Read the following paragraph carefully and answer the given questions.

In the year 1963 the two enzymes responsible for restricting the growth of bacteriophage in E. coli were isolated. The first restriction endonuclease - Hind II, whose functioning depended on a specific DNA nucleotide sequence was characterized five years later. It was found that Hind II always cut DNA molecules at a particular point by recognizing a specific sequence of six base pairs. This specific base sequence is known as the recognition sequence for Hind II. Besides Hind II, today we know more than 900 restriction enzymes that have been isolated from over 230 strains of bacteria, each of which recognize different recognition sequences.

In EcoR I the latter 'R' is derived from the -

Name of the strain

The correct answer is Option (2) → Name of the strain     

Restriction enzymes are named after the bacterial species from which they are originally isolated, and the Roman numeral is used to distinguish different enzymes isolated from the same species.

The convention for naming these enzymes is the first letter of the name comes from the genus and the second two letters come from the species of the prokaryotic cell from which they were isolated. For example, EcoRI is a type of restriction enzyme isolated from Escherichia coli (E. coli), and the Roman numeral I indicates that it was the first enzyme of this type to be discovered from this bacterial strain.