Molecular Biology of Parasitic ProtozoaProtozoans are interesting creatures for several reasons, not least of which is their ability to live inside or among the cells of their host while resisting the host's cellular defenses. The rigors of their lifestyle have resulted in the evolution of some remarkable adaptations at the biochemical level; many parasites have dispensed with entire metabolic pathways, and have evolved complex mechanisms for transmission to new hosts. Parasitic protozoa