Editing Chlorophyceae (section)

==Reproduction==
Chlorophyceae can reproduce both asexually and sexually. In [[asexual reproduction]], cells may produce [[autospore]]s, [[aplanospore]]s or [[zoospore]]s. Autospores (by definition) lack flagella and appear as smaller versions of vegetative cells. Zoospores typically have an elongate, hydrodynamic shape and often have [[eyespot apparatus|eyespots]]. Aplanospores are similar to zoospores in that they have characteristics typical of zoospores (such as [[contractile vacuole]]s), but lack flagella.<ref name=AlgaeBase>{{AlgaeBase genus|id= 43426 |title=''Chlorella'' Beyerinck [Beijerinck], 1890, nom. cons.|access-date=2025-01-14}}</ref>

In addition to normal asexual reproduction, some genera such as ''Chlamydomonas'' and ''Dunaliella'' can go through a temporary phase known as the "palmella stage", in which flagella are absent and the cells divide vegetatively within a common mucilaginous envelope.<ref>{{cite book|doi= 10.1007/978-94-017-7321-8_1|chapter= General Characteristics of Algae|title= The Algae World|series= Cellular Origin, Life in Extreme Habitats and Astrobiology|date= 2015|last1= Sahoo|first1= Dinabandhu|last2= Baweja|first2= Pooja|volume= 26|pages= 3–29|isbn= 978-94-017-7320-1}}</ref> Algae enter the palmella stage in response to stressful conditions, such as changes in salinity or predation.<ref>{{cite journal|doi=10.3389/fpls.2017.00810|doi-access=free |title=Salinity-Induced Palmella Formation Mechanism in Halotolerant Algae Dunaliella salina Revealed by Quantitative Proteomics and Phosphoproteomics |date=2017 |last1=Wei |first1=Sijia |last2=Bian |first2=Yangyang |last3=Zhao |first3=Qi |last4=Chen |first4=Sixue |last5=Mao |first5=Jiawei |last6=Song |first6=Chunxia |last7=Cheng |first7=Kai |last8=Xiao |first8=Zhen |last9=Zhang |first9=Chuanfang |last10=Ma |first10=Weimin |last11=Zou |first11=Hanfa |last12=Ye |first12=Mingliang |last13=Dai |first13=Shaojun |journal=Frontiers in Plant Science |volume=8 |page=810 |pmid=28588593 |pmc=5441111 }}</ref> Additionally, ''[[Haematococcus]]'' produces resistant stages with thick [[cell wall]]s, termed [[akinete]]s.<ref>{{cite journal|doi=10.4490/algae.2023.38.3.9 |title=The description of ''Haematococcus privus'' sp. nov. (Chlorophyceae, Chlamydomonadales) from North America |date=2023 |last1=Buchheim |first1=Mark A. |last2=Silver |first2=Ashley |last3=Johnson |first3=Haley |last4=Portman |first4=Richard |last5=Toomey |first5=Matthew B. |journal=Algae |volume=38 |pages=1–22 |doi-access=free }}</ref>

[[Sexual reproduction]] shows considerable variation in the type and formation of sex cells; it may be [[isogamous]] (with two morphologically identical gamete types), [[anisogamous]] (with two morphologically distinct gamete types), and [[oogamous]] (with larger, nonmotile eggs and smaller motile sperm cells). Members of Chlorophyceae that undergo sexual reproduction have a zygotic life cycle, in which the [[zygote]]s are the only [[diploid]] stages. Zygotes may have thick and/or spiny cell walls; these are called hypnozygotes and they also function as resting stages.<ref name=Graham/>
 
They share many similarities with higher plants, including the presence of asymmetrical flagellated cells, the breakdown of the nuclear envelope at mitosis, and the presence of phytochromes, flavonoids, and the chemical precursors to the cuticle.<ref>Raven, Evert and Eichhorn. ''The Biology of Plants'' 7th edition, pg. 335. W. H. Freeman and Company, New York, 2005.</ref> However, unlike higher plants they do not go through a multicellular [[alternation of generation]]s.<ref name=Graham/>