基因工程进行基因重组主要以粘性末端连接法为主。

A. 对
B. 错

琼脂糖凝胶电泳在分离度上优于聚丙烯酰胺凝胶，而在分离范围上比聚丙烯酰胺凝胶差。

A. 对
B. 错

所有生物DNA的基本结构是一样的，不同基因具有相同物质基础，因此基因可以重组互换。

A. 对
B. 错

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

DNA molecules can be cut into sections by using:

ATP
B. Gel electrophoresis
C. Plasmid
D. A probe
E. Restriction endonuclease

Bacteria containing recombinant plasmids are often identified by which process?

A. removing the DNA of all cells in a culture to see which cells have plasmids
B. examining the cells with an electron microscope
C. exposing the bacteria to an antibiotic that kills the cells lacking the plasmid
D. producing antibodies specific for each bacterium containing a recombinant plasmid

There are two kinds of DNA libraries, they are _____ libraries and _____ libraries。