Which one of the following diseases is caused by protozoans?
(a) Malaria
(b) Influenza
(c) AIDS
(d) Cholera

Correct Answer: (a) Malaria

Explanation:

Plasmodium, a microscopic-single celled protozoan organism, is responsible for causing malaria. The female Anopheles mosquito is the carrier of Plasmodium and spreads malaria from one person to another. Plasmodium reproduces by the asexual method of reproduction known as multiple fission.