tatum (1946)in Escherichia coli.

A) transformation
B) transduction
C) conjugation
D) fission

Question 17

What best describes a histidine,methionine auxotroph?

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

Question 18

Which of the following is NOT true regarding bacterial genetics?

A) Bacteria are usually haploid organisms.
B) Bacteria primarily reproduce asexually.
C) The patterns of inheritance in bacteria are studied using the same techniques as eukaryotic organisms.
D) DNA is transferred between individuals by either conjugation, transduction, or transformation.

Question 19

The site on a plasmid that is cut,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 20

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) Genes A and M have a genetic distance of 11 minutes.
B) Genes A and T have a genetic distance of 19 minutes.
C) Genes M and T have a genetic distance of 18 minutes.
D) The order of the genes is A T M.

Question 21

Loss of function mutations are easier to study in ________ organisms,such as bacteria.

A) haploid
B) diploid
C) triploid

Question 22

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

Question 23

During transformation,homologous recombination may occur if the sequence of the introduced DNA has no similarity to the host DNA.

Question 24

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

Question 25

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

A) Hfr
B) F+
C) a conjugative plasmid

Question 26

P1 phage can carry a piece of the chromosome that is 2 minutes in length.In a P1 phage transduction experiment,two genes have a cotransduction frequency of 0.68.Determine the distance between these two genes,assuming that pieces of chromosome are packaged randomly.

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

Question 27

What do competence factors do?

A) allow the formation of a sex pilus
B) promote bacteriophage 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

During homologous recombination,areas of mismatched DNA form structures called a heteroduplex.

Question 29

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 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

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

A) generalized transduction
B) cotransduction
C) transformation
D) conjugation

Question 32

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

A) temperature
B) ionic conditions
C) nutrient balance
D) F factor must be present
E) bacteriophage strain

Question 33

Cotransduction can only be used to map genes that are within 20 minutes of each other,because the phage can only package 50% of the genome at a time.

Question 34

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 35

Small circular pieces of DNA,separate from the bacterial chromosome,are called ________.

A) heteroduplexes
B) plasmids
C) relaxosomes

Question 36

The direct movement of DNA between two bacteria is called genetic transfer.

Question 37

If a researcher used a phage that could carry a larger piece of a bacterial chromosome,then cotransduction frequency would ________.

A) increase
B) decrease
C) be unaffected

Question 38

Which does not require any recombination with the bacterial chromosome?

A) conjugation
B) transduction
C) transformation

Question 39

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

 

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

Question 40

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

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

Question 41

How does a transducing phage directly contribute to DNA transfer between bacteria?

A) By injecting a fragment of the bacterial genome from a previous host into another bacterial cell
B) By stimulating the formation of a sex pilus
C) By injecting phage DNA into a living bacterial cell
D) By incorporating DNA fragments from two different bacterial cells so that recombination can occur within the phage

Question 42

What is the most important result of horizontal gene transfer as it relates to human health?

A) It spreads antibiotic resistance in pathogenic bacteria.
B) It can explain the occurrence of nonheritable genetic diseases.
C) It can cause the disappearance of genes from the human genome, leading to disease.
D) It has been used successfully to treat dozens of diseases, by replacing damaged DNA in the cells of the patient.

Question 43

Competent cells are those used in studies of conjugation.

Question 44

DNA transfer by transduction depends on what occasional mistake that can occur during a phage lytic cycle?

A) A piece of host cell DNA is packaged into a phage.
B) A host cell protein is incorporated into a phage.
C) The host cell undergoes lysis before any new phages are produced.
D) The phage and bacterial genome fragments recombine.