Centrioles control the direction of cilia or flagella movement and assist in mitosis.
Like Cilia and Flagella, Centrioles are also made of microtubules. The difference is that they contain 9 sets of triplets and no doublet in the center. How the triplets in the basal body turn into the cilium doublet remains a mystery. Centrioles come in pairs, each organized at right angles to the other.
Centrioles also organize the spindle apparatus on which the chromosomes move during mitosis.
When not reproducing centrioles are found near the golai body along the the cell periphery. They migrate to opposite ends of the cell when reproducing.
Always in pairs, normaly two.