Ontogeny

Ontogeny (also ontogenesis or morphogenesis) is the origin and the development of an organism – for example: from the fertilized egg to mature form. It covers in essence, the study of an organism's lifespan. The word "ontogeny" comes from the Greek ὄντος, ontos, present participle singular of εἶναι, "to be"; and from the suffix -geny, which expresses the concept of "mode of production". In more general terms, ontogeny is defined as the history of structural change in a unity, which can be a cell, an organism, or a society of organisms, without the loss of the organization which allows that unity to exist. More recently, the term ontogeny has been used in cell biology to describe the development of various cell types within an organism.