Question 1

Which of the following best describes the relationship between a chromosome and genes?

Accepted Answer

A chromosome is a very long molecule of DNA that contains many genes.

Question 2

What is the primary function of the promoter region in a gene?

Accepted Answer

It controls the access of RNA polymerase to the gene and initiates transcription.

Question 3

Which of the following statements about the sigma (σ) subunit in bacterial RNA polymerase is correct?

Accepted Answer

It provides specificity for promoter recognition by binding to consensus sequences.

Question 4

During bacterial transcription, what is the significance of the −10 and −35 consensus sequences?

Accepted Answer

They are recognized by the sigma subunit to position RNA polymerase for transcription initiation.

Question 5

Which of the following best describes intrinsic (rho-independent) termination in bacteria?

Accepted Answer

It involves a hairpin structure in the mRNA followed by a string of uracils, causing RNA polymerase to dissociate.

Question 6

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

Accepted Answer

RNA polymerase II

Question 7

A mutation is introduced into the TATA box of a eukaryotic promoter. What is the most likely outcome?

Accepted Answer

Transcription levels will significantly decrease.

Question 8

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

Accepted Answer

Signaling the end of translation

Question 9

What is the role of enhancer sequences in eukaryotic gene regulation?

Accepted Answer

They increase the level of transcription by binding activator proteins and coactivators.

Question 10

Which of the following accurately describes the process of alternative intron splicing?

Accepted Answer

It allows a single gene to produce multiple mature mRNAs with different exon combinations.

Question 11

A eukaryotic gene contains the following sequence near its 3' end: 5'-AAUAAA-3'. What is the function of this sequence?

Accepted Answer

It is the polyadenylation signal for cleavage and addition of the poly-A tail.

Question 12

Which of the following steps occurs FIRST during the initiation of bacterial transcription?

Accepted Answer

The RNA polymerase holoenzyme forms a closed promoter complex by loosely binding to the promoter.

Question 13

Which of the following is TRUE regarding the function of silencers in eukaryotic gene regulation?

Accepted Answer

They repress transcription by binding repressor proteins and inducing DNA bending.

Question 14

Which of the following is a direct result of a mutation in the 5' splice site consensus sequence (GU) of a eukaryotic intron?

Accepted Answer

Splicing will be impaired, potentially resulting in retention of the intron in the mature mRNA.

Question 15

Which of the following equations correctly represents the antiparallel nature of DNA and RNA synthesis during transcription?

Accepted Answer

$$3' \rightarrow 5'$$ DNA template is read to synthesize $$5' \rightarrow 3'$$ RNA$

Question 16

Which of the following best explains why eukaryotic mRNAs are generally more stable than bacterial mRNAs?

Accepted Answer

Eukaryotic mRNAs undergo post-transcriptional modifications such as 5' capping and 3' polyadenylation.

Question 17

A researcher mutates the branch point adenine in a eukaryotic intron. What is the most likely effect on mRNA processing?

Accepted Answer

The intron will not be properly spliced out, leading to abnormal mRNA.

Question 18

Which of the following is a function of the carboxyl terminal domain (CTD) of RNA polymerase II in eukaryotes?

Accepted Answer

It serves as an assembly platform and regulator for pre-mRNA processing machinery.

Transcription and RNA Processing: Mechanisms and Regulation in Prokaryotes and Eukaryotes

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