Question 1

Which of the following best describes the role of tRNA during translation?

Accepted Answer

tRNA matches mRNA codons with their corresponding amino acids using its anticodon.

Question 2

A mutation changes the DNA sequence from 3’ – TACCATGAA – 5’ to 3’ – TACCAAGAA – 5’. What type of mutation is this?

Accepted Answer

Missense mutation

Question 3

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

Accepted Answer

P site

Question 4

If an mRNA sequence is 5’ – AUGGACAAUGGUUUAUAA – 3’, how many amino acids will be in the resulting polypeptide (excluding the stop codon)?

Accepted Answer

6

Question 5

Which of the following is the correct anticodon sequence for a tRNA carrying methionine?

Accepted Answer

3’ – UAC – 5’

Question 6

A frameshift mutation is most likely to result from:

Accepted Answer

An insertion or deletion of nucleotides not in multiples of three

Question 7

Which of the following statements about translation in prokaryotes is TRUE?

Accepted Answer

Translation and transcription are coupled, occurring simultaneously.

Question 8

What is the effect of a nonsense mutation on a protein?

Accepted Answer

It introduces a premature stop codon, truncating the protein.

Question 9

Which enzyme is responsible for attaching the correct amino acid to its corresponding tRNA?

Accepted Answer

Aminoacyl-tRNA synthetase

Question 10

A polyribosome (polysome) is best described as:

Accepted Answer

A strand of mRNA with multiple ribosomes attached, synthesizing polypeptides simultaneously.

Question 11

Which of the following codons signals the start of translation?

Accepted Answer

AUG

Question 12

What is the main function of the release factor during translation termination?

Accepted Answer

It binds to the stop codon and releases the polypeptide from the ribosome.

Question 13

A silent mutation is defined as:

Accepted Answer

A mutation that does not change the amino acid sequence due to redundancy in the genetic code.

Question 14

Which of the following best explains why translation always begins at free ribosomes?

Accepted Answer

All ribosomes start translation in the cytosol, and those with a signal peptide sequence attach to the rough ER.

Question 15

Which of the following is a real-world application of the CRISPR-Cas9 system?

Accepted Answer

Editing genes to correct disease-causing mutations.

Question 16

A newly transcribed mRNA molecule has 120 bases in its exon regions and 30 bases in its intron regions. How many amino acids will the polypeptide contain?

Accepted Answer

39

Question 17

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that changes one amino acid in the protein sequence.

Question 18

If a DNA template strand is 3’ – TACCATGAA – 5’, what is the corresponding mRNA sequence?

Accepted Answer

$$5'	ext{ – AUGGUACUU – 3'}$$

Question 19

Which of the following is NOT a function of ribosomes?

Accepted Answer

Synthesizing DNA from RNA.

Question 20

A mutation changes the DNA sequence from 3’ – TACAACGAA – 5’ to 3’ – TACATCGAA – 5’. What type of mutation is this?

Accepted Answer

Missense mutation

DNA Translation and Mutations: Mechanisms and Biological Implications

Study Guide - Practice Questions

Study Guide - Flashcards