Q: During DNA replication in bacteria, what is the primary reason that Okazaki fragments are formed on the lagging strand?

Because DNA polymerase can only synthesize DNA in the $$5' \to 3'$$ direction, requiring repeated priming on the lagging strand.

Question 1

During DNA replication in bacteria, what is the primary reason that Okazaki fragments are formed on the lagging strand?

Accepted Answer

Because DNA polymerase can only synthesize DNA in the $$5' 	o 3'$$ direction, requiring repeated priming on the lagging strand.

Question 2

Which of the following best explains why most bacteria have circular chromosomes, while eukaryotes have linear chromosomes with telomeres?

Accepted Answer

Circular chromosomes prevent the end-replication problem, eliminating the need for telomeres.

Question 3

A mutation prevents the removal of RNA primers from Okazaki fragments during bacterial DNA replication. What is the most likely consequence?

Accepted Answer

The newly synthesized DNA will contain RNA segments, compromising genome integrity.

Question 4

In prokaryotes, what allows translation to begin on an mRNA molecule before transcription is complete?

Accepted Answer

The absence of a nuclear membrane allows ribosomes to access mRNA as it is being transcribed.

Question 5

Which of the following statements about operons in prokaryotes is correct?

Accepted Answer

Operons typically contain multiple genes with related functions, transcribed as a single mRNA.

Question 6

A bacterial cell is exposed to a chemical that specifically inhibits release factors RF1 and RF2 during translation. What is the most likely outcome for protein synthesis?

Accepted Answer

Polypeptides will remain attached to the ribosome and tRNA, unable to be released at stop codons.

Question 7

Which of the following best describes the function of the Shine-Dalgarno sequence in prokaryotic translation?

Accepted Answer

It base pairs with the $$16S$$ rRNA to position the ribosome at the correct start codon.

Question 8

If a prokaryotic mRNA lacks a stop codon due to a mutation, which mechanism allows the cell to rescue the stalled ribosome and degrade the aberrant protein?

Accepted Answer

tmRNA binds to the ribosome, adds a degradation tag to the polypeptide, and provides a stop codon for release.

Question 9

Which of the following is a key difference between transcription in prokaryotes and eukaryotes?

Accepted Answer

In eukaryotes, transcription occurs in the nucleus, physically separated from translation.

Question 10

What is the primary role of chaperone proteins such as GroEL in bacterial cells?

Accepted Answer

To assist in the proper folding of newly synthesized or misfolded proteins.

Question 11

Which of the following best describes the function of the sigma factor in prokaryotic transcription?

Accepted Answer

It recognizes promoter sequences and directs RNA polymerase to the correct initiation site.

Question 12

Which of the following is a similarity between Rho-dependent and Rho-independent transcription termination in bacteria?

Accepted Answer

Both mechanisms ultimately cause the release of the mRNA from the DNA template.

Question 13

A researcher introduces a mutation in the -10 region (TATA box) of a bacterial promoter. What is the most likely effect on gene expression?

Accepted Answer

Transcription initiation will be reduced or abolished due to impaired RNA polymerase binding.

Question 14

Which of the following statements about horizontal gene transfer in bacteria is correct?

Accepted Answer

Conjugation requires direct cell-to-cell contact and typically involves transfer of plasmid DNA.

Question 15

In the context of protein quality control, what is the fate of a misfolded protein that cannot be refolded by chaperones?

Accepted Answer

It is targeted for degradation by the protease complex.

Question 16

Which of the following best describes the relationship between the template and non-template strands of DNA during transcription?

Accepted Answer

The mRNA sequence is complementary to the template strand and nearly identical to the non-template (coding) strand, except uracil replaces thymine.

Question 17

A bacterial cell is unable to form a ribosome binding site upstream of a gene. What is the most likely consequence?

Accepted Answer

The gene's mRNA will not be efficiently translated, resulting in little or no protein production.

Question 18

Which of the following is a key feature of transformation as a mechanism of horizontal gene transfer in bacteria?

Accepted Answer

It involves the uptake of free DNA from the environment by a competent cell.

Question 19

Why is the $$16S$$ rRNA gene commonly used as a molecular clock in bacterial phylogenetics?

Accepted Answer

It is highly conserved across species but accumulates mutations at a measurable rate.

Question 20

Which of the following best describes vertical gene transfer?

Accepted Answer

The transmission of genetic material from parent to offspring during reproduction.

Microbial Genetics, Gene Expression, and Protein Quality Control

Study Guide - Practice Questions

Study Guide - Flashcards