Cilia

Cilia are, in essence, a shorter, more numerous version of the same basic structure as a flagellum. The plural form is cilia, and the singular is cilium; unlike the flagellum, which typically occurs singly or in small numbers, cilia are numerous, short, cellular projections of the plasma membrane, and, just like a flagellum, each individual cilium is built internally around a bundle of microtubules. Because a cilium shares the same 9+2 axoneme arrangement, the same dynein-based, ATP-driven sliding mechanism between adjacent microtubules that bends a flagellum is exactly what bends a cilium too - the interaction between the tubulin of the microtubules and the motor protein dynein is the shared mechanical basis for movem …