Why do the genomes of eukaryotes, such as Drosophila, need to have multiple origins of replication, whereas bacterial genomes, such as that of E. coli, have only a single origin?

Explanation:

The genome of euakaryotes in linear and its length is long, thus multiple replication origin ensures replication is carried out very fast in the eukaryotes in a short amount of time. While the genome of bacteria is circular in nature and not as long as that of eukaryotes and needs just one replication origin to carry out replication process within a short period of time

Sea floor spreading occurs at divergent plate boundaries where the seafloor is being pulled apart by convection currents in the mantle. As the plate pull apart magma up wells and new crust is being formed. This process on the sea floor creates a habitat for exotic sea creatures such as tube worms. The food chain in this region of the planet starts with bacteria that metabolizes sulfur coming from hydro-thermal vents along the spreading ridge.