Question 1

Which of the following best describes the semi-conservative nature of DNA replication in bacteria?

Accepted Answer

Each daughter cell receives one old (parental) strand and one new strand.

Question 2

During bacterial DNA replication, which enzyme is responsible for relieving supercoiling ahead of the replication fork?

Accepted Answer

DNA gyrase

Question 3

What is the function of the Shine-Dalgarno sequence in bacterial mRNA?

Accepted Answer

It aligns the mRNA on the ribosome for translation initiation.

Question 4

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand.

Question 5

Which of the following is NOT a component of a nucleotide?

Accepted Answer

Amino acid

Question 6

In E. coli, which protein is responsible for removing RNA primers and filling the gaps with DNA during replication?

Accepted Answer

DNA polymerase I

Question 7

Which of the following best explains the 'wobble' hypothesis in the genetic code?

Accepted Answer

The third base of the codon is less important for tRNA recognition, allowing some tRNAs to pair with multiple codons.

Question 8

Which of the following codons is a stop (nonsense) codon in the standard genetic code?

Accepted Answer

UAA

Question 9

What is the role of the sigma (σ) factor in bacterial transcription?

Accepted Answer

It helps the RNA polymerase core enzyme recognize the promoter region.

Question 10

Which of the following best describes the function of molecular chaperones in protein folding?

Accepted Answer

They assist in the proper folding of nascent polypeptides and protect cells from thermal damage.

Question 11

A mutation in the gene encoding DNA ligase in E. coli would most likely result in which of the following defects?

Accepted Answer

Failure to join Okazaki fragments on the lagging strand

Question 12

Which of the following equations correctly represents the hydrolysis of GTP required for the translocation step during translation elongation?

Accepted Answer

$$\mathrm{GTP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{GDP} + \mathrm{P_i}$$

Question 13

Which of the following is a unique feature of the Tat (twin arginine translocase) system in bacterial protein secretion?

Accepted Answer

It translocates folded proteins with twin arginine residues in their signal sequence.

Question 14

Which of the following best describes the function of the 16S rRNA in the bacterial ribosome?

Accepted Answer

It binds to the Shine-Dalgarno sequence on mRNA to initiate translation.

Question 15

A bacterial cell is exposed to a chemical that specifically inhibits the activity of topoisomerase IV. Which of the following processes would be most directly affected?

Accepted Answer

Separation of catenated daughter chromosomes after DNA replication

Question 16

Which of the following statements about polycistronic mRNA in bacteria is correct?

Accepted Answer

It contains directions for more than one polypeptide, each with its own start and stop codon.

Question 17

Which of the following is the correct order of events at the bacterial replication fork?

Accepted Answer

DnaA binds oriC, helicase unwinds DNA, primase synthesizes RNA primer, DNA polymerase III synthesizes DNA, DNA ligase joins Okazaki fragments

Question 18

Which of the following is a real-world example of a genetic code exception?

Accepted Answer

In mammalian mitochondria, the codon AGA codes for stop instead of arginine.

Question 19

Which of the following best describes the role of the Pribnow box in bacterial transcription?

Accepted Answer

It is a consensus sequence in the promoter region that helps RNA polymerase recognize the start site.

Bacterial Genome Replication and Expression: Study Notes for Genetics Students

Study Guide - Practice Questions

Study Guide - Flashcards