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Padina Japonica
''Padina japonica'' is a species of small brown alga found in the tropical and subtropical Indo-Pacific region. Description ''Padina japonica'' has a flat blade rolled into a circle. The upper surface is whitish while the underside is brown. It is similar to '' Padina australis'' but rather smaller and the blade is usually unsplit. Another very similar species is '' Padina sanctae-crucis''; the underside of the latter is more highly calcified, the oogonia and the tetrasporangia Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ... are large and globular rather than small and oblong, and there is a single row of tetrasporangial sori rather than the multiple irregular rows of ''P. japonica''. References {{Taxonbar, from=Q29890181 Dictyotaceae Protists described in 1931 Brown alg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Padina Australis
Padina may refer to: Geography In Bulgaria * Padina, Kardzhali Province * Padina, Silistra Province * Padina, Varna Province In Romania * Padina, Buzău, a commune in Buzău County * Padina, a village in Amărăști Commune, Vâlcea County * Padina, a tributary of the river Lotru in Vâlcea County * Padina Șirnii River, a headwater of the Padina Dâncioarei River, a headwater of the Dâmbovicioara River In Serbia * Padina (Kovačica), a Slovak-populated village in the region of Banat, Vojvodina * Padina (Merošina), a village in Nišava District * Padina (Belgrade), an urban neighborhood of Belgrade, in the municipality of Zvezdara As a part of the name In Antarctica * Kresnenska Padina, a depression in Perunika Glacier in eastern Livingston Island In Romania * Pădina Mare, a commune in Mehedinţi County, and its village of Pădina Mică In Serbia * Sunčana Padina, an urban neighborhood of Belgrade, in the municipality of Čukarica * Čukarička Padina Čukari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Padina Sanctae-crucis
''Padina sanctae-crucis'' is a species of brown macroalgae in the family Dictyotaceae. It is a tropical brown algae species native to the south pacific that belongs to the Padina genus. this alga includes sexual reproduction and spore-producing asexual reproduction which is moved with the tide until spores plants itself on a hard rocky substrate. Other habitats include rocks and shell fragments in the shallow sublittoral, seagrass meadows, mangrove roots and coral reefs on tidal flats. Description Padina sanctae-crucis forms curled, fanlike branches from a single stalk. The plant is about 15 cm tall. Blades are often irregularly split and branched. The upper surfaces of the fans are calcified and whitened, but the rest of the plant is brownish. All the branches are crossed by closely set growth lines. Locations Locations Padina sanctae-crucis prefers tropical waters and can be found in most of the world's tropical waters. Including Florida, the Caribbean sea, Brazil, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oogonium
An oogonium (plural oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in large numbers by mitosis early in fetal development from primordial germ cells. In humans they start to develop between weeks 4 and 8 and are present in the fetus between weeks 5 and 30. Structure Normal oogonia in human ovaries are spherical or ovoid in shape and are found amongst neighboring somatic cells and oocytes at different phases of development. Oogonia can be distinguished from neighboring somatic cells, under an electron microscope, by observing their nuclei. Oogonial nuclei contain randomly dispersed fibrillar and granular material whereas the somatic cells have a more condensed nucleus that creates a darker outline under the microscope. Oogonial nuclei also contain dense prominent nucleoli. The chromosomal material in the nucleu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrasporangia
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, 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. The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorus
A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient Greek σωρός (''sōrós'' 'stack, pile, heap'). Structure In lichens and other fungi, the sorus is surrounded by an external layer. In some red algae, it may take the form of depression into the thallus. In ferns, the sori form a yellowish or brownish mass on the edge or underside of a fertile frond. In some species, they are protected during development by a scale or film of tissue called the indusium, which forms an umbrella-like cover. Lifecycle significance Sori occur on the sporophyte generation, the sporangia within producing haploid meiospores. As the sporangia mature, the indusium shrivels so that spore release is unimpeded. The sporangia then burst and release the spores. As an aid to identification The shape, arrangemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictyotaceae
Dictyotaceae is large family (biology), family of brown algae (class Phaeophyceae). Members of this family generally prefer warmer waters than other brown algae. ''Lobophora variegata'' (= ''Pocockiella varieagata'') often presents a beautiful blue iridescence due to microscopic bacteria which live on the surface of the blades . A number of genera are known as forkweed (e.g. ''Dictyota'', ''Glosophora'', ''Dilophus'', ''Dictyopteris'', ''Pachydictyon'' and ''Lobospira''. References Further reading Algae Aquatic plants Brown algae families Dictyotaceae, Dictyotales Ochrophyta Plant families Plants described in 1822 Seaweeds {{Phaeophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protists Described In 1931
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a Common descent, common ancestor (the last eukaryotic common ancestor), the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like the groups ''algae'', ''invertebrates'', and ''protozoans'', the biological category ''protist'' is used for convenience. Others classify any unicellular eukaryotic microorganism as a protist. The study of protists is termed protistology. History The Taxonomy (biology), classification of a third Kingdom (biology), kingdom separate from animals and plants was first proposed by John Hogg (biologist), John Hogg in 1860 as the kingdom Protoctista; in 1866 Ernst Haeckel also proposed a third kingdom Protista as "the k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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