Class 12 NEET Biology Biotechnology Principles and Processes

(a) : Restriction endonucleases were found by Arber in 1962 in bacteria. They act as "molecular scissors" or chemical scalpels. They recognize the specific base sequence at palindrome sites in DNA duplex and cut its strands. For example, restriction endonuclease Eco RI found in the colon bacteria E. coli reocgnizes the base sequence GAATTC in DNA duplex and cuts its strands between G and A.