Class 12 Biology Zoology | Chapter 1 Reproduction in Organisms | Textbook Evaluation Questions | Q.No 16

Class 12 Biology Zoology | Chapter 1 Reproduction in Organisms | Textbook Evaluation Questions | Q.No 16 | 12th Bio Zoology | Chapter 1 | QB 16

QUESTION NO 16 : What is Parthenogenesis ? Explain its types.

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Answer for obtaining full marks :

Parthenogenesis: 

• Development of an egg into a complete individual without fertilization.
• First discovered by Charles Bonnet in 1745.
• Two main types: Natural Parthenogenesis and Artificial Parthenogenesis.

Natural Parthenogenesis: 

Occurs regularly, constantly, and naturally in an animal's life cycle.

1. Complete Parthenogenesis : The sole form of reproduction in certain animals; no biparental sexual reproduction, only females are present.
2. Incomplete Parthenogenesis : Both sexual reproduction and parthenogenesis occur (e.g., honeybees: fertilized eggs become queens and workers, unfertilized eggs become drones).
3. Paedogenetic Parthenogenesis (Paedogenesis) : Larvae produce a new generation of larvae by parthenogenesis (e.g., sporocysts and Redia larvae of liver fluke, larvae of some insects like gall flies).

Artificial Parthenogenesis:

• Unfertilized egg is induced to develop into a complete individual by physical or chemical stimuli (e.g., annelid and sea urchin eggs).

Answer for Slow Learners :

Parthenogenesis: Development of an unfertilized egg into a complete individual, discovered by Charles Bonnet (1745).

Types:

1. Natural Parthenogenesis: Occurs regularly and naturally.
   • Complete: Sole reproduction method; only females present (no sexual reproduction).
   • Incomplete: Both sexual reproduction and parthenogenesis occur (e.g., honeybees: fertilized eggs become queens and workers, unfertilized eggs become drones).
   • Paedogenesis: Larvae reproduce new larvae parthenogenetically (e.g., liver fluke larvae, some insect larvae).
2. Artificial Parthenogenesis: Unfertilized egg is induced to develop via physical or chemical stimuli (e.g., annelids, sea urchins).

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Previously Asked Questions As :

1. Differentiate Complete parthenogenesis from Incomplete parthenogenesis. March-2025 (Bio Zoology)