Question 1

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

Each new DNA molecule consists of one original strand and one newly synthesized strand.

Question 2

Which enzyme is responsible for removing supercoils during bacterial DNA replication?

Accepted Answer

Gyrase

Question 3

A mutation changes a codon from UAU (tyrosine) to UAA. What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 4

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids replicate independently of the chromosome.

Question 5

During transcription in prokaryotes, which sequence signals the end of transcription?

Accepted Answer

Terminator

Question 6

Which of the following is a function of DNA methylation in bacteria?

Accepted Answer

Protection against viral infection

Question 7

Which of the following best explains why triphosphate deoxyribonucleotides are required for DNA synthesis?

Accepted Answer

They serve as both the building blocks and the energy source for DNA synthesis.

Question 8

Which of the following is NOT a difference between prokaryotic and eukaryotic DNA replication?

Accepted Answer

Prokaryotes methylate only cytosine bases.

Question 9

Which of the following is a regulatory mechanism that allows a cell to conserve energy by controlling gene expression?

Accepted Answer

Halting transcription of unnecessary genes

Question 10

A bacterial cell is exposed to a chemical that causes the insertion of a single nucleotide into a gene. What is the most likely result?

Accepted Answer

A frameshift mutation

Question 11

Which of the following is TRUE regarding the lac operon in E. coli?

Accepted Answer

It is an inducible operon activated by the presence of lactose.

Question 12

Which of the following horizontal gene transfer mechanisms requires a bacteriophage?

Accepted Answer

Transduction

Question 13

Which of the following best describes a transposon?

Accepted Answer

A segment of DNA that can move from one location to another within a genome

Question 14

Which of the following is a direct result of a nonsense mutation?

Accepted Answer

A codon is changed to a stop codon, terminating translation prematurely.

Question 15

Which of the following is a key difference between prokaryotic and eukaryotic mRNA processing?

Accepted Answer

Eukaryotic mRNA undergoes splicing to remove introns.

Question 16

Which of the following is the correct sequence of events in translation?

Accepted Answer

Initiation, elongation, termination

Question 17

A scientist uses the Ames test to evaluate a chemical. What is the Ames test used for?

Accepted Answer

To identify mutagens and potential carcinogens

Question 18

Which of the following is a function of microRNAs (miRNAs) in genetic regulation?

Accepted Answer

They bind to complementary mRNA and inhibit its translation.

Question 19

Which of the following is required for bacterial conjugation?

Accepted Answer

Cell-to-cell contact and an F plasmid

Question 20

Which of the following best explains why mutagens increase the mutation rate?

Accepted Answer

They cause changes in the DNA sequence, such as base substitutions or frameshifts.

Microbial Genetics: Structure, Replication, and Expression of Genomes

Study Guide - Practice Questions