Algae's complex origins

Abstract

(Eukaryotes are organisms with nucleated cells, such as animals, plants and fungi, whereas cyanobacteria are prokaryotes, whose cells do not have a nucleus or other membrane-bound organelles.) This fateful encounter is called the primary endosymbiosis (Fig. 1a), because it led to all plastids known today. Many extant protist groups display organellar evidence of secondary endosymbiotic events, such as the dinoflagellates (the cause of red tides) and the apicomplexa (parasitic organisms that include the Plasmodium species that cause malaria).