DNA replication occurs during S phase. Each chromosome is duplicated and thereafter consists of two sister chromatids (the products of DNA replication). The sister chromatids remain joined together until mitosis, when they segregate into two daughter cells.

What happens when chromosomes replicate?

During every cell division, a cell must duplicate its chromosomal DNA through a process called DNA replication. The duplicated DNA is then segregated into two "daughter" cells that inherit the same genetic information. This process is called chromosome segregation.

What stage does chromosome replicate?

In the eukaryotic cell cycle, chromosome duplication occurs during "S phase" (the phase of DNA synthesis) and chromosome segregation occurs during "M phase" (the mitosis phase).