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Prasinophyte
The prasinophytes are a group of unicellular green algae. Prasinophytes mainly include marine planktonic species, as well as some freshwater representatives.Sym, S. D. and Pienaar, R. N. 1993. The class Prasinophyceae. In Round, F. E. and Chapman, D. J. (eds) ''Progress in Phycological Research'', Vol. 9. Biopress Ltd., Bristol, pp. 281-376. The prasinophytes are morphologically diverse, including flagellates with one to eight flagella and non-motile (coccoid) unicells, as well as dormant or cyst stage phycoma. The cells of many species are covered with organic body scales; others are naked. Well studied genera include '' Ostreococcus'', considered to be the smallest (ca. 0.95 μm) free-living eukaryote, and '' Micromonas'', both of which are found in marine waters worldwide. Prasinophytes have simple cellular structures, containing a single chloroplast and a single mitochondrion. The genomes are relatively small compared to other eukaryotes (about 12 Mbp for '' Ostreococcus'' an ... [...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] |
Chlorodendrophyceae
Chlorodendrales are an order of green, flagellated, thecate, unicellular eukaryotes, within the green algae class Chlorodendrophyceae.See the NCBIbr>webpage on Chlorodendrales Data extracted from the Prasinophyceae are defined by their cellular scales which are composed of carbohydrates, and Chlorodendrales are unique within this group due to these scales forming a fused thecal wall. Cells of Chlorodendrales are completely covered in scales, which fuse around the cell body producing the theca, but remain individually separated on the flagella, of which there are typically four per cell. Species within Chlorodendrales live in both marine and fresh water habitats, occupying both benthic and planktonic food webs. Additionally, they are photoautotrophs, meaning they produce their own food through the conversion of sunlight into chemical energy. Habitat and ecology Species within Chlorodendrales are found in marine and freshwater ecosystems around the world, including locations such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloropicophyceae
Chloropicophyceae is a class of green algae in the division Chlorophyta that, along with Picocystophyceae, coincides with the traditional " prasinophyte clade VII". Chloropicophyceae has a single order, Chloropicales with a single family, Chloropicaceae. Description Members of this class are coccoid green cells, with a diameter of 1.5–4 μm, found in marine waters, with one nucleus, one mitochondrion, and one chloroplast surrounded by two membranes, containing starch grain; their single chloroplast has chlorophylls '' a'' and '' b''; they lack pyrenoid and flagella; and they have a layered cell wall. Their sexual reproduction is unknown. Taxonomy In total, this class contains eight newly described species, belonging to two genera. The taxonomy goes as follows: *Division Chlorophyta Reichenbach 1834 ** Class Chloropicophyceae Lopes dos Santos & Eikrem 2017 *** Order Chloropicales Lopes dos Santos & Eikrem 2017 **** Family Chloropicaceae Lopes dos Santos & Eikrem 2017 ***** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picocystophyceae
''Picocystis'' is a monotypic genus of green algae, the sole species is ''Picocystis salinarum''. It is placed within its own class, Picocystophyceae in the division Chlorophyta. Structure ''Picocystis salinarum'' cells under normal conditions have a spherical or oval shape. Their size ranges from 2 to 3 μm in diameter. Under conditions of nutrient depletion they appear to form a trillobe shape. This trillobe shape gives it the nickname Mickey Mouse, due to its appearance to the famous character's head. The general appearance resembles that of a standard green alga. The pigments are composed mainly from chlorophyll a and b and the carotenoids violaxanthin, alloxanthin, monadoxanthin, neoxanthin, lutein, diatoxanthin and zeaxanthin. The cell wall is mainly composed of polymers of the monosaccharide arabinose, polyarabinose. Habitat The species have been found in saline or hypersaline alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prasinodermophyta
The marine Prasinodermophyta are a proposed basal Viridiplantae clade, as sister of another clade comprising the Chlorophyta and the Streptophyta Streptophyta (), informally the streptophytes (, from the Greek ''strepto'' 'twisted', for the morphology of the sperm of some members), is a clade of plants. The composition of the clade varies considerably between authors, but the definition e .... It consists of the Prasinodermophyceae and the Palmophyllophyceae, and is informally called prasinodermophytes. They were previously considered to be a basal Chlorophyta clade, or part of the " prasinophytes". References Green algae phyla {{green alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micromonas
''Micromonas'' is a genus of green algae in the family '' Mamiellaceae''. ''Micromonas'' is a widespread prasinophyte alga that is very small in size, motile, and phototactic. Before characterization and naming of a second species, ''Micromonas commoda'' through genome analysis, ''Micromonas pusilla'' was considered to be the only species in the genus. This led to a disproportionate amount of research discussing a single species and the suggestion that it was the dominant photosynthetic picoeukaryote in some marine ecosystems. Unlike many marine algae, this single species was thought to be distributed widely in both warm and cold waters, but genome sequencing confirmed indications from single-gene studies that its global distribution really reflected presence of multiple species occupying different niches in the ocean. [...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] |
Trebouxiophyceae
The Trebouxiophyceae, also known as trebouxiophytes, are a class of green algae, in the division Chlorophyta. Members of this class are single-celled, colonial, or multicellular and are found in freshwater, terrestrial or marine habitats worldwide. Many taxa in the Trebouxiophyceae form symbiotic relationships with other organisms; in particular, the majority of phycobionts within lichens are trebouxiophytes. A number of taxa have also lost the ability to photosynthesize, and have evolved to become parasitic; examples include '' Prototheca'' and '' Helicosporidium''. Trebouxiophyceae was originally defined by ultrastructural characteristics, but is now generally circumscribed based on phylogenetics, particularly based on the 18S rDNA locus. As of 2024, Trebouxiophyceae contains 211 genera and about 925 species. Morphology Members of the Trebouxiophyceae are microscopic or macroscopic organisms which exist in a variety of forms: non-flagellate coccoid or elliptical single cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellate
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, several derivations of the term "flagellate" (such as " dinoflagellate" and " choanoflagellate") are more formally characterized. Form and behavior Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body. In some flagellates, flagella direct food into a cytostome or mouth, where food is ingested. Flagella role in classifying eukaryotes. Among protoctists and microscopic animals, a flagellate is an organism with one or more flagella. Some cells in other animals may be flage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term 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, 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 cell (biology), 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 . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagocytosis
Phagocytosis () is the process by which a cell (biology), cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a Multicellular organism, multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. The two main cells that do this are the Macrophages and the Neutrophils of the immune system. Where phagocytosis is used as a means of feeding and provides the organism part or all of its nourishment, it is called phagotrophy and is distinguished from osmotrophy, which is nutrition taking place by absorption. History The history of phag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
