Question 1

Which of the following best describes the role of upstream promoter elements in eukaryotic gene regulation?

Accepted Answer

They are gene-specific sequences that are required for expression at physiological levels.

Question 2

What is the primary function of an insulator sequence in eukaryotic transcriptional regulation?

Accepted Answer

To block the action of enhancers on promoters when positioned between them.

Question 3

Which of the following statements about enhancers is TRUE?

Accepted Answer

Enhancers can act at a greater distance from the promoter than upstream promoter elements.

Question 4

A mutation occurs in the branch point sequence of an intron. What is the most likely consequence?

Accepted Answer

Impaired splicing, leading to intron retention or exon loss.

Question 5

Which consensus sequence is typically found at the 5' splice site of eukaryotic introns?

Accepted Answer

$$	ext{GU}$$

Question 6

During mRNA processing in eukaryotes, which modification is added to the 5' end of the pre-mRNA?

Accepted Answer

A 7-methylguanylate cap

Question 7

Which enzyme is responsible for adding the 7-methylguanylate cap to the 5' end of eukaryotic mRNA?

Accepted Answer

Guanylyl transferase

Question 8

What is the function of the carboxy-terminal domain (CTD) of RNA polymerase II during transcription?

Accepted Answer

It provides binding sites for RNA processing enzymes, such as capping and splicing factors.

Question 9

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

Accepted Answer

Eukaryotic mRNAs undergo splicing to remove introns.

Question 10

A patient has a mutation that disrupts the AAUAAA sequence in their pre-mRNA. What is the most likely effect?

Accepted Answer

Defective polyadenylation and improper mRNA 3' end formation.

Question 11

Which of the following best explains why the 7-methylguanylate cap is important for mRNA stability?

Accepted Answer

It prevents degradation by 5'-3' exonucleases.

Question 12

Which transcription factor is NOT released from RNA polymerase II during elongation and is involved in both transcription initiation and DNA repair?

Accepted Answer

TFIIH

Question 13

A gene contains an intron with a length that is not a multiple of 3 nucleotides and a mutation causes its retention. What is the most likely consequence for the protein product?

Accepted Answer

A frameshift mutation leading to a premature stop codon.

Question 14

Which of the following is TRUE regarding the assembly of the preinitiation complex (PIC) in eukaryotic transcription?

Accepted Answer

TFIID binds to the TATA box first, followed by other general transcription factors.

Question 15

Which of the following sequences is involved in the recognition of the 3' splice site during mRNA splicing?

Accepted Answer

$$	ext{AG}$$

Question 16

Which process is facilitated by the phosphorylation of the CTD of RNA polymerase II?

Accepted Answer

Promoter escape and transition to productive elongation

Question 17

A mutation in the donor splice site (5' end of an intron) most likely results in which of the following?

Accepted Answer

Retention of the intron in the mature mRNA

Question 18

Which of the following is a function of the spliceosome?

Accepted Answer

Removal of introns from pre-mRNA

Question 19

Which of the following best describes the difference in transcription termination between prokaryotes and eukaryotes?

Accepted Answer

Eukaryotic transcription termination can occur more than 1.5 kb downstream of the mature mRNA end.

Question 20

Which of the following is TRUE regarding the export of mature mRNA from the nucleus?

Accepted Answer

It requires the removal of introns and addition of both a 5' cap and a poly(A) tail.

Eukaryotic Transcriptional Regulation and RNA Processing

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