Q: Which of the following equations best represents the bidirectional replication of a circular bacterial chromosome?

$$\text{Origin of replication} \rightarrow \text{Replication forks} \rightarrow \text{Theta structure} \rightarrow \text{Two daughter chromosomes}$$

Question 1

Which of the following best describes horizontal gene transfer in bacteria?

Accepted Answer

The transfer of genetic material between unrelated individuals, often of different species.

Question 2

Which experiment provided the first evidence for bacterial transformation?

Accepted Answer

Griffith’s experiment with Streptococcus pneumoniae.

Question 3

A bacterium that can take up naked DNA from its environment is described as:

Accepted Answer

Competent

Question 4

Which structure is essential for bacterial conjugation?

Accepted Answer

Sex pilus

Question 5

What is the main difference between an F+ cell and an Hfr cell in bacterial conjugation?

Accepted Answer

F+ cells have the F plasmid as a separate plasmid, while Hfr cells have it integrated into their chromosome.

Question 6

Which of the following is NOT a method of horizontal gene transfer in bacteria?

Accepted Answer

Binary fission

Question 7

A bacteriophage accidentally packages bacterial DNA and transfers it to another bacterium. This process is called:

Accepted Answer

Transduction

Question 8

Which of the following best explains why the capsule of Streptococcus pneumoniae is associated with virulence?

Accepted Answer

It helps the bacterium resist phagocytosis by the host immune system.

Question 9

Which of the following statements about plasmids is FALSE?

Accepted Answer

Plasmids are always essential for bacterial survival.

Question 10

A hospital isolates a strain of E. coli that is resistant to multiple antibiotics. Which genetic element is most likely responsible for this phenotype?

Accepted Answer

F’ plasmid carrying R factors

Question 11

During conjugation, the transfer of DNA begins at a specific site on the F plasmid called:

Accepted Answer

oriT

Question 12

Which of the following equations best represents the bidirectional replication of a circular bacterial chromosome?

Accepted Answer

$$	ext{Origin of replication} ightarrow 	ext{Replication forks} ightarrow 	ext{Theta structure} ightarrow 	ext{Two daughter chromosomes}$$

Question 13

Which of the following scenarios best illustrates the concept of vertical gene transfer?

Accepted Answer

A bacterium passes its chromosome to its daughter cells during binary fission.

Question 14

Which of the following is a real-world consequence of horizontal gene transfer among bacteria?

Accepted Answer

Spread of antibiotic resistance genes among pathogenic bacteria.

Question 15

Which of the following best describes the role of the F’ plasmid in bacterial conjugation?

Accepted Answer

It carries extra bacterial genes in addition to the F factor.

Question 16

A scientist wants to introduce a foreign gene into a bacterium for recombinant DNA technology. Which method would be most appropriate?

Accepted Answer

Transformation

Question 17

Which of the following statements about R plasmids is TRUE?

Accepted Answer

They can carry multiple antibiotic resistance genes.

Question 18

Which of the following best explains why Hfr strains are useful for mapping bacterial genes?

Accepted Answer

They transfer chromosomal genes in a specific order during conjugation.

Question 19

Which of the following is a key feature of the process shown in the image where a bacteriophage injects DNA into a bacterial cell?

Accepted Answer

The process is called transduction.

Question 20

Which of the following best describes the medical significance of gene transfer in bacteria?

Accepted Answer

It can result in the spread of multidrug resistance among pathogens.

Bacterial Sex: Mechanisms of Genetic Variation in Bacteria

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