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Septal Pores
In algal anatomy, a pit connection is a hole in the septum between two algal cells, and is found only in multicellular red algae − specifically in the subphylum Eurhodophytina, except haploid Bangiales. They are often stoppered with proteinaceous "pit plugs". By contrast, many fungi (only ascomycetes and basidiomycetes, as most other groups lack septa) contain septal pores − an unrelated phenomenon. Characteristics A sieve-like membrane may cover the pit in living algae, but in the majority of algae a plug forms, they likely limit the transfer of metabolites between neighbouring cells. Formation Primary pit connections are formed between cells in the same filament, derived from the same parent cell by its division. Such connections are always single, and usually circular; this is a result of their method of formation. The septum is formed as the walls of a filament grow inwards, dividing the cell; this results in a hole in the middle of the tube where the walls don't quite mer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum (cell Biology)
A septum in cell biology is the new cell wall that forms between two daughter cells as a result of cell division. Cell division is an extremely complex process that contains four different subprocesses. These processes included the growth of a cell, DNA replication, the process of allocating replicated chromosomes to daughter cells, and septum formation. Ultimately, the septum is the crucial ending to mitosis, meiosis, and the division of bacterial cells. The formation of the septum (a new cell wall) allows the two daughter cells to be separate from one another and perform their respective functions independently. Composition In ''Schizosaccharomyces pombe'', the primary septum is composed of linear β(1,3)-D-glucan, β(1,6) branches, and α(1,3)-D-glucan. The secondary septum in Schizosaccharomyces pombe is composed of β(1,6)-D-glucan, β(1,6) branches, and α(1,3)-D-glucan. The synthesis of linear β(1,3)-D-glucan for the primary septum is done by the enzyme β(1,3)-D-glucan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Algae
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxonomic revisions. The majority of species (6,793) are Florideophyceae, and mostly consist of multicellular, ocean, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, no terrestrial species exist, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. Red algae form a distinct group characterized by eukaryotic cells without flagella and centrioles, chloroplasts without external endoplasmic reticulum or unstack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bangiales
Bangiales is an order of multicellular red algae of the class Bangiophyceae containing the families Bangiaceae, Granufilaceae, and possibly the extinct genus ''Rafatazmia'' with one species, ''Rafatazmia chitrakootensis''. They are one of the oldest eukaryotic organisms, possibly dating back to 1.6 billion years old. Many species are used today as food in different cultures worldwide. Their sizes range from microscopic ('' Bangiomorpha'') to up to two meters long ('' Wildemania occidentalis''). Many of its species are affected by '' Pythium porphyrae'', a parasitic oomycete. Similar to many other species of red algae, they reproduce both asexually and sexually. They can be both filamentous or foliose, and are found worldwide. History The first categorization of red algae currently placed inside Bangiales was the now-deprecated genus '' Phyllona'' by botanist John Hill in 1773. Bangiales itself was first categorized by Carl Nägeli in 1847. However, Bangiaceae had been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungi
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] |
Ascomycota
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus" (), a microscopic sexual reproduction, sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are Asexual reproduction, asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, yeast#Beer, brewers' and bakers' yeast, Xylaria, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens (loosely termed "ascolichens") such as ''Cladonia'' belong to the Ascomycota. Ascomycota is a monophyletic group (containing all of the descendants of a common ancestor). Previously placed in the Basidiomycota along with asexual species from other fungal taxa, asexual (or Teleomorph, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basidiomycota
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basidiomycota includes these groups: agarics, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi, boletes, chanterelles, earth stars, smuts, bunts, rusts, mirror yeasts, and '' Cryptococcus'', the human pathogenic yeast. Basidiomycota are filamentous fungi composed of hyphae (except for basidiomycota-yeast) and reproduce sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores (usually four). These specialized spores are called basidiospores. However, some Basidiomycota are obligate asexual reproducers. Basidiomycota that reproduce asexually (discussed below) can typically be recognized as members of this division by gross similarity to others, by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synarthrophyton
''Synarthrophyton'' is a genus of thalloid red algae comprising eight species. The monomerous, crustose thalli are composed of a single system of filaments which grow close to the underlying surface. ''Synarthrophyton'' reproduces by means of flask-shaped multiporate conceptacle Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational ...s; it produces tetraspores and dispores. Mucus plugs the opening of young conceptacles, which open as they mature. Species The valid species currently considered to belong to this genus are: *''S. chejuensis'' *''S. eckloniae'' *''S. magellanicum'' *''S. munimentum'' *''S. patena'' *''S. robbenense'' *''S. schielianum'' *''S. schmitzii'' References * Corallinaceae Red algae genera {{red alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phymatolithon
''Phymatolithon'' is a genus of non geniculate coralline red algae, known from the UK, and Australia. It is encrusting, flat, and unbranched; it has tetrasporangia and bisporangia borne in multiporate conceptacle Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational ...s. Some of its cells bear small holes in the middle; this distinctive thallus texture is termed a "''Leptophytum''-type" thallus surface, and has been posited as a taxonomically informative character. It periodically sloughs off its epithallus, reducing its overgrowth by algae by as much as 50% compared to bare rock. References Red algae genera Corallinales {{Rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
