Q. 22 What does H in ‘d’ and III refer to the enzyme Hind III?

(i) The first letter ‘H’ indicates the genus of the organism from which the enzyme was. isolated, H = genus Haemophilus.

(ii) The fourth letter d indicates the particular strain used to produce the enzyme, d =strain Rd.

(iil) The Roman numerals denoted the sequence in which the restriction endonuclease enzyme from that particular genus, species and strain of bacteria have been isolated III, i.e., third restriction endonuclease to be isolated from this species.