8. What is the primary role of DNA methylation in DNA replication of E. coli?
(A) The hemimethylated origin region of DNA replication are inactive for initiation
(B) The methylated CpG island is important for DNA initiation of DNA replication
(C) The methylation of DNA is important for restriction-modification systems
(D) The methylation of origin region containing GATC sequences is important for the regulation of DNA priming
(E) DNA methylation has no function in DNA replication

4. In a eukaryotic cell, when or where is the packing ratio of DNA being the highest? (A) DNA replication (B) Mitosis (C) Apoptosis (D) Euchromatin region (E) RNA transcription initiation

5. The features of a plasmid expression vector usually not including _____? (A) Replication origin (B) Antibiotic resistance gene (C) Multiple cloning site (D) Promoter (E) Telomere ?

6. In animal cells, which of the following organelles contains genetic material in addition to nucleus? (A) Golgi apparatus (B) Mitochondrion (C) Chloroplast (D) Endoplasmic reticulum (E) Lysosome

7. Which of the statements about nucleus is NOT CORRECT? (A) Structures as a double-membrane compartment (B) Containing bulk of genome (C) RNA transcription (D) DNA maintenance (E) Exosome secretion

9. The central dogma of molecular biology including two processes: transcription and _____? (A) Reverse transcription (B) Degradation (C) Replication (D) Translation (E) Reverse replication

10. Which of the following ones does NOT happen in mRNA processing? (A) Splicing (B) Editing (C) Polyadenylation (D) All of the above (E) None of the above

11. Which of the following statements about the CRISPER-Cas9 is wrong? (A) One of the great genome-editing tools (B) A naturally occurred system in yeast (C) A guide RNA is needed (D) With the ability to change an organism's DNA (E) More efficient than other existing genome-editing methods

12.How many of the 64 possible triplets together encode stop codons? (A) 1 (B) 2 (C) 3 (D) 5 (E) 10

13.Which promoter elements of the following RNA polymerase(s) possess TATA box? (A) RNA polymerase I, II and III (B) RNA Polymerase II and III (C) RNA polymerase I (D) RNA polymerase II (E) RNA polymerase III

14. Which of the following statements is NOT CORRECT for DNA topoisomerases? (A) DNA topoisomerases can cleave DNA backbone at phosphodiester bond (B) Only participate enzymatically in overwinding, knotting and catenation of DNA (C) Relive the torsion stresses associated with DNA replication and transcription elongation (D) Both type I and II topoisomerase change the linking number of DNA (E) Human topoisomerase I is the antigen recognized by Anti-Scl-70 in scleroderma