DNA replication

Every cell needs to make a copy of its DNA before it can divide into two new cells.

This can be quite a daunting task: the bacterial genome is 5 million bases long, and it needs to be copied in 40 minutes without making too many mistakes. Sometimes bacterial cells replicate faster than the 60 minutes necessary to copy the DNA and to organize cell division. In this case cells are born with a chromosome that has already begun replicating in the previous generation, or even two generations before, by the grandmother cell.