This phase is the longest lasting stage of the cell cycle, during this phase the cells conduct thuer normal cellular functions for example take up nutrients, grow produce proteins and read DNA, they prepare themselves for mitosis by replicating their DNA.This is the first stage of mitosis and here the chromosome starts to break down its structure and build the others up, they also start to condense which makes it easier to pull them apart later on. Now the mitotic spindle is formed as this organises the chromosome and help them move during the process of mitosis.
when the nucleolus disappears it means that the nucleus is ready to break down and chromosomes are now finished condensing and are very compact.The centrosomes that have been duplicated in G2 phase separate now, the chromosomes become visible and now consist of two chromatids that are joined together at the centromere.In metaphase the chromosomes are completely spiralized and the pair of chromosomes line up along the equator of the cell because they are condensed they move easily without getting tangled.At anaphase the protein ‘glue’ that is used to hold the sister chromatids together breaks down, the sister chromatids break apart becoming its own chromosome and the chromosomes are drawn to opposite poles of the elongated cell.
In this phase the cell is nearly done dividing because the spindle disappears, the chromosomes despirlize, the new nuclear envelope is formed and the the nucleoli are visible.Cytokinesis, the division of the cytoplasm to form two new cells, overlaps with the final stages of mitosis. It may start in either anaphase or telophase, depending on the cell, and finishes shortly after telophase.In animal cells, cytokinesis is contractile, pinching the cell in two like a coin purse with a drawstring. The “drawstring” is a band of filaments made of a protein called actin, and the pinch crease is known as the cleavage furrow. Plant cells can’t be divided like this because they have a cell wall and are too stiff so to make this work the cell plate forms down the middle of the cell, splitting it into two daughter cells separated by a new wall. When the process of cytokinesis finishes we end up with a complete set of identical chromosomes, and the daughter cells have their own cellular lives and may undergo mitosis themselves.
