Final answer:
Microtubules are used for both transient and permanent structures within cells, providing structural support, facilitating the movement of organelles and vesicles, and playing a crucial role in cell division.
Step-by-step explanation:
The statement that microtubules are used only for transient structures in cells is false. While it is true that microtubules exhibit dynamic instability, which means they can rapidly assemble and disassemble, they are not solely used for transient structures. Microtubules are key components of the cytoskeleton, providing structural support to the cell, helping it resist compression, and facilitating the movement of organelles and vesicles within the cytoplasm. They also play a critical role in cell division by forming spindle fibers that separate and move chromatids to opposite poles of dividing cells. Moreover, microtubules are the main structural elements of cilia, flagella, and centrioles, which are long-term structures of the cell. Therefore, microtubules are integral to both transient and permanent cell structures.