Cell cycle is the sequence of stages that a cell passes through between one cell division and the next. The cell cycle can be divided into four main sages: (i) M-phase, which consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division), (ii) Gi -phase, in which there is a high race of biosynthesis and growth (iii) S-phase, in which the DNA content of the cell doubles and me chromosomes replicate; (iv) the G2 -phase, during which die final preparations of cell division are made.