BOTANY Higher Secondary Second Year - Textbooks Online

Two DNA molecules with sticky ends (ends that are staggered or
uneven) tend to join with other molecules with a complementary sequence
of nucleotides in the ends. With the same enzyme, DNA fragments are
cut with the matching sequence of nucleotides which complements with
the sticky ends.
Action of restriction enzyme
Fragments of DNA from different organisms or even from different
species may be joined together at their sticky ends, thereby producing
recombinant DNA. This is made possible by the use of an enzyme called
ligase. Hence, ligase is used to join the two DNA fragments.
Fig.4.3. Action of restriction enzyme
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