Question

Explain why does a prokaryotic dna have a single origin of replication and an eukaryotic dna may have more than one origin of replication?

Answer 1

DNA replication does not start at random locations but a particular sites, called the origins of DNA replication.A unit of DNA in which replication starts from a origin and proceeds bidirectionally or unidirectionally to terminus site is called a replicon. Replicon can be linear or circular.
Prokaryotic cells contains a unique origin and DNA replication proceeds bidirectionally from the origin to the terminus. Therefore, the whole prokaryotic genome is a single replicon. On the other hand, eukaryotic cells contain multiple replication origins on single chromosome and hence many replicons.