Question 1

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

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 2

During bacterial transcription, what is the primary role of the sigma ($$\sigma) $$subunit of RNA polymerase?

Accepted Answer

It binds to the promoter region to initiate transcription.

Question 3

Which of the following is NOT a difference between DNA and RNA?

Accepted Answer

RNA is synthesized in the 3' to 5' direction, while DNA is synthesized in the 5' to 3' direction.

Question 4

Given the template DNA strand 3'-CTTTTTTGCCAT-5', what is the sequence of the mRNA produced during transcription?

Accepted Answer

$$5'	ext{-}GAAAAAACGGUA-3'$$

Question 5

Which of the following best explains why overlapping genes are more common in viruses and bacteria than in eukaryotes?

Accepted Answer

Overlapping genes allow for more efficient use of limited genetic material.

Question 6

Which of the following is a key difference between transcription in eukaryotes and prokaryotes?

Accepted Answer

Eukaryotic mRNA requires processing such as capping, polyadenylation, and splicing.

Question 7

Which enzyme is responsible for synthesizing mRNA in eukaryotes?

Accepted Answer

RNA polymerase II

Question 8

What is the function of the 5' cap added to eukaryotic mRNA during processing?

Accepted Answer

It protects the mRNA from degradation and assists in ribosome binding during translation.

Question 9

A mutation prevents the removal of the sigma ($$\sigma) $$subunit from bacterial RNA polymerase after initiation. What is the most likely effect on transcription?

Accepted Answer

Transcription will initiate but fail to efficiently elongate the RNA transcript.

Question 10

Which of the following best describes the role of introns in eukaryotic genes?

Accepted Answer

They are non-coding sequences that are removed from pre-mRNA during processing.

Question 11

Which of the following steps occurs first during the splicing of a eukaryotic pre-mRNA?

Accepted Answer

U1 snRNP binds to the 5' splice site.

Question 12

Which of the following is a direct result of the formation of a hairpin structure at the 3' end of a bacterial mRNA transcript?

Accepted Answer

RNA polymerase stalls and the transcript dissociates from the DNA template.

Question 13

Which of the following best explains why mature eukaryotic mRNA is typically shorter than the initial pre-mRNA transcript?

Accepted Answer

Introns are removed during splicing.

Question 14

A researcher observes that a eukaryotic gene is not being expressed even though RNA polymerase II is present. Which of the following is the most likely explanation?

Accepted Answer

The gene lacks a TATA box in its promoter region.

Question 15

Which of the following is true regarding the directionality of RNA synthesis during transcription?

Accepted Answer

RNA is synthesized in the 5' to 3' direction.

Question 16

Which of the following best describes the function of snRNAs in the spliceosome?

Accepted Answer

They catalyze the removal of introns from pre-mRNA.

Question 17

Which of the following is a consequence of alternative splicing in eukaryotes?

Accepted Answer

It increases the number of proteins that can be produced from a single gene.

Question 18

Which of the following is a real-world application of understanding bacterial transcription mechanisms?

Accepted Answer

Designing antibiotics that inhibit bacterial RNA polymerase.

Question 19

Which of the following statements about the coding and template strands of DNA is correct?

Accepted Answer

The template strand is complementary to the mRNA sequence.

Chapter 13: The Genetic Code and Transcription – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard