Figure 1.

The distribution of damaged cell constituents (DCC) in symmetrical and asymmetrical cell division. DCC (small grey circles) build up in cells as time goes on and are inherited by the next generation through cell division. In symmetrical division they are distributed more or less equally between sisters. In asymmetrical division, the mother can be rejuvenated at the expense of the daughter, as in epithelial stem cells; or the daughter can be rejuvenated at the expense of the mother, as in budding yeasts.