Only recently has great progress been made in understanding the function of the primary cilium. The cone body is derived from a cilium. These cells are cuboidal, with microvilli and a single cilium on their surface. The inner and outer segments are connected by a cilium. The inner and outer segments are connected by a cilium, which lines the distal segment. As the cell containing the cilium goes through the cell cycle, ciliogenesis must be regulated. The cells are flask-shaped, with long, slender ciliary processes (one cilium per cell). The sperm tail is a specialized type of cilium (aka flagella). One kinocilium is the longest cilium located on the hair cell next to 40-70 stereocilia. It is also known that the cilium must be disassembled before mitosis can occur. In many cell types the centrosome is replaced by a cilium during cellular differentiation. The cilium membrane and the basal body microtubules are connected by transition fibers. However, once the cell starts to divide, the cilium is replaced again by the centrosome.