Mitosis and The Cell Cycle dur The cell cycle consists of three major parts: 1) characterized by cell growth and of the chromosomes; 2) phase characterized by the division of the ; and 3) cell itself actually divides into two cells. during Before mitosis can begin, the chromosomes in the nucleus forms (a chromosome and its identical copy). During step is the sister chromatids condense and the nuclear membrane breaks d when the chromosomes line up down the middle of the cell. They which reach from the at opposite poles of the of each pair of sister chromatids. by the to the the chromosomes are pulled toward opposite ends of the In Finally, in new nuclear membranes begin to form around the chromoso of the cell. This is the end of mitosis. The next 2 phases of the cell cycle and