$$\text{NTP} \rightarrow \text{NMP} + 2\text{P}$$

Question 1

Which of the following statements correctly describes the directionality of mRNA synthesis during transcription?

Accepted Answer

mRNA is synthesized in the 5' to 3' direction.

Question 2

In prokaryotes, which of the following is TRUE regarding the coupling of transcription and translation?

Accepted Answer

Translation can begin while transcription is still ongoing.

Question 3

Which RNA polymerase is responsible for synthesizing pre-mRNA in eukaryotes?

Accepted Answer

RNA polymerase II

Question 4

What is the function of the sigma ($$\sigma) $$subunit in prokaryotic RNA polymerase?

Accepted Answer

It recognizes and binds to promoter regions to initiate transcription.

Question 5

Which of the following best describes the role of enhancers in eukaryotic gene expression?

Accepted Answer

Enhancers bind transcription factors and increase transcription efficiency, regardless of their position or orientation.

Question 6

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

Accepted Answer

Eukaryotic mRNA is processed by capping, polyadenylation, and splicing before translation.

Question 7

In the lac operon, what happens when lactose is present?

Accepted Answer

Lactose binds to the repressor, causing it to release from the operator and allowing transcription.

Question 8

Which of the following sequences is most likely to be found in a eukaryotic promoter region?

Accepted Answer

TATA box ($$	ext{TATAAA})$$

Question 9

Which mechanism is responsible for rho-independent termination in prokaryotic transcription?

Accepted Answer

Formation of a hairpin structure in the RNA transcript followed by a series of U's.

Question 10

A mutation in the CAAT box of a eukaryotic gene promoter would most likely affect which process?

Accepted Answer

Initiation of transcription

Question 11

Which of the following is TRUE regarding the stability of DNA-RNA duplexes compared to DNA-DNA duplexes?

Accepted Answer

DNA-RNA duplexes are less stable than DNA-DNA duplexes.

Question 12

Which of the following is NOT a function of post-transcriptional processing in eukaryotic pre-mRNA?

Accepted Answer

Addition of a sigma subunit

Question 13

Which equation best represents the hydrolysis of ribonucleoside triphosphates during transcription?

Accepted Answer

$$	ext{NTP} ightarrow 	ext{NMP} + 2	ext{P}$$

Question 14

Which of the following is a property of enhancers that distinguishes them from promoters?

Accepted Answer

Enhancers can function regardless of their position and orientation relative to the gene.

Question 15

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

Accepted Answer

Introns are removed and exons are joined together.

Question 16

Which of the following is TRUE about polycistronic mRNA?

Accepted Answer

It contains coding sequences for multiple proteins.

Question 17

Which of the following is a consequence of the removal of the sigma subunit from prokaryotic RNA polymerase after initiation?

Accepted Answer

RNA polymerase continues elongation of the RNA transcript.

Question 18

Which of the following is a function of the CCA sequence added to the 3' end of tRNA during post-transcriptional processing?

Accepted Answer

It serves as the site for amino acid attachment.

Question 19

Which of the following statements about the lac operon is correct?

Accepted Answer

The lac operon is regulated by a repressor that binds to the operator in the absence of lactose.

Transcription and Post-Transcriptional Processing in Prokaryotes and Eukaryotes

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