Final answer:
Cilia and flagella are composed of microtubules only. These microtubules are arranged in a '9+2' structure critical for their function in motion. Both microfilaments and intermediate filaments have other roles within the cell but are not components of cilia or flagella.
Step-by-step explanation:
The filaments found in cilia and flagella are microtubules only. Microtubules are structural filaments composed of alpha and beta-tubulin subunits, which are organized in a specific structure known as the axoneme in cilia and flagella. The axoneme consists of a ring of nine doublet microtubules surrounding two single microtubules at the center. This '9+2' structure is essential for the motion of cilia and flagella.
On the other hand, microfilaments, which are composed of actin, are primarily involved in cell movement and muscle contraction but are not a component of cilia or flagella. Intermediate filaments, which vary in composition among different cell types, provide structural support for cells and are involved in forming the nuclear lamina but do not form part of cilia or flagella.