Parasite biology is the study of organisms that live in or on another organism, known as a host, and rely on the host for their survival. Parasites can be unicellular or multicellular, and can cause a range of diseases in their hosts. Researchers in this field study various aspects of parasite biology, including their life cycles, modes of transmission, host-parasite interactions, and strategies for controlling and treating parasitic infections. This research is important for understanding the impact of parasites on human and animal health, as well as for developing effective strategies for preventing and treating parasitic diseases.