Do gymnosperms have microsporangia?
Do gymnosperms have microsporangia?
gymnosperms. Microsporangia, or pollen sacs, are borne on the lower surfaces of the microsporophylls. The number of microsporangia may vary from two in many conifers to hundreds in some cycads. Within the microsporangia are cells which undergo meiotic division to produce haploid microspores.
What is microsporangium in anther?
The microsporangia, which are usually bi-lobed, are pollen sacs in which the microspores develop into pollen grains. These are found in the anther, which is at the end of the stamen—the long filament that supports the anther.
Is a microsporangium haploid or diploid?
The microsporangia (plural of microsporangium) are pollen sacs in which the microspores develop into pollen grains. As a spore, the microspore is haploid, but it is derived from a diploid cell.
Do seedless plants have microsporangia?
The spike moss Selaginella is a heterosporous lycophyte. The same strobilus will contain microsporangia, which produce spores that will develop into the male gametophyte, and megasporangia, which produce spores that will develop into the female gametophyte.
Where are the microspores stored in a gymnosperm?
Male gymnosperm microspores are stored in the archegonium while female megaspores are stored in the megasporophylls. Male cones of gymnosperms are much larger than female cones and contain many more gametophytes. Contribute!
Where does the Microsporangia occur in a plant?
Microsporangia occur in all vascular plants that have heterosporic life cycles, such as seed plants, spike mosses and the aquatic fern genus Azolla. In gymnosperms and angiosperm anthers, the microsporangia produce microsporocytes, the microspore mother cells, which then produce four microspores through the process of meiosis.
When do microsporangia give rise to male gametophytes?
Microsporangia are sporangia that produce microspores that give rise to male gametophytes when they germinate. Microsporangia occur in all vascular plants that have heterosporic life cycles, such as seed plants, spike mosses and the aquatic fern genus Azolla.
How does the female megaspore form in a gymnosperm?
The megaspore mother cell divides by meiosis to produce four haploid megaspores. One of the megaspores divides to form the multicellular female gametophyte, while the others divide to form the rest of the structure. The female gametophyte is contained within a structure called the archegonium. Figure 3.
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