Final answer:
Circular DNA molecules that undergo theta replication have a single origin of replication, and this replication proceeds bidirectionally from that origin.
Step-by-step explanation:
True, circular DNA molecules that undergo theta replication indeed have a single origin of replication. This process is named after the Greek letter θ (“theta”) due to the shape that the replicating DNA assumes during the process. DNA replication in prokaryotes, such as bacteria, typically involves the circular chromosome beginning to replicate at a single origin of replication and then proceeding in both directions at the same time. This creates a replication bubble with two forks moving around the circle until they meet on the opposite side, completing the replication process.