Content Related to Microsporangia by Vedantu
Do you know that plants also go through the process of fertilization like humans?
How does reproduction occur in plants?
What is the role of Microsporangia in the process of fertilization and reproduction in plants?
Curious to Know?
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This article will help to clear your doubts about the following topics:
Introduction
What is Microsporangium?
Structure of Microsporangia
What is Microsporogenesis?
How are Microsporangia Formed?
Pollen Sacs
FAQs
Introduction to Microsporangia
In the pre-fertilization stages of plants, especially in angiosperms (flowering plants), Microsporangium plays an important role in the development and growth of pollen grains. These pollen grains contribute to the process of pollination & thus fertilization in plants.
Pop Quiz 1
Does Microsporangium play an important role in the process of reproduction in plants?
Yes
No
Plants and plant bodies show different changes when they reproduce sexually. There are different stages involved in the reproductive cycle of plants. For example, gametophyte and sporophyte stages are two important stages in the reproductive cycle of plants.
Male and female gametes are produced by gametophytes and they combine together to produce sporophytes. Microsporangium is an important part of the reproductive system of plants. The development of pollen grains takes place in microsporangium.
How Will You Define Microsporangium?
Male gametophytes of plants develop and grow in the anther of the plant. Microsporangium is a part of the anther where pollen and microspores are produced. First, you should know what a microspore is.
Microspores are the tiny spores that form male gametophytes which grow to form sperm cells and sperm cells combine with the egg cells to form a zygote.
Microsporangia take place in all the heterosporous plants. It goes through the process of meiosis to produce other microspore mother cells after cell division. The gradual development of these microsores turns them into pollen sacs, which consequently form pollen grains and help in reproduction in plants.
Explain the Structure of Microsporangia
Microsporangia has two lobes and they are also called pollen sacs. They are present in the anther of the plant and are located at the end of stamen which is long filament-like structures in a plant.
Microsporangium has a circular outline and it is surrounded by four layers. The four layers that surround the microsporangium are:
A single epidermal layer that stretches and falls when maturity is reached.
An endothecium in which cells contain fibrous endings
The middle layer of cells breaks down when another is developed fully.
The fourth layer is called tapetum which includes uninucleate, binucleate, or multinucleated cells and very dense cytoplasm.
The outermost layer of microsporangium is the protective layer and it protects microspores. It plays an important role in releasing the pollen grains from the other. The tapetum gives nourishment to the pollen and also helps in the formation of the wall of pollen.
A fun quiz is given here so that you can revise the microsporangium topic quickly.
Pop Quiz
Which is the outermost layer of microsporangium
Tapetum
Sporogenous tissue
Epidermis
Endothecium
What is Microsporogenesis?
Microsporogenesis is the process of formation of microspores from mother cells. There is a mass of sporogenous tissue at the center of each microsporangium in the young anther of the plant. When the anther develops, the sporogenous cells found in the sporogenous tissue make microspore tetrads through meiotic division. Each cell is called a microspore or pollen mother cell. The microspores arrange themselves in the form of a tetrad. When the anther matures and dehydration occurs, the microspores detach from each and form fully grown pollen grains.
How is Microsporangia Formed?
The formation of microsporangia is a complex biological process and it starts with the division of meristematic cells in the young anther of a plant. The another is a part of the stamen and it contains pollen grains. The meristematic cells are surrounded by a thin layer of the epidermis and it soon becomes a bilobed structure. Each lobe then forms a pair of pollen sacs and consequently, a double-lobed anther is formed giving rise to four pollen sacs. The sacs are located at the four corners of the anthers and they consist of cells that divide and form the primary sporogenous layer.
There is a difference between microsporangia and microsporangium. Microsporangia is a collection of sporogenous tissue whereas a single sporogenous tissue is called microsporangium.
Pollen Grains
A mature pollen grain consists of two different types of cells: A pollen tube cell and a generative cell. The tube cells develop to form a pollen tube after successful germination, and the generative cell travels to the ovary through the pollen tube. Generative cells are found in a large pollen tube cell and they divide from many gametes or sperm cells inside the tube. The anther releases the pollen grain to fertilize with the egg cells on maturation.
You can go through the revision notes and study material available on Vedantu to get more information on plant reproduction and microsporangia. You can download the Vedantu app for attending a demo class on your favorite topic.
FAQs on Microsporangia
1. What are microsporangia?
Microsporangia are usually bi-lobed structures that function as pollen sacs and are found in the anther of plants, located at the end of the long filament-like stamen. Male plant gametophytes develop and reach maturity in the anther of a plant. The microsporangia are the part of the anther in which the pollen or microspores are developed.
2. What is microsporogenesis?
Microsporogenesis is the process by which the pollen mother cells give rise to microspores. At the center of each microsporangium in the young anther of a plant, lies a mass of sporogenous tissue. As the anther develops, the sporogenous cells present in the tissue form microspore tetrads through meiotic division. Thus each sporogenous cell is known as the microspore or pollen mother cell.
3. What are the four main layers of a microsporangium?
The four layers of a microsporangium are:
A singular epidermis
An endothecium
The middle layers
A layer of uninucleate, binucleate or multinucleate layers of tapetum
4. What is the difference between Microspore and Microsporangia?
Microspore refers to the haploid spore produced by Sporophytes. They are generally smaller in size than the Megaspore and further develop into male gametophytes. Their formation takes place inside the anthers in plants. Whereas, Microsporangia is bi-lobed pollen sacs wherein the microspores further grow & develop into pollen grains. Segregated by a strip of sterile tissue, 2 microsporangia are found in each lobe of the anther of the plants. Microsporangia take place in all the vascular plants with the heterosporic life cycle.
5. How are Microsporangia formed?
Formation and development of Microsporangia is quite a complex process that goes through meiosis cell division. It takes place in gymnosperms and angiosperm anthers of the plants. It starts with the division of meristematic cells, present in the anthers of the plants. Epidermis, a thin layer surrounding these meristematic cells, further develops into a bi-lobed structure. Now, each of these lobes further develops into pollen sacs, which surround the anthers from all four corners, and result to form a layer of sporogenous cells, called Microsporangium.
6. Where Microsporangia are found in the plants?
Microsporangia are found in the anther. And, another is a part of the stamen that contains pollen grains. Pollen grains are also known as microgametophytes. Furthermore, stamen itself is a part of the flower's male reproductive system.
7. How many Microsporangia are present in a single another?
Stamen is the part of a flower in plants. It contains anthers, and each anther does have 4 Microsporangia present in it. These 4 Microsporangia are present in each corner of another, as another itself is a tetragonal structure.
8. What is the role of Microsporangia in plants?
Microsporangia plays a significant role in the male reproductive system or process of a plant. In flowers, stamen itself is known as the male reproductive part of the flower, in the plants. It consists of - Anther & Filament. The collection of these stamens in a flower is known as Androecium. Similarly, the anthers are also known as pollen sacs. These pollen sacs consist of microsporangia, which helps in creating pollen grains, and thus, plays a major role in pollination in flowering plants.
