Could not find any links for specified country. Please check back later. Xylem is the world leader in tough, portable and reliable pumps for multiple applications. Our broad product range in combined with extensive application experience ensure the right solution that meets your specific needs. Submersible pumps can handle small drainage jobs to larger dewatering projects.
An obligate parasite, or holoparasite, is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce.
On this Page. A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites. Protozoa. Protozoa are microscopic, one-celled organisms that can be free-living or parasitic in nature. They are able to multiply in humans, which contributes to their survival and also permits serious infections to develop from just a single organism. Transmission of protozoa that live in a human's intestine to another human typically occurs through a fecal-oral route (for example, contaminated food or water or person-to-person contact).