Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

In prokaryotes, which of the following statements about RNA polymerase is correct?

Accepted Answer

A single RNA polymerase transcribes all types of RNA.

Question 3

Which sequence is commonly found at the -10 region of prokaryotic promoters and is essential for transcription initiation?

Accepted Answer

$\mathrm{TATAAT}$

Question 4

A mutation in the sigma ($\sigma$) factor of E. coli RNA polymerase would most likely result in which of the following?

Accepted Answer

Random initiation of transcription at non-specific sites.

Question 5

During prokaryotic transcription, which direction is the RNA strand synthesized?

Accepted Answer

5' to 3'

Question 6

Which of the following best explains the difference between intrinsic (rho-independent) and rho-dependent termination in prokaryotes?

Accepted Answer

Intrinsic termination relies on a stem-loop structure in the RNA followed by uracils, while rho-dependent requires a helicase protein to separate the RNA-DNA hybrid.

Question 7

Which of the following is NOT a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

Facilitates splicing of introns

Question 8

A researcher mutates the GU sequence at the 5' end of an intron in a eukaryotic gene. What is the most likely consequence?

Accepted Answer

The intron will not be recognized and will remain in the mature mRNA.

Question 9

Which of the following best describes the role of snRNPs ('snurps') in eukaryotic cells?

Accepted Answer

They are components of the spliceosome and are essential for intron removal.

Question 10

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

Accepted Answer

In prokaryotes, transcription and translation are coupled, while in eukaryotes they are separated by the nuclear envelope.

Question 11

Which eukaryotic RNA polymerase is responsible for transcribing all protein-coding genes?

Accepted Answer

RNA polymerase II

Question 12

A patient is found to have a mutation that prevents the addition of a poly(A) tail to mRNA. Which of the following is a likely consequence?

Accepted Answer

The mRNA will be rapidly degraded in the cytoplasm.

Question 13

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

Accepted Answer

They recognize promoter sequences and help position RNA polymerase II at the transcription start site.

Question 14

In the context of prokaryotic transcription, what is the primary role of the NusA protein?

Accepted Answer

It is an elongation factor that replaces sigma after initiation.

Question 15

A gene in E. coli is under heat shock conditions. Which sigma factor is most likely to be involved in its transcription?

Accepted Answer

$\sigma^{32}$

Question 16

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

Accepted Answer

Eukaryotic promoters are first recognized by general transcription factors, while prokaryotic promoters are recognized by sigma factors.

Question 17

A scientist discovers a new antibiotic that inhibits the helicase activity of the Rho protein. Which process will be directly affected?

Accepted Answer

Rho-dependent termination of transcription

Question 18

Which of the following sequences signals the addition of a poly(A) tail during eukaryotic mRNA processing?

Accepted Answer

$\mathrm{AAUAAA}$

Question 19

A mutation in a eukaryotic cell prevents the assembly of the spliceosome. Which of the following is the most likely outcome?

Accepted Answer

Introns will not be removed from pre-mRNA, resulting in abnormal mRNA.

Question 20

Which of the following best explains why eukaryotic mRNA must be processed before translation?

Accepted Answer

To remove introns, add a 5' cap, and add a poly(A) tail, which are all necessary for stability and translation.

Transcription and RNA Processing: Key Concepts in Genetic Analysis

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