Question 1

Which of the following best describes the process of translation in cells?

Accepted Answer

The synthesis of a polypeptide using an mRNA template

Question 2

According to the 'one gene, one polypeptide' hypothesis, which of the following is true?

Accepted Answer

Each gene codes for a single polypeptide chain

Question 3

A frameshift mutation is most likely to result from which of the following genetic changes?

Accepted Answer

An insertion of a single base

Question 4

Which codon serves as the start codon for translation in most organisms?

Accepted Answer

$\mathrm{AUG}$

Question 5

If the DNA coding strand has the sequence 5'-ATGGGCTCC-3', what is the corresponding mRNA sequence?

Accepted Answer

5'-AUGGGCUCC-3'

Question 6

Which of the following statements about the genetic code is correct?

Accepted Answer

The code is degenerate, with multiple codons coding for the same amino acid

Question 7

A tRNA with the anticodon 3'-CGU-5' can bind to which mRNA codon?

Accepted Answer

5'-GCA-3'

Question 8

Which of the following best explains why a single base insertion in a coding sequence can have a dramatic effect on the resulting protein?

Accepted Answer

It causes a frameshift, altering the reading frame for all downstream codons

Question 9

Which of the following is NOT a function of molecular chaperones in the cell?

Accepted Answer

Catalyzing peptide bond formation during translation

Question 10

A mutation changes the DNA sequence from 5'-ATG GGC TCC-3' to 5'-ATG GGT TCC-3'. What type of mutation is this, and what is its likely effect?

Accepted Answer

Missense mutation; changes one amino acid

Question 11

Which of the following antibiotics would most likely disrupt bacterial translation by allowing any tRNA to bind at the A site?

Accepted Answer

Puromycin

Question 12

Which of the following post-translational modifications is an example of covalent modification?

Accepted Answer

Phosphorylation of a serine residue

Question 13

During translation, which site on the ribosome does the incoming aminoacyl-tRNA first bind to?

Accepted Answer

A site

Question 14

Which of the following best describes the 'wobble' hypothesis in tRNA-mRNA pairing?

Accepted Answer

The third base of the codon can form non-standard base pairs with the first base of the anticodon

Question 15

A patient has a mutation that introduces a premature stop codon (UAG) in the middle of a gene. What is the most likely result?

Accepted Answer

A truncated, likely nonfunctional protein

Question 16

Which of the following is a correct sequence of events during translation initiation in prokaryotes?

Accepted Answer

Binding of the small ribosomal subunit to the Shine-Dalgarno sequence, initiator tRNA binding, then large subunit joining

Question 17

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

Some amino acids are coded by more than one codon

Question 18

Which of the following post-translational modifications is essential for the activation of many proteins and involves the addition of a phosphate group?

Accepted Answer

Phosphorylation

Question 19

If a gene's coding sequence is mutated such that a codon for glycine (GGG) becomes a stop codon (UGA), what type of mutation has occurred?

Accepted Answer

Nonsense mutation

Question 20

Which of the following is a real-life example of a disease caused by a frameshift mutation?

Accepted Answer

Cystic fibrosis (ΔF508 mutation)

Translation and the Genetic Code: Structure, Function, and Mutations

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