are photosynthetic organisms with both photosystems I and II, hence, evolves oxygen. Most cyanobactera have chlorophyll a only, but exciting new studies show that there are ecologically important members with both chorophylls a and b.
Recognize these genera
(recognize heterocysts and know their function).
What photosystems are found in heterocysts and how does this relate to nitrogen fixation?
Recognize a stromatolite as a fossil of the Cyanobacteria