Which of the following are correct about type Ⅱ endonucleases?
(a) They require ATP for their activity.
(b) They are bifunctional enzymes having nuclease and methylase activity.
(c) They breaks the sugar-phosphate backbone at the recognition site.
(d) They are naturally found in prokaryotes.

Choose the correct option:

The correct option is D c and d
Endonucleases are of three types

Type I	Type II	Type III
Cut the DNA far from the recognition site	Cut the DNA at the recognition site	Cut the DNA 20-30 bp away from the recognition site
Requires ATP for its function	ATP is not required for its function	Requires ATP for its function
Bifunctional enzyme has both nuclease and methylase activity	Unifunctional enzyme has only nuclease activity	Bifunctional enzyme has both nuclease and methylase activity
Examples- EcoKⅠ	Examples- EcoRⅠ	Examples- EcoPⅠ

Restriction endonucleases are naturally present in the bacteria(prokaryotes) where they provide protection against invading bacteriophage DNA.