The key difference between zooidogamy and siphonogamy is that zooidogamy is a condition in which male gametes swim in the water to reach their female gametes while siphonogamy is a condition in which pollen tubes are developed to carry male gametes to female gametes.
Sexual reproduction happens in different ways among different groups of plants. In order to complete fertilization, male gametes should reach the female gametes. Zooidogamy and siphonogamy are two ways that explain how male gametes travel towards the female gametes. In zooidogamy, male gametes swim towards female gametes while in siphonogamy, male gametes travel through a pollen tube towards female gametes. For example, algae, bryophytes, pteridophytes, and some gymnosperms exhibit zooidogamy while seed plants show siphonogamy.
CONTENTS
1. Overview and Key Difference
2. What is Zooidogamy
3. What is Siphonogamy
4. Similarities Between Zooidogamy and Siphonogamy
5. Side by Side Comparison – Zooidogamy vs Siphonogamy in Tabular Form
6. Summary
What is Zooidogamy?
Zooidogamy is a type of fertilization seen in certain plants. In this fertilization method, male gametes swim in the water to reach female gametes. Thus, male gametes are motile and flagellated to enable swimming. For example, algae, bryophytes, pteridophytes and some gymnosperms show zooidogamy during sexual reproduction. Therefore, they are zooidogamous plants. Moreover, zooidogamy is similar to animal fertilization which produces at least one motile gamete.
What is Siphonogamy?
Siphonogamy is a way of fertilization in which pollen tubes are formed in order to transfer male gametes to female gametes/eggs. Most seed plants are siphonogamous. Thus, they accomplish their fertilization by the formation of pollen tubes. Male gametes or sperms of most siphonogamous plants are non-motile.
Figure 01: Pollen Tube
In angiosperms, when pollen grains are deposited on the stigma of the flower, pollen tube formation takes place. It happens as a response to chemicals. Therefore, the pollen tube grows down the stele and enters via micropyle. Then the male gametes are released into the female gametophyte for syngamy.
What are the Similarities Between Zooidogamy and Siphonogamy?
- Zooidogamy and siphonogamy are two types of plant fertilization strategies.
- They are seen during the sexual reproduction of plants.
- Cycads show both methods.
What is the Difference Between Zooidogamy and Siphonogamy?
Zooidogamy is a type of plant reproduction in which male gametes swim in the water to reach female gametes. On the other hand, siphonogamy is a type of plant reproduction in which male gametes travel through a pollen tube to reach the female gametes. Therefore, this is the key difference between zooidogamy and siphonogamy. Algae, bryophytes, pteridophytes, and some gymnosperms are zooidogamous while most of the seed plants are siphonogamous. Motile male gametes participate in zooidogamy with the help of water while non-motile gametes participate in siphonogamy with the help of a pollen tube.
The following infographic summarizes the difference between zooidogamy and siphonogamy in tabular form.
Summary – Zooidogamy vs Siphonogamy
Zooidogamy and siphonogamy are two types of plant reproduction. In zooidogamy, male gametes swim in the water to reach the female gametes. In contrast, pollen tube formation takes place in siphonogamy in order to carry male gametes towards the female gametes. Therefore, zooidogamy takes place with the help of water while siphonogamy takes place with the help of a pollen tube. Thus, this is the key difference between zooidogamy and siphonogamy. Moreover, zooidogamy is seen in lower plants mainly in algae, bryophytes and pteridophytes. Siphonogamy is seen in seed plants.
Reference:
1. “Siphonogamy”. En.Wikipedia.Org, 2020, Available here.
2. “Zoidogamy”. En.Wikipedia.Org, 2020, Available here.
Image Courtesy:
1. “Pollen-tube-growth-on-germinated-pollen-a-ungerminated-pollen-without-a-pollen-tube-b-400” By Melekber Sulusoglu, Aysun Cavusoglu – Melekber Sulusoglu et. al. “In Vitro Pollen Viability and Pollen Germination in Cherry Laurel ( Prunus laurocerasus L.)”, The Scientific World Journal doi:10.1155/2014/657123 (CC BY 4.0) via Commons Wikimedia