MCQ Quiz- Eukaryotic and Prokaryotic Transcription

MCQ Quiz: A Guide to Eukaryotic and Prokaryotic Transcription

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Transcription is the crucial first step in gene expression, where the genetic information encoded in DNA is copied into RNA. While the fundamental process is conserved, the machinery and regulation differ significantly between prokaryotes and eukaryotes, providing key targets for drug therapy. For PharmD students, understanding these mechanisms is essential for grasping how many antibiotics and anticancer agents work. This quiz will test your knowledge of the enzymes, factors, and processes that govern transcription in these two domains of life.

1. Transcription is the process of synthesizing:

  • DNA from an RNA template.
  • Protein from an mRNA template.
  • RNA from a DNA template.
  • DNA from a DNA template.

Answer: RNA from a DNA template.

2. The primary enzyme responsible for transcription is:

  • DNA Polymerase
  • RNA Polymerase
  • Helicase
  • Ligase

Answer: RNA Polymerase

3. In prokaryotes, a single type of RNA polymerase synthesizes all types of RNA. In contrast, eukaryotes have three main types. Which one is responsible for transcribing messenger RNA (mRNA)?

  • RNA Polymerase I
  • RNA Polymerase II
  • RNA Polymerase III
  • RNA Polymerase IV

Answer: RNA Polymerase II

4. The DNA strand that is read by RNA polymerase to synthesize a complementary RNA strand is called the:

  • Coding strand
  • Sense strand
  • Template strand (or antisense strand)
  • Leading strand

Answer: Template strand (or antisense strand)

5. A “promoter” is a specific DNA sequence that:

  • Signals the end of transcription.
  • Binds to RNA polymerase and transcription factors to initiate transcription.
  • Is transcribed into the final RNA product.
  • Is located thousands of base pairs downstream of the gene.

Answer: Binds to RNA polymerase and transcription factors to initiate transcription.

6. In prokaryotic transcription, the sigma (σ) factor is a protein subunit that is essential for:

  • The elongation of the RNA chain.
  • The termination of transcription.
  • Recognizing and binding the RNA polymerase to the promoter sequence.
  • Proofreading the newly synthesized RNA.

Answer: Recognizing and binding the RNA polymerase to the promoter sequence.

7. The -10 and -35 sequences (e.g., Pribnow box) are conserved elements of a promoter found in:

  • Eukaryotes
  • Prokaryotes
  • Both prokaryotes and eukaryotes
  • Viruses only

Answer: Prokaryotes

8. Which of the following is a key difference between eukaryotic and prokaryotic transcription?

  • Prokaryotic transcription occurs in the nucleus, while eukaryotic transcription occurs in the cytoplasm.
  • Eukaryotic transcription occurs in the nucleus and is separated from translation, while in prokaryotes, the two processes are coupled.
  • Prokaryotes use multiple RNA polymerases, while eukaryotes use only one.
  • Eukaryotic RNA is not processed after transcription.

Answer: Eukaryotic transcription occurs in the nucleus and is separated from translation, while in prokaryotes, the two processes are coupled.

9. The TATA box is a conserved promoter element in:

  • Prokaryotes
  • Eukaryotes
  • Both prokaryotes and eukaryotes
  • Mitochondria

Answer: Eukaryotes

10. In eukaryotes, the initiation of transcription by RNA Polymerase II requires the assembly of a preinitiation complex, which includes:

  • The sigma factor.
  • A series of general transcription factors (e.g., TFIID, TFIIH).
  • The ribosome.
  • DNA polymerase.

Answer: A series of general transcription factors (e.g., TFIID, TFIIH).

11. The general transcription factor TFIIH has two important enzymatic activities. They are:

  • Ligase and polymerase activity.
  • Nuclease and primase activity.
  • Helicase and kinase activity.
  • Methyltransferase and acetylase activity.

Answer: Helicase and kinase activity.

