Final answer:
Dynamic instability in microtubules is caused by the hydrolysis of GTP by tubulin dimers, not the hydrolysis of ATP, peptide bonds, or tubulin dimers themselves.
Step-by-step explanation:
Dynamic instability in microtubules is attributed to the intrinsic capacity of tubulin molecules to hydrolyze GTP (guanosine triphosphate). Microtubules are composed of polymerized dimers of α-tubulin and β-tubulin. These structures are integral to a cell's cytoskeleton, providing support, a pathway for vesicle transport, and facilitating chromosome movement during cell division. The rapid assembly and disassembly of microtubules are made possible by the hydrolysis of GTP, not ATP, peptide bonds, or tubulin dimers. This dynamic behavior is crucial for cellular processes such as mitosis and maintaining cell shape.