Mitosis Slide 3 of 10 Mitosis Nuclear division. The portions of the cell cycle, aside from mitosis, occur with a phase called interphase.
Chromosomes condense into visible, thread-like structures.
The spindle apparatus, composed on microtubules, is formed. Nuclear membrane disintegrates. The sister chromatids line up at the equator of the cell. Caused by shortening of microtubules attached to the centromeres. Continued shortening of the microtubules pulls the sister chromosomes apart, dragging them toward opposite poles of the cell.