12. “Post-transcriptional processing” is a series of modifications that occur to eukaryotic pre-mRNA. This includes:

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

Answer: All of the above.

13. The purpose of the 5′ cap on eukaryotic mRNA is to:

  • Signal the end of the message.
  • Protect the mRNA from degradation and facilitate ribosome binding for translation.
  • Mark the mRNA for destruction.
  • Help the mRNA exit the cytoplasm.

Answer: Protect the mRNA from degradation and facilitate ribosome binding for translation.

14. The 3′ poly(A) tail is added to a eukaryotic mRNA by the enzyme:

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

Answer: Poly(A) polymerase

15. “Splicing” is the process that removes non-coding regions from a pre-mRNA. These non-coding regions are called:

  • Exons
  • Promoters
  • Introns
  • Codons

Answer: Introns

16. The spliceosome, which carries out the splicing of pre-mRNA, is a large complex made of:

  • Only proteins.
  • Only RNA.
  • Small nuclear RNAs (snRNAs) and proteins, forming snRNPs.
  • Ribosomal RNAs (rRNAs) and proteins.

Answer: Small nuclear RNAs (snRNAs) and proteins, forming snRNPs.

17. “Alternative splicing” is a significant process in eukaryotes because it:

  • Allows a single gene to code for multiple different proteins.
  • Is the primary mechanism of gene regulation in prokaryotes.
  • Ensures that only one protein is made from each gene.
  • Is a major cause of mutations.

Answer: Allows a single gene to code for multiple different proteins.

18. The antibiotic rifampin is effective against tuberculosis because it selectively inhibits:

  • Eukaryotic RNA Polymerase II.
  • The bacterial (prokaryotic) RNA polymerase.
  • DNA gyrase.
  • The bacterial ribosome.

Answer: The bacterial (prokaryotic) RNA polymerase.

19. A key principle of pharmacology is that the difference between prokaryotic and eukaryotic transcription machinery allows for:

  • The development of selectively toxic antibiotics.
  • The guarantee that no antibiotic will have side effects.
  • The use of the same drugs to treat bacterial and human diseases.
  • The development of drugs that target both bacteria and viruses.

Answer: The development of selectively toxic antibiotics.

20. There are two main mechanisms of transcription termination in prokaryotes. “Rho-independent” termination involves:

  • The Rho protein physically dislodging the RNA polymerase.
  • A stable stem-loop structure forming in the nascent RNA, followed by a string of uracils.
  • A specific protein that binds to the end of the gene.
  • The RNA polymerase simply falling off at a random location.

Answer: A stable stem-loop structure forming in the nascent RNA, followed by a string of uracils.

21. “Enhancers” are DNA sequences in eukaryotes that:

  • Are located only in the promoter region.
  • Bind repressor proteins to shut down transcription.
  • Can be located far from the gene they regulate and bind activator proteins to increase transcription rates.
  • Are the primary binding site for RNA Polymerase I.

Answer: Can be located far from the gene they regulate and bind activator proteins to increase transcription rates.

22. A pharmacist’s knowledge of “DNA-protein interactions” is the foundation for understanding how:

  • Transcription factors and RNA polymerase bind to specific DNA sequences like promoters and enhancers.
  • DNA is replicated.
  • DNA is repaired.
  • The cell membrane is formed.

Answer: Transcription factors and RNA polymerase bind to specific DNA sequences like promoters and enhancers.

23. The “coding strand” of DNA has a sequence that is nearly identical to the:

  • Template strand.
  • Synthesized mRNA (with T in place of U).
  • tRNA anticodon.
  • rRNA sequence.

Answer: Synthesized mRNA (with T in place of U).

24. The mushroom toxin α-amanitin is a potent and specific inhibitor of which enzyme, making it a useful tool in research?

