Are selaginella haploid or diploid?
These single-celled haploid spores represent the beginning of the independent haploid gametophyte generation. The microgametophye produces motile sperm and the megagametophyte eggs. Bar, 0.1 mm.
Is Megasporangium haploid or diploid?
Diploid. Megasporangium (2n) produce one megaspore that gives rise to F gametophyte thru meiosis, so gametophyte is haploid.
Is selaginella a gametophyte or sporophyte?
Selaginella does have heterospory and sex allocation in its sporophyte generation. However, it does not have the protective, maternal features that occur after fertilization in angiosperms.
Is the sterile jacket haploid or diploid?
The outer wall of the sporangia is a sterile jacket of cells that surrounds and protects the enclosed sporogenous tissue. In the microsporangia, the diploid sporocyte cells undergo meiosis to form numerous meiospores which in turn form haploid microspores.
Are these Thalli haploid or diploid?
The life cycle of organisms with “alternation of generations” is characterized by each phase consisting of one of two separate, free-living organisms: a gametophyte ( thallus (tissue) or plant), which is genetically haploid, and a sporophyte (thallus or plant), which is genetically diploid.
What is the difference between Lycopodium and Selaginella?
The key difference between Lycopodium and Selaginella is that Lycopodium is a clubmoss which is homosporous (one type of spore) while Selaginella is a spike moss which is heterosporous (two distinct types of spores). They produce spores for reproduction. Moreover, lycophytes they have unique leaves called microphylls.
What is the megasporangium in angiosperms?
-Megasporangium is known as female sporangia and it produces megasporocytes. Megasporocytes further divide and give rise to megaspores. Hence, Nucellus is the megasporangium in an Angiosperm ovule. Nucellus (plural nucelli), is the inner part of the ovule.
Do angiosperms have a megasporangium?
The Flower and Its Pollination In most angiosperms, the flowers are perfect: each has both microsporangia and megasporangia. Some angiosperms are imperfect, having either microsporangia or megasporangia but not both.
What is a Megasporangium?
Noun. 1. megasporangium – a plant structure that produces megaspores. macrosporangium. sporangium, spore case, spore sac – organ containing or producing spores.
Is Selaginella a bryophyte?
Selaginella is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses….Selaginella.
| Spikemoss | |
|---|---|
| Clade: | Lycophytes |
| Class: | Lycopodiopsida |
| Order: | Selaginellales Prantl |
| Family: | Selaginellaceae Willk. |
Which structures are haploid?
The haploid structures are the pollen, endosperms, and megaspores, while the sporophyte is diploid, which eventually forms the plant body, such as leaves.
What part of a bryophyte is diploid?
Like all land plants (embryophytes), bryophytes have life cycles with alternation of generations. In each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cell contain two sets of paired chromosomes.
Where are the sporangia located in a Selaginella?
• In most of the species of Selaginella sporophylls are aggregated at the apex of the main stem or lateral branch and forms compact cones, called strobili. (Singular – strobilus) • The sporophylls are spirally arranged around a central axis. • The sporangia are borne singly in the axils of sporophylls.
Where are microsporophylls found in a Selaginella patula?
Microsporophyll and Megasporophyll are aggregated in strobilli and cones at the apex of the stem or lateral branches. in Selaginella patula produces shoot with sporophyll and folliage leaves in alternate zone along the stems. Sporophylls may born in different srobilli.
Which is the only genus in the Selaginellaceae?
Selaginella sp. is a sole genus of vascular plant under family Selaginellaceae and order Selaginellales. The member of this order have herbaceous stems that are usually without any indication of a secondary thickening. Commonly known as spike mosses. Selaginella m os tly occurs in tropical region. It is worldwide in distribution.
How is the plant body of Selaginella differentiated?
The plant body of Selaginella is differentiated into well developed roots, stem and leaves. Besides, some species also have rhizophore (Fig.7.46A).