Question 1

Which of the following statements best describes the direction in which RNA polymerase synthesizes RNA during transcription?

Accepted Answer

RNA polymerase synthesizes RNA in the 5' to 3' direction, using the template strand in the 3' to 5' direction.

Question 2

What is the primary function of the promoter region in eukaryotic transcription?

Accepted Answer

It is the DNA sequence where RNA polymerase and transcription factors bind to initiate transcription.

Question 3

Which of the following events occurs during the elongation phase of transcription?

Accepted Answer

RNA polymerase adds ribonucleotides to the growing RNA strand, matching bases to the DNA template.

Question 4

In eukaryotic cells, which of the following modifications occurs to pre-mRNA before it becomes mature mRNA?

Accepted Answer

Addition of a 5' cap and a poly(A) tail, and removal of introns by splicing.

Question 5

Which enzyme is responsible for attaching amino acids to their corresponding tRNAs during translation?

Accepted Answer

Aminoacyl-tRNA synthetase

Question 6

During translation, which ribosomal site holds the tRNA carrying the growing polypeptide chain?

Accepted Answer

P-site (peptidyl site)

Question 7

What is the role of the polyadenylation signal sequence (AAUAAA) in eukaryotic transcription termination?

Accepted Answer

It signals the RNA transcript to be cut and the poly(A) tail to be added.

Question 8

Which of the following best explains why splicing is important in eukaryotic gene expression?

Accepted Answer

Splicing removes introns, allowing exons to be joined and different mRNAs to be produced from a single gene.

Question 9

A mutation prevents the addition of the 5' cap to a eukaryotic mRNA. Which of the following is the most likely consequence?

Accepted Answer

The mRNA will be rapidly degraded and not efficiently translated.

Question 10

Which of the following statements about translation in bacteria is correct?

Accepted Answer

Translation and transcription are coupled, allowing ribosomes to begin translating mRNA before transcription is finished.

Question 11

A tRNA has the anticodon 5'-GAA-3'. Which mRNA codon will it recognize, and which amino acid will it carry?

Accepted Answer

Codon 5'-CUU-3', carrying leucine

Question 12

Which of the following best describes the process of post-translational modification?

Accepted Answer

The chemical modification and folding of a newly synthesized polypeptide to become a functional protein.

Question 13

Which of the following is NOT a function of the spliceosome?

Accepted Answer

Adding a poly(A) tail to the 3' end of mRNA.

Question 14

A scientist mutates the gene for a specific aminoacyl-tRNA synthetase so that it cannot bind its amino acid. What is the most likely effect on translation?

Accepted Answer

The corresponding tRNA will not be charged, and the amino acid will not be incorporated into proteins.

Question 15

Which of the following equations correctly represents the energy requirement for charging a tRNA with its amino acid?

Accepted Answer

$$\mathrm{Amino~acid} + \mathrm{tRNA} + \mathrm{ATP} \rightarrow \mathrm{Aminoacyl{-}tRNA} + \mathrm{AMP} + 2\mathrm{P_i}$$

Question 16

Which of the following best describes the sequence of events during translation elongation?

Accepted Answer

A new aminoacyl-tRNA enters the A site, peptide bond forms, ribosome translocates.

Question 17

Which of the following is a direct result of a mutation that prevents the removal of introns from pre-mRNA?

Accepted Answer

The mature mRNA will contain non-coding sequences, potentially resulting in a nonfunctional protein.

Question 18

Which of the following best explains why eukaryotic transcription and translation are separated in space and time?

Accepted Answer

Transcription occurs in the nucleus, and translation occurs in the cytoplasm, allowing for RNA processing before translation.

Question 19

A mutation changes the sequence of the TATA box in a eukaryotic gene promoter. What is the most likely effect?

Accepted Answer

Transcription factors will not bind efficiently, reducing or preventing transcription initiation.

Gene Expression: Transcription, RNA Processing, and Translation

Study Guide - Practice Questions

Study Guide - Flashcards