What happens to the nuclear membrane before matephase?

Before metaphase, the nuclear membrane undergoes breakdown during prophase, a stage of mitosis. The nuclear lamina disassembles and the nuclear envelope fragments, allowing the spindle fibers to access the chromosomes. This disassembly is crucial for the proper alignment and separation of chromosomes during the subsequent stages of cell division. Once metaphase is reached, the chromosomes are fully condensed and aligned at the metaphase plate, with the nuclear membrane no longer present.