Microtubules are macromolecules that build both, cilia and flagella.
Microtubules are cytoskeletal fibres that are formed by polymerization of α,β-tubulin and they are important components of cilia, flagella and some other cellular structures. Cilia and flagella are very similar in their organization, both have a central bundle of microtubules-axoneme. Axoneme is compound of nine outer doublet microtubules which surround a central pair of singlet microtubules. Even thought cilia and flagella are structurally similar, they are differentiated based on their function and/or length. Flagella are longer and the primary role of the flagella is locomotion. On the other hand, shorten cilia often has the function in sensing the extracellular environment.