Right now, for instance. Liver cells will divide when damaged. Muscle cells will divide when stimulated. Fibroblasts will divide upon wounding. It must divide material equally.
Students are familiar with visual images of mitosis - the division of chromosomes.
They are also increasingly familiar with a more recent depiction of cell division - the cell cycle . It is important to distinguish these descriptions of the process of cell division. Again, it was the observers, the 'cellular naturalists' that drove these early studies. They were 'easy' to observe by microscopy. An animation of the events shown.