Centrosome Research 2001

   The centrosome is a non-membranous organelle whose function is to organization the microtubule systems in cells. The structure of a centrosome is often a core with a pair of centrioles embedded in an amorphous matrix, which is the sites for microtubule nucleation.
A centriole is a hollow cylinder found in most animal cells, fungi and algae. The walls of centrioles are composed of nine triplets of microtubules. Usually found in pairs at a right-angle to each other they may be important in the animal cell division process (replicating during interphase of the cell cycle), organizing spindle fibers upon which the chromosomes are pulled apart. Plant cells lack centrioles, so their role in cell division is in doubt.
Centrioles replicate autonomously like mitochondria and peroxisomes. They begin within centrosomes with tubulin proteins where a single microtubule forming a triplet. Once a centriole is made, daughter centrioles can grow out from the tubules at right angles. These then add to the daughter cell (in a dividing cell), or they move to the cell membrane and form the basal body for the cilium.