Question

What makes lagging strand DNA synthesis so much more of a challenge for the cell than leading strand DNA synthesis?

Answer 1

Leading strands takes only one primer, one time attachement of single strand binding protein and DNA polymerase and then keep one polymerizing DNA over it. While lagging strand takes intermittent binding of primers, SSB proteins and DNA pol. These primers are replaced at the time of proofreading and are sealed by ligase. More steps involved in the process of DNA synthesis on lagging strand so there are chance for mistakes. This may lead to mutation. So for cells its more challenging to proofread the lagging strand than leading strand of DNA replication.