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Quiescent Centre
The quiescent centre is a group of cells, up to 1,000 in number, in the form of a hemisphere, with the flat face toward the root tip of vascular plants. It is a region in the apical meristem of a root where cell division proceeds very slowly or not at all, but the cells are capable of resuming meristematic activity when the tissue surrounding them is damaged. Cells of root apical meristems do not all divide at the same rate. Determinations of relative rates of DNA synthesis show that primary roots of '' Zea'', ''Vicia'' and ''Allium'' have quiescent centres to the meristems, in which the cells divide rarely or never in the course of normal root growth (Clowes, 1958). Such a quiescent centre includes the cells at the apices of the histogens of both stele and cortex. Its presence can be deduced from the anatomy of the apex in ''Zea'' (Clowes, 1958), but not in the other species which lack discrete histogens. History In 1953, during the course of analysing the organization and func ...
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Vascular Plant
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the term ...
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Zea (plant)
''Zea'' is a genus of flowering plants in the grass family. The best-known species is ''Z. mays'' (variously called maize, corn, or Indian corn), one of the most important crops for human societies throughout much of the world. The four wild species are commonly known as teosintes and are native to Mesoamerica. Etymology ''Zea'' is derived from the Greek name () for another cereal grain (possibly spelt).Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 411 Recognized species The five accepted species names in the genus are: ''Zea mays'' is further divided into four subspecies: ''Z. m. huehuetenangensis'', ''Z. m. mexicana'', '' Z. m. parviglumis'' (Balsas teosinte, the ancestor of maize), and ''Z. m. mays''. The first three subspecies are teosintes; the last is maize, or corn, the only domesticated taxon in the genus ''Zea''. The genus is divided into two sections: ''Luxuriantes'', with ''Z. diploperennis'', ''Z. luxu ...
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Vicia
''Vicia'' is a genus of over 240 species of flowering plants that are part of the legume family (Fabaceae), and which are commonly known as vetches. Member species are native to Europe, North America, South America, Asia and Africa. Some other genera of their subfamily Faboideae also have names containing "vetch", for example the vetchlings (''Lathyrus'') or the milk-vetches (''Astragalus''). The broad bean (''Vicia faba'') is sometimes separated in a monotypic genus ''Faba''; although not often used today, it is of historical importance in plant taxonomy as the namesake of the order Fabales, the Fabaceae and the Faboideae. The tribe Vicieae in which the vetches are placed is named after the genus' current name. Among the closest living relatives of vetches are the lentils (''Lens'') and the true peas (''Pisum''). Use by humans Bitter vetch ('' V. ervilia'') was one of the first domesticated crops. It was grown in the Near East about 9,500 years ago, starting perhaps ev ...
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Allium
''Allium'' is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The generic name ''Allium'' is the Latin word for garlic,Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 43 and the type species for the genus is '' Allium sativum'' which means "cultivated garlic".''Allium'' In: Index Nominum Genericorum. In: Regnum Vegetabile (see ''External links'' below). Carl Linnaeus first described the genus ''Allium'' in 1753. Some sources refer to Greek ἀλέω (aleo, to avoid) by reason of the smell of garlic. Various ''Allium'' have been cultivated from the earliest times, and about a dozen species are economically important as crops, or garden vegetables, and an increasing number of species are important as ornamental plants. The decision to include a species in the genus ''Allium'' is taxonomically difficult, and spec ...
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University Of Oxford
, mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor = The Lord Patten of Barnes , vice_chancellor = Louise Richardson , students = 24,515 (2019) , undergrad = 11,955 , postgrad = 12,010 , other = 541 (2017) , city = Oxford , country = England , coordinates = , campus_type = University town , athletics_affiliations = Blue (university sport) , logo_size = 250px , website = , logo = University of Oxford.svg , colours = Oxford Blue , faculty = 6,995 (2020) , academic_affiliations = , The University of Oxford is a collegiate research university in Oxf ...
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Fagus Sylvatica
''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae. Description ''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though more typically tall and up to trunk diameter. A 10-year-old sapling will stand about tall. It has a typical lifespan of 150–200 years, though sometimes up to 300 years. In cultivated forest stands trees are normally harvested at 80–120 years of age. 30 years are needed to attain full maturity (as compared to 40 for American beech). Like most trees, its form depends on the location: in forest areas, ''F. sylvatica'' grows to over , with branches being high up on the trunk. In open locations, it will become much shorter (typically ) and more massive. The leaves are alternate, simple, and entire or with a slightly crenate margin, long and 3–7 cm broad, with 6–7 veins on each side of the leaf (as opposed to 7–10 veins in ...
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Vicia Faba
''Vicia faba'', commonly known as the broad bean, fava bean, or faba bean, is a species of vetch, a flowering plant in the pea and bean family Fabaceae. It is widely cultivated as a crop for human consumption, and also as a cover crop. Varieties with smaller, harder seeds that are fed to horses or other animals are called field bean, tic bean or tick bean. Horse bean, ''Vicia faba'' var. ''equina'' Pers., is a variety recognized as an accepted name. This legume is very common in Southern European, Northern European, East Asian, Latin American and North African cuisines. Some people suffer from favism, a hemolytic response to the consumption of broad beans, a condition linked to a metabolism disorder known as G6PDD. Otherwise the beans, with the outer seed coat removed, can be eaten raw or cooked. In young plants, the outer seed coat can be eaten, and in very young plants, the seed pod can be eaten. Description ''Vicia faba'' is a stiffly erect, annual plant tall, with two ...
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Zea Mays
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits. The term ''maize'' is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike ''corn'', which has a complex variety of meanings that vary by context and geographic region. Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and ...
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Triticum Vulgare
Common wheat (''Triticum aestivum''), also known as bread wheat, is a cultivated wheat species. About 95% of wheat produced worldwide is common wheat; it is the most widely grown of all crops and the cereal with the highest monetary yield. Taxonomy Numerous forms of wheat have evolved under human selection. This diversity has led to confusion in the naming of wheats, with names based on both genetic and morphological characteristics. List of common cultivars * Albimonte * Manital Phylogeny Bread wheat is an allohexaploid (an allopolyploid with six sets of chromosomes: two sets from each of three different species). Of the six sets of chromosomes, two come from ''Triticum urartu'' (einkorn wheat) and two from a species related to ''Aegilops speltoides''. This spontaneous hybridisation created the tetraploid species ''Triticum turgidum'' (an ancestor of wild emmer wheat and durum wheat) 580,000–820,000 years ago. The last two sets of chromosomes came from wild goat-gras ...
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Encyclopædia Britannica
The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various times through the centuries. The encyclopaedia is maintained by about 100 full-time editors and more than 4,000 contributors. The 2010 version of the 15th edition, which spans 32 volumes and 32,640 pages, was the last printed edition. Since 2016, it has been published exclusively as an online encyclopaedia. Printed for 244 years, the ''Britannica'' was the longest running in-print encyclopaedia in the English language. It was first published between 1768 and 1771 in the Scottish capital of Edinburgh, as three volumes. The encyclopaedia grew in size: the second edition was 10 volumes, and by its fourth edition (1801–1810) it had expanded to 20 volumes. Its rising stature as a scholarly work helped recruit eminent con ...
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