Final answer:
Mitotic inhibitors, such as chemotherapy drugs vincristine and colchicine, disrupt cell division by preventing the formation of microtubule spindles, which are crucial for chromosome separation during mitosis.
Step-by-step explanation:
Mitotic inhibitors, such as chemotherapy drugs vincristine and colchicine, disrupt cell division by binding to tubulin, a protein subunit of microtubules that form spindles. These spindles are essential for the separation of chromosomes during mitosis. By inhibiting the assembly and disassembly of microtubules, the drugs prevent the formation of functional spindles, leading to arrest in metaphase and ultimately inhibiting cell division.