Gene Transcription: A Comprehensive Guide for Medical Students

Question 1

Which enzyme catalyzes the synthesis of RNA from a DNA template?

Accepted Answer

RNA Polymerase

Answer

DNA Polymerase

Answer

Primase

Answer

Reverse Transcriptase

Question 2

Transcription typically initiates at a specific DNA sequence known as the:

Accepted Answer

Promoter

Answer

Enhancer

Answer

Terminator

Answer

Operator

Question 3

Enhancers in gene expression function primarily to:

Accepted Answer

Increase the rate of transcription

Answer

Determine the start site of transcription

Answer

Stabilize RNA polymerase binding to the promoter

Answer

Terminate transcription

Question 4

The DNA sequence that signals the termination of transcription is known as the:

Accepted Answer

Terminator

Answer

Promoter

Answer

Enhancer

Answer

Operator

Question 5

Constitutive genes, in contrast to inducible genes, are characterized by:

Accepted Answer

Continuous transcription

Answer

Transcription only in response to specific stimuli

Answer

Transcription only in prokaryotes

Answer

Transcription only in eukaryotes

Question 6

Alternative splicing is a crucial process in gene expression because it allows for:

Accepted Answer

Production of multiple protein isoforms from a single gene

Answer

Regulation of gene expression by controlling mRNA stability

Answer

Proper function of the immune system

Answer

It is uniquely found in eukaryotic cells

Question 7

Enhancers increase transcription rates by:

Accepted Answer

Both of the above

Answer

Recruiting RNA polymerase to the promoter

Answer

Modifying histones to make DNA more accessible

Question 8

The primary structure of RNA is:

Accepted Answer

A single-stranded polymer of ribonucleotides linked by phosphodiester bonds

Answer

A double-stranded polymer of ribonucleotides

Question 9

RNA polymerase II synthesizes:

Accepted Answer

Messenger RNA (mRNA)

Answer

Synthesis of transfer RNA (tRNA)

Question 10

A key difference between prokaryotic and eukaryotic transcription is that:

Accepted Answer

Eukaryotes have multiple RNA polymerases, while prokaryotes have only one.

Answer

Prokaryotes have promoters, while eukaryotes do not.

Question 11

Which of the following accurately describes the function of a transcription factor?

Accepted Answer

Binds to specific DNA sequences to regulate transcription initiation, elongation, or termination

Answer

To synthesize RNA molecules

Question 12

Which enzyme is solely responsible for synthesizing RNA molecules during transcription?

Accepted Answer

RNA polymerase

Answer

DNA polymerase

Question 13

Where does transcription typically initiate in eukaryotic genes?

Accepted Answer

Promoter

Answer

Terminator

Answer

Enhancer

Answer

Silencer

Question 14

Which of the following is NOT a mechanism by which transcription can be regulated?

Accepted Answer

RNA interference

Answer

Activator binding

Answer

Co-activator binding

Answer

Repressor binding

Question 15

What is the primary structure of the RNA molecule produced during transcription?

Accepted Answer

Complementary to the template DNA strand

Answer

Identical to the template DNA strand

Answer

Semi-complementary to the template DNA strand

Answer

Randomly arranged nucleotides

Question 16

What is the primary role of silencers in transcription?

Accepted Answer

Block transcription

Answer

Facilitate transcription

Answer

Enhance transcription

Answer

Terminate transcription

Question 17

How does DNA methylation primarily affect gene expression?

Accepted Answer

Suppresses transcription initiation

Answer

Enhances transcription initiation

Answer

Accelerates transcription elongation

Answer

Has no impact on transcription

Question 18

Which component is NOT present in the structure of RNA polymerase?

Accepted Answer

Helicase

Answer

Sigma factor

Answer

Core enzyme

Question 19

In eukaryotic cells, where does transcription initiation usually take place?

Accepted Answer

Promoter

Answer

Enhancer

Answer

Coding sequence

Answer

Terminator

Question 20

During transcription, which enzyme is responsible for unwinding the DNA double helix?

Accepted Answer

Helicase

Answer

Primase

Answer

DNA polymerase

Answer

RNA ligase

Question 21

What is the primary function of enhancers in gene expression?

Accepted Answer

Enhance gene transcription

Answer

Terminate transcription

Answer

Facilitate translation

Answer

Initiate transcription

Question 22

Which of the following modifications are characteristic of mature eukaryotic mRNAs?

Accepted Answer

5' cap and 3' poly(A) tail

Answer

Promoter and terminator sequences

Answer

5' UTR and 3' UTR

Answer

Introns and exons

Question 23

What is the purpose of the sigma factor in transcription?

Accepted Answer

Directs RNA polymerase to specific promoter regions

Answer

Proofreads the RNA transcript for errors

Answer

Synthesizes the RNA transcript

Question 24

What is the role of the transcription termination signal?

Accepted Answer

Terminates RNA polymerase transcription

Answer

Promotes RNA processing

Answer

Recruits proteins involved in transcription

Answer

Initiates transcription

Question 25

What is the main difference between mRNA and tRNA?

Accepted Answer

mRNA carries genetic information, while tRNA transfers amino acids during protein synthesis.

Answer

mRNA is single-stranded, while tRNA is double-stranded.

Answer

mRNA is synthesized in the cytoplasm, while tRNA is synthesized in the nucleus.