Question 1

Which of the following best describes the role of the TATA box in eukaryotic transcription initiation?

Accepted Answer

It is a promoter element that binds general transcription factors, facilitating the recruitment of RNA polymerase II.

Question 2

During transcription, which of the following correctly describes the direction in which RNA is synthesized?

Accepted Answer

RNA is synthesized in the 5' to 3' direction, using the DNA template strand read 3' to 5'.

Question 3

Which of the following is a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It facilitates the export of mRNA from the nucleus and protects it from degradation.

Question 4

A patient is exposed to α-amanitin, a toxin that inhibits RNA polymerase II. Which process would be most directly affected?

Accepted Answer

Synthesis of messenger RNA (mRNA)

Question 5

Which of the following sequences acts as the polyadenylation signal in eukaryotic mRNA processing?

Accepted Answer

$$AAUAAA$$

Question 6

In prokaryotes, genes are often organized in operons. What is a key feature of polycistronic mRNA produced from operons?

Accepted Answer

It contains multiple coding regions, each translated into a different protein.

Question 7

Which of the following best explains why certain antibiotics selectively inhibit bacterial RNA polymerase but not eukaryotic RNA polymerase?

Accepted Answer

Bacterial and eukaryotic RNA polymerases differ in their protein structure and subunit composition.

Question 8

Which of the following is the correct sequence of events in eukaryotic mRNA processing?

Accepted Answer

Addition of 5' cap, splicing of introns, addition of poly(A) tail

Question 9

A mutation in the splice donor site (5' end of an intron) of a gene would most likely result in which of the following?

Accepted Answer

Retention of the intron in the mature mRNA

Question 10

Which of the following statements about the template strand in transcription is correct?

Accepted Answer

It is read by RNA polymerase in the 3' to 5' direction to synthesize RNA in the 5' to 3' direction.

Question 11

Which of the following is a direct consequence of the hydrolysis of pyrophosphate ($$PP_i) $$during RNA synthesis?

Accepted Answer

It provides energy to drive the polymerization reaction forward.

Question 12

Which of the following is true regarding the function of general transcription factors in eukaryotes?

Accepted Answer

They facilitate the binding of RNA polymerase II to the promoter region.

Question 13

Which of the following best describes the difference between prokaryotic and eukaryotic mRNA?

Accepted Answer

Eukaryotic mRNA undergoes extensive processing, including capping, polyadenylation, and splicing, while prokaryotic mRNA does not.

Question 14

Which of the following enzymes is responsible for adding the poly(A) tail to eukaryotic mRNA?

Accepted Answer

Poly(A) polymerase

Question 15

A researcher isolates a mature eukaryotic mRNA and finds that it contains the sequence $$AGGU at $$the exon-intron boundary. What is the significance of this sequence?

Accepted Answer

It is the consensus sequence for the splice donor site, necessary for proper intron removal.

Question 16

Which of the following statements about the HIV life cycle is correct?

Accepted Answer

HIV integrates its DNA into the host genome, allowing host RNA polymerase II to transcribe viral genes.

Question 17

Which of the following is a unique feature of eukaryotic tRNA maturation compared to mRNA maturation?

Accepted Answer

Removal of introns and addition of CCA sequence at the 3' end

Question 18

Which of the following best explains why eukaryotic genes are often interrupted by introns?

Accepted Answer

Introns allow for alternative splicing, increasing protein diversity.

Question 19

Which of the following is the correct order of events for the removal of introns from pre-mRNA in eukaryotes?

Accepted Answer

Binding of U1 and U2 snRNPs, formation of the lariat structure, cleavage at the 3' splice site, ligation of exons

Transcription: Synthesis of RNA – Biochemistry Study Notes

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