How does cell division occur?

Cell division can be divided under three main phases: 

- Interphase: actvie period in life of a cell when metabolic reactions occur, with protein synthesis and DNA replication

- Mitosis: it is divided in four sections and involves the preparation of the cell for the actual division

- Cytokinesis: is the phyiscal divison of the cell membrane into two distinct cells. 

INTERPHASE:

G1- growth of cell, duplicaiton of organelles, sythesises proteings and production of ATP

S - DNA replication occurs

G2 - DNA si checked for mutations and final metabolic reactions occur

MITOSIS: 

- Prophase: 

DNA supercoils, causing chromosomes to condense and become visible under a light microscope

As DNA was replicated during interphase, the chromosomes are each comprised of two genetically identical sister chromatids joined at a centromere

The centrosomes move to opposite poles of the cell and spindle fibres begin to form between them (in animals, each centrosome contains 2 centrioles)

The nuclear membrane is broken down and disappears

Metaphase

Spindle fibres from the two centrosomes attach to the centromere of each chromosome

Contraction of the microtubule spindle fibres cause the chromosomes to line up separately along the centre of the cell (equatorial plane)

Anaphase

Continued contraction of the spindle fibres cause the two sister chromatids to separate and move to the opposite poles of the cell

Once the two chromatids in a single chromosome separate, each constitutes a chromosome in its own right

Telophase

Once the two sets of identical chromosomes arrive at the poles, the spindle fibres dissolve and a new nuclear membrane reforms around each set of chromosomes

The chromosomes decondense and are no longer visible under a light microscope

CYTOKINESIS

The division of the cell into two daughter cells