A foreign DNA and plasmid cut by the same restriction endonuclease can be joined to form a recombinant plasmid using

The alien DNA and the plasmid cut by the same restriction endonuclease are joined by the enzyme DNA ligase to form r-DNA molecule. Ligase joins the alien DNA molecule and plasmid nucleotides by forming phosphodiester bonds between them.

(1) EcoRI is a restriction endonuclease which identifies the palindromic sequence 5’ GAATTC 3’ in both the complementary strands of DNA and cuts each strand between G and A.

(2) Taq polymerase is a type of DNA polymerase obtained from Thermus aquaticus, which is used for gene
amplification in a thermocycler during PCR.

(3) DNA polymerase III is the main enzyme involved in replication or synthesis of DNA in prokaryotes, like bacteria. However, RNA polymerase III is an enzyme of eukaryotes involved in the synthesis of tRNA, snRNA and 5S rRNA.