Final answer:
Cytochalasin B primarily affects cytokinesis by inhibiting actin filaments, thereby preventing cell division. Chemotherapy drugs like vincristine and colchicine target microtubule assembly, affecting the mitotic spindle and ultimately inhibiting cancer cell proliferation or leading to cell death.
Step-by-step explanation:
Cytochalasin B is known to inhibit the function of actin filaments within the cell. The process of the cell cycle that would be most impacted by the treatment of eukaryotic cells with cytochalasin B is cytokinesis, which is the physical process of cell division that cleaves the cell into two daughter cells after mitosis is completed. Actin filaments are crucial for the formation of the contractile ring that pinches the cell in two during cytokinesis. Therefore, blocking the activity of actin filaments with cytochalasin B would likely result in the inability of the cell to complete cell division.
Chemotherapy drugs like vincristine, colchicine, and vinblastine disrupt mitosis by targeting tubulin and interfering with microtubule assembly and disassembly. Specifically, these drugs affect the mitotic spindle, which is essential for the separation of chromosomes during cell division. Impairment of spindle function generally arrests the cell cycle or leads to errors in chromosome separation, potentially resulting in cell death or the prevention of cancer cell proliferation.