Which of the following statements is correct about the synthesis of DNA lagging strands in the replication:()
A. The synthesis of lagging strand is semi-conservative.
B. The synthesis of lagging strand is discontinuous.
C. The synthesis of lagging strand is asymmetric.
D. Lagging strand is synthesized in the form of Okazaki fragment.
E. Several DNA polymerases are participated in the synthesis of lagging strand.
Which of the following statement is correct about DNA topoisomerase inE.coli:()
A. to catalyze the ligation of gaps in DNA double strands.
B. to release the supercoiled structure of DNA ahead of replication fork.
C. to break hydrogen bond and base stacking force and improve the extension activity of DNA polymerase.
D. to break phosphodiester bond of DNA and separate two strands of DNA.
E. to hydrolyze ATP and connect two strands of DNA.
Which of the following statement is correct about the DNA replication in E. coli:()
A. One strand of DNA double helix is synthesized discontinuously.
B. Okazaki fragments are generated in this process.
C. RNA primer is needed.
D. Single-strand binding protein can prevent the unwinding of DNA double helix in the replication process.
E. DNA polymerase I are mainly responsible for DNA replication.
DNA replication requires: (1) DNA polymerase III, (2) helicase, (3) DNA polymerase I, (4) DNA-directed RNA polymerase, (5) DNA ligase, the correct order of their participation is:()
A. 4,3,1,2,5
B. 2,3,4,1,5
C. 4,2,1,5,3
D. 4,2,1,3,5
E. 2,4,1,3,5
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