Question 1

Which of the following best describes the Central Dogma of Genetics?

Accepted Answer

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

Question 2

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

Accepted Answer

It serves as the binding site for RNA polymerase to initiate transcription.

Question 3

During transcription in bacteria, which sequence is recognized by the sigma factor for tight binding of RNA polymerase?

Accepted Answer

The -10 and -35 regions of the promoter

Question 4

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

Accepted Answer

The coding strand is identical to the RNA transcript, except T is replaced by U.

Question 5

Which of the following is NOT a function of the 7-methylguanosine cap added to eukaryotic mRNA?

Accepted Answer

Directs the addition of the poly(A) tail

Question 6

A mutation in the CAAT box of a eukaryotic promoter would most likely affect which process?

Accepted Answer

The efficiency of transcription

Question 7

Which of the following best explains why uracil is used in RNA instead of thymine?

Accepted Answer

Uracil allows cells to distinguish RNA from DNA and is less energy-intensive to produce.

Question 8

Which of the following is a key difference between rho-dependent and rho-independent termination in bacteria?

Accepted Answer

Rho-dependent termination requires a protein factor, while rho-independent relies on a stem-loop structure and uracil-rich sequence.

Question 9

Which of the following equations correctly represents the direction of RNA synthesis by RNA polymerase?

Accepted Answer

$$5' \rightarrow 3'$$

Question 10

A eukaryotic gene is transcribed but the resulting mRNA is not exported from the nucleus. Which modification is most likely missing?

Accepted Answer

Addition of the 5' cap

Question 11

Which of the following best describes alternative splicing?

Accepted Answer

The process by which different exons are joined in various combinations to produce multiple mRNAs from a single gene

Question 12

Which of the following is a cis-acting element in eukaryotic gene regulation?

Accepted Answer

TATA box

Question 13

Which of the following is true regarding the function of the mediator complex in eukaryotic transcription?

Accepted Answer

It mediates interactions between RNA polymerase II and regulatory transcription factors, influencing the switch from initiation to elongation.

Question 14

Which of the following modifications is unique to eukaryotic mRNA and not found in prokaryotic mRNA?

Accepted Answer

Addition of a 5' cap and a 3' poly(A) tail

Question 15

A mutation prevents the removal of introns from a pre-mRNA in a eukaryotic cell. Which cellular structure is most likely defective?

Accepted Answer

Spliceosome

Question 16

Which of the following best describes the role of splicing factors in alternative splicing?

Accepted Answer

They regulate which exons are included or excluded in the final mRNA.

Question 17

Which of the following is an example of RNA editing in mammals?

Accepted Answer

C-to-U conversion in apolipoprotein B mRNA

Question 18

Which of the following equations represents the complementary base pairing rule during transcription?

Accepted Answer

$$A_{DNA} \rightarrow U_{RNA}$$, $$T_{DNA} \rightarrow A_{RNA}$$, $$C_{DNA} \rightarrow G_{RNA}$$, $$G_{DNA} \rightarrow C_{RNA}$$

Question 19

Which of the following is a direct result of alternative splicing in humans?

Accepted Answer

Production of multiple protein isoforms from a single gene

Question 20

Which of the following best explains why the poly(A) tail is important for eukaryotic mRNA?

Accepted Answer

It protects the mRNA from degradation and assists in export from the nucleus.

Gene Transcription and RNA Modification: Structured Study Notes

Guida di studio - Domande di pratica