The first restriction endonuclease isolated was :

The correct answer is Option (2) → Hind II

Option (2) Hind II — Correct. Of the two enzymes found in 1963 that restrict phage growth in E. coli, one cut DNA: a restriction endonuclease. The first restriction endonuclease to be isolated and characterised was Hind II.

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NCERT Extract:
Restriction Enzymes – “The first restriction endonuclease–Hind II, whose functioning depended on a specific DNA nucleotide sequence was isolated and characterised five years later. It was found that Hind II always cut DNA molecules at a particular point by recognising a specific sequence of six base pairs. This specific base sequence is known as the recognition sequence for Hind II.”