The protists — the Phylum Chlorella
Chlorophyta is a phylum of the protists that contains about 8,000 species, most of which are aquatic photosynthetic eukaryotes. Like terrestrial plants (bryophytes and vascular plants), chlorella contains chlorophyll a and c and converts energy into starch in its pigment body. The phylum Green Algae and the Phylum Rotundifolia are associated with embryonic plants and are collectively called green plants.
This phylum contains both single-celled and multicellular species. Most species live in freshwater, many others live in seawater, and some others adapt to many environments, such as snow algae, which inhabit alpine snowfields in summer. Others are attached to rocks or trees. Some lichens and fungi have a symbiotic relationship with green algae, and the algae in the phylum of green algae will also form a symbiotic relationship with protozoa, sponges and spiny animals. Some will have flagella to facilitate movement, and some will perform sexual reproduction such as homogeneous reproduction or heterogeneous reproduction.
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According to Guiry & Guiry's (2020) AlgaeBase database record, the sub-categories under this gate are as follows:
Chlorophytina Cavalier-Smith
Chlorodendrophyceae Massjuk
Chlorophyceae Wille
Pedinophyceae Moestrup
Trebouxiophyceae Friedl
Ulvophyceae K.R. Mattox & K.D. Stewart: The protophycea (only one member of the order Uluvophyceae) was incorporated into this order.
Chlorophyta classis incertae sedis
Chloropicophyceae Lopes dos Santos & Eikrem
Prasinophytina Round: Or subphylum Phylum Phylum
Mamiellophyceae Marin & Melkonian
Nephrophyceae Cavalier-Smith
Tautocystis (Pyramimonadophyceae)
Nephroselmidophyceae
Palmophyllophyceae Leliaert et al.)
Picocystophyceae Eikrem & Lopes dos Santos
Pseudoscourfieldiophyceae
Undefined taxa:
Prasinophyte clade VIIA
Prasinophyte clade VIIC
<h1 class="pgc-h-arrow-right" data-track="26" >2. morphological characteristics</h1>
This phylum contains both single-celled and multicellular species. Most species live in freshwater, many others live in seawater, and some species are adapted to many environments, such as snow algae, which live in alpine snowfields in summer. Others are attached to rocks or trees. Some lichens and fungi have a symbiotic relationship with green algae, and the algae in the phylum of green algae will also form a symbiotic relationship with protozoa, sponges and spiny animals. Some will have flagella to facilitate movement, and some will perform sexual reproduction such as homogeneous reproduction or heterogeneous reproduction.
Key features:
(1) Photosynthetic pigments are chlorophyll a and b; and β carotene and several luteins;
(2) The stored food is mainly starch;
(3) In the life history, swimming cells with apical growth, mostly 2 to 4, iso-long flagella;
(4) Sexual reproduction is very common, and it is homophile, heterogeneous or egg matching. Algae have various types such as single cells, populations, filaments, phylloids, tubular polynuclear bodies, etc.
There are about 8600 species in this gate, which are distributed from the poles to the equator and from high mountains to flat land. The vast majority of species are produced in freshwater, a few are produced in seawater, both planktonic and fixed, parasitizing and causing plant diseases; in addition, there are aerophytic species, some symbiotic with green hydra, and a few species parasitic or symbiotic with fungi to form lichens.
There are 3 types:
(1) Haploid algal body type, in the life history only zygotes are doubled, zygotes undergo meiosis when germination; there are many green algae of this type, such as Chlamydia;
(2) Diploid algal body type, only gametes are haplotic in life history, meiosis is only carried out when gametes are formed; there are very few examples of this type, such as umbelliferous. Neither of the above types has a generational alternation;
(3) The algal body type of diploid or haploid, this type of green algae has generational alternation, that is, in the history of life, sexual generations and asexual generations alternate: the plant body of the sexual generation is the gametophyte, which produces haplotypes; Gametes combine to become double zygotes; zygotes develop into asexual generations of plant bodies, namely spores, producing spores; meiosis proceeds in the process of producing spores; spores develop into gametosomes, and so on. There are many green algae that fall into this type, such as lychee.
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There are single-celled, population or multicellular; population-defined or amorphous; multicellular individuals are spherical, branched and unbranched filamentous, flattened leaves, cup-shaped and empty tubes; with very few exceptions, vegetative cells of green algae mostly have cell walls, the outer layer of the cell wall is pectin, and the inner layer is fibrous; the cell walls of the genus Bristolites, Sphingospira and Sphingosum are also chitin, and the innermost layer of the cell wall of the order Pinus is composed of callosum; usually has 1 to more nucleus, with vacuoles.
In some populations, algae have obvious intercellular filaments; each vegetative cell has 1 to several pigment bodies, and the shape of the pigment body is diverse, such as cup-shaped, star-shaped, band-like, flaky, reticular, granular, etc.; the vast majority of species of vegetative cells contain 1 to more protein nuclei, a few species do not; swimming cells have 2, 4 or more equal-length flagella.
