At the end of prophase, the nuclear envelope breaks down into vesicles. The chromosomes align at the equitorial plate and are held in place by microtubules attached to the mitotic spindle and to part of the centromere. Crossing-over can happen at this point. The centromeres divide. Sister chromatids separate and move toward the corresponding poles.
Daughter chromosomes arrive at the poles and the microtubules disappear.
The condensed chromatin expands and the nuclear envelope reappears.