Question 1

Which of the following best describes the role of the F factor in prokaryotic gene mapping?

Accepted Answer

It is a plasmid that can replicate independently and integrate into the host genome, facilitating conjugation.

Question 2

During conjugation in bacteria, which gene is directly responsible for pilus formation?

Accepted Answer

TraA

Question 3

A bacterial cell with an integrated F factor is referred to as:

Accepted Answer

Hfr cell

Question 4

Which process involves the uptake of naked DNA from the environment by a bacterial cell?

Accepted Answer

Transformation

Question 5

In mapping genes by interrupted conjugation, what is the primary purpose of interrupting the mating process at specific time intervals?

Accepted Answer

To determine the order and relative distance of genes on the chromosome.

Question 6

Which of the following statements about transformation mapping is correct?

Accepted Answer

Transformation mapping can be used to determine gene proximity based on the likelihood of co-transformation.

Question 7

A strain of E. coli is sonicated and transformed into a recipient strain negative for all six traits but positive for streptomycin resistance. After growth on streptomycin-containing media, which trait is most likely to be observed in the transformants?

Accepted Answer

Only streptomycin resistance will be present, as selection was for this trait.

Question 8

Which of the following best describes the function of TraM in bacterial conjugation?

Accepted Answer

It facilitates the transfer of DNA during conjugation.

Question 9

What is the significance of the F factor excising from the bacterial chromosome and carrying some bacterial genes with it?

Accepted Answer

It results in the formation of an F' plasmid, which can transfer bacterial genes to recipient cells.

Question 10

Which of the following is NOT a method used for prokaryotic gene mapping?

Accepted Answer

Translation mapping

Question 11

If a bacterial cell is described as a prototroph, what does this mean?

Accepted Answer

It can grow on minimal media without supplemental nutrients.

Question 12

Which equation best represents the frequency of co-transformation for two genes located close together on a bacterial chromosome?

Accepted Answer

$$P_{co-transformation} = e$$^{-d}$$

Question 13

Electroporation is used in transformation to:

Accepted Answer

Increase the permeability of the bacterial cell membrane to allow DNA uptake.

Question 14

Which of the following statements about Hfr cells is correct?

Accepted Answer

Hfr cells have the F factor integrated into their chromosome, allowing high-frequency recombination.

Question 15

During conjugation, which end of the nicked DNA strand enters the recipient cell first?

Accepted Answer

5' end

Question 16

Which gene is responsible for nicking the F factor at the origin of transfer during conjugation?

Accepted Answer

Tra y/I

Question 17

A competent cell is best defined as:

Accepted Answer

A cell able to take up DNA from its environment during transformation.

Question 18

Which of the following is a real-world application of bacterial conjugation?

Accepted Answer

Spread of antibiotic resistance genes among pathogenic bacteria.

Question 19

If a bacterial cell is susceptible to certain phages due to the presence of F t genes, what is the likely consequence?

Accepted Answer

The cell may be infected and lysed by those phages.

Question 20

Which of the following best explains why minimal media is used in prokaryotic gene mapping experiments?

Accepted Answer

To distinguish between prototrophs and autotrophs based on their growth requirements.

Prokaryotic Gene Mapping and DNA Exchange Mechanisms

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