Centrioles exist inside each animal-like cell, in pairs, and their job is to assist the cell at the time of division. Whether the cell goes through mitosis or meiosis, centrioles facilitate the process of division. They appear near the nucleus, and they are networks of microtubules that ensure that the division process goes smoothly.
Centrioles are small sets of microtubules that are set up in a particular pattern. Nine different microtubule groups exist, and when two centrioles appear adjacent to one another, they sit at 90-degree angles. At the time of cellular division, the centrioles move toward opposing ends o the nucleus, and threads appear connected to them. These threads comprise the mitotic spindle.
When the cell is not in the process of dividing, centrioles do not appear clearly in the cell. Instead, you find a darker, more condensed section of the cytoplasm known as the centrosome. Centrioles only appear visible when it is time for the cell to divide, and then they make their moves to the nucleus' opposite ends. After division, it is possible to see four centrioles, two in each cell. Prophase and anaphase are the time periods in cell division when these are the most visible.