Chromosomes are replicated before cell division.
Cells divide through mitosis and then mature before dividing again. It is during this interphase that the DNA is replicated and the cell is prepared for division. This happens in the following order:
-G1: cell grows, carries out life functions
Many cells stay in G1 for an extended period of there is no need for them to continue to divide. When a cell is signaled to divide it leaves G1 phase and enters S phase.
-S: DNA replication - cell copies chromosomes
-G2: cell makes microtubules, prepares for mitosis