Final answer:
Cells require tubulin to form cilia or flagella.
Step-by-step explanation:
The formation of cilia or flagella in cells requires tubulin which is a structural filament composed of subunits of a protein called tubulin. Microtubules, made up of tubulin, are the thickest of the three cytoskeletal fibers. Microtubules play a role in the movement of cilia and flagella, which are important for cell locomotion.