Question

Define parthenogenesis. Give two examples.

Answer 1

Hint: In this, reproduction occurs asexually when a female egg cell develops into the new individual without any fertilization.

Complete answer:
The term ‘parthenogenesis’ was defined by Richard Owen in 1849 who defined parthenogenesis as ‘procreation without the immediate influence of a male’. This includes various processes such as fission (breakdown of parent cell into two new daughter cells) and budding. Then, in 1950, Suomalainen defined the term parthenogenesis which means the development of an egg into a new cell without fertilization(asexually). It is very clear that parthenogenesis does not importantly imply that mother has no access to a male. Parthenogenesis is different from asexual reproduction in the way that in asexual reproduction, new individuals are formed from the parent cell whereas in parthenogenesis, it involves the production of egg cells. Examples of parthenogenesis: Honey bees, reptiles like fishes.

Additional information:
There are two types of parthenogenesis:
Natural parthenogenesis: In some animals, parthenogenesis occurs naturally, regularly(constantly) throughout their life cycle. The natural parthenogenesis is of two types i.e., complete or complete. Further, the complete or incomplete type of natural parthenogenesis may be of two types: 1. Haploid or arrhenotokous. 2. Diploid or thelytokous.
Artificial parthenogenesis: The eggs that develop with the help of fertilization sometimes may develop parthenogenetically (without fertilization) under the artificial conditions and this is called as artificial parthenogenesis. This type of parthenogenesis may induce by physical and by chemical means.

Note: Parthenogenesis is the phenomenon of biological interest which leads to production of living young in many types of animals as well as in plants. Parthenogenesis may initiate early embryonic development in mammals.