  • Prokaryotic RNA polymerase
  • Eukaryotic RNA Polymerase II
  • Eukaryotic RNA Polymerase I
  • Eukaryotic RNA Polymerase III

Answer: Eukaryotic RNA Polymerase II

25. A key leadership role for a pharmacist in a biotech company would be to understand the process of transcription to:

  • Guide the development of recombinant DNA technologies for producing protein drugs.
  • Manage the company’s human resources.
  • Negotiate contracts with suppliers.
  • Write the company’s financial reports.

Answer: Guide the development of recombinant DNA technologies for producing protein drugs.

26. The “forging ahead” mindset means pharmacists must be aware of new therapies, such as RNA interference (RNAi), which works at the level of:

  • Post-transcriptional gene regulation.
  • DNA replication.
  • DNA repair.
  • Protein synthesis.

Answer: Post-transcriptional gene regulation.

27. A “business plan” for a new anticancer drug that targets a specific transcription factor would need to include:

  • Strong preclinical data on its mechanism of action.
  • A detailed market analysis.
  • A financial model.
  • All of the above.

Answer: All of the above.

28. The “regulation” of gene expression at the level of transcription is the primary way that:

  • Cells differentiate and respond to their environment.
  • DNA is copied.
  • The cell divides.
  • The cell generates energy.

Answer: Cells differentiate and respond to their environment.

29. A “Clinical Decision Support” system of the future might use a patient’s transcriptomic data (gene expression profile) to:

  • Personalize their drug therapy.
  • Bill their insurance company.
  • Schedule their next appointment.
  • It cannot use this type of data.

Answer: Personalize their drug therapy.

30. The “lac operon” in E. coli is a classic example of gene regulation at the level of:

  • Transcriptional initiation.
  • RNA splicing.
  • Post-translational modification.
  • DNA replication.

Answer: Transcriptional initiation.

31. In the lac operon, the repressor protein binds to the operator in the absence of lactose. When lactose is present, it binds to the repressor, causing it to:

  • Bind more tightly to the operator.
  • Fall off the operator, allowing transcription to proceed.
  • Act as an activator.
  • Be degraded.

Answer: Fall off the operator, allowing transcription to proceed.

32. The “enzymes of DNA metabolism” like topoisomerases are also important during transcription because:

  • They are required to synthesize the RNA.
  • They help relieve the supercoiling that occurs as RNA polymerase unwinds the DNA.
  • They add the 5′ cap.
  • They splice out the introns.

Answer: They help relieve the supercoiling that occurs as RNA polymerase unwinds the DNA.

33. The “cloning” of a eukaryotic gene into a prokaryotic plasmid for expression requires a cDNA copy of the gene because:

  • The eukaryotic gene is too long.
  • The prokaryotic host cannot splice out the introns from the eukaryotic gene.
  • The prokaryotic plasmid cannot replicate eukaryotic DNA.
  • The eukaryotic gene is unstable in bacteria.

Answer: The prokaryotic host cannot splice out the introns from the eukaryotic gene.

34. The “molecular biology technique” of a Northern blot is used to analyze:

  • The size and abundance of a specific mRNA transcript.
  • The sequence of a gene.
  • The presence of a specific protein.
  • The structure of a chromosome.

Answer: The size and abundance of a specific mRNA transcript.

35. A pharmacist’s knowledge of “DNA repair mechanisms” is relevant because:

  • Damage to a gene’s promoter can prevent its transcription.
  • These mechanisms are the same as transcription.
  • They are not relevant to transcription.
  • They only repair damage in non-coding regions.

Answer: Damage to a gene’s promoter can prevent its transcription.

36. “Prokaryotic DNA replication” and transcription can be coupled in time and space. This is not possible in eukaryotes due to the presence of the:

  • Cell wall.
  • Nuclear membrane.
  • Mitochondria.
  • Ribosomes.

Answer: The Nuclear membrane.

37. “Special recombination” like V(D)J recombination is a DNA-level process that ultimately allows for the transcription of:

  • A vast diversity of unique antibody and T-cell receptor genes.
  • Housekeeping genes.
  • Bacterial genes.
  • Viral genes.

