ontogeny

ontogeny, all the developmental events that occur during the existence of a living organism. Ontogeny begins with the changes in the egg at the time of fertilization and includes developmental events to the time of birth or hatching and afterward—growth, remolding of body shape, and development of secondary sexual characteristics.

This article was most recently revised and updated by John P. Rafferty.
Citation Information
Article Title: ontogeny
Website Name: Encyclopaedia Britannica
Publisher: Encyclopaedia Britannica, Inc.
Date Published: 10 November 2010
Access Date: February 22, 2025