The name proposed by T. Cavalier-Smith for a kingdom to contain those eukaryotic species that show the following specific ultrastructural similarities. They all posses, at some time during their life cycles, cells containing specialized undulopodia that have regularly spaced tufts of fibers extending from them. Such an undulopodium is often called a hairy or tinsel flagellum. The lateral fibers are called mastigonemes, and they are tubules that are rooted in the flagellar axonemes. The other organelle that characterizes the Chromista is the chloroplast ER. This refers to a chloroplast that is surrounded by four membranes, the last of which is continuous with the endoplasmic reticulum (q.v.). Species belonging to the phyla Chrysophyta, Cryptophyta, Xanthophyta, Eustimatophyta, Bacillanophyta, Phaeophyta, Labyrinthulomycota, Hypochytridiomycota, and Oomycota fall into this group. See Classification, Protoctista; Chrysophyta.
Subjects: Genetics and Genomics.