Chapter 5: Cell Division (Mitosis)
InterphaseThe cell appears a non-dividing cell. The chromosomes appear as threadlike structures.
Chromosomes become visible as they contract, and shrink. Centrioles appear at opposite sides of the nucleus. Spindle fibres start to form. The chromosomes become shorter and fatter. It consists of 2 chromatids joined at the centromere. Nucleolus disappear. Prophase ends with the breakdown of nuclear membrane.
Chromosomes arrange themselves on the equator of the spindle.
Chromatids separate at the centromere and migrate to opposite poles of the cell, the centromeres leading.
Chromosomes reach their destination. The cell starts to constrict across the middle. Nuclear membrane and nucleolus are reformed in each daughter cell. The spindle disappears. Chromosomes eventually regain their threadlike form and the cells return to resting condition (interphase).The daughter cells have the same chromosome constitution as the original parent cell.