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Elisabeth Tschermak-Woess
Elisabeth Tschermak-Woess (28 January 1917 – 26 April 2001) was an Austrian University lecturer, cytologist, and phycologist who worked with lichen photobionts. In 1994, Tschermak-Woess was awarded the Acharius Medal for her lifetime contributions to lichenology. She had a Festschrift dedicated to her in 1988, in the journal '' Plant Systematics and Evolution'' (volume 158, pages 73–340). Lichen taxa that have been named after Tschermak-Woess include the genus '' Woessia'' and the species '' Asterochloris woessiae''. Biography Tschermak-Woess studied botany and chemistry at the University of Vienna. In 1948 she began her career as a cytologist with Lothar Geitler. From 1971 to 1985 she was a professor of botany (cytology and genetics) at the University of Vienna. Noted for her excellent technique with the light microscope, she discovered the presence of polytene chromosomes in plants. She published several studies about the interactions between mycobionts and phycobi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Znaim
Znojmo (; german: Znaim) is a town in the South Moravian Region of the Czech Republic. It has about 33,000 inhabitants. Znojmo is the historical and cultural centre of southwestern Moravia and the second most populated town in the South Moravian Region. The historical centre of Znojmo is well preserved and is protected by law as an urban monument reservation. Administrative parts Villages of Derflice, Kasárna, Konice, Mramotice, Načeratice, Oblekovice, Popice and Přímětice are administrative parts of Znojmo. Geography The town is situated on a rock outcropping on the steep left bank of the Thaya River, about southwest of the regional capital Brno. Located near the border with Austria, it is connected to Vienna by railway and road. History A fortress at the site possibly already existed during the time of the Great Moravian Empire in the 9th century. From about 1055, Znojmo Castle served as the residence of a Přemyslid principality within the Bohemian March of Mora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytene Chromosome
Polytene chromosomes are large chromosomes which have thousands of DNA strands. They provide a high level of function in certain tissues such as salivary glands of insects. Polytene chromosomes were first reported by E.G.Balbiani in 1881. Polytene chromosomes are found in dipteran flies: the best understood are those of ''Drosophila'', ''Chironomus'' and '' Rhynchosciara''. They are present in another group of arthropods of the class Collembola, a protozoan group Ciliophora, mammalian trophoblasts and antipodal, and suspensor cells in plants. In insects, they are commonly found in the salivary glands when the cells are not dividing. They are produced when repeated rounds of DNA replication without cell division forms a giant chromosome. Thus polytene chromosomes form when multiple rounds of replication produce many sister chromatids ''which stay fused together''. Polytene chromosomes, at interphase, are seen to have distinct thick and thin banding patterns. These patterns w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allium Paniculatum
''Allium paniculatum'', common name pale garlic, is a species of monocot in the family Amaryllidaceae. It is widely cultivated and is now naturalized in several places outside its native range. Description ''Allium paniculatum'' produces several egg-shaped bulbs, each up to 1.5 cm across. It has no rhizomes. Leaves are tubular and hollow, up to 35 cm long. Scape is round in cross-section, solid, up to 75 cm tall. Inflorescence is (despite the name of the species referring to a panicle) an umbel with as many as 100 flowers. Flowers are bell-shaped, about 6 mm across; tepals white to lilac; pollen and anthers yellow. Taxonomy ''A. paniculatum'' is placed within section ''Codonoprasum'', subgenus ''Allium''. The species has been regarded as highly variable, with up to 30 taxa included in what has been referred to as the ''A. paniculatum'' complex, many of which are now regarded as separate species within the section, including '' Allium dentiferum'', '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptochloris
''Elliptochloris'' is a genus of green algae in the order Prasiolales Prasiolales is an order of green algae in the class Trebouxiophyceae.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institute .... References Prasiolales Trebouxiophyceae genera {{green algae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilabifilum
''Dilabifilum'' is a genus of thalloid green algae comprising approximately 4 species. The thalli take a crustose form. ''Choreonema'' reproduces by means of conceptacles; it produces tetraspores and dispores and carpospores. It is a source of agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is .... Species The species currently recognised are: '' Dilabifilum arthropyreniae'' and '' Dilabifilum prostratum''. References * External links Ulvophyceae genera Ulvales {{Green algae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumscription (taxonomy)
In biological taxonomy, circumscription is the content of a taxon, that is, the delimitation of which subordinate taxa are parts of that taxon. If we determine that species X, Y, and Z belong in Genus A, and species T, U, V, and W belong in Genus B, those are our circumscriptions of those two genera. Another systematist might determine that T, U, V, W, X, Y, and Z all belong in genus A. Agreement on circumscriptions is not governed by the Codes of Zoological or Botanical Nomenclature, and must be reached by scientific consensus. A goal of biological taxonomy is to achieve a stable circumscription for every taxon. This goal conflicts, at times, with the goal of achieving a natural classification that reflects the evolutionary history of divergence of groups of organisms. Balancing these two goals is a work in progress, and the circumscriptions of many taxa that had been regarded as stable for decades are in upheaval in the light of rapid developments in molecular phylogenetics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margalith Galun
Margalith Galun ( he, מרגלית גלון, 21 February 1927 – 16 April 2012) was an Israeli lichenologist. She was a member of the Israel Academy of Sciences and Humanities and established the Israeli collection of lichens at Tel Aviv University. Founder of the academic journal ''Symbiosis'', she served as its editor-in-chief between 1985 and 2006. In 1994, she was awarded the Acharius Medal and in 1996 won the Meitner-Humboldt Prize, for her contributions to the field. The International Association for Lichenology grants an award which bears her name to honor scholarship at their quadrennial symposium. Early life Melitta Katz was born on 21 February 1927 in Vienna, Austria to Amalia (née Teitelbaum) and Arie Katz. Originally from Lviv, her father was a merchant and was involved in the Zionist and socialist movements. After completing her elementary school in Vienna and beginning her gymnasium studies, her family decided to immigrate in 1938. They were unsuccessful in leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systematics
Biological systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: cladograms, phylogenetic trees, phylogenies). Phylogenies have two components: branching order (showing group relationships) and branch length (showing amount of evolution). Phylogenetic trees of species and higher taxa are used to study the evolution of traits (e.g., anatomical or molecular characteristics) and the distribution of organisms (biogeography). Systematics, in other words, is used to understand the evolutionary history of life on Earth. The word systematics is derived from the Latin word '' systema,'' which means systematic arrangement of organisms. Carl Linnaeus used 'Systema Naturae' as the title of his book. Branches and applications In the study of biological systematics, researchers use the different branches to further understand the relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiphytic
An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an epibiont. Epiphytes are usually found in the temperate zone (e.g., many mosses, liverworts, lichens, and algae) or in the tropics (e.g., many ferns, cacti, orchids, and bromeliads). Epiphyte species make good houseplants due to their minimal water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyology
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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