Noun
cyanobacterium (plural cyanobacteria)
(biology) Any of very many photosynthetic prokaryotic microorganisms, of phylum Cyanobacteria, once known as blue-green algae.
A cell must have captured a photosynthetic cyanobacterium and failed to digest it. Source: Internet
Both the chloroplast and cyanobacterium depicted are idealized versions (the chloroplast is that of a higher plant )—a lot of diversity exists among chloroplasts and cyanobacteria. Source: Internet
Paulinella chromatophora is a freshwater amoeboid which has recently (evolutionarily speaking) taken on a cyanobacterium as an endosymbiont. Source: Internet
Primary endosymbiosis Primary endosymbiosis Primary endosymbiosis A eukaryote with mitochondria engulfed a cyanobacterium in an event of serial primary endosymbiosis, creating a lineage of cells with both organelles. Source: Internet
He could not even have known all of the sources of photosynthesis: for example the cyanobacterium Prochlorococcus —which accounts for more than half of marine photosynthesis—was not discovered until 1986. Source: Internet
Notice the inclusion of the cyanobacterium Nostoc with plants. Source: Internet