Question

explain how protozoans are helpful as well as harmful to mankind​

Answer 1

Answer:

They do breathe, move, and reproduce like multi-celled animals. They live in water or at least where it is damp. Some protozoans are harmful to man because they can cause serious diseases. Others are helpful because they eat harmful bacteria and are food for fish and other animals.

Explanation:

mark me as brainliest

Answer 2

Advantages:

Ecological and industrial importance of protozoans. Protozoans play important roles in the fertility of soils. By grazing on soil bacteria, they regulate bacterial populations and maintain them in a state of physiological youth—i.e., in the active growing phase.

Disadvantages:

Protozoa make humans sick when they become human parasites. Trypanosoma protozoa cause Chagas disease and sleeping sickness. Giardia protozoa cause giardiasis, and Plasmodium protozoa cause malaria

Hope it helps you.......