title: Absence of the pigments of photosystem II of photosynthesis in heterocysts of a blue-green alga.
mesh_terms: D002734:Chlorophyll / Q000032:analysis; D000458:Cyanobacteria / Q000378:metabolism*; D009586:Nitrogen Fixation; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D010860:Pigments, Biological / Q000032:analysis / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D010860:Pigments, Biological; D002734:Chlorophyll; D010100:Oxygen