Final answer:
True. Eukaryotic chromosomes have replication bubbles at each origin of replication, where the DNA unwinds and replication begins. The replication forks move bidirectionally, allowing for simultaneous replication in both directions.
Step-by-step explanation:
True. In eukaryotic chromosomes, at each origin of replication, the DNA unwinds and produces a replication bubble. Replication begins at the origin of replication, where a complex made up of several proteins, including helicase, forms. Helicase separates the DNA strands by breaking the hydrogen bonds between the base pairs, resulting in the formation of Y-shaped structures called replication forks. These forks move bidirectionally, allowing for simultaneous replication in both directions and the formation of replication bubbles.