Do protozoans that are parasites have more than one host?

Yes. Many of these parasites have more than one hosts. For example, Plasmodium is a protozoan that causes malaria, disease of the blood. Two hosts are involved in Plasmodium's life cycle--humans and a species of mosquitoes found in tropical areas. The disease spreads when a healthy mosquito bites a person with malaria, becomes infected, and then bites a healthy person. Symptoms of malaria include high fevers that alternate with severe chills. These symptoms can last for weeks, then disappear, only to reappear a few months later

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