Answer: A vast diversity of unique antibody and T-cell receptor genes.

38. Histone modifications, such as acetylation, are a key epigenetic mechanism for regulating ________ transcription.

  • Prokaryotic
  • Eukaryotic
  • Both prokaryotic and eukaryotic
  • Viral

Answer: Eukaryotic

39. A key “policy” debate surrounding the use of genetic information involves:

  • Who should have access to a person’s gene expression data.
  • The price of antibiotics that target transcription.
  • The regulation of academic research labs.
  • All of the above.

Answer: All of the above.

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

  • Eukaryotic and prokaryotic transcription to support drug discovery.
  • Only marketing.
  • Only finance.
  • Only human relations.

Answer: Eukaryotic and prokaryotic transcription to support drug discovery.

41. The “financials” of developing a drug that targets a novel transcription factor would involve:

  • A high-risk, high-reward investment in research and development.
  • A guaranteed and rapid profit.
  • Low manufacturing costs.
  • A simple and inexpensive clinical trial process.

Answer: A high-risk, high-reward investment in research and development.

42. A pharmacist’s role as a patient “advocate” might involve:

  • Explaining the results of a genetic test that affects how a patient’s genes are transcribed and how this impacts their therapy.
  • Insisting the patient take a medication.
  • Refusing to answer any clinical questions.
  • Only discussing the cost of the medication.

Answer: Explaining the results of a genetic test that affects how a patient’s genes are transcribed and how this impacts their therapy.

43. A pharmacist’s understanding of “health disparities” is relevant because:

  • Access to advanced therapies that modulate transcription may not be equitable.
  • Environmental factors that disproportionately affect certain communities can alter gene expression.
  • Both A and B are correct.
  • The concept is not relevant to transcription.

Answer: Both A and B are correct.

44. A key part of the “Introduction to Pharmacy Informatics” is understanding how an EHR can store and use data related to a patient’s gene expression profile to:

  • Guide personalized therapy.
  • Make healthcare less personal.
  • Increase the risk of medication errors.
  • Complicate the billing process.

Answer: Guide personalized therapy.

45. A “negotiation” with a payer for a new, expensive drug that targets transcription would require a strong case based on:

  • Evidence of improved clinical outcomes from clinical trials.
  • The drug’s high price.
  • The novelty of its mechanism alone.
  • The personal preference of the physician.

Answer: Evidence of improved clinical outcomes from clinical trials.

46. “RNA interference (RNAi)” is a mechanism of gene silencing that acts:

  • During transcription.
  • Post-transcriptionally, by targeting mRNA for degradation.
  • During DNA replication.
  • During DNA repair.

Answer: Post-transcriptionally, by targeting mRNA for degradation.

47. Eukaryotic RNA Polymerase I is responsible for transcribing which type of RNA?

  • mRNA
  • tRNA
  • Most rRNA genes
  • snRNA

Answer: Most rRNA genes

48. The “C-terminal domain (CTD)” of RNA Polymerase II is a key feature that:

  • Binds to the DNA promoter.
  • Is the catalytic site for RNA synthesis.
  • Becomes phosphorylated during transcription initiation and serves as a scaffold for RNA processing factors.
  • Is responsible for proofreading.

Answer: Becomes phosphorylated during transcription initiation and serves as a scaffold for RNA processing factors.

49. “Operons,” which allow for the coordinated transcription of multiple genes, are a feature of gene organization found in:

  • Eukaryotes.
  • Prokaryotes.
  • Both prokaryotes and eukaryotes.
  • Plants only.

Answer: Prokaryotes.

50. The ultimate principle of why pharmacists study transcription is because:

  • It is the fundamental process that translates genetic information into function, and its machinery is a critical target for many important drugs.
  • It is an interesting but clinically irrelevant topic.
  • It is only important for understanding bacteria.
  • It is the only way to pass the NAPLEX exam.

Answer: It is the fundamental process that translates genetic information into function, and its machinery is a critical target for many important drugs.

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