MCQ Quiz- Eukaryotic RNA Processing

MCQ Quiz: A Guide to Eukaryotic RNA Processing

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In eukaryotic cells, the journey from a newly transcribed RNA molecule to a functional messenger RNA (mRNA) is a complex and highly regulated process. This series of modifications, known as RNA processing, is essential for creating a stable and translatable message and provides a major source of protein diversity. For PharmD students, understanding these steps—capping, splicing, and polyadenylation—is key to grasping gene expression and the mechanisms of certain advanced therapies. This quiz will test your knowledge of the critical events that turn a pre-mRNA into a mature mRNA.

1. Eukaryotic RNA processing occurs in which cellular compartment?

  • Cytoplasm
  • Nucleus
  • Mitochondria
  • Endoplasmic Reticulum

Answer: Nucleus

2. Which of the following is a key post-transcriptional processing event for eukaryotic pre-mRNA?

  • Addition of a 5′ cap
  • Splicing to remove introns
  • Addition of a 3′ poly(A) tail
  • All of the above

Answer: All of the above

3. The 5′ cap structure added to eukaryotic mRNA is a:

  • Standard guanine nucleotide.
  • 7-methylguanosine nucleotide linked via a 5′-5′ triphosphate bridge.
  • Polyadenine tail.
  • Sequence of uracil nucleotides.

Answer: 7-methylguanosine nucleotide linked via a 5′-5′ triphosphate bridge.

4. What is a primary function of the 5′ cap?

  • To signal the end of the mRNA molecule.
  • To protect the mRNA from degradation by 5′ exonucleases and facilitate ribosome binding.
  • To mark the mRNA for splicing.
  • To help the mRNA bind to DNA.

Answer: To protect the mRNA from degradation by 5′ exonucleases and facilitate ribosome binding.

5. “Splicing” is the process that removes which non-coding segments from a pre-mRNA transcript?

  • Exons
  • Promoters
  • Introns
  • Codons

Answer: Introns

6. The coding segments of a pre-mRNA that are joined together after splicing to form the mature mRNA are called:

  • Introns
  • Exons
  • Splice sites
  • Promoters

Answer: Exons

7. The large molecular machine that carries out the process of pre-mRNA splicing is the:

  • Ribosome
  • Proteasome
  • Spliceosome
  • RNA Polymerase II

Answer: Spliceosome

8. The spliceosome is composed of:

  • Only proteins.
  • Only RNA molecules.
  • Small nuclear RNAs (snRNAs) and a complex of proteins (forming snRNPs).
  • Ribosomal RNAs (rRNAs) and proteins.

Answer: Small nuclear RNAs (snRNAs) and a complex of proteins (forming snRNPs).

9. A key consensus sequence found at the 5′ splice site of an intron is typically:

  • AG
  • GU
  • AU
  • GG

Answer: GU

10. The 3′ splice site of an intron is marked by which conserved dinucleotide sequence?

  • GU
  • GG
  • AU
  • AG

Answer: AG

11. During the splicing reaction, a key intermediate structure is formed that resembles a loop. This structure is called a:

  • Stem-loop
  • Hairpin
  • Lariat
  • Cruciform

Answer: Lariat

12. “Alternative splicing” is a regulated process that allows:

  • A single gene to produce multiple different protein isoforms.
  • Introns to be left in the final mRNA.
  • The 5′ cap to be removed.
  • The DNA sequence of a gene to be changed.

Answer: A single gene to produce multiple different protein isoforms.

13. The 3′ poly(A) tail is a long string of which nucleotide?

  • Cytosine
  • Guanine
  • Uracil
  • Adenine

Answer: Adenine

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

  • RNA Polymerase II
  • DNA Ligase
  • Poly(A) polymerase
  • Dicer

Answer: Poly(A) polymerase

15. A key function of the 3′ poly(A) tail is to:

  • Increase the stability of the mRNA and promote its translation.
  • Signal for the termination of transcription.
  • Act as a binding site for the spliceosome.
  • Help the mRNA re-enter the nucleus.

Answer: Increase the stability of the mRNA and promote its translation.

16. How does prokaryotic mRNA processing differ from eukaryotic mRNA processing?

  • Prokaryotic mRNA undergoes extensive processing, including capping and polyadenylation.
  • Prokaryotic mRNA is generally not processed; transcription and translation are coupled.
  • Prokaryotic mRNA has introns that must be spliced out.
  • There is no difference.

Answer: Prokaryotic mRNA is generally not processed; transcription and translation are coupled.

17. The C-terminal domain (CTD) of RNA Polymerase II plays a crucial role in coordinating RNA processing by:

  • Acting as the catalytic site for RNA synthesis.
  • Serving as a scaffold or platform that recruits the capping, splicing, and polyadenylation factors.
  • Proofreading the newly synthesized RNA.
  • Binding to the TATA box in the promoter.

Answer: Serving as a scaffold or platform that recruits the capping, splicing, and polyadenylation factors.

