The kingdom Chromista, = Heterkonta (also known as Straminopiles or Chromalveolata) is characterised by the fact that the (unicellular) motile stages possess two flagella that are strongly different in shape and function. One is a simple whip flagellum that also is found in primitive fungi. The other is a dragging flagellum with complex structure, somewhat resembling a test tube brush. This second type is unique to the Heterkonta.
Most groups have photosynthic pigments and are autotrophic, like Bacillariophyceae (diatoms), Chrysophyceae (gold algae), Phaeophyceae (brown algae), Xanthophyceae (yellow-green algae); others lack pigments and are saprophytes or parasites, like the Oomycota (“water moulds”)