Parthenogenesis- Asexual Reproduction

In this type of reproduction, development of a new individual takes place from an egg or a spermatozoon without the participation of a germ cell from the opposite sex. In animals only the maternal cell give rise to a parthenogenetic individual. Certain algae however, give rise to individual from paternal germ cell, therefore, parthenogenesis is considered an asexual reproductive mechanism. Natural Parthenogenesis is known to occur in rotifers, some nematodes, crustaceans, insects and several species of fish, amphibians and desert lizards.

In many parthenogenetic invertebrates there is a cyclical alternation of asexual with bisexual reproduction. Parthenogenesis may be seasonal and related to temperature or food supply, or it may appear at irregular intervals. In the honeybees and some wasps unfertilised eggs develop into haploid males and fertilised eggs give rise to diploid females.