Practice question

SAR acronym denotes monophyletic megaassembly of three major protistan groups confirmed by multigene phylogenomic analyses and shared rare genomic characters: Stramenopiles also called heterokonts possessing tripartite tubular hairs on longer flagellum, Alveolates possessing cortical alveoli beneath plasma membrane, and Rhizaria extending filose pseudopodia for feeding and test formation. Stramenopiles include diatoms, brown algae, oomycetes; Alveolates include ciliates, apicomplexans, dinoflagellates; Rhizaria include foraminifera, radiolaria, cercozoans. Together SAR comprises greater than half of protist diversity, dominating marine plankton and benthic ecosystems ecologically and functionally.