QCM : Genetic Translation and Protein Synthesis — 10 questions

Questions et réponses du QCM

1. What is the role of RNA polymerase during gene expression?

It reads stop codons and ends translation
It carries amino acids to the ribosome
It folds the new polypeptide into its final shape
It synthesizes mRNA during transcription

It synthesizes mRNA during transcription

Explication

RNA polymerase is the enzyme that builds mRNA in transcription. tRNA carries amino acids, and stop-codon recognition belongs to translation, not RNA polymerase.

2. What is transcription?

The release of a polypeptide at a stop codon
The conversion of protein into RNA
The pairing of anticodons with amino acids
The nuclear synthesis of mRNA from a DNA template strand

The nuclear synthesis of mRNA from a DNA template strand

Explication

Transcription is the nuclear step that produces mRNA from a DNA template strand. The other options describe translation or unrelated processes.

3. What happens during translation initiation?

Peptide bonds stop forming
The ribosome begins at the start codon on mRNA
The polypeptide is released at a stop codon
The protein folds before the ribosome binds

The ribosome begins at the start codon on mRNA

Explication

Initiation is the start of translation at the start codon, which is AUG. Termination and folding occur later, not at initiation.

4. How do polyribosomes increase protein production?

By stopping translation after the first peptide bond
By allowing multiple ribosomes to translate the same mRNA at the same time
By converting mRNA back into DNA
By making each ribosome read only one codon

By allowing multiple ribosomes to translate the same mRNA at the same time

Explication

Polyribosomes are complexes of many ribosomes translating the same mRNA simultaneously, which boosts protein output. They do not reverse transcription or halt translation.

5. Which codon serves as the translation start codon and codes for methionine?

UGG
AUG
UAA
UAG

AUG

Explication

AUG is the start codon and it codes methionine. UAA and UAG are stop codons, while UGG codes tryptophan.

6. What best describes a gene in relation to DNA?

A specific sequence of nucleotides located on a DNA molecule
A protein that stores hereditary information
A short RNA molecule that carries amino acids to the ribosome
A base found only in RNA molecules

A specific sequence of nucleotides located on a DNA molecule

Explication

A gene is defined as a specific nucleotide sequence on DNA. The other choices describe RNA-related features or proteins, not genes.

7. What does a codon specify?

A ribose-containing sugar
An amino acid or a stop signal
A ribosome subunit
A DNA repair enzyme

An amino acid or a stop signal

Explication

A codon is a triplet of bases on mRNA that specifies an amino acid or a stop signal. The other choices are unrelated to codons.

8. What is the main function of tRNA in translation?

To catalyze the folding of proteins after translation ends
To copy DNA into mRNA
To form the small ribosomal subunit
To match mRNA codons and deliver the corresponding amino acids

To match mRNA codons and deliver the corresponding amino acids

Explication

tRNA uses its complementary anticodon to recognize mRNA codons and brings the matching amino acid. The other choices describe different molecules or processes.

9. Which feature distinguishes RNA from DNA in this material?

It is the nuclear support of inherited traits
It contains uracil and ribose
It is located only in the nucleus
It is made of deoxyribose and thymine

It contains uracil and ribose

Explication

RNA is described as containing ribose and uracil. DNA is the nuclear support of inherited traits, so the other choices describe DNA or are incorrect.

10. What occurs after translation terminates at a stop codon?

The polypeptide is released and folds into its three-dimensional structure
The mRNA is converted into DNA
The tRNA remains permanently attached to the ribosome
The ribosome adds another amino acid and continues

The polypeptide is released and folds into its three-dimensional structure

Explication

When a stop codon is reached, the polypeptide is released and then folds into its functional three-dimensional form. Translation does not continue past a stop codon.

Révisez avec les flashcards

Mémorisez les réponses avec 20 flashcards sur Genetic Translation and Protein Synthesis.

Genes — definition?

Sequences of nucleotides on DNA.

DNA — location?

Located in the nucleus.

RNA — role?

Messenger carrying genetic info from DNA.

Voir les flashcards →

Approfondir avec la fiche

Consultez la fiche de révision complète sur Genetic Translation and Protein Synthesis.

Voir la fiche →

Cours similaires

Cartilaginous Tissue

Anatomie

Tissu cartilagineux

Anatomie

Cours sur la Maladie de Parkinson

Introduction à la maladie de Parkinson

Cours d'Urgences Médicamenteuses et Protocoles

Évolution et classification de la névrose

Crée tes propres QCM

Importe ton cours et l'IA génère des QCM avec corrections en 30 secondes.

Générateur de QCM