Question

Enzymes that cut DNA straight across both of the double helix strands produce ______ ends?

1) Blunt
2) Sticky
3) Overhanging
4) None of the above

Answer 1

Enzymes that cut DNA straight across both strands produce blunt ends. Sticky ends result from staggered cuts and have overhanging unpaired bases that can bond with complementary sequences.

Step-by-step explanation:

Enzymes that cut DNA straight across both strands of the double helix without leaving overhangs produce blunt ends. In contrast, enzymes like EcoRI and HindIII make staggered cuts in the DNA, which leaves unpaired bases known as sticky ends or cohesive ends. These sticky ends can form hydrogen bonds with complementary sequences on other DNA fragments cut by the same enzyme, allowing for easier annealing and ligation during the construction of recombinant DNA molecules. On the other hand, blunt ends can also be joined together, albeit less efficiently than sticky ends, due to the absence of overhanging strands that help to facilitate the bonding process.