Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

A mutation in the DNA sequence of a gene results in which of the following possible outcomes?

Accepted Answer

It may be neutral, beneficial, or harmful depending on the change.

Question 3

Which of the following statements about bacterial chromosomes is correct?

Accepted Answer

They are circular and associated with proteins.

Question 4

During DNA replication in bacteria, which enzyme is primarily responsible for proofreading and ensuring high fidelity?

Accepted Answer

DNA polymerase

Question 5

Which of the following best describes an operon?

Accepted Answer

A set of operator and promoter sites and the structural genes they control.

Question 6

In the lac operon of E. coli, what happens when lactose is present?

Accepted Answer

Allolactose binds to the repressor, preventing it from binding to the operator, allowing transcription.

Question 7

Which of the following is a function of transfer RNA (tRNA) during protein synthesis?

Accepted Answer

It transports amino acids to the ribosome during translation.

Question 8

Which type of horizontal gene transfer involves the uptake of naked DNA from the environment?

Accepted Answer

Transformation

Question 9

A chemical mutagen causes adenine to pair with cytosine instead of thymine. Which mutagen is most likely responsible?

Accepted Answer

Nitrous acid

Question 10

Which of the following best describes the Ames test?

Accepted Answer

It uses a histidine auxotroph of Salmonella to detect mutagenic substances by measuring reversion to prototrophy.

Question 11

Which of the following is true about plasmids?

Accepted Answer

They are self-replicating circular DNA molecules that may carry antibiotic resistance genes.

Question 12

Which process involves the transfer of DNA from one bacterium to another via a bacteriophage?

Accepted Answer

Transduction

Question 13

Which of the following is a key difference between generalized and specialized transduction?

Accepted Answer

Generalized transduction can transfer any bacterial gene, while specialized transduction transfers only specific genes.

Question 14

Which of the following best describes vertical gene transfer?

Accepted Answer

Transfer of genes from parent to offspring.

Question 15

Which of the following is a likely consequence of UV radiation on bacterial DNA?

Accepted Answer

Formation of thymine dimers, which block replication and transcription.

Question 16

Which of the following is NOT a component of the lac operon control region?

Accepted Answer

tRNA gene

Question 17

Which of the following best explains why R factors are clinically significant?

Accepted Answer

They encode antibiotic resistance genes that can be transferred between bacteria.

Question 18

Which of the following is a correct statement about the flow of genetic information in a bacterial cell?

Accepted Answer

Information flows from DNA to RNA to protein.

Question 19

A researcher exposes bacteria to a new chemical and observes an increased rate of mutation. Which of the following best describes the chemical?

Accepted Answer

It is a mutagen.

Question 20

Which of the following is a real-world example of horizontal gene transfer impacting human health?

Accepted Answer

The spread of antibiotic resistance genes among pathogenic bacteria in hospitals.

Microbial Genetics: Structure, Function, and Mechanisms of Genetic Change

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