Test Bank For Molecular Diagnostics: Fundamentals, Methods, and Clinical Applications, 3rd Edition

Chapter 2: Gene Expression and Epigenetics Multiple Choice 1. DNA sequences that are involved in the regulation of gene expression are called A. cis factors. B. trans factors. C. attenuators. D. repressors. ANS: A OBJ: 2-2 2. Which of the following is the binding site for the repressor protein of the lactose operon? A. P site B. Operator C. A site D. Promoter ANS: B OBJ: 2-2 3. Which of the following would prevent transcription of the lactose operon? A. Loss of promoter B. Presence of inducer C. Loss of the repressor protein D. RNA polymerase binding to the promoter ANS: A OBJ: 2-2 4. Which of the following is a cis factor of the lactose operon? A. Inducer B. Operator C. Repressor D. Polymerase ANS: B Copyright © 2019 by F. A. Davis Company OBJ: 2-2 5. In the lactose operon, which of the following configurations would result in gene expression? A. Promoter +, Operator +, Repressor +, no inducer present B. Promoter –, Operator +, Repressor +, no inducer present C. Promoter –, Operator –, Repressor +, inducer present D. Promoter +, Operator +, Repressor –, no inducer present ANS: D OBJ: 2-2 6. When gene expression is regulated by mechanisms other than the interaction of cis elements and trans factors, the regulation is called A. induction. B. epigenetics. C. attenuation. D. combinatorial control. ANS: B OBJ: 2-1 7. Genomic imprinting is accomplished primarily through A. methylation. B. acetylation. C. transcription. D. cis and trans factor interactions. ANS: A OBJ: 2-5 8. The most frequently methylated base in vertebrates is A. adenine. B. cytosine. C. guanine. D. thymine. ANS: B Copyright © 2019 by F. A. Davis Company OBJ: 2-5 9. MicroRNAs, short endogenous RNAs, perform what function in the eukaryotic cell? A. Control of DNA replication B. Priming RNA synthesis C. RNA splicing D. Repression of gene expression ANS: D OBJ: 2-3 10. What mechanism may explain the difference in symptoms in Prader–Willi and Angelman syndromes? A. Genomic imprinting B. Alternative splicing C. Genetic recombination D. Capping ANS: C OBJ: 2-5 11. Alteration of the nucleotide sequence of RNA after transcription is called A. methylation. B. RNA silencing. C. RNA editing. D. capping. ANS: C OBJ: 2-5 12. Which RNA results from exogenous nucleic acids? A. siRNA B. lncRNA C. mRNA D. miRNA ANS: A Copyright © 2019 by F. A. Davis Company OBJ: 2-3 13. Which DNA methyltransferase (DNMT) is responsible for maintenance of DNA methylation patterns? A. DNMT3A B. DNMT2 C. DNMT1 D. DNMT3B ANS: C OBJ: 2-5 14. Which of the following is an epigenetic mechanism? A. Binding of transcription factors B. DNA hairpin formation C. Cis factors D. DNA methylation ANS: D OBJ: 2-1 15. Which is a histone mark? A. Binding of histone H1 to euchromatin B. A modified nucleosime C. Histone H3 tail sequence D. Acetylation of histone H3 ANS: D OBJ: 2-4 16. Which histone is not included in the core histones? A. H1 B. H2B C. H3 D. H4 ANS: A Copyright © 2019 by F. A. Davis Company OBJ: 2-4 17. This is a list of histone modifications that affect gene expression. A. Transcriptome B. Histone code C. Proteome D. Genetic code ANS: B OBJ: 2-4 18. Methylation of lysine at position 20 in histone 2B is expressed in this way. A. K20H2BMe B. H2BK20Me C. MeK20H2B D. H2K20Me ANS: B OBJ: 2-4 19. Acetylation of histone H3 would result in which of the following effects? A. Degradation of mRNA B. Formation of heterochromatin C. Exclusion of activator proteins D. Increased gene expression ANS: D OBJ: 2-4 20. These DNA sequence structures function in epigenetic gene regulation. A. Operators B. CpG islands C. Inverted repeats D. Regulator genes ANS: B OBJ: 2-5 Copyright © 2019 by F. A. Davis Company 21. Which proteins perform demethylation of DNA? A. DNA polymerases B. TET enzymes C. METTL enzymes D. TFIID protein ANS: B OBJ: 2-5 22. This complex is required for miRNA and siRNA association to mRNA targets. A. Replisome B. Retrotransposon C. RISC D. XIC ANS: C OBJ: 2-3 23. Enhancer regulation of gene expression is facilitated by this RNA. A. lncRNA B. miRNA C. siRNA D. Ri Xist RNA ANS: A OBJ: 2-3 24. DNA hypermethylation would have what effect of movement of retrotransposons through RNA intermediates? A. Increase movement by activating transcription B. Increase movement by repressing transcription C. No effect on movement nor transcription D. Inhibiy movement by repressing transcription ANS: D OBJ: 2-5 Copyright © 2019 by F. A. Davis Company 25. Multiple products are generated from the same gene by what mechanism? A. Alternative splicing B. Polyadenylation C. Capping D. Splicing ANS: A Copyright © 2019 by F. A. Davis Company