A centriole is a cylindrical organelle found in the centrosome of certain eukaryotic cells. Structurally, it consists of a formation of nine triplets of microtubules arranged in a characteristic ring pattern. Its primary biological role involves the organization of the microtubule-based spindle fibers during the cell division process. The centrosome, which contains multiple centrioles, functions to organize the mitotic spindle, an apparatus critical for separating chromosomes and ensuring that genetic material is correctly distributed to the forming daughter cells. Centrioles are foundational components of the cytoskeleton that play a vital role in maintaining proper cellular architecture and division.