sentences:  At the replication fork, the gap in DNA after removal of the flap is sealed by DNA ligase I, which repairs the nicks that are left between the 3'-OH and 5'phosphate of the newly synthesized strand.Owing to the relatively short nature of the eukaryotic Okazaki fragment, DNA replication synthesis occurring discontinuously on the lagging strand is less efficient and more time-consuming than leading-strand synthesis.DNA synthesis is complete once all RNA primers are removed and nicks are repaired.