Hexoidea are a major kingdom of multicellular, eukaryotic HDGTNA (Hexa Deoxyribo Glycerol Threose nucleic acid) based organisms. Their body plan becomes fixed as they develop, usually early on in their development as embryos, although some undergo a process of metamorphosis later on in their life. Many are motile. Hexoideans are both phototrophic and heterotrophic, but generally one or the other is dominant.
Hexoidea cells differ in several key respects from the cells of other eukaryotic organisms. Their distinctive features include a large central vacuole like centrosome, and a variety of plastids including chloroplast-, peroxisome-, mitochondria-, and lysosome -like organelles.
Some cells have a cell wall and some do not. In cases where it is present, the cell wall is composed of cellulose, chitin and silica. Wall cells have plasmodesmata through which the plasmalemma and endoplasmic reticulum of adjacent cells are continuous.
Wall cell division is via construction of a phragmoplast as a template for building a cell plate late in cytokinesis. Two groups of wall cells exist: fibres and sclereids. Wall cells are the principal supporting cells in most tissues. Most mature wall tissue is composed of dead cells with extremely thick cell walls (secondary walls) that make up to 90% of the whole cell volume.
Hexoidea consists of three simple phyla: hexoflagella, aculeatuschorionia, and aculeatusnebula.