What is meant by heterospory?
Definition of heterospory
: the production of microspores and megaspores (as in seed plants)
What is heterospory what is its significance Class 11?
Heterospory is the phenomenon of formation of two types of spores, i.e., smaller microspore and larger megaspore. … The phenomenon of heterospory lead to the reduction of gametophyte, in situ germination of spores, retention of megagametophyte in the megasporangia and finally to the seed development.
Why is heterospory important for seed formation?
Heterospory Advanced to the Seed Habitat in Land Plants:
One of the most important advantages of heterospory is the formation of seed habitat. In homosporous plants, the male and female gametes are formed in the same prothallus. Thus the chance of fertilizing an egg with the sperm of the same prothallus is very high.
What is mean by heterospory write the significance of heterospory?
Heterospory is the phenomenon in which two different kinds spores are produced. These spores differ in size. The smaller spore is called microspore while the larger spore is called megaspore. … The heterospory is the first step of evolution of seed development in gymnosperms and angiosperms.
What is Diplohaplontic life cycle?
(of an alga or other lower plant) having a life cycle in which full-grown haploid and diploid forms alternate. … ‘Sporic life cycles are sometimes called diplohaplontic, indicating that both diploid and haploid free-living stage occur.
What is meant by Heterosporous Fern give two examples?
Selaginella and Salvinia are two examples of heterosporous pteridophytes. These pteridophytes consist of two types of spores, large spores that germinate to produce female gametophyte and small spores germinate to produce male gametes.
What is the importance of Heterospory in pteridophytes?
The phenomenon of Heterospory is of great biological advantage because of the fact that a large megaspore which contains female gametophyte derives its food from the sporophyte, and is independent of the external conditions as might interfere with the growth of a free living gametophyte.
Do you think Heterospory have some evolutionary significance in plant kingdom?
Heterospory is the production of spores of two diffetent sizes and sexes by sporophyte of land plants. Yes it is an evolutionary significance as plants have anthers and pistils with all these features.
What are the economic importance of pteridophytes?
Pteridophytes commonly known as Vascular Cryptogams, are the seedless vascular plants that evolved after bryophytes. Besides being a lower plant, pteridophytes are economically very important. Dry fronds of many ferns are used as a cattle feed. Pteridophytes are also used as a medicine.
Why seeds are not formed in pteridophytes?
A pteridophyte is a vascular plant (with xylem and phloem) that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as “cryptogams”, meaning that their means of reproduction is hidden.
What is heterospory in Selaginella?
Heterospory is a character of Selaginella. In this plant, two different kinds of spores are produced i.e. microspores formed in microsporangia and megaspores formed in megasporangia. … So here we can say that Selaginella is an important evolutionary link between pteridophytes and seed-producing plants.
What is heterospory explain with reference in pteridophytes?
Heterosporous refers to the plants producing different types of spores that are different in structure, size and function. They produce two kinds of spores, smaller microspores and bigger megaspores. Most pteridophytes are homosporous, i.e. they produce all spores of a similar kind.
Which fern is Woody?
The fronds of tree ferns also exhibit circinate vernation, meaning the young fronds emerge in coils that uncurl as they grow. Unlike flowering plants, tree ferns do not form new woody tissue in their trunk as they grow. Rather, the trunk is supported by a fibrous mass of roots that expands as the tree fern grows.
Are ferns pteridophytes?
The Pteridophytes (Ferns and fern allies) are vascular plants. Most of them have leaves (known as fronds), roots, and sometimes true stems or trunks as in the tree ferns.
What is heterospory PDF?
Heterospory in Pteridophytes:
Most of the Pteridophytes produce one kind of similar spore. … However, there are some Pteridophytes which produce two different types of spores (differing in size, structure and function). Such Pteridophytes are known as heterosporous and the phenomenon is known as heterospory.
Is fern a bryophyte?
No, ferns are not bryophytes. They are pteridophytes. They are non-flowering, vascular plants. Unlike bryophytes, they possess true roots, stem and leaves.
What is fern Minecraft?
Ferns are versions of Tall Grass that spawn only in Jungle Biomes and Mega Taiga Biomes. They have a small chance of spawning as double-tall fern when generated in the biomes above but this is quite rare.
Is a fern a tree?
Tree ferns are true ferns. … A tree fern’s unusual trunk consists of a thin stem surrounded by thick, fibrous roots. The fronds on many tree ferns remain green throughout the year. In a few species, they turn brown and hang around the top of the trunk, much like palm tree leaves.