|
Atla Oulankaensis
''Atla oulankaensis'' is a rare species of saxicolous (rock-dwelling) lichen in the family Verrucariaceae. It has been recorded in Finland and in the Canadian arctic, growing on calciferous rock and on high- pH soil. Taxonomy The lichen was formally described as a new species in 2016 by Juha Pykälä and Leena Myllys. The type specimen was collected by the first author from the Jäkälävuoma gorge in Oulanka National Park ( Juuma, Koillismaa) at an altitude of ; there it was found growing on a shady dolomitic rock outcrop on a northwest-facing wall. The species epithet ''oulankaensis'' refers to the type locality, which is, according to the authors, "one of the lichenologically most valuable areas in Finland". It has also been collected from Banks Island in the Canadian Arctic Archipelago, where it was growing on high- pH soil. Molecular analysis of the internal transcribed spacer DNA regions suggests that '' Atla alaskana'' is the closest relative of ''A. oulankaensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saxicolous Lichen
A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, given the absence of external disturbances. The importance of the mineral composition of the rock substrate, as well as the elemental geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ... is also important to the distribution of saxicolous lichens, but the relationship between the substrate influence on lichens, either chemical or textural, is still obscure. Communities of saxicolous lichens are often species-rich in terms of number. References Lichenology {{lichen-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Transcribed Spacer
Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. ITS across life domains In bacteria and archaea, there is a single ITS, located between the 16S and 23S rRNA genes. Conversely, there are two ITSs in eukaryotes: ITS1 is located between 18S and 5.8S rRNA genes, while ITS2 is between 5.8S and 28S (in opisthokonts, or 25S in plants) rRNA genes. ITS1 corresponds to the ITS in bacteria and archaea, while ITS2 originated as an insertion that interrupted the ancestral 23S rRNA gene. Organization In bacteria and archaea, the ITS occurs in one to several copies, as do the flanking 16S and 23S genes. When there are multiple copies, these do not occur adjacent to one another. Rather, they occur in discrete locations in the circular chromosome. It is not uncommon in bacteria to carry tRN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verrucariales
Verrucariales is an order of ascomycetous fungi within the subclass Chaetothyriomycetidae of the class Eurotiomycetes. Although most of the Verrucariales are lichenised, the family Sarcopyreniaceae consists of 11 species of lichenicolous (lichen-dwelling) fungi. Phylogenomic analysis suggests that the divergence between the lichenized Verrucariales and nonlichenized Chaetothyriales The Chaetothyriales are an order of ascomycetous fungi in the class Eurotiomycetes and within the subclass Chaetothyriomycetidae. The order was circumscribed in 1987 by mycologist Margaret Elizabeth Barr-Bigelow. Families and genera , Species ... occurred about 131 million years ago. Genera of uncertain placement There are some genera in the Verrucariales that have not been placed with certainty into any family. These are: *'' Botryolepraria'' – 2 spp. *'' Gemmaspora'' – 1 sp. *'' Kalbiana'' – 1 sp. *'' Merismatium'' – 10 spp. References Ascomycota orders Lichen orders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatrial septum, the wall of tissue that is a sectional part of the left and right atria of the heart * Interventricular septum, the wall separating the left and right ventricles of the heart * Lingual septum, a vertical layer of fibrous tissue that separates the halves of the tongue. *Nasal septum: the cartilage wall separating the nostrils of the nose * Alveolar septum: the thin wall which separates the alveoli from each other in the lungs * Orbital septum, a palpebral ligament in the upper and lower eyelids * Septum pellucidum or septum lucidum, a thin structure separating two fluid pockets in the brain * Uterine septum, a malformation of the uterus * Vaginal septum, a lateral or transverse partition inside the vagina * Intermuscular sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascus
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one (e.g. ''Monosporascus cannonballus''), two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci (e.g. ''Tympanis'') with hundreds of conidia, or the ascospores may fragment, e.g. some ''Cordyceps'', also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic (lacking a septum), and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm (the portion of cytoplasm not used in ascospore formation) that is surrounded by the "bourrelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascospore
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one (e.g. ''Monosporascus cannonballus''), two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci (e.g. ''Tympanis'') with hundreds of conidia, or the ascospores may fragment, e.g. some ''Cordyceps'', also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic (lacking a septum), and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm (the portion of cytoplasm not used in ascospore formation) that is surrounded by the "bourrelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . The longest human chromosome, chromosome 1, is approximately in length. Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostiole
An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores. The word is a diminutive of "ostium", "opening". The term is also used in higher plants, for example to denote the opening of the involuted syconium (fig inflorescence) through which fig wasps enter to pollinate and breed. Sometimes a stoma In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bor ...tal aperture is called an "ostiole"."Synergistic Pectin Degradation and Guard Cell Pressurization Underlie Stomatal Pore Formation", See also * Ostium (other) References Fungal morphology and anatomy Plant anatomy {{botany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perithecia
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodia
{{Short description, Morphological structure found in some lichens Cephalodia (singular cephalodium) are small gall-like structures found in some species of lichens that contain cyanobacterial symbionts Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit .... Cephalodia can occur within the tissues of the lichen, or on its upper or lower surface. Lichens that have both green algal and cyanobacterial symbionts restrict the cyanobacteria to cephalodia. Lichens that have only cyanobacterial symbionts do not have cephalodia: instead the cyanobacteria are widely distributed throughout the lichen. Lichens with cephalodia can fix nitrogen, and can be an important contributor of nitrogen to the ecosystem. References *Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North Ame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nostoc
''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in various environments that may form colonies composed of filaments of moniliform cells in a gelatinous sheath of polysaccharides. ''Nostoc'' is a genus of photosynthetic, Gram-negative cyanobacteria that can be found in both terrestrial and aquatic environments. It may also grow symbiotically within the tissues of plants, providing nitrogen to its host through the action of terminally differentiated cells known as heterocysts. ''Nostoc'' is a genus that includes many species that are diverse in morphology, habitat distribution, and ecological function. ''Nostoc'' can be found in soil, on moist rocks, at the bottom of lakes and springs, and rarely in marine habitats. It may also be found in terrestrial temperate, desert, tropical, or polar env ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Corda_175174.jpg "Click for more on -> Ostiole")
_Figure_2.jpg "Click for more on -> Nostoc")
