Editing Chlorophyta (section)

=== Classification ===
{{Multiple image|perrow=2|total_width=330
| image1 = Tetraselmis suecica in a vegetative non-motile stage 01.jpg
| caption1 = ''Tetraselmis suecica'' (Chlorodendrophyceae)
| image2 = Volvox_aureus.jpg
| caption2 = ''Volvox aureus'' (Chlorophyceae)
| image3 = Chloropicon sieburthii LM A2.png
| caption3 = ''Chloropicon sieburthii'' (Chloropicophyceae)
| image4 = Deposition velocity versus cell diameters-6.jpg
| caption4 = ''Micromonas pusilla'' (Mamiellophyceae)
| image5 = Nephroselmis_olivacea,_Stein_(1878),_plate_19_cropped.jpg
| caption5 = ''Nephroselmis olivacea'' (Nephroselmidophyceae)
| image6 = Mantoniella tinhauana fmicb-15-1358574-g003.jpg
| caption6 = ''Mantoniella tinhauana'' (Pedinophyceae)
| image7 = Picocystis_salinarum.jpg
| caption7 = ''Picocystis salinarum'' (Picocystophyceae)
| image8 = Pyramimonas longicauda 1.jpg
| caption8 = ''Pyramimonas longicauda'' (Pyramimonadophyceae)
| image9 = Coccomyxa polymorpha.png
| caption9 = ''Coccomyxa polymorpha'' (Trebouxiophyceae)
| image10 = Sea_lettuce_in_Brofjorden_1_-_cropped.jpg
| caption10 = ''Ulva lactuca''{{Br}}(Ulvophyceae)
| header = {{Small|Representatives of all living classes of chlorophytes}}
}}
Currently eleven chlorophyte classes are accepted, here presented in alphabetical order with some of their characteristics and [[biodiversity]]:

* [[Chlorodendrophyceae]] (60 species, 15 extinct):{{Sfn|Guiry|2024|p=5}} unicellular [[flagellate]]s (monadoids) surrounded by an outer cell covering or [[theca]] of organic extracellular scales composed of [[protein]]s and ketosugars. Some of these scales make up hair-like structures. Capable of [[asexual reproduction]] through cell division inside the theca. No [[sexual reproduction]] has been described. Each cell contains a single chloroplast and exhibits two [[flagella]]. Present in marine and freshwater habitats.{{Sfn|Hori|Norris|Chihara|1986}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}{{Sfn|Graham|Graham|Wilcox|Cook|2022|p=17-2}}

* [[Chlorophyceae]] (3,974 species):{{Sfn|Guiry|2024|p=5}} either unicellular monadoids (flagellated) or [[wikt:coccoid|coccoid]]s (without flagella) living solitary or in varied colonial forms (including [[coenocyte|coenobial]]), or [[multicellular]] filamentous (branch-like) [[thalli]] that may be ramified, or foliose (leaf-like) thalli. Cells are surrounded by a crystalline covering composed of [[glycoprotein]]s abundant in [[glycine]] and [[hydroxyproline]], as well as [[pectin]]s, [[arabinogalactan protein]]s, and [[extensin]]. They exhibit a [[Biological_life_cycle#Haplontic_life_cycle|haplontic life cycle]] with [[isogamy]], [[anisogamy]] or [[oogamy]]. They are capable of asexual reproduction through flagellated [[zoospore]]s, [[aplanospore]]s, or [[autospore]]s. Each cell contains a single chloroplast, a variable number of [[pyrenoid]]s (including lack thereof), and from one to hundreds of flagella without [[mastigoneme]]s. Present in marine, freshwater and terrestrial habitats.{{Sfn|Domozych|Ciancia|Fangel|Mikkelsen|2012}}{{Sfn|Leliaert|Smith|Moreau|Herron|2012}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=36–37}}{{Sfn|Graham|Graham|Wilcox|Cook|2022|p=19-2–19-5}}

* [[Chloropicophyceae]] (8 species):{{Sfn|Guiry|2024|p=5}} unicellular solitary coccoids. Cells are surrounded by a multi-layered [[cell wall]]. No sexual or asexual reproduction has been described. Each cell contains a single chloroplast with [[astaxanthin]] and [[loroxanthin]], and lacks pyrenoids or flagella. They are exclusively marine.{{Sfn|Lopes dos Santos|Pollina|Gourvil|Corre|2017}}

* [[Chuariophyceae]] (3 extinct species): exclusively fossil group containing carbonaceous megafossils found in [[Ediacaran]] rocks, such as ''[[Tawuia]]''.{{Sfn|Guiry|2024|p=5}}{{Sfn|Srivastava|2002}}

* [[Mamiellophyceae]] (25 species):{{Sfn|Guiry|2024|p=5}} unicellular solitary monadoids. Cells are naked or covered by one or two layers of flat scales, mainly with spiderweb-like or reticulate ornamentation. Each cell contains one or rarely two chloroplasts, almost always with [[prasinoxanthin]]; two equal or unequal flagella, or just one flagellum, or lacking any flagella. If flagella are present, they can be either smooth or covered in scales in the same manner as the cells. Present in marine and freshwater habitats.{{Sfn|Marin|Melkonian|2010}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}

