Question 1

Which of the following best describes the primary function of homologous recombination in eukaryotic cells?

Accepted Answer

To repair double-strand breaks in DNA using a homologous template

Question 2

During bacterial transcription, which sequence is typically found about 10 base pairs upstream of the transcription start site and is crucial for RNA polymerase binding?

Accepted Answer

The -10 sequence (TATAAT or Pribnow box)

Question 3

Which of the following statements about the coupling of transcription and translation in prokaryotes is correct?

Accepted Answer

Multiple ribosomes can bind to a single mRNA while it is still being transcribed

Question 4

What is the role of the sigma ($$ \sigma ) $$factor in bacterial RNA polymerase?

Accepted Answer

It promotes binding of RNA polymerase to the correct promoter sequences

Question 5

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

Accepted Answer

Eukaryotic transcription requires general transcription factors for RNA polymerase binding

Question 6

A mutation in the -10 sequence of a bacterial promoter would most likely result in which of the following?

Accepted Answer

Reduced binding of RNA polymerase and decreased transcription initiation

Question 7

Which enzyme activity is responsible for relieving supercoiling ahead of the transcription bubble during elongation?

Accepted Answer

Topoisomerase

Question 8

In eukaryotic transcription, which core promoter element is recognized and bound by the TATA-binding protein (TBP)?

Accepted Answer

The TATA box

Question 9

Which of the following best explains why RNA polymerase does not require a primer to initiate RNA synthesis?

Accepted Answer

RNA polymerase can start synthesis de novo by binding ribonucleoside triphosphates (NTPs) complementary to the DNA template

Question 10

Which of the following is a possible outcome of homologous recombination during meiosis?

Accepted Answer

Gene conversion without crossing over

Question 11

A bacterial gene has a strong promoter with an UP element. What is the most likely effect of the UP element?

Accepted Answer

It enhances the binding of RNA polymerase, increasing transcription

Question 12

Which of the following best describes the process of abortive synthesis during transcription initiation?

Accepted Answer

RNA polymerase repeatedly synthesizes and releases short RNA fragments before escaping the promoter

Question 13

Which of the following is true regarding the termination of transcription in bacteria?

Accepted Answer

Termination can occur either with or without the rho ($$ \rho ) $$factor, depending on the sequence

Question 14

Which eukaryotic RNA polymerase is responsible for synthesizing mRNA?

Accepted Answer

RNA polymerase II

Question 15

A mutation prevents the release of the sigma factor from bacterial RNA polymerase after initiation. What is the most likely consequence?

Accepted Answer

RNA polymerase will not be able to escape the promoter, reducing elongation

Question 16

Which of the following best describes the function of general transcription factors in eukaryotic transcription?

Accepted Answer

They are required for RNA polymerase binding to the promoter

Question 17

Which of the following is a direct result of the formation and resolution of a Holliday junction during homologous recombination?

Accepted Answer

Permanent exchange of DNA segments between homologous chromosomes

Question 18

Which of the following best explains why eukaryotic transcription is more complex than prokaryotic transcription?

Accepted Answer

Eukaryotic transcription involves multiple RNA polymerases and requires transcription factors

Question 19

Which of the following is a function of the TFIID complex in eukaryotic transcription initiation?

Accepted Answer

It binds to the TATA box and recruits other transcription factors

Question 20

Which of the following best describes the role of RNA backtracking in RNA proofreading?

Accepted Answer

RNA polymerase backs up, removing the incorrect nucleotide and the previous one

DNA Recombination and Transcription Mechanisms in Prokaryotes and Eukaryotes

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