Answer:
In DNA replication, gaps between newly synthesized segments of DNA and existing segments of DNA are sealed by enzymes called ligases, which form covalent bonds between the two segments.
Step-by-step explanation:
During DNA replication, there is a continuous strand of DNA and fragments of DNA called Okazaki fragments. The DNA ligase will join the Okazaki fragments using ATP's energy and creating a covalent bond between the phosphate of a nucleotide in an Okazaki fragment and the sugar of a nucleotide in another Okazaki fragment. As a result, there are two continuous DNA fragments.