Question 1

Which of the following best describes the role of the TATA box in eukaryotic transcription initiation?

Accepted Answer

It is a core promoter element recognized by transcription factors to position RNA polymerase II for transcription initiation.

Question 2

A mutation in the gene encoding the enzyme guanylyltransferase would most directly affect which process?

Accepted Answer

Addition of a 7-methylguanosine cap to the 5’ end of mRNA

Question 3

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

Accepted Answer

RNA polymerase II

Question 4

A patient is found to have a mutation in the gene encoding CPSF (Cleavage and Polyadenylation Specificity Factor). Which of the following processes is most likely to be disrupted?

Accepted Answer

Cleavage and polyadenylation of pre-mRNA

Question 5

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

Accepted Answer

Initiation of polyadenylation at the 3’ end

Question 6

Which sequence of events correctly describes the order of eukaryotic mRNA processing?

Accepted Answer

5’ capping → splicing → polyadenylation

Question 7

A researcher observes that a certain eukaryotic gene is transcribed but the resulting mRNA is not exported from the nucleus. Which defect is most likely responsible?

Accepted Answer

Failure to add a 5’ cap

Question 8

Which of the following best explains the outcome of a mutation that prevents the binding of TFIIB during transcription initiation?

Accepted Answer

RNA polymerase II cannot bind to the promoter, blocking transcription initiation.

Question 9

Which of the following is a unique feature of RNA editing in eukaryotes?

Accepted Answer

It can change the base sequence of an RNA after it is synthesized.

Question 10

Which of the following equations correctly represents the hydrolysis reaction catalyzed by guanylyltransferase during 5’ capping?

Accepted Answer

$$\mathrm{GTP \rightarrow GMP + PP_i}$$

Question 11

A mutation in the polyadenylation signal sequence (AAUAAA) of a gene would most likely result in which of the following?

Accepted Answer

Improper cleavage and polyadenylation of the pre-mRNA

Question 12

Which of the following is TRUE regarding the function of RNA polymerase III in eukaryotic cells?

Accepted Answer

It transcribes all tRNA genes and the 5S rRNA gene.

Question 13

Which of the following best describes the effect of histone acetylation on transcription?

Accepted Answer

It relaxes chromatin structure, facilitating transcription factor access.

Question 14

A scientist discovers a eukaryotic cell line with defective snRNA production. Which process is most likely impaired?

Accepted Answer

RNA splicing

Question 15

Which of the following is a direct consequence of a mutation that inactivates the enzyme poly(A) polymerase (PAP)?

Accepted Answer

mRNA molecules lack a poly(A) tail and are rapidly degraded in the cytoplasm.

Question 16

Which of the following best explains why RNA editing can have significant effects on protein function?

Accepted Answer

It can alter codons in the mRNA, leading to changes in the amino acid sequence of the protein.

Question 17

Which of the following is the correct sequence for the binding of transcription factors and RNA polymerase II during eukaryotic transcription initiation?

Accepted Answer

TFIID binds to the TATA box, followed by other transcription factors and then RNA polymerase II.

Question 18

Which of the following best describes the process of RNA splicing?

Accepted Answer

Removal of introns and joining of exons

Question 19

Which of the following is a real-life example of RNA editing affecting human health?

Accepted Answer

Editing of apolipoprotein B mRNA resulting in two different protein isoforms, impacting cholesterol metabolism

Eukaryotic Transcription and RNA Processing

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