Some members of the family Nostocaceae of these organisms are motile due to filamentous hormogonia, while heterocysts enable nitrogen fixation by members of this phylum.
These organisms, which produce the acetylcholine-like compound anatoxin-a, cycle through a dormant akinete cell stage. Some members of the family Nostocaceae of these organisms are motile due to filamentous hormogonia, while heterocysts enable nitrogen fixation by members of this phylum. Phycobilins are associated with their pigmentation, and their evolution has resulted in an oxidizing atmosphere. Endosymbiosis of these organisms is thought to be the source of chloroplasts, and these organisms account for the majority of photosynthesis in the ocean. Appearing in green algal blooms, for 10 points, identify this phylum of photosynthetic bacteria, also known as blue-green algae.
These organisms, which produce the acetylcholine-like compound anatoxin-a, cycle through a dormant akinete cell stage.
 cyanobacteria [or cyanophyta; or blue-green algae early]