Question 1

Which of the following best describes the process of semiconservative DNA replication in bacteria?

Accepted Answer

Each new DNA molecule consists of one old strand and one new strand.

Question 2

A mutation in the DNA sequence changes the codon from $$	ext{UAC} to$$ $$	ext{UAA}. $$What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 3

Which of the following statements about plasmids is TRUE?

Accepted Answer

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

Question 4

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

Accepted Answer

Terminator sequence

Question 5

Which of the following best explains why UV radiation can cause mutations in bacterial DNA?

Accepted Answer

UV radiation causes the formation of thymine dimers, which disrupt DNA replication and transcription.

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 mechanism of horizontal gene transfer in bacteria?

Accepted Answer

Conjugation

Question 8

A frameshift mutation occurs when:

Accepted Answer

One or more nucleotide pairs are inserted or deleted, shifting the reading frame.

Question 9

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 10

In bacterial translation, what is the function of the tRNA anticodon?

Accepted Answer

It base-pairs with the mRNA codon to ensure the correct amino acid is added.

Question 11

Which of the following best describes the difference between exons and introns in eukaryotic genes?

Accepted Answer

Exons are expressed DNA that code for proteins, while introns are intervening DNA that do not code for proteins.

Question 12

Which of the following is TRUE regarding the genetic code?

Accepted Answer

The genetic code is degenerate, meaning multiple codons can code for the same amino acid.

Question 13

A bacterium is exposed to a nucleoside analog. What is the most likely outcome?

Accepted Answer

The analog will incorporate into DNA and cause mistakes in base pairing, leading to mutations.

Question 14

Which of the following is NOT a function of plasmids in bacteria?

Accepted Answer

Encoding ribosomal RNA

Question 15

Which of the following statements about bacterial conjugation is correct?

Accepted Answer

Conjugation requires cell-to-cell contact and transfer of plasmids via sex pili in Gram-negative bacteria.

Question 16

Which of the following is an example of a repressible operon?

Accepted Answer

trp operon

Question 17

A bacterial cell undergoes transformation. Which of the following best describes this process?

Accepted Answer

The cell takes up naked DNA from the environment and incorporates it into its chromosome.

Question 18

Which of the following is TRUE about the proofreading capability of DNA polymerase?

Accepted Answer

It increases the accuracy of DNA replication by correcting errors.

Question 19

Which of the following best describes generalized transduction in bacteria?

Accepted Answer

Random bacterial DNA is packaged inside a phage and transferred to a recipient cell.

Question 20

A bacterial cell is exposed to ionizing radiation. Which of the following is most likely to occur?

Accepted Answer

Formation of ions that can oxidize nucleotides and break the deoxyribose-phosphate backbone.

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

Study Guide - Practice Questions