|
Dioscorea Chouardii
''Dioscorea chouardii'' (synonym: ''Borderea chouardii'') is a herbaceous plant in the family Dioscoreaceae. It is endemic to a single cliff located in the Pyrenees of Aragon, Spain. History A previously unknown species, ''Dioscorea chouardii'' was discovered in the 1950s growing in cracks in a limestone cliff in the Pyrenees Mountains in northeastern Spain. The fissures in which it lives are so inaccessible that it proved difficult to estimate the number of plants. At first it was thought that there were some 300 to 500 plants scattered across the rock face, but later, with the erection of some scaffolding and the help of binoculars and telescopes, individual plants could be monitored, and a total figure of around 9,000 plants was reached. Taxonomy ''Dioscorea chouardii'' was originally separated from '' Dioscorea'', along with its close relative ''D. pyrenaica'', in the genus ''Borderea'' on the basis of the seeds lacking the wings of most ''Dioscorea'', although it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of the '' Shorter Oxford English Dictionary'' defines "herb" as: #"A plant whose stem does not become woody and persistent (as in a tree or shrub) but remains soft and succulent, and dies (completely or down to the root) after flowering"; #"A (freq. aromatic) plant used for flavouring or scent, in medicine, etc.". (See: Herb) The same dictionary defines "herbaceous" as: #"Of the nature of a herb; esp. not forming a woody stem but dying down to the root each year"; #"BOTANY Resembling a leaf in colour or texture. Opp. scarious". Botanical sources differ from each other on the definition of "herb". For instance, the Hunt Institute for Botanical Documentation includes the condition "when persisting over more than one growing season, the parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Amplification Of Polymorphic DNA
Random amplification of polymorphic DNA (RAPD), pronounced "rapid", is a type of polymerase chain reaction (PCR), but the segments of DNA that are amplified are random. The scientist performing RAPD creates several arbitrary, short primers (10- 12 nucleotides), then proceeds with the PCR using a large template of genomic DNA, hoping that fragments will amplify. By resolving the resulting patterns, a semi-unique profile can be gleaned from an RAPD reaction. No knowledge of the DNA sequence of the targeted genome is required, as the primers will bind somewhere in the sequence, but it is not certain exactly where. This makes the method popular for comparing the DNA of biological systems that have not had the attention of the scientific community, or in a system in which relatively few DNA sequences are compared (it is not suitable for forming a cDNA databank). Because it relies on a large, intact DNA template sequence, it has some limitations in the use of degraded DNA samples. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Flora Of Spain
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Endemic Flora Of Spain")
