Editing Chlorella (section)

== Description ==
''Chlorella'' consists of small, rounded cells which are spherical, subspherical, or ellipsoidal, and may be surrounded by a layer of [[mucilage]]. The cells contain a single [[chloroplast]] which is parietal (lying against the inner side of the cell membrane), with a single [[pyrenoid]] that is surrounded by grains of starch.<ref name=AlgaeBase>{{AlgaeBase genus|id= 43426 |title=''Chlorella'' Beyerinck [Beijerinck], 1890, nom. cons.|access-date=2025-01-14}}</ref>

===Reproduction===
Reproduction occurs by the formation of [[autospore]]s; [[zoospore]]s or gametes are not known to be produced in ''Chlorella''.<ref name=AlgaeBase/> In autosporulation, the contents of the cell divide into two, four or sometimes eight [[protoplast]]s. Each daughter protoplast rounds off, and are liberated by the rupture of the parent cell wall. On release, each autospore grows to become a new individual.{{cn|date=February 2025}} The daughter cell may remain attached to the parent cell wall, thereby forming colonies of cells.<ref name=AlgaeBase/> The presence of [[sulphur]] in the culture medium is considered essential for cell division. It takes place even in the dark with sulphur alone as the source material but under light conditions nitrogen also required in addition.{{cn|date=February 2025}} Pearsall and Loose (1937)<ref name="Pearsall 1937">{{cite journal|vauthors=Pearsall WH, Loose L|title=The Growth of Chlorella Vulgaris in Pure Culture|journal=Proc Roy Soc B|date=1937 |volume=121 |issue=824 |pages=451–501 |url=https://royalsocietypublishing.org/doi/10.1098/rspb.1936.0075|doi=10.1098/rspb.1936.0075|access-date=2024-08-13|url-access=subscription}}</ref> reported the occurrence of motile cells in ''Chlorella''. Bendix (1964)<ref>{{cite journal|vauthors=Bendix S|title=Phenotypic Variability in Certain Chlorella pyrenoidosa Strains|journal=Phycologia|pages=84–92|volume=4|issue=2|date=1964-01-22|doi=10.2216/i0031-8884-4-2-84.1|bibcode=1964Phyco...4...84B }}</ref> also observed that ''Chlorella'' produces motile cells which might be gametes. These observations have an important bearing on the concept of the life cycle of ''Chlorella,'' which at present is considered to be strictly asexual in character.{{cn|date=February 2025}}

Asexual reproduction in ''Chlorella ellipsoides'' has been studied in detail and the following four phases have been observed during the asexual reproduction.
#Growth phase - During this phase the cells grow in size by utilizing the photosynthetic products.
#Ripening phase - In this phase the cells mature and prepare themselves for division.
#Post ripening phase - During this phase, each mature cell divides twice either in dark or in light. The cells formed in dark are known as dark to light phase, cells again grow in size.
#Division phase - During this phase the parent cell wall ruptures and unicells are released.{{cn|date=February 2025}}