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Conifers typically bear their microsporangia on microsporophylls aggregated into papery pollen strobili, and the ovules, are located on modified stem axes forming compound ovuliferous cone scales. Flowering plants contain microsporangia in the anthers of stamens (typically four microsporangia per anther) and megasporangia inside ovules inside ...
Encephalartos villosus microsporophylls with microsporangia. A microsporangium (pl. microsporangia) is a sporangium that produces 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.
An anther and its filament together form a typical (or filantherous) stamen, part of the male floral organ. The typical anther is bilocular, i.e. it consists of two thecae. Each theca contains two microsporangia, also known as pollen sacs. The microsporangia produce the microspores, which for seed plants are known as pollen grains.
The microsporangia of gymnosperms develop in pairs toward the bases of the scales, which are therefore called microsporophylls. Each of the microsporocytes in the microsporangia undergoes meiosis, producing four haploid microspores. These develop into pollen grains, each consisting of four cells and, in conifers, a pair of external air sacs.
In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or microsporangia and are called microsporophylls. The overlap of the prefixes and roots makes these terms a particularly confusing subset of botanical nomenclature.
In 2012, Albania's GDP per capita stood at 30% of the European Union average, while GDP (PPP) per capita was 35%. [212] In the first quarter of 2010, after the Great Recession, Albania was one of three countries in Europe to record economic growth. [213] [214] The International Monetary Fund predicted 2.6% growth for Albania in 2010 and 3.2% in ...
President Donald Trump recently touted the of "DOGE dividends," which came to a 30-year-old investor in a dream and caught the attention of Elon Musk on X.
The Academy of Sciences of Albania (Albanian: Akademia e Shkencave e Shqipërisë), founded in 1972, is the most important scientific institution in Albania. [1] In the 1980s, several research institutes began at the University of Tirana were transferred to the Academy's jurisdiction. [ 2 ]