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Spermatozopsis Exsultans
''Spermatozopsis'' is a genus of green algae in the class Chlorophyceae. It is found in freshwater habitats; it is widespread but not common. ''Spermatozopsis'' consists of single, flagellated cells. Cells are 7–10(–12) μm wide long and 2–4 μm long, fusiform, curved (one side convex, the other side concave) and sometimes twisted. The anterior of the cell has two or four flagella, which are longer than the cell, with two contractile vacuoles near the base of the flagella. The cell has a single parietal chloroplast along the convex side of the cell with a stigma, lacking a pyrenoid. Asexual reproduction occurs by longitudinal binary fission. ''Spermatozopsis'' swims with in a spiral motion, with its anterior in the front and its flagella oriented backwards. Cells can also jerk backwards by pushing their flagella forwards. ''Spermatozopsis'' is able to produce microbial cysts, which are globose with several parietal chloroplasts. Motile cells are able to withstand temperat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrenoid
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''Annu. Rev. Plant Biol.'', 56, 99-131. and in a single group of land plants, the hornworts.Villarreal, J. C., & Renner, S. S. (2012) Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years. ''Proceedings of the National Academy of Sciences'',109(46), 1873-1887. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2-rich environment around the photosynthesis, photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonadales Genera
Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae.See the NCBIbr>webpage on Chlamydomonadales Data extracted from the Chlamydomonadales can form planar or spherical colonies. These vary from '' Gonium'' (four to 32 cells) up to '' Volvox'' (500 cells or more). Each cell has two flagella, and is similar in appearance to ''Chlamydomonas'', with the flagella throughout the colony moving in coordination. Both asexual and sexual reproduction occur. In the former, cells divide until they form new colonies, which are then released. In the smaller forms, typically all cells are involved, but larger forms have anterior vegetative and posterior reproductive cells. Sexual reproduction varies from isogamy (both genders produce flagellated gametes of equal size) to oogamy (one gender produces a much larger, nonmotile gamete). The classification of the Chlamydomonadales varies. Very often they are taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunaliella
''Dunaliella'' is a single-celled, photosynthetic Green algae, green alga, that is characteristic for its ability to outcompete other organisms and thrive in Hypersaline lake, hypersaline environments. It is mostly a marine organism, though there are a few freshwater species that tend to be more rare. It is a genus in which certain species can accumulate relatively large amounts of β-carotenoids and glycerol in very harsh growth conditions consisting of high light intensities, high salt concentrations, and limited oxygen and nitrogen levels, yet is still very abundant in lakes and lagoons all around the world. It becomes very complicated to distinguish and interpret species of this genus on simply a morphology (biology), morphological and physiological level due to the organism's lack of cell wall that allows it to have malleability and change shape and its different biological pigment, pigments that allows it to change colours depending on the environmental conditions. Molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeropleales
Sphaeropleales is an order of green algae that used to be called Chlorococcales. The order includes some of the most common freshwater plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...ic algae such as '' Scenedesmus'' and '' Pediastrum''. The Sphaeropleales includes vegetatively non-motile unicellular, colonial , or filamentous taxa. They have biflagellate zoospores with flagella that are directly opposed in direction (the DO arrangement): '' Sphaeroplea'', '' Atractomorpha'', '' Neochloris'', '' Hydrodictyon'', and '' Pediastrum''. All of these taxa have basal body core connections. Motile cells generally lack cell walls or have only a very fine layer surrounding the cell membrane. Other common characteristics include a robust vegetative cell wall, cup-shaped ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenomic
Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields of phylogenetics and genomics. Phylogenomics draws information by comparing entire genomes, or at least large portions of genomes. Phylogenetics compares and analyzes the sequences of single genes, or a small number of genes, as well as many other types of data. Four major areas fall under phylogenomics: * Prediction of gene function * Establishment and clarification of evolutionary relationships * Gene family evolution * Prediction and retracing lateral gene transfer. The ultimate goal of phylogenomics is to reconstruct the evolutionary history of species through their genomes. This history is usually inferred from a series of genomes by using a genome evolution model and standard statistical inference methods (e.g. Bayesian inference or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinoflagellate
The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also common in freshwater habitats. Their populations vary with sea surface temperature, salinity, and depth. Many dinoflagellates are photosynthetic, but a large fraction of these are in fact mixotrophic, combining photosynthesis with ingestion of prey ( phagotrophy and myzocytosis). In terms of number of species, dinoflagellates are one of the largest groups of marine eukaryotes, although substantially smaller than diatoms. Some species are endosymbionts of marine animals and play an important part in the biology of coral reefs. Other dinoflagellates are unpigmented predators on other protozoa, and a few forms are parasitic (for example, '' Oodinium'' and '' Pfiesteria''). Some dinoflagellates produce resting stages, called dinoflagellate cys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyespot Apparatus
The eyespot apparatus (or '' stigma'') is a photoreceptive organelle found in the flagellate or (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids. It allows the cells to sense light direction and intensity and respond to it, prompting the organism to either swim towards the light (positive phototaxis), or away from it (negative phototaxis). A related response ("photoshock" or photophobic response) occurs when cells are briefly exposed to high light intensity, causing the cell to stop, briefly swim backwards, then change swimming direction. Eyespot-mediated light perception helps the cells in finding an environment with optimal light conditions for photosynthesis. Eyespots are the simplest and most common "eyes" found in nature, composed of photoreceptors and areas of bright orange-red red pigment granules. Signals relayed from the eyespot photoreceptors result in alteration of the beating pattern of the flagella, generating a photo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatozopsis Similis
''Spermatozopsis'' is a genus of green algae in the class Chlorophyceae. It is found in freshwater habitats; it is widespread but not common. ''Spermatozopsis'' consists of single, flagellated cells. Cells are 7–10(–12) μm wide long and 2–4 μm long, fusiform, curved (one side convex, the other side concave) and sometimes twisted. The anterior of the cell has two or four flagella, which are longer than the cell, with two contractile vacuoles near the base of the flagella. The cell has a single parietal chloroplast along the convex side of the cell with a stigma, lacking a pyrenoid. Asexual reproduction occurs by longitudinal binary fission. ''Spermatozopsis'' swims with in a spiral motion, with its anterior in the front and its flagella oriented backwards. Cells can also jerk backwards by pushing their flagella forwards. ''Spermatozopsis'' is able to produce microbial cysts, which are globose with several parietal chloroplasts. Motile cells are able to withstand temperat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the Radiant energy, energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
