And the original chromosome and the replicated chromosome are joined together in a region known as the centromere, which involves different types of proteins that assist in the joining process. So let's take a look at the following diagram. So, at the beginning of S phase, we have individual original chromosomes. But as the S phase proceeds, we basically use the cell machinery to replicate our DNA molecule, the chromosomes. So each one of the 46 individual chromosomes in human cells are replicated. And we produce the following two chromosomes, the original as well as the replicated.