Which two enzymes are needed to produce recombinant DNA?
A. Endonuclease, transcriptase
B. DNA polymerase, topoisomerase
C. Polymerase, ligase
D. Restriction enzyme, ligase
E. Transcriptase, ligase
Plasmids were usually isolated from:
A. viruses
B. DNA
C. bacteria.
D. Fungi.
E. human cell
Plasmids are important in biotechnology because they are
A. a vehicle for the insertion of recombinant DNA into bacteria.
B. surfaces for respiratory processes in bacteria.
C. recognition sites on recombinant DNA strands.
D. surfaces for protein synthesis in eukaryotic recombinants.
E. proviruses incorporated into the host DNA
Please put them in order①Transfer of the ligated plasmid into an E. coli strain②isolation the desired target fragment③Selection of transformed bacteria④Ligation of the fragment into a new plasmid vector
A. ①②③④
B. ④③②①
C. ②④①③
D. ②④③①
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