Final answer:
Microtubules are not static; they are dynamic structures of the cytoskeleton that can rapidly assemble and disassemble. They are essential for cell shape, internal transport, and cell division, as they adapt in length according to cellular functions.
Step-by-step explanation:
No, microtubules are not static structures. They are dynamic components of the cytoskeleton within eukaryotic cells. Composed of polymerized dimers of α-tubulin and β-tubulin, microtubules form hollow tubes approximately 25 nm in diameter. They function in maintaining cell shape, providing pathways along which vesicles and organelles move, and facilitating the separation of chromosomes during cell division.
Microtubule dynamics involve rapid assembly and disassembly, governed by the hydrolysis of GTP. They can quickly reform, allowing the cytoskeleton to adapt to the cell's needs. This process is crucial for cell motility, including the movements of cilia, flagella, and during the separation of DNA in cell division.
Therefore, microtubules are not static, they are inherently adaptable structures that can grow or shrink by adding or removing tubulin subunits. This property is essential for various cellular activities, including the formation of the mitotic spindle during cell division, which segregates chromosomes into daughter cells.