What is the main structural role of microtubules in the cell?

Microtubules serve a crucial structural role in the cell primarily by providing structural support. They are part of the cytoskeleton, which gives shape and support to the cell, akin to the steel framework of a building. Microtubules are hollow tubes made of tubulin protein subunits that can grow and shrink rapidly, allowing them to maintain cell shape and to resist compression. This structural support is essential for various cellular functions, including maintaining the organization within the cell and assisting in the positioning of organelles.

Other functions of microtubules, such as facilitating cell movement or transporting genetic material during cell division, do exist but are secondary to their primary role in structural support. For instance, while they do aid in the movement of cilia and flagella, which are types of cellular appendages, the overarching purpose of microtubules remains their role in maintaining the integrity and shape of the cell.