The enzyme DNA ligase is required continuously during DNA replication in order for
A) fragments of the leading strand to be joined together.
B) fragments of the lagging strand to be joined together.
C) the parental strands to be joined back together.
D) 3ʹ-deoxynucleoside triphosphates to be converted to 5ʹ-deoxynucleoside triphosphates.
E) the complex of proteins that work together at the replication fork to remain intact.

Question

Quizplus · Accepted Answer

DNA ligase is required to join the Okazaki fragments that are formed during the synthesis of the lagging strand in DNA replication. The fragments of the leading strand are synthesized continuously and do not require joining by DNA ligase. The parental strands are already joined together, so DNA ligase is not required for that either. Conversion of nucleoside triphosphates and the stability of the replication fork are not directly related to DNA ligase activity.

The Enzyme DNA Ligase Is Required Continuously During DNA Replication