Which structure dissolves during prophase, allowing spindle fibers to contact chromosomes?

During prophase of mitosis, the nuclear membrane dissolves to allow spindle fibers to access and interact with the chromosomes. The disintegration of the nuclear envelope marks an important transition where the chromatin condenses into distinct chromosomes, making them visible under a microscope. This process is essential for the proper segregation of chromosomes during cell division.

By dissolving the nuclear membrane, spindle fibers, which are formed by the centrioles, can extend into the area where the chromosomes are located. This enables the spindle apparatus to attach to the chromosomes at their kinetochores, facilitating their alignment and eventual separation during the later stages of mitosis. Understanding the role of the nuclear membrane's dissolution provides insight into the dynamics of cellular division and the orchestration of chromosomal behavior within the cell cycle.