Mitosis is a form of eukaryotic cell division that produces two daughter cells with the same genetic component as the stem cell. During this process, chromosomes replicated during S phase are divided in such a way as to ensure that each daughter cell receives a copy of each chromosome. This process usually takes about an hour in actively dividing animal cells. The result of this division is duplicate nuclear material, also known as chromatin.
The rupture of the nuclear envelope allows sister chromatids to be freed from the nucleus, which is necessary for the separation of the nuclear material into two cells.