Here the genetic material replicates itself. This allows the cell to contain enough material to fully supply 2 cells upon division. The G 2 phase soon begins. Here the cellular organelles are produced to allow for an adequate amount for the new cell being produced. After interphase Mitosis begins.
Mitosis is considered nuclear division, since the focus is upon the genetic material of the cell.
The first part of mitosis is Prophase . During prophase the nucleus begins to disappear. The chromatin pulls together and forms pairs of rope-like structures called chromatid pairs . These chromatid pairs are actually identical chromosomes that developed during the S phase of interphase. The chromatid pairs are held together by a structure called the centromere .