複選題

31. Point mutations in the DNA sequence can cause:
(A) silent mutation
(B) missense mutation
(C) nonsense mutation
(D) frameshift mutations
(E) none of the above

複選題27. Which of the following is correct regarding yeast three-hybrid analysis? (A) A useful tool in analyzing RNA-protein interactions (B) It contain a fusion protein of LexA, which binds the reporter construct, and MS2 which specifically binds an RNA tag that has been added to every RNA produced by the plasmid library. (C) It needs a plasmid library that contains random sequences from the genome tagged with a unique hairpin sequence that MS2 will bind. (D) It requires a reporter construct that contains a LexA operator (binding site) and a reporter gene. (E) It needs a fusion protein of the protein of interest and two tags - the calmodulin binding site and protein A.

28. Which of the following is a function of telomeres? (A) Serve as an attachment site for the proteins of the kinetochore. (B) They are sequences at the ends of the linear eukaryotic chromosome that protect the ends from proteases. (C) They are sequences of the eukaryotic chromosome that ensure proper distribution during mitosis. (D) In most eukaryotes, telomeres are protected from shortening by a protein-RNA complex called telomere terminal transferase. (E) Drosophila species maintain telomere lengths by the regulated insertion of retrotransposons into telomeres.

29. Which of the following is the function of histone H1? (A) Stabilizing nucleosomes (B) Promoting higher order chromosome structure (C) Modulating the repression of transcription by nucleosomes (D) Binding to regions undergoing active RNA synthesis (E) Mediating epigenetic regulation

複選題30. Which of the following is affected by the presence of epigenetic marks? (A) Development (B) Imprinting (C) X-chromosome inactivation (D) Maturation of RNA (E) Unique expression patterns in different cells

複選題32. Which of the following is/are a step in nonhomologous end joining? (A) Phosphorylation of the Ku70-Ku80 complex (B) Degradation of any single-strand overhangs or hairpins from the broken ends of the chromosomes to be repaired (C) Binding of the Ku70-Ku80 complex to the broken chromosome ends (D) Binding of a kinase and a nuclease to the Ku70-Ku80 complex on the DNA (E) None of the above

複選題33. Which of the following is/are coded for by the retroviral genome? (A) Viral coat proteins (B) tRNA (C) Reverse transcriptase (D) Integrase (E) Envelope protein

複選題34. Which of the following transcription factors is/are utilized by all three eukaryotic RNA polymerases? (A) TFIID (B) TBP (C) DNA helicase (D) THIIIC (E) THIIF

35. Which of the following is NOT usually involved in the processing of primary mRNA transcripts? (A) Addition of multiple adenosines to the 3' end (B) Insertion of intron sequences (C) Covalent joining of exons (D) Methylation of nucleotides at the 5' end (E) None of the above

複選題36. Which of the following statements is/are FALSE? (A) A transcription factor that enhances gene expression is called enhancer. (B) A transcription factor that enhances gene expression is called activator. (C) A transcription factor that reduces gene expression is called repressor. (D) A transcription factor that enhances gene expression is called operator. (E) Insulator is a regulatory DNA site.

複選題37. Which of the following is/are FALSE about the E. coli Lac operon? (A) Transcription produces a single polycistronic mRNA containing the lacZ, lacY, and lacA genes. (B) The lacl gene is controlled from the same promoter as the lacZ gene. (C) The Lac repressor protein is constitutively expressed. (D) The operator region regulates transcription through interaction with the Lac repressor protein. (E) The amount of glucose in the growth medium does not affect the level of gene expression activated by lactose.