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Carex Arctogena
''Carex arctogena'' is a member of the sedge family (Cyperaceae) which grows in high alpine areas. It is one of the few "bipolar" species; it has populations in Greenland, Scandinavia, Russia, Canada and southern South America. Plants in the far north and south appear to be genetically identical, having taken advantage of a similar niches on opposite ends of the globe. ''Carex arctogena'' has often been confused with the closely related ''Carex capitata''. They were classified as one species until Harry Smith distinguished the differences between them 1940. Defining morphological characteristics of this species include: toothed scales which cover the female reproductive parts of the inflorescence, a larger seed relative to the size of the female reproductive sac (perigynia) and round perigynia which quickly taper towards the apex. It produces a single spike on each stem and has long elongated leaves which are characteristic for the genus ''Carex''. Description ''C. arctogena'' ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyperaceae
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' with over 2,000 species. These species are widely distributed, with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges may be found growing in almost all environments, many are associated with wetlands, or with poor soils. Ecological communities dominated by sedges are known as sedgelands or sedge meadows. Some species superficially resemble the closely related rushes and the more distantly related grasses. Features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections (with occasional exceptions, a notable example being the tule which has a round cross-section) and leaves that are spirally arranged in three ranks. In comparison, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adjectival term applied to anatomical structures which are made primarily of calcium carbonate, in animals such as gastropods, i.e., snails, specifically about such structures as the operculum, the clausilium, and the love dart. The term also applies to the calcium carbonate tests of often more or less microscopic Foraminifera. Not all tests are calcareous; diatoms and radiolaria have siliceous tests. The molluscs are calcareous, as are calcareous sponges ( Porifera), that have spicules which are made of calcium carbonate. In botany ''Calcareous grassland'' is a form of grassland characteristic of soils containing much calcium carbonate from underlying chalk or limestone rock. In medicine The term is used in pathology, for example i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthropochory
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, such as the wind, and living (biotic) vectors such as birds. Seeds can be dispersed away from the parent plant individually or collectively, as well as dispersed in both space and time. The patterns of seed dispersal are determined in large part by the dispersal mechanism and this has important implications for the demographic and genetic structure of plant populations, as well as migration patterns and species interactions. There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus. These modes are typically inferred based on adaptations, such as wings or fleshy fruit. However, this simplified view may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Analyses
Genetic analysis is the overall process of studying and researching in fields of science that involve genetics and molecular biology. There are a number of applications that are developed from this research, and these are also considered parts of the process. The base system of analysis revolves around general genetics. Basic studies include identification of genes and inherited disorders. This research has been conducted for centuries on both a large-scale physical observation basis and on a more microscopic scale. Genetic analysis can be used generally to describe methods both used in and resulting from the sciences of genetics and molecular biology, or to applications resulting from this research. Genetic analysis may be done to identify genetic/inherited disorders and also to make a differential diagnosis in certain somatic diseases such as cancer. Genetic analyses of cancer include detection of mutations, fusion genes, and DNA copy number changes. History of genetic analysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eric Hultén
Oskar Eric Gunnar Hultén (18 March 1894 – 1 February 1981) was a Swedish botanist, plant geographer and 20th century explorer of The Arctic. He was born in Halla in Södermanland. He took his licentiate exam 1931 at Stockholm University and obtained his doctorate degree in botany at Lund University in 1937. In his thesis, he coined the term ''Beringia'' for the ice-age land bridge between Eurasia and North America. From 1945 to 1961, he was a professor and head of the Botany Section at the Swedish Museum of Natural History. In 1953, he was elected to the Royal Swedish Academy of Sciences as member number 977. Hultén travelled extensively in the Scandes Mountains and Siberia, Kamchatka (1920–22 together with his spouse Elsie Hultén, Sten Bergman and René Malaise), the Aleutian Islands and Alaska (1932). He published extensive accounts on the flora of several of these regions and distribution maps of thousands of species. He was the father of the professor of art history ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin; his name is rendered in Latin as and, after his 1761 ennoblement, as . Linnaeus was born in Råshult, the countryside of Småland, in southern Sweden. He received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and also published the first edition of his ' in the Netherlands. He then returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he continued to collect an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplotype
A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA organized in two sets of pairwise similar chromosomes. The offspring gets one chromosome in each pair from each parent. A set of pairs of chromosomes is called diploid and a set of only one half of each pair is called haploid. The haploid genotype (haplotype) is a genotype that considers the singular chromosomes rather than the pairs of chromosomes. It can be all the chromosomes from one of the parents or a minor part of a chromosome, for example a sequence of 9000 base pairs. However, there are other uses of this term. First, it is used to mean a collection of specific alleles (that is, specific DNA sequences) in a cluster of tightly linked genes on a chromosome that are likely to be inherited together—that is, they are likely to be con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magadan Oblast
Magadan Oblast ( rus, Магаданская область, r=Magadanskaya oblast, p=məgɐˈdanskəjə ˈobləsʲtʲ) is a federal subject (an oblast) of Russia. It is geographically located in the Far East region of the country, and is administratively part of the Far Eastern Federal District. Magadan Oblast has a population of 156,996 ( 2010 Census), making it the least populated oblast and the third-least populated federal subject in Russia. Magadan is the largest city and the capital of Magadan Oblast. The majority of the Oblast's inhabitants live in the city. The coastline has a less severe climate than the interiors, although both are very cold for its latitude. It borders Chukotka Autonomous Okrug in the north, Kamchatka Krai in the east, Khabarovsk Krai in the south and the Sakha Republic in the west. The economy is primarily based on mining, particularly gold, silver and other non-ferrous metals. History Magadan Oblast was established on December 3, 1953Decree of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
52nd Parallel South
The 52nd parallel south is a circle of latitude that is 52 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, the Pacific Ocean and South America. The parallel defines part of the border between Argentina and Chile. At this latitude the sun is visible for 16 hours, 44 minutes during the December solstice and 7 hours, 44 minutes during the June solstice. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 52° south passes through: : See also *51st parallel south *53rd parallel south The 53rd parallel south is a circle of latitude that is 53 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, the Pacific Ocean and South America. At this latitude the sun is visible for 16 hours, 5 ... References {{Reflist s52 Argentina–Chile border ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
55th Parallel North
The 55th parallel north is a circle of latitude that is 55 degrees north of the Earth's equatorial plane. It crosses Europe, Asia, the Pacific Ocean, North America, and the Atlantic Ocean. At this latitude the sun is visible for 17 hours, 22 minutes during the summer solstice and 7 hours, 10 minutes during the winter solstice. This latitude also roughly corresponds to the minimum latitude in which nautical twilight can last all night near the summer solstice. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 55° north passes through: : Notable cities and towns on 55°N *Chelyabinsk, Chelyabinsk Oblast, Russia *Omsk, Omsk Oblast, Russia *Novosibirsk, Novosibirsk Oblast, Russia *Derry, Northern Ireland, UK *Newcastle upon Tyne, England, UK *South Shields, England, UK. *Thompson, Manitoba, CA *Grande Prairie, Alberta, Canada Use as a boundary The 55th parallel serves as the southern boundary of Nunavik territory in Quebec. See also *54th pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Line
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowpack, or associated lack of available moisture). The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed Canopy (biology), canopy. At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as ''krummholz'' (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach the tree line, above which they are unable to grow at all. Given a certain latitude, the tree line is approximately 300 to 1000 meters below the permanent snow line and roughly parallel to it. Causes Due to their vertical structure, tree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
