Key Difference – Parthenogenesis vs Parthenocarpy
Two types of gametes are fused during the fertilization. Male parent produces the male gametes, and the female parent produces the female gametes. Male gamete reaches female gamete by the process called pollination. These two gametes fuse with each other to produce a diploid zygote which develops into a new organism. In some plants and animals, without the fusion of two gametes (egg and sperm), fruits develop, and new individuals develop. Parthenogenesis and parthenocarpy are two such processes that results in fruits and individuals from unfertilized ovules or eggs prior to fertilization. The key difference between parthenogenesis and parthenocarpy is, parthenogenesis is shown by animals and plants while parthenocarpy is shown only by plants.
CONTENTS
1. Overview and Key Difference
2. What is Parthenogenesis
3. What is Parthenocarpy
4. Side by Side Comparison -Parthenogenesis vs Parthenocarpy
5. Summary
What is Parthenogenesis?
Parthenogenesis is a type of reproduction commonly shown in organisms mainly by some invertebrates and lower plants. It can be described as a process in which unfertilized ovum develops into an individual (virgin birth) without fertilization. Therefore, it can be considered as a method of asexual reproduction. However, it is also possible to define it as an incomplete sexual reproduction since only the fusion of two gametes is failed in the sexual reproduction process.
Parthenogenesis can be artificially stimulated even in mammals to produce an individual without fertilization. During the parthenogenesis process, unfertilized egg is developed into a new organism. Hence, the resulting organism is haploid, and it cannot undergo meiosis. They are mostly genetically identical to the parent.
There are several types of parthenogenesis. They are facultative parthenogenesis, haploid parthenogenesis, artificial parthenogenesis, and cyclic parthenogenesis. In nature, parthenogenesis takes places in many insects. As an example, in bees, the queen bee can produce either fertilized or unfertilized eggs, and unfertilized eggs become male drones by parthenogenesis.
Figure 01: Male drone bee
What is Parthenocarpy?
In most plants, flowers need to be pollinated and fertilized to produce fruits. However, some plants can produce fruits before fertilization or without fertilization. Parthenocarpy is the process which produces fruits from unfertilized ovules in plants. Unfertilized ovules develop into fruits prior to fertilization. These fruits do not contain seeds. Parthenocarpy can occur in two ways named vegetative and stimulative parthenocarpy.
Parthenocarpy is not a normal process shown by plants. Plants normally prefer the cross pollination and fertilization. There are several reasons for parthenocarpy of plants. In some cases when pollination fails and the availability of functional eggs and sperms is less, virgin ovules become fruits before fertilization. Lack of successful fertilization due to chromosomal imbalance is another reason for parthenocarpy.
The process of parthenocarpy has been exploited by certain farmers to produce seedless oranges and watermelons which are more preferred by consumers. And also these parthenocarpic fruits have long shelf life compared to seeded fruits. During the growing of these seedless fruit plants, the requirement of pollinating insects can be eliminated and covered to protect the plantation from other attackers.
Due to the high consumer appeal of seedless fruits over seeded fruits, plant biologists try to induce this parthenocarpic property in some other fruit plants which normally don’t show it. They have identified that by using auxin hormone and genetic engineering techniques, it is possible to produce many types of seedless fruits in the near future.
Examples: seedless watermelons, banana, and oranges.
Figure 02: Seedless watermelon
What is the difference between Parthenogenesis and Parthenocarpy?
Parthenogenesis vs Parthenocarpy |
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| Parthenogenesis is a type of reproduction in which unfertilized egg or ovule is developed into a new organism. | Parthenocarpy is a process in which unfertilized ovule is developed into a seedless fruit. |
| Result | |
| Parthenogenesis produces haploid organisms. | Parthenocarpy always produces seedless fruits. |
| Seen in | |
| Parthenogenesis is common in plants and animals. | Parthenocarpy is common in flowering plants. |
Summary – Parthenogenesis vs Parthenocarpy
Parthenogenesis can be defined simply as a reproduction without fertilization. It occurs when a female gamete develops into a new individual without being fertilized by a male gamete. Parthenogenesis is a normal process seen in many plants, vertebrates, invertebrates, etc. Parthenocarpy is a process which produces fruits without the fusion of ovule with sperm cell in flowering plants. It occurs due to unsuccessful pollination and fertilization. Also, it can happen due to nonfunctional ovules and sperms. These are the differences between parthenogenesis and parthenocarpy.
Reference:
1. Angelo Spena (3), and Giuseppe Leonardo Rotino (4). “Parthenocarpy.” Springer. Springer Netherlands, 01 Jan. 1970. Web. 02 May 2017
2.”Parthenogenesis.” The Free Dictionary. Farlex, n.d. Web. 02 May 2017 [http://www.thefreedictionary.com/parthenogenesis]
3. “Parthenocarpy.” Wikipedia. Wikimedia Foundation, 30 Mar. 2017. Web. 02 May 2017 [https://en.wikipedia.org/wiki/Parthenocarpy]
Image Courtesy:
1. “Drone 24a” By Waugsberg – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Mini Seedless Watermelon Dulcinea Farms PureHeart June 05, 20105” by Steven Depolo (CC BY 2.0) via Flickr