Final answer:
The reassembly of the nuclear envelope is driven by dissociation of the nuclear envelope into small vesicles during prophase, allowing the chromosomes to become accessible. The fragmentation and dispersion of membranous organelles towards the periphery of the cell also contributes to the reassembly.
Step-by-step explanation:
The reassembly of the nuclear envelope is driven by dissociation of the nuclear envelope into small vesicles during prophase, the first phase of mitosis. This process allows the chromosomes to become accessible. The membranous organelles in the cell, such as the Golgi complex and endoplasmic reticulum, fragment and disperse towards the periphery of the cell. The formation of the mitotic spindle, which consists of microtubules, also plays a role in reassembling the nuclear envelope.