Question 1

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

Accepted Answer

It is a DNA sequence that acts as a promoter, helping to position RNA polymerase II for transcription initiation.

Question 2

A mutation in the promoter region of the FMR1 gene leads to fragile X syndrome. Why can a promoter mutation cause disease even if the coding sequence is unchanged?

Accepted Answer

The promoter mutation can prevent transcription initiation, so the gene is not expressed.

Question 3

During eukaryotic transcription, what is the function of the FACT protein complex?

Accepted Answer

It modifies histones to facilitate the movement of RNA polymerase through nucleosomes.

Question 4

Which of the following correctly matches the DNA template strand sequence to the mRNA start codon 5’AUG3’?

Accepted Answer

3’TAC5’

Question 5

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

Accepted Answer

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

Question 6

A DNA coding sequence undergoes a deletion of 2 base pairs. What is the most likely consequence?

Accepted Answer

A frameshift mutation, altering the reading frame of the gene.

Question 7

Alternative splicing of pre-mRNA in eukaryotes leads to which of the following outcomes?

Accepted Answer

Production of multiple protein variants from a single gene.

Question 8

Where on a tRNA molecule is the amino acid attached?

Accepted Answer

At the 3’ end of the tRNA.

Question 9

A DNA sequence 3’AGT5’ is transcribed. What is the corresponding mRNA codon, tRNA anticodon, and the amino acid carried by the tRNA?

Accepted Answer

mRNA: 5’UCA3’, tRNA: 3’AGU5’, amino acid: Serine

Question 10

Which of the following best explains why not all proteins in human cells start with Methionine, even though translation always begins with Methionine?

Accepted Answer

The initial Methionine is often removed after translation during post-translational modification.

Question 11

A mutation changes a DNA codon from 3’AGT5’ to 3’AGG5’. What type of mutation is this?

Accepted Answer

Missense mutation

Question 12

Which of the following is NOT a step in the post-transcriptional modification of eukaryotic pre-mRNA?

Accepted Answer

Attachment of amino acids to the mRNA

Question 13

What is the function of the release factor during translation?

Accepted Answer

It recognizes the stop codon and promotes the release of the polypeptide from the ribosome.

Question 14

Which of the following statements about ATP hydrolysis during ribosome assembly is correct?

Accepted Answer

ATP hydrolysis is not required for ribosome assembly.

Question 15

A DNA sequence is 5’CAG3’ (coding strand) and 3’GTC5’ (template strand). Which base pair substitution would result in a silent mutation?

Accepted Answer

Changing the third base of the coding strand from G to A (5’CAA3’)

Question 16

Which of the following best describes the process of eukaryotic translation initiation?

Accepted Answer

The small ribosomal subunit binds to the 5’ cap of mRNA, scans for the start codon, and the initiator tRNA binds to AUG.

Question 17

Why does increasing the length of an intron, as seen in the FXN gene mutation causing Friedreich’s Ataxia, potentially disrupt gene function?

Accepted Answer

It can interfere with proper splicing, leading to abnormal mRNA and nonfunctional protein.

Question 18

Which of the following best explains why deletion of 6 base pairs in a gene’s coding sequence does NOT cause a frameshift mutation?

Accepted Answer

Six base pairs correspond to two codons, so the reading frame is preserved.

Question 19

What is an anticodon?

Accepted Answer

A sequence of three nucleotides on tRNA that pairs with a complementary mRNA codon.

Transcription, Translation, and Point Mutations – Step-by-Step Study Guidance

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