Types and roles of RNA MCQs With Answer

Introduction

Understanding the types and roles of RNA is essential for B. Pharm students studying molecular biology, pharmacology, and drug design. This concise guide examines major RNA types—mRNA, tRNA, rRNA, snRNA, snoRNA, miRNA, siRNA, piRNA, lncRNA and circular RNA—along with functional roles in transcription, translation, splicing, RNA processing, stability, RNA interference and regulation of gene expression. Emphasis is placed on clinical and pharmaceutical relevance, including RNA-based therapeutics, RNA editing, vaccine technology and RNA as drug targets. Familiarity with RNA biogenesis, structural features and mechanisms will strengthen understanding of drug action and modern therapies. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which RNA type directly carries the genetic code from DNA to ribosomes for protein synthesis?

• rRNA (ribosomal RNA)
• mRNA (messenger RNA)
• tRNA (transfer RNA)
• miRNA (microRNA)

Correct Answer: mRNA (messenger RNA)

Q2. Which RNA molecule has an anticodon and is charged with a specific amino acid by aminoacyl-tRNA synthetase?

• mRNA
• rRNA
• tRNA
• snRNA

Correct Answer: tRNA

Q3. Which RNA type is the major structural and catalytic component of the ribosome?

• miRNA
• rRNA
• snoRNA
• lncRNA

Correct Answer: rRNA

Q4. Which small RNAs guide chemical modification (methylation and pseudouridylation) of rRNA in the nucleolus?

• snRNAs
• snoRNAs
• siRNAs
• piRNAs

Correct Answer: snoRNAs

Q5. snRNAs are best known for their role in which cellular process?

• Translation elongation
• RNA interference
• Pre-mRNA splicing as part of the spliceosome
• rRNA methylation

Correct Answer: Pre-mRNA splicing as part of the spliceosome

Q6. Which mechanism is primarily used by microRNAs (miRNAs) to regulate gene expression?

• Enhancing transcription initiation
• Cleaving DNA at promoters
• Translational repression and mRNA degradation via RISC
• Directly catalyzing peptide bond formation

Correct Answer: Translational repression and mRNA degradation via RISC

Q7. Small interfering RNAs (siRNAs) are most distinct from miRNAs because they:

• Are single-stranded and act in the nucleus
• Derive from long double-stranded RNA and promote cleavage of perfectly complementary mRNA
• Are components of the ribosome
• Guide rRNA processing

Correct Answer: Derive from long double-stranded RNA and promote cleavage of perfectly complementary mRNA

Q8. Piwi-interacting RNAs (piRNAs) primarily function in:

• Ribosome assembly
• Silencing transposable elements in germ cells
• mRNA polyadenylation
• Alternative splicing regulation

Correct Answer: Silencing transposable elements in germ cells

Q9. Long non-coding RNAs (lncRNAs) commonly act by:

• Encoding small peptides
• Serving as templates for tRNA synthesis
• Scaffolding chromatin modifiers and regulating transcription
• Directly forming ribosomes

Correct Answer: Scaffolding chromatin modifiers and regulating transcription

Q10. Circular RNAs (circRNAs) can regulate gene expression mainly by:

• Acting as templates for ribosomal RNA
• Functioning as miRNA sponges and modulating miRNA availability
• Mediating transcription termination
• Serving as spliceosomal components

Correct Answer: Functioning as miRNA sponges and modulating miRNA availability

Q11. Which RNA species contains the Kozak sequence context important for eukaryotic translation initiation?

• tRNA
• mRNA
• snRNA
• rRNA

Correct Answer: mRNA

Q12. Which modification at the 5′ end of eukaryotic mRNA enhances stability and translation?

• Poly-A tail addition
• 5′ triphosphate
• 5′ cap (7-methylguanosine)
• 3′ untranslated region shortening

Correct Answer: 5′ cap (7-methylguanosine)

Q13. The enzyme responsible for adding the poly(A) tail to eukaryotic pre-mRNA is:

• RNA polymerase II
• Poly(A) polymerase
• RNAse H
• Capping enzyme

Correct Answer: Poly(A) polymerase

Q14. Which RNA polymerase synthesizes pre-mRNA in eukaryotic cells?

