複選題
34. Which of the following pairs between the type of DNA damage repair and the corresponding enzyme are correct?
(A) Nucleotide excision repair: DNA glycosylase.
(B) Photoreactivation: DNA photolyase.
(C) Base excision repair: UvTABC endonuclease.
(D) Mismatch repair: MutS and MutL.
(E) Double-strand break repair: Rec A recombinase.

30. Which of the following statements is correct regarding small RNA-mediated silencing pathways in eukaryotes? (A) Piwi-interaction RNAs (piRNAs) are expressed predominantly in vegetative cells. (B) Both small interfering RNAs (siRNAs) and microRNAs (miRNAs) are generated from longer RNA molecules by Dicer. (C) The major component of the RNA-induced silencing complex is called Drosha. (D) The size of small RNAs is typically in the range of 30-40 nucleotides. (E) The miRNA is typically highly specific with only one mRNA target. editing.

複選題31. Which of the following statements are correct regarding the central dogma of molecular biology, as firstly stated by Francis Crick in 1957? (A) The sequential information can be transferred from DNA to RNA. (B) The sequential information can be transferred from RNA to DNA. (C) The sequential information can be transferred from RNA to protein. (D) The sequential information can be transferred from protein to RNA. (E) The sequential information can be transferred from protein to protein.

複選題32. Which of the following histones form a tetramer in the first step of the assembly of a nucleosome? (A) H1. (B) H2A. (C) H2B. (D) H3. (E) H4.

複選題33. Which of the following features are correct regarding the mechanism of DNA polymerase? (A) DNA polymerase uses a single active site to catalyze the addition of any of the four deoxynucleoside triphosphates. (B) Steric constraints prevent DNA polymerase from using ribonucleoside triphosphates as substrate. (C) The thumb domain of DNA polymerase is intimately involved in catalysis. (D) Processivity is a crucial character for DNA polymerase and defines the average number of nucleotides added per template binding event. (E) Removal of incorrectly base-paired nucleotides is mediated by intrinsic endonuclease activity of DNA polymerase.

複選題35. Which of the following mechanistic features of RNA polymerase are correct? (A) RNA polymerase acts to make RNA copies from the whole genome. (B) RNA polymerase uses DNA as a template for RNA synthesis. (C) RNA polymerase needs a primer for initiation of RNA synthesis. (D) The error rate of RNA polymerase is lower than that of DNA polymerase. (E) Prokaryotic mRNA and non-coding RNA are synthesized by the same RNA polymerase.

36. Which of the following eukaryotic RNA polymerases transcribe ribosomal RNA? (A) RNA polymerase I. (B) RNA polymerase I. (C) RNA polymerase III. (D) RNA polymerase IV. (E) RNA polymerase V.

複選題37. Which of the following processes are associated with phosphorylation of the C- terminal domain (CTD) tail of the eukaryotic RNA polymerase II? (A) Transcription preinitiation. (B) Promoter escape. (C) Transcription elongation. (D) RNA 5' capping. (E) RNA splicing.

複選題38. Which of the following statements are correct regarding mRNA? (A) Each mRNA has at least one open reading frame (ORF). (B) Many eukaryotic mRNAs are polycistronic. (C) Polycistronic mRNAs usually encode proteins involved in related functions. (D) The 5' cap is required to recruit ribosome to the eukaryotic mRNA. (E) The Kozak sequence acts as a ribosome binding site of eukaryotic mRNA.

複選題39. Three operators (OR1, OR2, OR3) are located between the PR and PRMpromoters in the genome of bacteriophage λ. Which of the following are correct regarding these three operators?(A) OR1 is located within PR, while OR3 is located within PRM. (B) All three operators can bind to either λ repressor or Cro. (C) The binding affinity of the three operators to Cro is OR1 ＞ OR2 ＞ OR3. (D) X repressor at OR1 helps the repressor bind to OR2 by cooperative binding. (E) Binding of λ repressor to OR3 leads to increase in the λ repressor gene expression. 

複選題40. Which of the following processes belong to epigenetic regulation? (A) Maintenance of the lysogenic state of bacteriophage  λ through cell division. (B) Maintenance of the pattern of point mutations through cell division. (C) Maintenance of the pattern of DNA methylation through cell division. (D) Maintenance of the state of chromatin modification through generations. (E) Expression of a gene controlled by an activator which is active only in the presence of a given inducer.