What role do spindle fibers play during mitosis?

Spindle fibers play a crucial role in the process of mitosis by helping to separate chromosomes. During mitosis, one of the key tasks is to ensure that each daughter cell receives an identical set of chromosomes. Spindle fibers, which are made of microtubules, emanate from the centrosomes (the cell's microtubule organizing centers) and attach to the centromeres of the chromosomes.

Once the spindle fibers are connected, they utilize their dynamic nature to exert forces that pull the sister chromatids apart towards opposite poles of the cell. This ensures proper segregation of genetic material, which is essential for the formation of two genetically identical daughter cells. The precise action of spindle fibers is fundamental to the fidelity of cell division, preventing errors that could lead to conditions such as cancer or genetic disorders.

The other choices address unrelated functions: dissolving the nuclear membrane is a separate initial step of prophase, generating new cells pertains to the overall process of cell division but does not specifically relate to spindle fibers, and producing energy for the cell is the function of mitochondria and is not connected to the role of spindle fibers in mitosis.