Question 1

Which of the following best describes the role of the core promoter in eukaryotic transcription?

Accepted Answer

It is necessary but not sufficient for physiological levels of gene expression.

Question 2

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

Accepted Answer

It prevents the enhancer from acting on the promoter when placed between them.

Question 3

Which of the following is TRUE regarding the difference between prokaryotic and eukaryotic transcription initiation?

Accepted Answer

Eukaryotes require general transcription factors for RNA polymerase II to bind the promoter.

Question 4

A mutation occurs in the branch site of an intron in a eukaryotic gene. What is the most likely consequence?

Accepted Answer

Splicing will be prevented, leading to intron retention and possible exon loss.

Question 5

Which sequence is recognized as the polyadenylation signal during eukaryotic mRNA processing?

Accepted Answer

$$AAUAAA$$

Question 6

What is the primary function of the 7-methylguanylate cap added to the 5' end of eukaryotic mRNA?

Accepted Answer

It facilitates mRNA export from the nucleus and protects against 5'-3' exonucleases.

Question 7

Which of the following statements about the carboxy-terminal domain (CTD) of RNA polymerase II is CORRECT?

Accepted Answer

It contains repeats of the sequence $$YSPTSPS$$ and is phosphorylated during transcription initiation.

Question 8

During eukaryotic mRNA processing, which of the following events occurs FIRST?

Accepted Answer

Addition of the 7-methylguanylate cap to the 5' end

Question 9

A patient has a mutation that disrupts the donor sequence at the 5' splice site of an intron. What is the most likely effect on the resulting protein?

Accepted Answer

The protein may be truncated due to intron retention and possible frame shift or premature stop codon.

Question 10

Which of the following is a function of TFIIH during eukaryotic transcription?

Accepted Answer

It phosphorylates the CTD of RNA polymerase II and has helicase activity.

Question 11

Which of the following best explains why eukaryotic mRNA is more stable than prokaryotic mRNA?

Accepted Answer

Eukaryotic mRNA has a 5' cap and a poly(A) tail that protect it from exonucleases.

Question 12

Which of the following is TRUE regarding the spatial and temporal separation of transcription and translation in eukaryotes?

Accepted Answer

Transcription occurs in the nucleus, and translation occurs in the cytoplasm.

Question 13

A gene contains an intron with a length that is not a multiple of 3 nucleotides. If this intron is retained in the mature mRNA, what is the most likely consequence?

Accepted Answer

A frame shift mutation will occur, potentially leading to a premature stop codon.

Question 14

Which of the following is a key difference between enhancer and promoter elements in eukaryotic gene regulation?

Accepted Answer

Promoters position RNA polymerase II for transcription initiation, while enhancers provide additional binding sites for transcription factors.

Question 15

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

Accepted Answer

$$GU$$

Question 16

During the splicing reaction, which nucleotide in the branch site attacks the 5' splice site to form the lariat structure?

Accepted Answer

Adenine ($$A)$$

Question 17

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

Accepted Answer

Removes introns from pre-mRNA

Question 18

Which of the following statements about the spliceosome is CORRECT?

Accepted Answer

It is a large ribonucleoprotein complex that removes introns from pre-mRNA.

Question 19

A mutation in the upstream promoter element of a gene reduces the binding of activator transcription factors. What is the most likely effect?

Accepted Answer

Decreased expression of the gene due to reduced recruitment of transcription factors

Eukaryotic Transcriptional Regulation and RNA Processing

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