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In botany, a sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls , or microsporangia and are called microsporophylls .
Early land plants had sporophytes that produced identical spores (isosporous or homosporous) but the ancestors of the gymnosperms evolved complex heterosporous life cycles in which the spores producing male and female gametophytes were of different sizes, the female megaspores tending to be larger, and fewer in number, than the male microspores.
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year. bifid Forked; cut in two for about half its length. Compare trifid. bifoliate
Urdu Name Roman Urdu Name Remarks Flax seeds: السی: Aalsi Star anise: بادیان : Baadyan Ginger: ادرک: Adrak Grated or paste Mango powder: آمچور: Amchoor Dried unripe mango slices or powder Pakistani pickles: اچار: Achar Different types of pickles Parsley: جعفری: Jafari Carom seed اجوائن: Ajwain Emblica ...
If the plant is heterosporous, the sporangia-bearing leaves are distinguished as either microsporophylls or megasporophylls. In seed plants, sporangia are typically located within strobili or flowers. Clusters of sporangia on a fern. Cycads form their microsporangia on microsporophylls which are aggregated into strobili. Megasporangia are ...
The plants have an underground sexual phase that produces gametes, and this alternates in the lifecycle with the spore-producing plant. The prothallium developed from the spore is a subterranean mass of tissue of considerable size, and bears both the male and female organs ( antheridia and archegonia ). [ 6 ]
Besides fragmentation, a nearly ubiquitous form, these hornworts exhibit tubers, persistent apices, and apospory. Tubers and persistent apices can remain dormant and survive harsh conditions to form new thalli. Apospory, a form of apomixis, involves the formation of diploid gametophyte spores directly from the tissue of the plant's sporophyte.
Heterosporous plants that produced microspores in microsporangia and megaspores in separate megasporangia evolved independently in several plant groups during the Devonian period. [ 1 ] Fossils of these plants show that they produced endosporic gametophytes, meaning that their gametophytes were not free-living as in bryophytes but developed ...