Continue duplicating some organelles. M-cyclin synthesized and binds to cdc, converting it to cdcm. Nucleoli disappear as chromosomes become more distinct. Spindles of microtubules begin to form. Nuclear membrane disintegrates.
Spindles are complete.
Centrioles are at poles. Chromosomes become attached by their centromeres to the spindles. Chromosomes line up. Chromatids are pulled by the spindle fibers to opposite poles. Each set of chromosomes becomes enclosed by a nuclear membrane.