The element is a clause if there is a subject and a verb, and it is a phrase if both of these parts of speech are not present. What comes after the introductory element is always an independent clause, or complete sentence, on its own, and the introductory element gives meaning to it.
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.
Parasitic infections can be caused by three types of organisms: protozoa, helminths, and ectoparasites. Protozoa are single-celled organisms that can live and multiply inside of humans. Some infections caused by protozoa include giardiasis.This is a serious infection that can happen from drinking water infected with the protozoa. Helminths are multi-celled organisms that can live alone or in humans. These are commonly known as worms and include flatworms, tapeworms, ringworms, and roundworms.arasitic infections can be caused by three types of organisms: protozoa, helminths, and ectoparasites. Protozoa are single-celled organisms that can live and multiply inside of humans. Some infections caused by protozoa include giardiasis.