How do restriction endonucleases work? they add nucleotides to dna. they cut dna at specific sequences. they cause gene mutations.

The correct answer is: They cut DNA at specific sequences.

Restriction enzyme or restriction endonuclease enzyme is specialized scissors used in molecular processes takes place in cells such as transcription.  

These scissors or enzymes cut on specific sequences on DNA strands and produce two types of ends:

-Sticky ends

-Blunt ends  

Restriction endonuclease enzymes are further divided into 4 types and all of them are site specific on DNA strands.