* [[Nephroselmidophyceae]] (29 species):{{Sfn|Guiry|2024|p=5}} unicellular monadoids. Cells are covered by scales. They are capable of sexual reproduction through [[hologamy]] (fusion of entire cells), and of asexual reproduction through [[binary fission]]. Each cell contains a single cloroplast, a pyrenoid, and two flagella covered by scales. Present in marine and freshwater habitats.{{Sfn|Nakayama|Suda|Kawachi|Inouye|2007}}{{Sfn|Yamaguchi|Suda|Nakayama|Pienaar|2010}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}

* [[Pedinophyceae]] (24 species):{{Sfn|Guiry|2024|p=5}} unicellular asymmetrical monadoids that undergo a coccoid palmelloid phase covered by [[mucilage]]. Cells lack extracellular scales, but in rare cases are covered on the posterior side by a theca. Each cell contains a single chloroplast, a pyrenoid, and a single flagellum usually covered in mastigonemes. Present in marine, freshwater and terrestrial habitats.{{Sfn|Marin|2012}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}{{Sfn|Graham|Graham|Wilcox|Cook|2022|p=17-3}}

* [[Picocystophyceae]] (1 species):{{Sfn|Guiry|2024|p=5}} unicellular coccoids, ovoid and trilobed in shape. Cells are surrounded by a multi-layered cell wall of poly-[[arabinose]], [[mannose]], [[galactose]] and [[glucose]]. No sexual reproduction has been described. They are capable of asexual reproduction through autosporulation, resulting in two or rarely four daughter cells. Each cell contains a single bilobed chloroplast with diatoxanthin and monadoxanthin, without any pyrenoid or flagella. Present in [[saline lake]]s.{{Sfn|Lewin|Krienitz|Goericke|Takeda|2000}}{{Sfn|Lopes dos Santos|Pollina|Gourvil|Corre|2017}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}

* [[Pyramimonadophyceae]] (166 species, 59 extinct):{{Sfn|Guiry|2024|p=5}} unicellular monadoids or coccoids. Cells are covered by two or more layers of organic scales. No sexual reproduction has been described, but some cells with only one flagellum have been interpreted as potential gametes. Asexual reproduction has only been observed in the coccoid forms, via zoospores. Each cell contains a single chloroplast, a pyrenoid, and between 4 and 16 flagella. The flagella are covered in at least two layers of organic scales: a bottom layer of pentagonal scales organized in 24 rows, and a top layer of limuloid scales distributed in 11 rows. They are exclusively marine.{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=37}}{{Sfn|Daugbjerg|Fassel|Moestrup|2020}}

* [[Trebouxiophyceae]] (926 species, 1 extinct):{{Sfn|Guiry|2024|p=5}} unicellular monadoids occasionally without flagella, or colonial, or ramified filamentous thalli, or living as the [[photobiont]]s of [[lichen]]. Cells are covered by a cell wall of [[cellulose]], [[algaenan]]s, and β-galactofuranane. No sexual reproduction has been described with the exception of some observations of gamete fusion and presence of [[meiosis|meiotic]] [[gene]]s. They are capable of asexual reproduction through autospores or zoospores. Each cell contains a single chloroplast, a pyrenoid, and one or two pairs of smooth flagella. They are present in marine, freshwater and terrestrial habitats.{{Sfn|Domozych|Ciancia|Fangel|Mikkelsen|2012}}{{Sfn|Fučíková|Pažoutová|Rindi|2015}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=36}}{{Sfn|Graham|Graham|Wilcox|Cook|2022|p=17-4–17-11}}

* [[Ulvophyceae]] (2,695 species, 990 extinct):{{Sfn|Guiry|2024|p=5}} macroscopic thalli, either filamentous (which may be ramified) or foliose (composed of monostromatic or distromatic layers) or even compact tubular forms, generally [[multinucleate]]. Cells surrounded by a cell wall that may be [[Marine biogenic calcification|calcified]], composed of cellulose, β-manane, β-xilane, sulphated or piruvilated polysaccharides or sulphated ramnogalacturonanes, arabinogalactan proteins, and extensin. They exhibit a [[Biological_life_cycle#Haplodiplontic_life_cycle|haplodiplontic life cycle]] where the alternating generations can be isomorphic or heteromorphic. They reproduce asexually via zoospores that may be covered in scales. Each cell contains a single chloroplast, and one or two pairs of flagella without mastigonemes but covered in scales. They are present in marine, freshwater and terrestrial habitats.{{Sfn|Domozych|Ciancia|Fangel|Mikkelsen|2012}}{{Sfn|Adl|Bass|Lane|Lukeš|2019|p=36}}{{Sfn|Graham|Graham|Wilcox|Cook|2022|p=18-2–18-24}}