Descriptive of a class of protozoan parasites that pass part of their life cycles in mammalian cells, e.g. the malaria pathogen Plasmodium falciparum, and which contain in their apices organelles that assist penetration of host cells. Also characteristic are the apicoplast, an organelle which contains maternally-inherited circular DNA, possibly of green algal evolutionary origin, and enzymes of the C6C3 metabolic pathway.