Centrosome: In the animal cell there is a spherical body outside the nucleus, which is called centrosome. It is an organelle near the nucleus of a cell that contains the centrioles (in animal cells) and from which the spindle fibres develop in cell division. The fluid of which it is composed is called centrosphere. At the centre of centrosphere, there are two cylindrical objects called centriole. At the time of cell division, the pair of centriole is separated and moves to two opposite pole (of the cell).
Function: At the time of cell division centrosome directs the poles of spindle apparatus and help in cell division. The function of the centrosome is to assist organize microtubules to be utilized during cell division. It also works to use the microtubules to create part of the cytoskeleton of the cell. This helps give the cell its structure. In a sense, the centrosome helps to stabilize the structure of the cell. While these might seem like simplistic tasks, they are extremely important and critical roles.
They are responsible for the initiation of cytokinesis or splitting up of the mother cell into two. In the absence of centrosomes, it has been observed that cytokinesis does not initiate even after the completion of mitosis.