Final answer:
Microtubules are small hollow tubes made of polymerized dimers of α-tubulin and ß-tubulin. They provide structural support, facilitate intracellular transport, and assist in cell division.
Step-by-step explanation:
Microtubules are small hollow tubes made of polymerized dimers of α-tubulin and ß-tubulin, two globular proteins. With a diameter of about 25 nm, microtubules are the widest components of the cytoskeleton.
They help the cell resist compression, provide a track along which vesicles move through the cell, and pull replicated chromosomes to opposite ends of a dividing cell. Microtubules can disassemble and reform quickly.