Answer:prophase----the chromosomes shorten and thicken.the nuclear membrane has open up and the nucleolus has disappeared
Metaphase----the chromosomes migrate to the central plane of the cell and attach to the spindle fibres microtubules
Anaphase---the chromatids of each chromosomes part and move towards opposite poles of the spindle as the spindle fibres shorten
Telophase----the chromatids are in the polar end of the spindle .the spindle breaks down,the centrioles replicate,the nuclear membrane is reformed,the chromosomes gradually uncoil.
It is a mode of natural selection where an extreme phenotype is favored by the other phenotypes causing the allele frequency to shift over time in the direction of that phenotype
