109年 - 109 國立臺灣大學_碩士班招生考試：分子生物學(B)#125811

1. RNA molecules that exhibit catalytic activities are called (A) mRNAs (B) rRNAs (C) ribosomes (D) ribonucleotides (E) ribozymes

2. Cellular proteins destined for secretion are sorted and packaged in (A) nucleolus (B) endosomes (C) endoplasmic reticulum (D) trans Golgi network (E) lysosomes

3. Which of the following is true about a circular double-stranded DNA genome that is determined by chemical means to be 23 percent adenosine? (A) The genome is 11.5% guanosine. (B) The genome is 23% guanosine. (C) The genome is 27% guanosine. (D) The genome is 54% guanosine. (E) The base percent composition of guanosine in the genome cannot be determined from the information given.

4. In the classical model of transcriptional control, a repressor protein binds to (A) an AUG sequence (B) an operator (C) a TATA box (D) a Shine-Dalgarno sequence (E) an enhancer

5. "Zinc fingers" are important in cellular functions because they are (A) at the catalytic site of many kinases (B) structures with high redox potential (C) introduce double-stranded DNA breaks (D) a structural motif of many DNA-binding proteins (E) characteristic of palindromic stretches of unique-sequence DNA

6. CRISPR/Cas9 is the most talked about techniques in the past few years for targeted genome editing. Which of the following statement about CRISPR/Cas9 is NOT correct? (A) An RNA molecule, called guide RNA, directs Cas9 to the target (B) Cas9 is an exonuclease that cut double-stranded DNA (C) The system was originally discovered as part of adaptive immunity in bacteria (D) The system has been shown to work in many organisms. (E) The system can be used to control gene expression.

7. Which of the following is NOT required by DNA polymerase for in vitro synthesis of DNA? (A) tRNA (B) ATP (C) primer (D) dATP (E) DNA template

8. The "2018 Nobel Prize in Chemistry" was awarded to scientists who pioneered directed evolution. Which of the following statement about directed evolution is NOT correct? (A) It mimics natural evolution and directs protein engineering toward a user-defined goal. (B) It involves iterative rounds mutagenesis, selection and amplification. (C) High fidelity DNA polymerases are used for random mutagenesis in vitro. (D) The fidelity of the Taq DNA polymerase can be modulated by alteration of the composition of the reaction buffer. (E) DNA shuffling is another powerful method for directed evolution, which generates diversity by recombination.

9. Which of the following restrict enzymes will produce a blunt end (the cutting site is indicated with * in the recognition sequence)? (A) HaeIII (GG*CC) (B) EcoRI (G*AATTC) (C) NotI (GC*GGCCGC) (D) XbaI (T*CTAGA) (E) PstI (CTGCA*G)

10. Which of the following can NOT be determined by NGS (next-generation sequencing)? (A) the genome of a cell. (B) the transcriptome of a cell. (C) the IncRNA of a cell. (D) the proteome of a cell. (E) the genome of chloroplast.

11. Transcriptionally inactive genes (A) are always located within euchromatin. (B) are often methylated. (C) are often ubiquitinated. (D) are not located within nucleosomes. (E) are not resistant to DNase I.

12. Which of the following technique is usually used to detect genome-wide chromatin accessibility? (A) Yeast two-hybrid (B) SDS-PAGE (C) ATAC-seq (D) Co-immunoprecipitation (E) Electroporation

13. Which of the following type of bonds or interactions are LEAST likely to be involved in stabilizing the three-dimensional folding of most proteins? (A) Ester bonds (B) Hydrogen bonds (C) Electrostatic bonds (D) Hydrophobic interactions (E) Disulfide bonds

14. The amino acid sequence of a novel membrane protein contains six immunoglobulin-like domains and four fibronectin-like repeats. This protein is most likely a (A) G protein (B) transcriptional factor (C) motor protein (D) cell adhesion molecule (E) serine/threonine protein kinase

15. Which of the following is most likely to lead to a loss of gene function? (A) A missense mutation in the open reading frame (B) A change from TAA codon to TAG codon in the coding region (C) A change from C to T in the promoter region (D) A sequence change in the 5' untranslated region (E) A frameshift mutation in the coding region

16. Which of the following best describes the function of the sigma subunit of the RNA polymerase in E. coli? (A) It is required for transcriptional termination. (B) It is required for elongation of the RNA transcript. (C) It increases the accessibility of RNA polymerase to any DNA template. (D) It is essential for the recognition and binding to the promoter sequence. (E) It keeps the core complex from dissociating.

17. Which of the following is the most likely mechanism for the origin of multigene families? (A) Endosymbiosis (B) Horizontal gene transfer (C) Gene duplication (D) Bacterial conjugation (E) Convergent evolution of dissimilar genes

18. Which of the following is NOT required for Rec-A dependent recombination between two DNA molecules? (A) ATP hydrolysis (B) Mismatch repair (C) Ligation (D) Strand migration (E) DNA synthesis

19. The ribosome is involved in all of the following EXCEPT (A) peptide bond formation (B) tRNA aminoacylation (C) binding of aminoacyl-tRNA to mRNA (D) binding of mRNA at an initiation codon (E) binding to Shine-Dalgarno sequence

20. Operator constitutive mutants of the lac operon would (A) express the lac repressor constitutively. (B) block the binding of RNA polymerase to the promoter. (C) enhance the binding of RNA polymerase to the promoter. (D) prevent the inducer from binding to the repressor. (E) express ẞ-galactosidase constitutively.

