Q: Which equation best represents the semiconservative nature of DNA replication?

$$\text{Parent DNA} \rightarrow \text{1 old strand} + \text{1 new strand}$$

Question 1

Which of the following best describes the structure of a typical bacterial chromosome?

Accepted Answer

A closed, circular, double-helical DNA molecule located in the nucleoid

Question 2

Which of the following statements about plasmids is FALSE?

Accepted Answer

Plasmids always carry essential genes required for bacterial survival under normal conditions

Question 3

A bacterium that cannot synthesize arginine is called an auxotroph. If this bacterium receives the arginine synthesis gene via conjugation from an Hfr cell, what is the most likely outcome?

Accepted Answer

The recipient cell may gain the ability to synthesize arginine but will remain F-

Question 4

Which mechanism of horizontal gene transfer requires a bacteriophage?

Accepted Answer

Transduction

Question 5

In Frederick Griffith’s experiment, what was the key finding when heat-killed S strain and live R strain of Streptococcus pneumoniae were injected together into mice?

Accepted Answer

The mice died and both S and R strains were recovered

Question 6

Which type of plasmid is responsible for encoding antibiotic resistance genes?

Accepted Answer

Resistance (R) plasmid

Question 7

During generalized transduction, which DNA is transferred to the recipient bacterium?

Accepted Answer

A random fragment of donor bacterial DNA

Question 8

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

Accepted Answer

Rapid spread of antibiotic resistance genes in hospital settings

Question 9

What is the main function of the sex pilus during bacterial conjugation?

Accepted Answer

To facilitate the transfer of plasmid DNA from donor to recipient

Question 10

Which equation best represents the semiconservative nature of DNA replication?

Accepted Answer

$$	ext{Parent DNA} ightarrow 	ext{1 old strand} + 	ext{1 new strand}$$

Question 11

Which of the following bacteria is known for acquiring Shiga toxin genes via horizontal gene transfer, leading to severe disease outbreaks?

Accepted Answer

Escherichia coli O157:H7

Question 12

A bacterium is found to have multiple identical copies of a small, circular DNA molecule that confers antibiotic resistance. What is this DNA molecule called?

Accepted Answer

Plasmid

Question 13

Which of the following best explains why vaccine effectiveness against some bacterial pathogens is low and short-term?

Accepted Answer

Horizontal gene transfer allows rapid acquisition of new virulence factors

Question 14

Which of the following is NOT a requirement for bacterial conjugation?

Accepted Answer

A bacteriophage

Question 15

What is the role of a prophage in bacterial genetics?

Accepted Answer

It is a bacteriophage genome integrated into the bacterial chromosome

Question 16

Which of the following best describes the process of transformation in bacteria?

Accepted Answer

Uptake of free, naked DNA from the environment by a competent cell

Question 17

A laboratory strain of E. coli is made competent by treatment with calcium chloride ($$	ext{CaCl}_2). $$What process does this enable?

Accepted Answer

Transformation

Question 18

Which of the following is a direct result of specialized transduction?

Accepted Answer

Transfer of specific bacterial genes adjacent to the prophage

Question 19

Which of the following equations best represents rolling circle replication during conjugation?

Accepted Answer

$$	ext{Circular DNA} ightarrow 	ext{Nick at oriT} ightarrow 	ext{One strand transferred}$$

Question 20

Which of the following is a function of bacteriocin plasmids?

Accepted Answer

They encode toxins that inhibit the growth of similar or closely related bacterial strains

Microbial Genetics: Mechanisms of Genetic Exchange in Bacteria

Study Guide - Practice Questions

Study Guide - Flashcards