Cell division is required for an organism to be developed

Cell division is required for an organism to be developed, to mature and to hold tissues. The cell cycle of a eukaryotic cell is a complicated process that involves a variety of regulatory proteins that direct a given cell through a specific sequence of events culminating in mitosis and the production of two cells identical to the initial-parental one (daughter cells). The cell cycle can be morphologically subdivided in two stages: into interphase which consists of C1, S and G2 phases and into M (mitotic) phase which include prophase, prometaphase, metaphase, anaphase, telophase and cytokinesis. G1 and G2 symbolizes the time spent by a cell between the two landmarks• DNA synthesis and mitosis (Schafer, 1998; Vermeulen et al., 2003).
G1 phase is especially important for the cell fate. If the external conditions and extracellular signals from other cells are suitable, the cell is actively transcribed and prepares its self for DNA synthesis which occurs in the S phase. DNA synthesis is followed by G2 where the integrity of DNA is checked and the cell is prepared for mitosis. Although the traditional phases of cell cycle are the above mentioned ones, there are cells that enter in a subtype of G1 phase, the phase G0 in which they are not actively cycling anymore. G0 phase is a resting state where the cells do not grow and do not proliferate and they can remain for days, weeks, or even years before resuming proliferation depending on the cell type and on the type of signals the cell accepts from the external microenvironment (Schafer, 1998; Alberts et al., 2002).
During the mitotic phase (M phase), nuclear division (mitosis) is followed by cell division (cytokinesis) generating two daughter cells with the same genetic components as the parent cell. After the split, the two new cells enter G1 stage of interphase and are ready to begin their growth (Schafer, 1998; Alberts et al., 2002; Vermeulen et al., 2003). It is essential for the cells to replicate their DNA with maximum fidelity, which guarantees the maintenance of genomic stability. This is why the cells have developed several control mechanisms ensuring that each DNA segment is replicated completely and only once per cell cycle (De Pamphilis, 2006)