Final answer:
The statement that a pilus is comprised of microtubules is false; pili are protein appendages in bacteria, whereas microtubules are components of the eukaryotic cell cytoskeleton.
Step-by-step explanation:
It is false that the pilus is comprised of microtubules. Pili, specifically the types found in bacteria like the F pilus or sex pilus, are protein appendages that assist in DNA transfer between bacterial cells, aiding in surface attachment and genetic diversity. These structures are composed of proteins such as pilin, not microtubules. Microtubules, on the other hand, are major components of the cytoskeleton in eukaryotic cells and consist of tubulin polymers that form hollow tubes utilized for maintaining cell shape, cell motion, and organelle movement.
Furthermore, the structural composition of microtubules differs substantially from that of bacterial pili, as demonstrated by various studies, including the work highlighted in the Proceedings of the National Academy of Sciences and Cellular and Molecular Life Sciences. While both play critical roles in their respective cellular frameworks, their structural elements and functions are distinct.