Question 1

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

Accepted Answer

Each new DNA molecule consists of one parental and one daughter strand.

Question 2

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

Accepted Answer

Gyrase

Question 3

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

Accepted Answer

Nonsense mutation

Question 4

Which of the following statements about plasmids is FALSE?

Accepted Answer

Plasmids are essential for normal metabolism and growth.

Question 5

In the lac operon, what is the role of allolactose?

Accepted Answer

It acts as an inducer by inactivating the repressor.

Question 6

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

Accepted Answer

Protection against viral infection

Question 7

A scientist exposes bacteria to UV light, resulting in the formation of thymine dimers. Which DNA repair mechanism is most likely to fix this damage?

Accepted Answer

Photoreactivation (direct repair)

Question 8

Which of the following best describes generalized transduction?

Accepted Answer

A bacteriophage transfers random DNA segments from donor to recipient.

Question 9

Which of the following is TRUE regarding eukaryotic mRNA processing?

Accepted Answer

Eukaryotic mRNA undergoes capping, polyadenylation, and splicing before translation.

Question 10

Which of the following is a characteristic of a repressible operon such as the trp operon?

Accepted Answer

It is usually active and can be turned off by a corepressor.

Question 11

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.

Question 12

Which of the following is NOT a step in prokaryotic transcription?

Accepted Answer

Polyadenylation

Question 13

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

Accepted Answer

Insertion or deletion of one or two nucleotides

Question 14

Which of the following is a property of transposons?

Accepted Answer

They can move from one location to another within the genome.

Question 15

Which of the following is a direct result of the antiparallel structure of DNA?

Accepted Answer

One strand is synthesized continuously, and the other discontinuously.

Question 16

Which of the following best describes the function of tRNA during translation?

Accepted Answer

It brings amino acids to the ribosome and matches them to the mRNA codon.

Question 17

Which of the following is a key difference between prokaryotic and eukaryotic translation initiation?

Accepted Answer

Eukaryotic translation begins with methionine, while prokaryotic translation begins with formyl-methionine.

Question 18

Which of the following is the best definition of a genotype?

Accepted Answer

The set of genes in the genome of an organism.

Question 19

Which of the following horizontal gene transfer mechanisms requires physical contact between donor and recipient cells?

Accepted Answer

Conjugation

Microbial Genetics: Structure, Function, and Transfer of Genetic Material

Study Guide - Practice Questions