18. A pharmacist’s knowledge of “eukaryotic and prokaryotic transcription” is the foundation for understanding:

  • Why RNA processing is a hallmark of eukaryotic gene expression.
  • How antibiotics like rifampin can be selectively toxic.
  • The basic steps of gene expression.
  • All of the above.

Answer: All of the above.

19. The “molecular biology technique” of creating a cDNA library requires isolating mature mRNA. A key feature of this mRNA that is used to capture it is the:

  • 5′ cap
  • Splice sites
  • 3′ poly(A) tail
  • Intron sequences

Answer: 3′ poly(A) tail

20. The reason a cDNA clone of a eukaryotic gene can be expressed in a prokaryote is that the cDNA:

  • Contains all the introns from the original gene.
  • Lacks the introns, representing the final processed mRNA sequence.
  • Has a 5′ cap.
  • Is more stable than genomic DNA.

Answer: Lacks the introns, representing the final processed mRNA sequence.

21. A “self-splicing” intron is a rare type of intron that:

  • Requires the spliceosome to be removed.
  • Can catalyze its own excision from an RNA molecule without the need for proteins.
  • Is only found in viruses.
  • Is never removed from the RNA.

Answer: Can catalyze its own excision from an RNA molecule without the need for proteins.

22. A mutation in a splice site consensus sequence is likely to cause:

  • A change in the protein’s primary amino acid sequence.
  • A frameshift mutation.
  • The retention of an intron or the skipping of an exon, leading to an aberrant protein.
  • All of the above are possible outcomes.

Answer: All of the above are possible outcomes.

23. Many genetic diseases are caused by mutations that affect:

  • Only the coding sequence of an exon.
  • The promoter region of a gene.
  • The splicing of pre-mRNA.
  • The termination of transcription.

Answer: The splicing of pre-mRNA.

24. The “leadership” skill of staying current is vital for a pharmacist in biotechnology because:

  • New therapies are being developed that target RNA processing, such as antisense oligonucleotides that can modulate splicing.
  • The principles of RNA processing are constantly changing.
  • It is a requirement for hospital administration.
  • It is not relevant to this field.

Answer: New therapies are being developed that target RNA processing, such as antisense oligonucleotides that can modulate splicing.

25. A “business plan” for a new drug that works by correcting a splicing defect would need a deep understanding of:

  • The molecular basis of RNA processing.
  • The target patient population.
  • The regulatory pathway for approval.
  • All of the above.

Answer: All of the above.

26. The “regulation” of gene expression in eukaryotes can occur at which stage?

  • Transcriptional initiation.
  • Post-transcriptional processing (e.g., alternative splicing).
  • Translational control.
  • All of the above.

Answer: All of the above.

27. The “forging ahead” mindset in pharmacy involves understanding how these molecular processes can be:

  • Harnessed for next-generation therapeutics.
  • Ignored as they are too complex.
  • Viewed as a barrier to drug development.
  • Used only in basic science.

Answer: Harnessed for next-generation therapeutics.

28. A key part of the “Introduction to Pharmacy Informatics” is understanding that an EHR of the future will need to handle data from:

  • Transcriptomics (RNA expression profiles), which is a direct output of the transcription and processing machinery.
  • Only a patient’s vital signs.
  • Only a patient’s billing information.
  • Only a pharmacist’s notes.

Answer: Transcriptomics (RNA expression profiles), which is a direct output of the transcription and processing machinery.

29. The “enzymes of DNA metabolism” are distinct from the enzymes of RNA processing. A DNA ligase __________, while the spliceosome __________.

  • Joins DNA fragments; removes introns from RNA.
  • Removes introns from RNA; joins DNA fragments.
  • Copies DNA; adds a poly(A) tail.
  • Adds a poly(A) tail; copies DNA.

Answer: Joins DNA fragments; removes introns from RNA.

30. The ultimate reason pharmacists study eukaryotic RNA processing is that:

  • It is a fundamental process of gene expression that is essential for understanding human biology, disease, and the mechanism of many modern drugs.
  • It is an interesting but clinically irrelevant topic.
  • It is only important for understanding bacteria.
  • It is the primary way that cells generate energy.

Answer: It is a fundamental process of gene expression that is essential for understanding human biology, disease, and the mechanism of many modern drugs.

31. The branch point “A” is a conserved adenine nucleotide within the ________ that is crucial for initiating the splicing reaction.

  • Exon
  • Promoter
  • Intron
  • 5′ cap

Answer: Intron

32. The first chemical step of splicing is a nucleophilic attack by the 2′-OH of the branch point adenine on the:

  • 3′ splice site.
  • 5′ splice site.
  • Poly(A) signal.
  • 5′ cap.

Answer: 5′ splice site.

33. What happens to the intron after it is spliced out as a lariat?

  • It is exported to the cytoplasm to be translated.
  • It is rapidly degraded in the nucleus.
  • It is re-inserted into another gene.
  • It becomes a new, smaller chromosome.

Answer: It is rapidly degraded in the nucleus.

34. The “policy” debate surrounding RNA-based vaccines (like some for COVID-19) involves:

  • Public understanding of how these molecules work, which is based on the principles of transcription and translation, not RNA processing itself.
  • The high cost of the vaccines.
  • The speed of their development.
  • All of the above.

