Q: Which equation correctly represents the elongation step of RNA synthesis?

$$\text{RNAn-OH} + \text{NTP} \rightarrow \text{RNAn+1-OH} + \text{PPi}$$

Question 1

Which of the following best describes the function of transfer RNA (tRNA) during translation?

Accepted Answer

tRNA carries amino acids to the ribosome for incorporation into the growing polypeptide chain.

Question 2

During transcription, which strand of DNA is used as the template for RNA synthesis?

Accepted Answer

The template (antisense) strand.

Question 3

Which equation correctly represents the elongation step of RNA synthesis?

Accepted Answer

$$	ext{RNAn-OH} + 	ext{NTP} ightarrow 	ext{RNAn+1-OH} + 	ext{PPi}$$

Question 4

Which of the following is NOT a post-transcriptional modification of eukaryotic mRNA?

Accepted Answer

Addition of a 3'-cap.

Question 5

What is the primary role of the sigma (σ) subunit in bacterial transcription?

Accepted Answer

It guides RNA polymerase to the promoter region.

Question 6

Which of the following statements best distinguishes transcription from replication?

Accepted Answer

Replication produces double-stranded DNA, while transcription produces single-stranded RNA.

Question 7

A mutation in the -10 region (TATA box) of a bacterial promoter is most likely to:

Accepted Answer

Reduce the strength of the promoter, decreasing transcription initiation.

Question 8

Which of the following is a characteristic of factor-independent termination of transcription in bacteria?

Accepted Answer

Formation of a hairpin loop in the RNA transcript due to palindromic sequences.

Question 9

In the context of gene expression regulation, which gene category is most likely to be expressed in response to environmental stimuli such as hormones?

Accepted Answer

Inducible genes.

Question 10

Which of the following best explains why mRNA is considered short-lived compared to tRNA and rRNA?

Accepted Answer

mRNA is constantly degraded after translation to prevent unnecessary protein synthesis.

Question 11

Which of the following sequences is most likely to be found in a strong bacterial promoter?

Accepted Answer

A sequence that closely matches the consensus sequences at the -10 and -35 regions.

Question 12

During transcription, in which direction does RNA polymerase synthesize the new RNA strand?

Accepted Answer

5' to 3' direction relative to the new strand.

Question 13

Which of the following is a correct description of the role of the 5'-cap in eukaryotic mRNA?

Accepted Answer

It protects mRNA from cleavage and serves as a ribosome attachment site for translation initiation.

Question 14

Which of the following best describes the action of the rho factor in factor-dependent termination?

Accepted Answer

Rho factor binds to nascent RNA, migrates towards the pause site, and releases the RNA transcript using ATP.

Question 15

A patient has a genetic mutation that prevents the removal of introns from pre-mRNA. Which of the following is the most likely consequence?

Accepted Answer

The mRNA will not be properly translated, resulting in nonfunctional proteins.

Question 16

Which of the following is true regarding the accuracy of RNA polymerase compared to DNA polymerase?

Accepted Answer

RNA polymerase is less accurate than DNA polymerase.

Question 17

Which of the following best describes the relationship between the coding strand and the RNA transcript?

Accepted Answer

The RNA transcript is identical to the coding strand except for the replacement of T with U.

Question 18

Which of the following is a multi-step process that integrates several concepts from transcription and RNA processing?

Accepted Answer

A gene is transcribed by RNA polymerase, the resulting pre-mRNA undergoes 5'-capping, polyadenylation, and intron removal before being exported for translation.

Question 19

Which of the following is a real-world example of gene expression regulation?

Accepted Answer

Insulin gene expression increases in response to elevated blood glucose levels.

Transcription and RNA Processing: Biochemistry Study Notes

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