|
Homothallism
In fungi and algae, homothallism refers to the condition in which a single individual or thallus carries the genetic determinants (i.e., both mating types or sexes) required to undergo sexual reproduction without the need for a distinct mating partner. The opposite sexual functions are performed by different cells of a single mycelium. It can be contrasted to heterothallic. It is often used to categorize fungi. In yeast, heterothallic cells have mating types a and α. An experienced mother cell (one that has divided at least once) will switch mating type every cell division cycle because of the ''HO'' allele. Sexual reproduction commonly occurs in two fundamentally different ways in fungi. These are outcrossing (in heterothallic fungi) in which two different individuals contribute nuclei to form a zygote, and self-fertilization or selfing (in homothallic fungi) in which both nuclei are derived from the same individual. Homothallism in fungi can be defined as the capability of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochliobolus Homomorphus
The fungal genus ''Cochliobolus'' includes 19 species, it includes some plant pathogenic species such as ''Cochliobolus heterostrophus''. A lot of former ''Cochliobolus'' species were transferred to either ''Curvularia'' or ''Bipolaris'' genera. ''Cochliobolus heterostrophus'' is known from "southern corn blight" which affects corn and maize. Heterothallism and homothallism Those fungi that need a partner to mate are referred to as heterothallic (self-sterile), and those fungi not needing a partner are referred to as homothallic (self-fertile). A study of DNA sequences of mating type loci from different heterothallic and homothallic species in the genus ''Cochliobolus'' suggests that homothallism can be derived from heterothallism by recombination.Yun SH1, Berbee ML, Yoder OC, Turgeon BG. Evolution of the fungal self-fertile reproductive life style from self-sterile ancestors. Proc Natl Acad Sci U S A. 1999 May 11;96(10):5592-7. PMCID: PMC21905 DOI: 10.1073/pnas.96.10.559 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochliobolus Luttrellii
The fungal genus ''Cochliobolus'' includes 19 species, it includes some Plant pathology, plant pathogenic species such as ''Cochliobolus heterostrophus''. A lot of former ''Cochliobolus'' species were transferred to either ''Curvularia'' or ''Bipolaris'' genera. ''Cochliobolus heterostrophus'' is known from "southern corn blight" which affects corn and maize. Heterothallism and homothallism Those fungus, fungi that need a partner to mate are referred to as heterothallism, heterothallic (self-sterile), and those fungi not needing a partner are referred to as homothallism, homothallic (self-fertile). A study of DNA sequences of mating type loci from different heterothallic and homothallic species in the genus ''Cochliobolus'' suggests that homothallism can be derived from heterothallism by homologous recombination, recombination.Yun SH1, Berbee ML, Yoder OC, Turgeon BG. Evolution of the fungal self-fertile reproductive life style from self-sterile ancestors. Proc Natl Acad Sci U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one of the kingdom (biology)#Six kingdoms (1998), traditional eukaryotic kingdoms, along with Animalia, Plantae, and either Protista or Protozoa and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of motility, mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochliobolus Cymbopogonis
''Cochliobolus cymbopogonis'' is a fungal plant pathogen. Those fungi that do not need a partner to mate are termed homothallic In fungi and algae, homothallism refers to the condition in which a single individual or thallus carries the genetic determinants (i.e., both mating types or sexes) required to undergo sexual reproduction without the need for a distinct mating partn ... (self-fertile). ''C. cymbopogonis'' is homothallic. References External links USDA ARS Fungal Database Fungal plant pathogens and diseases Cochliobolus Fungi described in 1942 Fungus species {{fungus-plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pneumocystis Jirovecii
''Pneumocystis jirovecii'' (previously ''P. carinii'') is a yeast-like fungus of the genus ''Pneumocystis''. The causative organism of ''Pneumocystis'' pneumonia, it is an important human pathogen, particularly among immunocompromised hosts. Prior to its discovery as a human-specific pathogen, ''P. jirovecii'' was known as ''P. carinii''. Lifecycle The complete lifecycles of any of the species of ''Pneumocystis'' are not known, but presumably all resemble the others in the genus. The terminology follows zoological terms, rather than mycological terms, reflecting the initial misdetermination as a protozoan parasite. It is an extracellular fungus. All stages are found in lungs and because they cannot be cultured '' ex vivo'', direct observation of living ''Pneumocystis'' is difficult. The trophozoite stage is thought to be equivalent to the so-called vegetative state of other species (such as '' Schizosaccharomyces pombe''), which like ''Pneumocystis'', belong to the Taphrino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desert
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or Semi-arid climate, semi-arid. This includes much of the Polar regions of Earth, polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night strain the Rock (geology), rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting frag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic, Antarctic. Tundra vegetation is composed of dwarf shrubs, Cyperaceae, sedges, Poaceae, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating Climate change feedback, a feedback cycle t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. . Lichens are the lifeform that first brought the term symbiosis (as ''Symbiotismus'') into biological context. Lichens have since been recognized as important actors in nutrient cycling and producers which many higher trophic feeders feed on, such as reindeer, gastropods, nematodes, mites, and springtails. Lichens have properties different from those of their component organisms. They come in man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep within the charophytes as a sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae, many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiosis
Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can for example be in Mutualism (biology), mutualistic, commensalism, commensalistic, or parasitism, parasitic relationships. In 1879, Heinrich Anton de Bary defined symbiosis as "the living together of unlike organisms". The term is sometimes more exclusively used in a restricted, mutualistic sense, where both symbionts contribute to each other's subsistence. This means that they benefit each other in some way. Symbiosis can be ''obligate'' (or ''obligative''), which means that one, or both of the organisms depend on each other for survival, or ''facultative'' (optional), when they can also subsist independently. Symbiosis is also classified by physical attachment. Symbionts forming a single body live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
