Question 1

Which of the following best describes a key structural difference between DNA and RNA?

Accepted Answer

DNA contains the base thymine, while RNA contains uracil.

Question 2

During DNA replication in bacteria, which enzyme is responsible for synthesizing the new DNA strand by adding nucleotides to the growing chain?

Accepted Answer

DNA polymerase

Question 3

What is the primary function of the enzyme helicase during DNA replication?

Accepted Answer

Unwinding the DNA double helix

Question 4

Which molecule acts as the template during transcription?

Accepted Answer

DNA

Question 5

What is the main purpose of translation in the cell?

Accepted Answer

To synthesize proteins from an mRNA template

Question 6

Which of the following best describes an inducible operon?

Accepted Answer

It is turned on in the presence of a specific substrate.

Question 7

A mutation that results in a premature stop codon is known as which type of mutation?

Accepted Answer

Nonsense mutation

Question 8

Which of the following is a chemical mutagen that can cause base-pair substitutions by mimicking normal bases?

Accepted Answer

Base analogs

Question 9

Which type of genetic transfer involves the direct transfer of DNA from one bacterial cell to another via a pilus?

Accepted Answer

Conjugation

Question 10

Which of the following plasmids carries genes for antibiotic resistance?

Accepted Answer

Resistance (R) plasmid

Question 11

A bacterial cell is exposed to UV light, resulting in the formation of thymine dimers. What type of mutation is most likely to occur?

Accepted Answer

Pyrimidine dimer mutation

Question 12

Which of the following best describes the role of mRNA during translation?

Accepted Answer

It provides the template for the sequence of amino acids in the protein.

Question 13

Which process is responsible for the synthesis of an RNA molecule from a DNA template?

Accepted Answer

Transcription

Question 14

How does a repressible operon typically function?

Accepted Answer

It is usually on but can be turned off when a corepressor binds to the repressor.

Question 15

Which of the following is NOT a way that mutations can arise in cells?

Accepted Answer

Horizontal gene transfer

Question 16

A frameshift mutation is most likely to result from which of the following?

Accepted Answer

An insertion or deletion of one or more nucleotides

Question 17

Which of the following best describes generalized transduction?

Accepted Answer

Transfer of any bacterial gene by a bacteriophage

Question 18

Which enzyme is responsible for joining Okazaki fragments on the lagging strand during DNA replication?

Accepted Answer

Ligase

Question 19

Which of the following is a key difference between transformation and conjugation in bacteria?

Accepted Answer

Conjugation involves the transfer of DNA via a pilus, while transformation involves uptake of naked DNA.

Question 20

Which of the following best explains why gene expression is tightly regulated in bacterial cells?

Accepted Answer

To conserve energy and resources by producing proteins only when needed

Microbiology Study Guide: Genetics, Gene Expression, and Mutation

Study Guide - Practice Questions