Question

Which one of the following diseases is caused by protozoans?
A. Malaria
B . Influenza
C. AIDS
D. Cholera

Answer 1

Hint: The diseases are caused by some causative agents in order to complete the life cycle. One of the diseases mentioned above is caused by a Protozoan Plasmodium sp.

Complete answer: The causative agents of diseases can be protozoans, bacteria, fungi or virus. It happens because of two reasons: either the agent requires another organism’s internal environment for completion of their reproductive cycle or life cycle, or they require the host organism for both metabolism and reproduction.
Let us find out which organisms or causative agents are responsible for the above-mentioned diseases.
Malaria is caused by a parasitic Protozoan Plasmodium sp. Different species of the organism may be responsible for other types of Malaria.
Influenza is caused by the Influenza virus. AIDS is caused by HIV (Human Immunodeficiency Virus) and the bacterium Vibrio cholerae causes cholera.

So, the correct option is A. Malaria

Note: Plasmodium vivax, Plasmodium falciparum and few other species can be responsible for Malaria. It is transmitted to humans by female Anopheles mosquito bites. Only five species of the protozoan can cause the disease, others cannot.