• RNA polymerase I
• RNA polymerase II
• RNA polymerase III
• RNA-dependent RNA polymerase

Correct Answer: RNA polymerase II

Q15. Ribozymes are RNA molecules that:

• Act only as structural scaffolds
• Have intrinsic catalytic activity and can catalyze cleavage or ligation reactions
• Always encode proteins
• Function only in the cytoplasm

Correct Answer: Have intrinsic catalytic activity and can catalyze cleavage or ligation reactions

Q16. RNA editing (e.g., A-to-I editing) alters RNA function by:

• Changing nucleotides post-transcriptionally and potentially altering coding sequences or splicing
• Removing introns from pre-mRNA
• Adding poly(A) tails
• Methylating DNA promoters

Correct Answer: Changing nucleotides post-transcriptionally and potentially altering coding sequences or splicing

Q17. In prokaryotes, the Shine–Dalgarno sequence on mRNA is important for:

• Termination of transcription
• Ribosome binding and translation initiation
• Polyadenylation
• mRNA splicing

Correct Answer: Ribosome binding and translation initiation

Q18. Wobble base pairing allows flexibility at which position of the codon-anticodon interaction?

• First codon position
• Second codon position
• Third codon position
• All three positions equally

Correct Answer: Third codon position

Q19. Which process reduces mRNA levels through recruitment of deadenylases followed by decapping?

• RNA splicing
• Nonsense-mediated decay and general mRNA decay pathways
• Ribosome biogenesis
• Translation initiation

Correct Answer: Nonsense-mediated decay and general mRNA decay pathways

Q20. Antisense oligonucleotide (ASO) drugs exert therapeutic effects by:

• Binding proteins in the ribosome
• Binding complementary RNA to block translation or alter splicing
• Directly modifying DNA sequences
• Activating RNA polymerase I

Correct Answer: Binding complementary RNA to block translation or alter splicing

Q21. Which RNA feature is most directly associated with mRNA stability in eukaryotic cells?

• 3′ untranslated region (3′ UTR) elements and poly(A) tail
• Presence of introns
• Length of coding sequence only
• Number of start codons

Correct Answer: 3′ untranslated region (3′ UTR) elements and poly(A) tail

Q22. Which enzyme complex is central to RNA interference-mediated suppression of target mRNAs?

• Spliceosome
• RISC (RNA-induced silencing complex)
• Ribosome
• Polymerase II holoenzyme

Correct Answer: RISC (RNA-induced silencing complex)

Q23. In bacterial translation, which RNA guides peptide bond formation and catalyzes peptidyl transferase activity?

• 5S rRNA
• 16S rRNA
• 23S rRNA
• tRNA

Correct Answer: 23S rRNA

Q24. Which RNA modification commonly occurs on tRNA and rRNA to stabilize structure and function?

• DNA methylation
• Base methylation and pseudouridylation
• Polyadenylation
• 5′ capping

Correct Answer: Base methylation and pseudouridylation

Q25. Which RNA-based therapeutic platform was central to rapid COVID-19 vaccine development?

• siRNA vaccines
• mRNA vaccines
• rRNA vaccines
• lncRNA vaccines

Correct Answer: mRNA vaccines

Q26. Which statement best differentiates lncRNAs from mRNAs?

• lncRNAs are always shorter than mRNAs
• lncRNAs typically lack long open reading frames and regulate gene expression without encoding proteins
• lncRNAs are translated into small peptides in all cases
• lncRNAs are components of the ribosome

Correct Answer: lncRNAs typically lack long open reading frames and regulate gene expression without encoding proteins

Q27. Which experimental technique detects and quantifies specific RNA transcripts by reverse transcription followed by amplification?

• Western blot
• Northern blot
• RT-qPCR (reverse transcription quantitative PCR)
• Chromatin immunoprecipitation

Correct Answer: RT-qPCR (reverse transcription quantitative PCR)

Q28. The term “riboswitch” refers to:

• A protein that regulates mRNA decay
• An RNA element that binds small molecules to regulate its own transcription or translation
• A type of rRNA modification enzyme
• A DNA regulatory element

Correct Answer: An RNA element that binds small molecules to regulate its own transcription or translation

Q29. Which process creates mature tRNA from precursor transcripts?

• Polyadenylation and capping
• 5′ and 3′ end processing, intron removal (in some tRNAs), and base modification
• RISC-mediated cleavage
• Spliceosome-mediated alternative splicing only

Correct Answer: 5′ and 3′ end processing, intron removal (in some tRNAs), and base modification

Q30. A chemically modified nucleotide in siRNA or antisense oligonucleotides is commonly used to:

• Prevent cellular uptake
• Reduce nuclease degradation and improve stability in vivo
• Eliminate target specificity
• Increase DNA replication errors

Correct Answer: Reduce nuclease degradation and improve stability in vivo

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