$$\text{NTP} + \text{RNA}_{n} \rightarrow \text{RNA}_{n+1} + 2\text{PP}_i$$

$$\text{RNA polymerase moves 3' \rightarrow 5' on the template strand, synthesizing RNA 5' \rightarrow 3'}$$

Question 1

Which of the following statements best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

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

Accepted Answer

The template strand

Question 3

Which RNA molecule is directly involved in translation and carries the genetic message from DNA?

Accepted Answer

Messenger RNA (mRNA)

Question 4

What is the consensus sequence found at the −10 position of bacterial promoters, and what is its function?

Accepted Answer

5'-TATAAT-3'; it is recognized by RNA polymerase for transcription initiation

Question 5

Which equation correctly represents the formation of a phosphodiester bond during RNA synthesis?

Accepted Answer

$$	ext{NTP} + 	ext{RNA}_{n} ightarrow 	ext{RNA}_{n+1} + 2	ext{PP}_i$$

Question 6

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

Accepted Answer

Initiating DNA replication

Question 7

A mutation in the branch point adenine of an intron would most likely affect which process?

Accepted Answer

Intron splicing by the spliceosome

Question 8

Which of the following best explains why eukaryotic genes can produce more than one protein product?

Accepted Answer

Alternative splicing of pre-mRNA

Question 9

Which sequence is most likely to be found at the 5' splice site of a eukaryotic intron?

Accepted Answer

GU

Question 10

In the torpedo model of transcription termination in eukaryotes, what is the role of the specialized RNase?

Accepted Answer

It digests the residual uncapped transcript, leading to RNA polymerase II release

Question 11

Which of the following is a key difference between bacterial and eukaryotic transcription?

Accepted Answer

Eukaryotic genes contain introns that require splicing, while bacterial genes do not.

Question 12

Which of the following best describes the function of enhancer sequences in eukaryotic transcription?

Accepted Answer

They increase transcription by interacting with promoter-bound proteins.

Question 13

Which equation represents the directionality of RNA synthesis by RNA polymerase?

Accepted Answer

$$	ext{RNA polymerase moves 3' ightarrow 5' on the template strand, synthesizing RNA 5' ightarrow 3'}$$

Question 14

Which of the following is a plausible consequence of a mutation in the −10 consensus sequence (Pribnow box) of a bacterial promoter?

Accepted Answer

RNA polymerase will fail to recognize the promoter, reducing transcription.

Question 15

Which of the following is NOT a function of polyadenylation at the 3' end of eukaryotic mRNA?

Accepted Answer

Initiating transcription

Question 16

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

Accepted Answer

RNA polymerase II

Question 17

A patient is found to have a mutation that prevents the addition of the 5' cap to mRNA. Which cellular process would be most directly affected?

Accepted Answer

Transport of mRNA out of the nucleus

Question 18

Which of the following best describes the role of the sigma subunit in bacterial transcription?

Accepted Answer

It enables RNA polymerase to recognize and bind to specific promoter sequences.

Question 19

Which of the following scenarios illustrates alternative polyadenylation in gene expression?

Accepted Answer

A gene produces two mRNAs with different 3' ends due to the use of distinct polyadenylation signals.

RNA Transcription and Processing: Molecular Mechanisms and Regulation

Study Guide - Practice Questions