In prophase, chromatin condenses to form chromosomes and nuclear envelope disappears along with the cell organelles.
In metaphase, the equatorial plate is formed and spindle fibres attach to the kinetochores of the chromosomes.
In anaphase the daughter chromosomes move to the opposite poles ushering in telophase, in which chromatin fibres, nuclear membrane and cell organelles begins to reappear. This completes the process of mitosis.