The development of egg into a complete individual without fertilization is known as pathogenesis. It occurs in many animals like various arthropods, some vertebrates Like Lacerta saxicola armaniaca (a Caucasian rock lizard), Typhlina brahmina (a small snake) etc.
- Artificial parthenogenesis
1) Natural parthenogenesis :- it occurs regularly in the life cycle of certain animals.
a) Complete parthenogenesis :- it occurs in those animals in which all eggs produced are developed by parthenogenesis. Hence, there is no biparental sexual reproduction.
e. g. Typhlina brahmina
b) Incomplete parthenogenesis :- it is found in those animals in which both sexual reproduction and parthenogenesis occur. e. g Honey bee
2) Artificial parthenogenesis:- in which egg is induced to develop into a complete individual by artificial stimuli;
e.g. Eggs of annelids, seaurchin frogs etc.