Table of Contents
How do Selaginella reproduce?
Vegatateve Reproduction: Selaginella reproduces by tubers, bulbils, dormant buds and by fragmentation. The prostrate branches produce roots during favourable conditions. These roof bearing prostrate branches separate from the parent plant and grow into new sporophytes. This has been reported in S.
How many types of Sporophylls are found in Selaginella?
Selaginella produces two types of spores— megaspores and microspores. The dimorphic condition of the spores is known as heterospory. In between the sporophyll and sporangium is present a small membranous structure known as ligule i.e., the sporophyll is similar to a vegetative leaf.
What type of leaf arrangement is found in Selaginella?
Selaginella species are creeping or ascendant plants with simple, scale-like leaves (microphylls) on branching stems from which roots also arise. The stems are aerial, horizontally creeping on the substratum (as in Selaginella kraussiana), sub-erect (Selaginella trachyphylla) or erect (as in Selaginella erythropus).
How many spores are in a Microsporangium of Selaginella?
The microsporangia can produce enormous numbers of microspores—as many as 1,000,000—and the megasporangia give rise to 50 to 300 megaspores. The spores are liberated as the older sporophylls decay. Unlike those of Selaginella, the spores of Isoetes do not germinate until they have been shed from their sporangia.
How does selaginella Lepidophylla reproduce?
If it encounters moisture, Selaginella lepidophylla may rehydrate and take root in the new location. lepidophylla does not produce flowers or seeds but reproduces through spores.
Which is absent in leaf Selaginella?
Centrally located stele (or steles) is connected with the cortex with the help of many long, radially elongated cells called trabeculae. Trabeculae are absent in species like S. adunca, S. rupestris, etc.
What is Microsporophyll and Megasporophyll?
Hint: A sporophyll is a part of the leaf that contains sporangia. In a plant if the sporophyll bears megasporangia, they are called megasporophylls. If it bears microsporangia then it’s called microsporophylls. Sporophylls lead to the development of male and female gametophytes of seed plants (spermatophytes).
What is sporophyll example?
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. Cycads produce strobili, both pollen-producing and seed-producing, that are composed of sporophylls. Ginkgo produces microsporophylls aggregated into a pollen strobilus.
Is Selaginella Monoecious or dioecious?
The gametophytes produced in Selaginella are heterozygous containing microspores and megaspores as male and female gametophytes respectively. Thus, Selaginella produces dioecious gametophytes. So, the correct answer is ‘Dioecious’.
What is present in Selaginella stem?
Note: The stem of Selaginella is shaped like a vascular stele which is protostele. Xylem is available in the middle and is encircled by phloem and phloem is encircled by pericycle. Pith is missing. Trabeculae are available which are tube loved structures and are adjusted endodermal cells with casparian strips.
Which types of reproduction is observed in Selaginella *?
Selaginella reproduces by two methods: Vegetatively and by formation of spores.
What is Selaginella Strobilus?
The genus Selaginella is classified in the division Lycophyta, which includes the numerous plants commonly known as clubmosses and spike mosses. Similar to their close relatives, Selaginella plants develop strobili, spike-like reproductive organs that form on fertile branches.