Question 1

Which of the following statements best describes the process of bacterial conjugation?

Accepted Answer

It is a one-way transfer of genetic material from a donor (F+) to a recipient (F-) cell via direct contact.

Question 2

In the Lederberg and Tatum experiment, what was the key finding regarding bacterial genetics?

Accepted Answer

Bacteria can swap genetic material, resulting in new phenotypes.

Question 3

Which experimental setup demonstrated that physical contact is required for bacterial conjugation?

Accepted Answer

A U-tube apparatus with a filter that prevents cell contact but allows media exchange.

Question 4

What is the role of the F factor in bacterial conjugation?

Accepted Answer

It codes for proteins necessary for pilus formation and DNA transfer.

Question 5

Which of the following best describes an Hfr cell?

Accepted Answer

A cell with the F plasmid integrated into its chromosome.

Question 6

During conjugation between an Hfr cell and an F- cell, what is the most likely outcome?

Accepted Answer

The F- cell receives some chromosomal genes but usually remains F-.

Question 7

Which mechanism of horizontal gene transfer is most likely responsible for the rapid spread of antibiotic resistance genes in hospitals?

Accepted Answer

Conjugation involving plasmids carrying resistance genes.

Question 8

A bacteriophage accidentally packages host bacterial DNA instead of its own. What process is this?

Accepted Answer

Transduction

Question 9

Which of the following is true about bacterial transformation?

Accepted Answer

It involves the uptake of naked DNA by competent cells.

Question 10

If a gene is transferred early during Hfr conjugation, what does this indicate about its location?

Accepted Answer

It is close to the origin of transfer on the chromosome.

Question 11

Which of the following best describes the difference between the lytic and lysogenic cycles of a bacteriophage?

Accepted Answer

The lytic cycle results in cell lysis and release of new phages, while the lysogenic cycle involves integration of phage DNA as a prophage.

Question 12

A bacterial cell that has taken up an F' plasmid is best described as:

Accepted Answer

A merozygote, containing extra genes from the donor.

Question 13

Which of the following equations best represents the probability $$P of co-$$transduction of two genes $$A$$ and $$B as a $$function of their distance $$d (in kb) $$apart, assuming a phage can carry up to $$k kb of $$DNA?

Accepted Answer

$$P = e$$^{-d/k}$$

Question 14

Which of the following is NOT a possible outcome of bacterial transformation?

Accepted Answer

The recipient cell always becomes more fit than before.

Question 15

Why is mapping genes using Hfr conjugation possible?

Accepted Answer

Genes are transferred in a linear fashion from the origin of transfer.

Question 16

Which of the following best explains why antibiotic resistance can spread rapidly in a hospital setting?

Accepted Answer

Horizontal gene transfer mechanisms such as conjugation allow rapid spread of resistance genes.

Question 17

Which of the following is a key feature of the F factor that enables conjugation?

Accepted Answer

It encodes the sex pilus and conjugation bridge proteins.

Question 18

A bacterium is described as 'competent.' What does this mean in the context of genetic exchange?

Accepted Answer

It can take up naked DNA from the environment.

Question 19

Which of the following scenarios would NOT result in genetic recombination in bacteria?

Accepted Answer

A bacterial cell dividing by binary fission.

Genetic Analysis and Mapping in Bacteria and Bacteriophages

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