Which Enzyme is Used to Join Two Complementary DNA Fragments

Question

Which enzyme is used to join two complementary DNA fragments after a cut has been made?
A) restriction endocnucleases
B) RNA polymerase
C) DNA gyrase
D) DNA ligase
E) Helicase

Accepted Answer

DNA ligase is the enzyme responsible for joining two complementary DNA fragments after a cut has been made. This enzyme catalyzes the formation of phosphodiester bonds between the 3'-hydroxyl of one nucleotide and the 5'-phosphate of another nucleotide in the presence of ATP. This results in the formation of a continuous strand of DNA.