17.Which of the following methods can separate proteins based on their mass?
(A) SDS polyacrylamide gel electrophoresis
(B) Isoelectric focusing electrophoresis
(C) Ion exchange chromatography
(D) Gel filtration chromatography
(E) Centrifugation

複選題13. Which of the following statements is/are TRUE? (A)Restriction endonucleases can produce "blunt ends". (B) Enzymes that seal nicks in DNA are called ligases. (C) Proteins are the only substrates of kinases. (D) Enzymes known as HATs phosphorylate histones. (E) Enzymes known as HDACs deacetylate histones.

複選題14. What mechanism can microRNAs, small non-coding regulatory RNAs, utilize to reduce gene expression? (A) Repress the translation of target mRNA (B) Trigger the cleavage of target mRNA (C) Trigger the decapping of target mRNA (D) Enhance the polyadenylation of target mRNA (E) Accumulate target mRNAs in the P-bodies for degradation.

複選題15. Which of the following techniques can be used to measure the amount of a specific mRNA in a sample? (A)Western blot analysis (B) Southern blot analysis (C) Northern blot analysis (D) RNase protection assay (E) quantitative reverse transcription PCR

複選題16. Which of the following statements regarding protein synthesis is/are CORRECT? Ribosomes use the information carried by mRNA to make protein (B) Since the genetic code is read in groups of three bases, any nucleic acid sequence contains three possible frames (C) In protein synthesis, the anticodon of rRNA recognizes the codon on mRNA by base pairing. (D) Codons that differ in either of their first two bases can be recognized by the same tRNA. (E) Proteins are linear polymers made from amino acids. Most proteins fold into complex 3D structures. (A)

複選題18.The fluidity of lipid membrane in cells is influenced by? (A) Temperature (B) The amount of unsaturated fatty acyl chain (C) The length of the fatty acid chain (D) The amount of the cholesterol (E) The nature of the membrane-associated proteins

複選題19. Which of the following statements regarding to cell cycle is/are CORRECT? (A) DNA replication starts from the G1 phase (B) Mitosis occurs in the M phase (C) Degradation of cyclins is important in mitosis (D) DNA damage can cause cell cycle arrest (E) The GO phase is the interval between the termination of DNA replication and the onset of mitosis

20.Which of the following events occurs in prokaryotes but not in eukaryotes? (A)Post-transcriptional splicing (B) Translation in the absence of a ribosome (C) Concurrent transcription and translation (D) Post-translational modification (E) Alanine can be added to polypeptide chain by tRNA with different codon.

21.A class of mutations that results in multiple contiguous (side-by-side) amino acid changes in proteins is/are probably caused by which the following types of mutations? (A) recombinant (B) base analog (C) transversion (D) frameshift (E) transition

複選題22. Which of the following is/are functional elements of a plasmid? (A) centromere (B) drug-resistance gene (C) polylinker sequence (D) origin of replication (E) autonomously replicating sequence

複選題23. Unlike bacterial mRNA, eukaryotic mRNA must undergo______before it may be used for translation. (A) folding mRNA into hairpin loops (B) export to the cytoplasm (C) capping (D) splicing (E) polyadenylation