EMBRYOLOGY

EMBRYOLOGY

Embryology (Gr. Embryon= mbryo ; logos = discourse) is the science which deals with the development of an organism. Development is the series of change that take place in a Zygote (fertilized egg) or bud (formed in asexual reproduction) to form a complete organism. Development can be divided into two phases-

(i) Pre-natal or embryonic development. This development which takes place within the egg or womb of the mother upto birth. The study of the changes taking place during this period is also called embryology.

(ii) Post-natal or post-embryonic development. This period is the development from the birth of the organism up to death of the organism.

Ontology is the entire development of the fertilized egg (e.g. life-cycle) whereas phylogeny is the ancestral or revolutionary history of species of higher groups.