31. Which property of DNA is crucial for the conservation of genetic information?
(A) antiparallelism
(B) semiconservative replication
(C) the ability to form a circular DNA
(D) base-pair complementarity
(E) The amount of A is the same as the amount of C

27. You are working with a gene associated with an essential pathway that is necessary at two time points in an organism's lifetime. With regard to gene regulation, you would expect the gene to be (A) associated with response to distinct events. (B) not constitutive. (C) "activated" by particular signals (induced). (D) "turned off" by particular signals (repressed). (E) None of the above.

28. In a histone protein, what modification(s) to lysine mark the nucleosome as a transcription target? (A) alkylation (B) acetylation (C) phosphorylation (D) methylation (E) ubiquitylation

29. microRNAs play a key role in which of the following? (A) repressed translation of the mRNA. (B) degradation of viral RNA (C) rapid translation of the mRNA. (D) degradation of the mRNA (E) repeated translation as the miRNA prevents destruction of the mRNA

複選題30. Which of the following statements is/are TRUE? (A) Restriction endonucleases can cut DNA and RNA. (B) It is common to use ddNTPs (dideoxyribonucleoside triphosphates) in DNA sequencing. (C) Enzymes that seal nicks in DNA are called ligases. (D) In recombinant DNA technology, a YAC is an enzyme isolated from a large South American four-legged mammal. (E) The "c" in cDNA stands for Circular.

複選題32. The ability of DNA to denature is important for which process? (A) DNA synthesis (B) nucleic acid hybridization experiments (C) RNA synthesis (D) PCR reaction (E) DNA separation by agarose gel electrophoresis

33. Which of the following is required for both DNA replication and RNA transcription? (A) DNA (B) primers (C) RNA polymerase (D) phosphodiesterase (E) topoisomerase

34. Which of the following mobile elements is a retrotransposon? (A) yeast Ty element (B) bacterial IS sequence (C) Drosophila P element (D) maize activator (Ac) element (E) RNA genome of influenza H7N9 virus

複選題35. Which of the following is correct for the eukaryotic chromosomes? (A) The ends of eukaryotic chromosomes are called telomeres, and contain special repeat sequences, called telomeric sequences. (B) Telomere terminal transferase containing the reverse transcriptional activity is important to maintain the chromosomal ends in eukaryotes. (C) The centromeric sequences are important for proper chromosome segregation during replication. (D) Kinetochores assemble at the centrosome. (E) Telomerase activity declines with age and this could explain why cells lose their ability to divide after many replications.

複選題36. For the DNA replication in E. coli, which of the following is correct? (A) The leading strand is initially synthesized as Okazaki fragments (B) It has the DNA strand synthesized in a 5'-3' direction (C) DNA polymerase I adds nucleotides to the primer strand (D) The leading strand is synthesized continuously (E) It synthesizes each strand in the opposite direction (one 5'->3', one 3'->5'), so they can be synthesized at once.

37. A mutation that changes the recognition sequence for the restriction enzyme EcoRI from GAATTC to GATTTC is an example of a (A) restriction fragment length polymorphism (RFLP). (B) single nucleotide polymorphism (SNP). (C) simple sequence repeat (SSR). (D) genetic heterogeneity (E) none of the above