Objective: A hypothesis is presented here, that 'in the ontogenetic growth-aging process from conception to death of an organism, each cell has a reducing predefined finite reproductive potential and somatic life span of its own, defined by its temporal occurrence within the life-cycle of the organism'.
Methods: Phenomenological and Reductionist observations. Different species of living organisms have different species-specific finite life spans. In each of the species different cell lines have finite replicative potential, and, different cells have different life-spans.
Findings: The growth-aging process of ontogeny unfolds in a specific biocybernatic process. Either in the native state or explanted or transplanted or cloned or grafted state, the cell has memory of its original age and its remaining replicative potential and somatic life span.
Applications: are in the selection of cell in animal cloning, cell line in tissue transplantation, and the donor for organ transplantation and plant grafting.