L4 unriddle MCQs.pdf

Q1. What is the key difference between prokaryotic and eukaryotic gene expression? A. Prokaryotes have separate compartments for transcription and translation, while eukaryotes do not. B. **Eukaryotes have separate compartments for transcription and translation, providing opportunities for posttrans...

Q1. What is the key difference between prokaryotic and eukaryotic gene expression? A. Prokaryotes have separate compartments for transcription and translation, while eukaryotes do not. B. **Eukaryotes have separate compartments for transcription and translation, providing opportunities for posttranscriptional regulation.** C. Prokaryotes have more complex gene structures with longer introns compared to eukaryotes. D. Eukaryotes have simpler core cis-elements for splicing compared to prokaryotes. E. Regulatory RNA-binding proteins are only found in eukaryotic cells. Q2. Which of the following is not a core cis-element required for pre-mRNA splicing? A. 5' splice site B. 3' splice site C. Branch point sequence D. Polypyrimidine tract E. **Exonic splicing enhancer** Q3. How do regulatory RNA-binding proteins like SR proteins and hnRNPs affect splicing? A. They always repress splicing by binding to cis-elements. B. They always promote splicing by binding to cis-elements. C. **Their effect on splicing depends on their binding position relative to the regulated exon.** D. They only interact with the core spliceosomal components, not cis-elements. E. They are not involved in the regulation of splicing. Q4. What is the role of the spliceosome in pre-mRNA splicing? A. The spliceosome recognizes and binds to the 5' and 3' splice sites. B. The spliceosome catalyzes the removal of introns and ligation of exons. C. The spliceosome is involved in the export of mature mRNA from the nucleus. D. The spliceosome regulates alternative splicing by interacting with splicing enhancers and silencers. E. ** The spliceosome recognizes and binds to the 5' and 3' splice sites and the spliceosome catalyzes the removal of introns and ligation of exons. Q5. How do eukaryotes ensure accurate splicing despite having longer and more degenerate splice sites compared to prokaryotes? A. Eukaryotes have simpler gene structures with fewer introns. B. Eukaryotes rely solely on the core spliceosomal components for splicing. C. **Eukaryotes have additional cis-elements and trans-acting factors that provide splicing specificity.** D. Eukaryotes do not need to ensure accurate splicing, as they have mechanisms to tolerate splicing errors. E. Eukaryotes have shorter introns compared to prokaryotes. Improve your knowledge of molecular mechanisms underlying RNA splicing, editing and transport: Q6. What is the primary function of the spliceosome in pre-mRNA splicing? A. The spliceosome recognizes and binds to the 5' and 3' splice sites. B. **The spliceosome catalyzes the removal of introns and ligation of exons.** C. The spliceosome regulates alternative splicing by interacting with splicing enhancers and silencers. D. The spliceosome is involved in the export of mature mRNA from the nucleus. E. The spliceosome is responsible for RNA editing. Q7. Which of the following is an example of RNA editing in eukaryotes? A. Conversion of adenosine to guanine B. Conversion of cytidine to uridine C. **Conversion of adenosine to inosine** D. Conversion of uridine to cytidine E. Conversion of guanine to adenine Q8. What is the primary function of mRNA localization in eukaryotic cells? A. Localization of mRNAs ensures their efficient translation. B. **Localization of mRNAs controls the development of multicellular organisms.** C. Localization of mRNAs is not important for eukaryotic gene expression. D. Localization of mRNAs is only observed in specialized cell types. E. Localization of mRNAs is a mechanism for RNA degradation. Q9. Which enzyme is responsible for the conversion of cytidine to uridine in eukaryotic mRNAs? A. ADAR B. **APOBEC1** C. Spliceosome D. U1 snRNP E. Tra2 Q10. What is the primary function of the IRE-IRE-BP system in regulating mRNA stability? A. It promotes the degradation of transferrin receptor mRNA when iron levels are high. B. **It stabilizes transferrin receptor mRNA when iron levels are low.** C. It has no role in the regulation of mRNA stability. D. It is involved in the regulation of alternative splicing. E. It catalyzes the conversion of adenosine to inosine in mRNAs. Appreciate the role that alternative splicing plays in regulating gene expression: Q11. What is the primary mechanism by which alternative splicing increases protein diversity in eukaryotes? A. **Alternative splicing allows a single gene to produce multiple mRNA isoforms.** B. Alternative splicing increases the number of exons in eukaryotic genes. C. Alternative splicing is responsible for the chemical modification of mRNA transcripts. D. Alternative splicing is required for the export of mRNA from the nucleus. E. Alternative splicing is a mechanism for the degradation of mRNA. Q12. How do splicing enhancers and silencers regulate alternative splicing? A. Splicing enhancers and silencers directly interact with the spliceosomal components. B. **Splicing enhancers and silencers are recognized by RNA-binding proteins that can either promote or repress inclusion of specific exons.** C. Splicing enhancers and silencers are involved in the chemical modification of mRNA transcripts. D. Splicing enhancers and silencers control the localization of mRNA within the cell. E. Splicing enhancers and silencers have no role in the regulation of alternative splicing. Q13. What is the role of the Sxl, Tra, and Dsx proteins in sex determination in Drosophila? A. These proteins are involved in the regulation of transcription. B. These proteins are responsible for the chemical modification of mRNA transcripts. C. These proteins control the localization of mRNAs within the cell. D. **These proteins regulate the alternative splicing of key genes involved in sex determination.