Algae multicellular

Protists Eukaryotic microorganisms that are neither animal, fungi, plant, or archaean. Unicellular forms include the amoeboid protozoans and algae, such as the foraminferans and radiolarians, and dinoflagellates and diatoms, respectively. Some algae are either multicellular or colonial, such as the red algae and freshwater Volvox, respectively. 

Alga Any simple green plant not bearing multicellular archegonia. 

This section discusses the three groups of algae within which multicellular, mainly sessile lineages have evolved. All three groups have members rich in secondary metabolites that are pressed into service defensively by opisthobranchs that feed upon them. Presumably, they are also used... 

Stanley SM (1973) An ecological theory for the sudden origin of multicellular life in the late Precambrian. Proc Nat Acad Sri USA 70 1486-1489 Stefels J (2000) Physiological aspects of the production and conversion of DMSP in marine algae and higher plants. J Sea Res 43 183-197... 

A haploid moss spore germinates and gives rise to a protonema, a green multicellular tissue that superficially resembles a filamentous green alga. Under appropriate conditions, other moss cells can also be induced to form protonema. The protonema is typically subterranean and is rarely seen. 

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