Answer: All of the above.

35. A “health disparity” could arise if a new, expensive drug that targets RNA processing is:

  • Made accessible to all populations equally.
  • Only available to the wealthiest patients.
  • Covered by government insurance programs.
  • Easy to administer.

Answer: Only available to the wealthiest patients.

36. The “cloning” of a eukaryotic gene often starts with mRNA. The resulting cDNA lacks introns because:

  • The mRNA used as a template had already been spliced.
  • The reverse transcriptase enzyme removes them.
  • The bacterial host removes them.
  • cDNA is a different type of genetic material.

Answer: The mRNA used as a template had already been spliced.

37. The “molecular biology technique” of RT-PCR (Reverse Transcription PCR) is used to:

  • Amplify and quantify the amount of a specific mRNA, which is a product of transcription and processing.
  • Amplify a segment of DNA.
  • Separate proteins by size.
  • Sequence an entire genome.

Answer: Amplify and quantify the amount of a specific mRNA, which is a product of transcription and processing.

38. A pharmacist’s knowledge of “DNA repair mechanisms” is distinct from RNA processing, but both are essential for:

  • Maintaining the integrity of the genetic information.
  • Regulating gene expression.
  • Producing functional proteins.
  • The process of cell division.

Answer: Maintaining the integrity of the genetic information.

39. “Prokaryotic DNA replication” is often coupled with transcription and translation. This is impossible in eukaryotes due to:

  • The physical separation of these processes by the nuclear membrane.
  • The small size of the eukaryotic genome.
  • The lack of ribosomes in eukaryotes.
  • The slow speed of eukaryotic DNA polymerase.

Answer: The physical separation of these processes by the nuclear membrane.

40. The “special recombination” event of V(D)J recombination occurs at the DNA level, and the resulting gene must then be ________ and processed to produce an antibody mRNA.

  • Replicated
  • Repaired
  • Transcribed
  • Translated

Answer: Transcribed

41. The field of “epigenetics” influences transcription initiation, which is the step that occurs _______ RNA processing.

  • After
  • During
  • Before
  • Instead of

Answer: Before

42. “DNA methylation” in a promoter typically _________ transcription, thus preventing the creation of a pre-mRNA that would need processing.

  • Enhances
  • Represses
  • Has no effect on
  • Initiates

Answer: Represses

43. A “chemotherapeutic” like a monoclonal antibody is produced in eukaryotic cells using recombinant DNA. A key step in its production is ensuring the correct ________ of the antibody gene’s mRNA.

  • Replication
  • Repair
  • Splicing and processing
  • Mutation

Answer: Splicing and processing

44. An “antidote” for a poison that inhibits the spliceosome would most likely be:

  • Naloxone
  • Flumazenil
  • Supportive care, as no specific chemical antidote exists.
  • N-acetylcysteine

Answer: Supportive care, as no specific chemical antidote exists.

45. A “human resources” department in a biotech company would need to hire scientists with expertise in:

  • Eukaryotic gene expression and RNA processing.
  • Marketing.
  • Finance.
  • Only human relations.

Answer: Eukaryotic gene expression and RNA processing.

46. The “financials” of developing a drug that modulates splicing (like some for spinal muscular atrophy) are characterized by:

  • High research and development costs but the potential to treat a severe genetic disease.
  • A guaranteed and rapid profit.
  • Low manufacturing costs.
  • A simple and inexpensive clinical trial process.

Answer: High research and development costs but the potential to treat a severe genetic disease.

47. A “negotiation” with a payer for an expensive RNA-based therapy would require a strong case based on:

  • Evidence of its clinical efficacy and impact on patient quality of life.
  • The drug’s high price alone.
  • The novelty of its mechanism.
  • The personal preference of the physician.

Answer: Evidence of its clinical efficacy and impact on patient quality of life.

48. In which “practice setting” would a pharmacist be most likely to manage a patient on an advanced therapy that modulates RNA processing?

  • A community pharmacy.
  • A specialized hospital or ambulatory care clinic (e.g., neurology, oncology).
  • A mail-order pharmacy.
  • A supermarket pharmacy.

Answer: A specialized hospital or ambulatory care clinic (e.g., neurology, oncology).

49. An “Electronic Health Record” (EHR) of the future will need the capacity to store and interpret data on a patient’s:

  • Transcriptome (the full range of mRNA molecules), which reflects the output of RNA processing.
  • Only basic demographic information.
  • Financial records.
  • Daily diet.

Answer: Transcriptome (the full range of mRNA molecules), which reflects the output of RNA processing.

50. The ultimate principle of why pharmacists study RNA processing is that it is:

  • A key control point in gene expression that is fundamental to understanding human health, disease, and the development of novel therapeutics.
  • An interesting but clinically minor topic.
  • Only relevant to understanding viruses.
  • A process that is the same in all forms of life.

Answer: A key control point in gene expression that is fundamental to understanding human health, disease, and the development of novel therapeutics.

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