** E. These proteins have no role in sex determination in Drosophila. Q14. How does alternative splicing of the Transformer (Tra) gene contribute to sex determination in Drosophila? A. **Alternative splicing of Tra produces a functional protein only in females.** B. Alternative splicing of Tra produces a functional protein only in males. C. Alternative splicing of Tra has no impact on sex determination. D. Alternative splicing of Tra is regulated by the Sxl protein. E. Alternative splicing of Tra is the same for males and females. Q15. What is the significance of the alternative splicing of the Doublesex (Dsx) gene in Drosophila sex determination? A. **Alternative splicing of Dsx produces transcription factors that promote either male or female development.** B. Alternative splicing of Dsx has no impact on sex determination. C. Alternative splicing of Dsx is regulated by the Tra and Tra2 proteins. D. Alternative splicing of Dsx is controlled by the Sxl protein. E. Alternative splicing of doublesex only affects females. Appreciate the diversity of biological functions of RNA-based mechanisms in health and disease: Q16. What is the primary function of RNA editing by ADAR enzymes in eukaryotes? A. RNA editing by ADAR converts cytidine to uridine in mRNA transcripts. B. RNA editing by ADAR converts adenosine to guanine in mRNA transcripts. C. **RNA editing by ADAR converts adenosine to inosine in mRNA transcripts.** D. RNA editing by ADAR has no biological function. E. RNA editing by ADAR is involved in the regulation of alternative splicing. Q17. How does the IRE-IRE-BP system regulate the stability of the transferrin receptor mRNA? A. The IRE-IRE-BP system promotes the degradation of transferrin receptor mRNA when iron levels are low. B. The IRE-IRE-BP system stabilizes transferrin receptor mRNA when iron levels are high. C. **The IRE-IRE-BP system stabilizes transferrin receptor mRNA when iron levels are low.** D. The IRE-IRE-BP system has no role in the regulation of transferrin receptor mRNA stability. E. The IRE-IRE-BP system is involved in the regulation of alternative splicing. Q18. What is the primary biological function of mRNA localization in eukaryotic cells? A. Localization of mRNAs ensures their efficient translation. B. **Localization of mRNAs controls the development of multicellular organisms.** C. Localization of mRNAs is a mechanism for RNA degradation. D. Localization of mRNAs is involved in the regulation of alternative splicing. E. Localization of mRNAs has no biological function. Q19. How can dysregulation of RNA-based mechanisms contribute to disease in humans? A. Dysregulation of alternative splicing has no impact on human health. B. Dysregulation of RNA editing can lead to neurological disorders. C. Dysregulation of mRNA localization is not associated with any human diseases. D. Dysregulation of mRNA stability regulation can contribute to metabolic disorders. E. **All of the above.** Q20. What is the primary biological function of the APOBEC1-mediated RNA editing in eukaryotes? A. APOBEC1-mediated RNA editing converts adenosine to inosine in mRNA transcripts. B. **APOBEC1-mediated RNA editing converts cytidine to uridine in mRNA transcripts.** C. APOBEC1-mediated RNA editing is involved in the regulation of alternative splicing. D. APOBEC1-mediated RNA editing has no biological function. E. APOBEC1-mediated RNA editing controls the localization of mRNA within the cell. Learn about some modern experimental approaches used in this area of research: Q21. What is the primary purpose of using reporter assays to study splicing regulation? A. Reporter assays are used to identify the core cis-elements required for splicing. B. **Reporter assays are used to measure the activity of splicing enhancers and silencers.** C. Reporter assays are used to purify the spliceosomal components. D. Reporter assays are used to study the localization of mRNA within the cell. E. Reporter assays are used to analyze the chemical modification of mRNA transcripts. Q22. Which of the following techniques is commonly used to identify RNA-binding proteins that interact with specific cis-elements? A. RNA immunoprecipitation B. Crosslinking and mass spectrometry C. Genetic approaches D. ** RNA immunoprecipitation and Crosslinking and mass spectrometry ** E. All of the above Q23. What is the primary advantage of using high-throughput sequencing methods to study posttranscriptional regulation? A. **High-throughput sequencing allows researchers to profile alternative splicing patterns genome-wide.** B. High-throughput sequencing is used to identify the core spliceosomal components. C. High-throughput sequencing is used to analyze the chemical modification of mRNA transcripts. D. High-throughput sequencing is used to study the localization of mRNAs within the cell. E. High-throughput sequencing has no application in the study of posttranscriptional regulation. Q24. How do researchers use biochemical approaches to study the interaction between RNA-binding proteins and cis-elements? A. Biochemical approaches are used to purify the spliceosomal components. B. Biochemical approaches are used to identify the core cis-elements required for splicing. C. Biochemical approaches are used to analyze the chemical modification of mRNA transcripts. D. Biochemical approaches are used to study the localization of mRNAs within the cell. E. **Biochemical approaches are used to identify RNA-binding proteins that interact with specific cis-elements.** Q25. What is the primary advantage of using genetic approaches to study posttranscriptional regulation? A. Genetic approaches are used to identify the core spliceosomal components. B. Genetic approaches are used to analyze the chemical modification of mRNA transcripts. C. Genetic approaches are used to study the localization of mRNAs within the cell. D. **Genetic approaches are used to identify novel regulatory mechanisms and RNA- binding proteins.** E. Genetic approaches have no application in the study of posttranscriptional regulation.