21. Which of the following elements can function as eukaryotic promoters? a. a TATA box. b. an initiator element. c. CpG islands. d. start codon. (A) only a. (B) a and b. (C) a and c. (D) a, b and c. (E) a, b, c and d.

22. Which of the following elements are typical features of prokaryotic genes? a. polycistronic messenger RNAs b. complex transcription units c. introns (A) only a. (B) b and c. (C) a and c. (D) a, b and c. (E) none of the above.

23. Short micro RNAs (miRNAs) a. code for proteins. b. are common in bacteria but not eukaryotes. c. can lead to mRNA degradation. d. can lead to translational repression. (A) only a. (B) only c. (C) b and c. (D) c and d. (E) none of the above.

24. Which of the following statements about mitochondrial DNA are true? a. Mammalian mitochondrial DNA contains introns. b. Mitochondrial DNA encodes rRNAs and tRNAs. c. The human mitochondrial DNA is circular. (A) only a. (B) only b. (C) only c. (D) b and c. (E) a, b and c.

25. A small molecule that binds directly to the active site of an enzyme and disrupts its catalytic reaction is called (A) an allosteric inhibitor. (B) a competitive inhibitor. (C) a noncompetitive inhibitor. (D) RNAi. (E) ATP binding pocket.

26. Which of the following plays a role in the degradation of proteins? a. RNAi b. ubiquitin c. proteasome d. nuclease (A) a and b. (B) b and c. (C) a and c. (D) a, b and c. (E) a, c and d.

27. Which of the followings are constituents of deoxyribonucleotides? a. phosphate moieties b. deoxyribose c. ribose d. organic bases (A) a and b. (B) a and c. (C) b and d. (D) a, b and d. (E) a, b, c and d.

28. Which of the following are removed from mRNAs during processing? a. exons b. introns c. noncoding sequences d. RNA cap structure e. poly（Ａ） tail (A) only a. (B) only c. (C) b and c. (D) a and c. (E) all of the above.

29. Which of the following is a protein that is involved in translation? a. topoisomerase b. ribosomal RNA c. RNA polymerase d. aminoacyl-tRNA synthetase (A) only a. (B) only b. (C) only d. (D) b and d. (E) all of the above.

30. Cellular protein synthesis proceeds in which direction? a. carboxyl to amino terminus b. amino to carboxyl terminus c. 3' to 5' d. 5' to 3' (A) only a. (B) only b. (C) only c. (D) only d. (E) b and d.

31. DNA replication begins at sequences called a. promoters. b. initiators. c. origins. d. operons. e. Okazaki fragments. (A) only a. (B) only c. (C) a and b. (D) c and e. (E) b and d.

32. A mutation that changes a cysteine codon to a tryptophan codon is called a (A) missense mutation. (B) nonsense mutation. (C) frameshift mutation. (D) silent mutation. (E) suppressor mutation.

33. DNA ligase a. synthesizes DNA from a template. b. forms a phosphodiester bond. c. forms a peptide bond. d. joins Okazaki fragments. (A) only b. (B) only c. (C) only d. (D) a and b. (E) b and d.

34. Which of the following evidence is indicative of the presence of a gene in an unknown DNA sequence? a. alignment to a partial cDNA sequence b. sequence similarity to genes of other organisms c. ORF consistent with the rules for exon and intron sequences (A) only a. (B) only b. (C) only c. (D) b and c. (E) a, b and c.

35. Telomeres a. consist of repetitive sequences with high G content. b. are a few hundred base-pairs long in vertebrates. c. have specific proteins bound at the DNA ends. (A) only a. (B) only b. (C) only c. (D) a and c. (E) a, b and c.

36. Splice sites in pre-mRNA are marked by two universally conserved sequences contained (A) in the middle of the intron. (B) in the middle of the exon. (C) at the ends of the exons. (D) at the ends of the introns. (E) none of the above.

37. Which type of RNA participates in nuclear export of mRNA? (A) hnRNA (B) snRNA (C) tRNA (D) rRNA (E) miRNA

38. Which of the following about prokaryotes is correct? (A) lack of cell walls (B) lack of nucleus (C) most of prokaryotic chromosomes is linear (D) they contain mitochondria (E) all of the above

39. The polymerase chain reaction (PCR) technique can be used for a. direct isolation of a specific segment of genomic DNA. b. preparation of probes. c. synthesis of RNA from genomic DNA. d. introduction of mutations in a DNA fragment. (A) only a. (B) only b. (C) a and b. (D) a and c. (E) a, b and d.

40. The ability of DNA to denature is important for which process? a. DNA synthesis b. nucleic acid hybridization experiments c. RNA synthesis d. Protein synthesis (A) only a. (B) only b. (C) a and b. (D) a, b and c. (E) all of the above.