chromosomes begin to spread out into a tangle of chromatin

chromosomes line up across the center of the cell

chromatids suddenly separate and begin to move apart

chromosomes separate and move along spindle fibers to opposite ends of the cell

chromatids separate to become individual chromosomes

nucleolus
disappears

the longest phase

chromosomes attach to the two poles of the spindle

the spindle begins
to break apart

the shortest phase

nuclear membrane
re-forms

centrioles start to move toward opposite poles

nuclear membrane disappears