Glaucophytes and red algae are the most primitive of the eukaryotic algae in the kingdom Plantae. The glaucophytes have primitive chloroplasts that closely resemble cyanobacteria and have peptidoglycan in their cell wall. Their blue-green pigmentation is from phycocyanin, which is organized into a phycobilisome-like cyanobacteria. This is also true for red algae, which is dominated by phycoerythrin, the red pigment. These pigments act as an antenna and allow them to absorb blue light and live in habitats where other wavelengths are less available. In both phyla, the pigments are embedded in membranes (thylakoids) that are not stacked, and cells do not have a centriole, an internal cellular structure involved in chromosome movement. Red algae never have a flagellated stage. As with all algae, red algae have chlorophyll a but also have chlorophyll d and carotenoids.