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In freshwater and seawater, marine species account for about 10 per cent and freshwater species about 90 per cent. Some species live exclusively in seawater, such as Sphingos algae and Bistral algae. Lycaenidae and Bulbophyllum are dominant marine species. Filamentosa is predominantly freshwater species, and many other species live in semi-brackish water. Marine species are mostly distributed along the ocean coast and often attach to rocks in shallow water above 10 meters. Many seafood species have a certain geographical distribution, which is determined by the temperature of the water. Freshwater species are widely distributed, in rivers, lakes, ditches, puddles, on wet soil surfaces, on walls, on rocks, on tree trunks, around pots, and even on snow and ice. Many single-celled and swarm species float in water, but there are no floating green algae in seawater, and some green algae can also parasitize in animals or form lichens in symbiosis with fungi. Freshwater species in general are not limited by water temperature and are mostly distributed around the world.
Green algae is the largest of the algae plants, with about 350 genera and 5000-8000 species. It is divided into two classes, namely green algae and rotifers. China generally divides the green algae into 13 orders, namely clump algae, tetrasporos, chlorella, filamentous algae, hairy algae, lithophyllum, xicai, sheath algae, bristles, tube algae, tube algae, velvet and zygophyllum. There is only rotunda in the order Rotifera.
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< h1 class="pgc-h-arrow-right" data-track="45" >(1) for vegetative reproduction</h1>
Populations, filaments divide cells to increase the number of cells. Large groups and filaments are often broken by mechanical actions such as animal feeding and flowing water impact. Or because certain cells in the filament form spores or gametes, they break at empty cells after the gametes or spores are released. Or as a result of the expansion and separation of intercellular glial in filaments, short filaments of a single cell or several cells are formed (such as Stichococcus), and each small segment of the rupture can develop into a new algae. When some single-celled green algae encounter a bad environment, the cells divide many times to form a gum colony, and when the environment improves, each cell can develop into a new plant body.
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Zoospores or static spores may form. Zoospores have no walls and other structures similar to those of Chlamydomycetes. There is no difference between the cells that form zoospores and the cells that are ordinary vegetative. In some species of algae, all cells can produce zoospores, but not all cells of the population type of algae form zoospores at the same time. Some algae are limited to producing zoospores in certain cells. When zoospores are formed, intracellular protoplasts contract to form one zoospore, or divide to form multiple zoospores in numbers to the power of 2. Zoospores are mostly formed at night, released at dawn, or formed when the environment is abrupt. After the zoospores are released, they swim for a period of time, retract or shed their flagella, secrete a layer of walls, become a vegetative cell, and then develop into a new plant body. Some algae reproduce with static spores. Static spores have no flagella, cannot move, and have cell walls. There is another type of static spore, which is morphologically the same as that of a mother cell, called a prospore. In poor environmental conditions, cell protoplasts secrete thick walls, surround the protoplasts, and heal with the original cell walls, while accumulating a large amount of nutrients in the cell, forming thick-walled spores, and when the environment is suitable, they develop into new individuals.
<h1 class="pgc-h-arrow-right" data-track="49" >(3) sexual reproduction</h1>
Two germ cells combine to form zygotes, which germinate directly into new individuals, or form spores through meiosis and develop into new individuals. The combination of two gametes that are identical in shape, structure, size, and athleticity is called homogeneous reproduction. In terms of shape and structure, but the size and motility are different, the large and slow motor ability is the female gamete, the small and strong motor ability is the male gamete, the combination of the two gametes is called heterophilia reproduction. Gametes that are different in shape, size and structure, large and non-flagellar can not move the egg, small and flagella can move for the sperm, sperm, sperm-egg combination is called egg reproduction. Two gametes that do not have flagella can be deformed are combined, called joint reproduction.
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Tycopodium ( scientific name : Pyramimonadophyceae ) is a class of chlorophylla. The order Phyamimonadales is the order Tachylopodium.
Subordinate categories:
Palmophyllales
Prasinococcales
Pseudoscourfieldiales
Tycamorecetes Pyramimonadales
<h1 class="pgc-h-arrow-right" data-track="58" >(1) Tycopodae</h1>
Tylopodium ( scientific name : Pyramimonadales ) is an order of Tautomatostomycetes . The pattern for this purpose is Pyramimonas.
Subordinate Sections:
Polyblepharidaceae P.A. Dangeard, 1889
Tycaenidae Pyramimonadaceae Korshikov, 1938
<h1 class="pgc-h-arrow-right" data-track="63" >(2) Taucytocetes</h1>
Tautocystis ( scientific name : Pyramimonadaceae ) is a family of Taumes. The model genus of this family is Tamoytos (Pyramimonas).
underling:
Angulomonas Skvortzov, 1968
Coccopterum P.C.Silva
Cymbomonas J.Schiller, 1913
Halosphaera K.J.F.Schmitz, 1878
Kuzminia B.V.Skvortzov, 1957
Pocillomonas Stone Corner, 1926
Prasinochloris Belcher, 1966
Protoaceromonas Skvortzov, 1968
Protochroomonas Skvortzov, 1968
Tycopodium Pyramimonas Schmarda, 1849
Tasmanites E.T.Newton, 1875
Trichloridella P.C.Silva, 1970
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Nephroselmidophyceae ( scientific name : Nephroselmidophyceae ) is a class of chlorophyllians. The order Of the order Is Nephroselmidales.
Anticomonas
Argillamonas
Bipedinomonas
Fluitomonas
Hiemalomonas
Myochloris
Nephroselmis
Prototractomonas
Pseudopedinomonas
Sennia
Sinamonas
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