question_answer 45)

  Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at 'specific'-recognition sequence? What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?

Answer:

                  If the restriction enzymes would cut DNA atrandom sites instead of at specific sites, then the DNA fragments obtained will not have 'sticky ends'. In the absence of sticky ends ,construction of recombinant DNA molecule would not be possible.