Parthenogenesis MCQ - Practice Questions with Answers

• Usually, an unfertilized ovum develops into a new individual only after the union with the sperm or fertilization but in certain cases, the development of the egg takes place without fertilization. 
• This peculiar mode of sexual reproduction in which egg development occurs without fertilization is known as parthenogenesis (Gr., Parthenos = virgin; genesis = origin).
• The phenomenon of parthenogenesis occurs in different groups of animals as in certain insects (Hymenoptera, Homoptera, Coleoptera), crustaceans and rotifers.
• The parthenogenesis may be of two types:
  • Natural parthenogenesis
  • Artificial parthenogenesis

1. Natural Parthenogenesis:

• In certain animals, parthenogenesis occurs regularly, constantly and naturally in their life cycles and is known as the natural parthenogenesis.
• Certain insects have no sexual phase and no males. 
• They depend exclusively on the parthenogenesis for self-reproduction. 
• This type of parthenogenesis is known as the complete parthenogenesis or obligatory parthenogenesis.
• The life cycle of certain insects includes two generations, the sexual generation, and parthenogenetic generation, both of which alternate to each other. 
• In such cases, the diploid eggs produce females and the unfertilized eggs produce males. 
• This type of parthenogenesis is known as partial or incomplete or cyclic parthenogenesis.

2. Artificial Parthenogenesis:

• The eggs which always develop into the young individuals by the fertilization sometimes may develop parthenogenetically under certain artificial conditions. 
• This type of parthenogenesis is known as artificial parthenogenesis. 
• The artificial parthenogenesis may be induced by various chemical and physical means.
• Temperature the range of temperature may induce parthenogenesis in the eggs. 
• For instance, when the egg is transferred from the 30°C to 0-10°C, parthenogenesis is induced.
• Electrical shocks can cause parthenogenesis.
• Ultraviolet light can cause parthenogenesis.
• Chloroform; Hypertonic and Hypotonic sea waters; Acids such as butyric acid, lactic acid, oleic acid, and other fatty acids, etc. can also induce parthenogenesis.