Key Difference – Syngamy vs Triple Fusion
Reproduction is a fundamental process of life. It can be either asexual or sexual. During the sexual reproduction, the parent produces haploid cells called gametes. Male and female gametes fuse with each other to produce diploid cells which develop into new organisms. Syngamy and triple fusion are two processes seen in fertilization. Syngamy is a process in which two gametes or two nuclei are fused together during the sexual reproduction in plants and animals. Triple fusion is a process involved in the fusion of two polar nuclei with one sperm nucleus during the double fertilization of seed plants. This is the key difference between syngamy and triple fusion.
CONTENTS
1. Overview and Key Difference
2. What is Syngamy
3. What is Triple Fusion
4. Side by Side Comparison – Syngamy vs Triple Fusion
5. Summary
What is Syngamy?
Syngamy is a process in sexual reproduction. The fusion of two gametes (cells) or their nuclei is known as syngamy. It is also referred to as fertilization. Two haploid cells fuse with each other by their nuclei to form one diploid cell which can result in a new organism. In animals, gametes (sperm and egg) mix with their contents and produce a diploid cell called zygote. In plants, male and female spores (microgamete and macrogamete) fuse with each other and produce a diploid cell to make a new plant. In protozoans, two parents share their nuclei to result in a new protozoan during the conjugation.
Classification
Based on the source of gametes, syngamy is classified into two types named endogamy and exogamy. Endogamy is seen during self fertilization which involves only one parent to produce two types of gametes. Exogamy is a common process seen in cross fertilization which involves two parents to produce two types of gametes.
Syngamy can be categorized into three groups named isogamy, heterogamy and hologamy, based on the structures or the morphology of the gametes. When two games are morphologically and physiologically similar, the fusion of those gametes is known as isogamy. When two gametes differ from morphology and physiology, it is known as heterogamy. Hologamy is a special type of syngamy in which two organisms themselves act as gametes and fuse with each other during the reproduction.
Figure 01: Fusion of sperm and egg
What is Triple Fusion?
Double fertilization is a complex sexual reproduction method seen in angiosperms (flowering plants). Two fertilization processes occur in triple fusion. During double fertilization, one sperm nuclei fuses with egg cell and produce the diploid zygote (syngamy) while another sperm nuclei fuse with two polar nuclei of the large central cell. The fusion of sperm nuclei with two polar nuclei to produce triploid cell is known as triple fusion. Triple fusion occurs inside the embryo sac of angiosperms. This triploid cell develops into endosperm of the seed which provides nourishment to the developing embryo.
Figure 02: Double fertilization and triple fusion of seed plants
What is the difference between Syngamy and Triple Fusion?
Syngamy vs Triple Fusion |
|
| Syngamy is the fusion of two gametes. | Triple fusion is the fusion of sperm nuclei with two polar nuclei of the seed plants. |
| Nature of the Cell | |
| Syngamy results in a 2n cell. | Triple fusion results in a 3n cell. |
| Observed in | |
| Syngamy is common in plants, animals, and other organisms. | Triple fusion can be observed in seed plants. |
| Resultant Cell | |
| Syngamy produces a zygote. | Triple fusion results in the endosperm of seeds. |
Summary – Syngamy vs Triple Fusion
Syngamy and triple fusion are two processes in sexual reproduction. Syngamy can be defined as a process that fuses male gamete with egg to form a zygote. Zygote is a diploid cell which develops into the embryo. Triple fusion is a process seen only in seed plants during double fertilization. Triple fusion can be defined as the fusion of sperm nuclei with two polar nuclei in the embryo sac of flowering plants. It results in triploid cells which develop into endosperm of the seed to nourish the embryo. This is the difference between syngamy and triple fusion.
Reference:
“Double fertilization.” Wikipedia. Wikimedia Foundation, 14 Apr. 2017. Web. 30 April 2017
Whitaker, Michael. “Syngamy and Cell Cycle Control.” Reviews in Cell Biology and Molecular Medicine – Whitaker – Wiley Online Library. Wiley‐VCH Verlag GmbH & Co. KGaA, 15 Sept. 2006. Web. 30 April 2017
Image Courtesy:
1. “Sperm-egg” By Unknown – (Public Domain) via Commons Wikimedia
2. “Figure 32 02 07” By CNX OpenStax – (CC BY 4.0) via Commons Wikimedia