Question

Harmful and useful effects of
Protozoa.​

Answer 1

Useful protozoans:

1. Protozoans serve as food for many small aquatic organisms. Zooplankton are tiny protozoans which live in the sea. They form the principal diet of blue whales, who gulp them in with sea water.

2. They are the ultimate decomposers in nature, as they feed on bacteria and fungi, which decompose dead organic matter. They are, thus, useful in the treatment of sewage.

3. Some protozoans live in the body of other organisms and help them. Termites, for example, have protozoans living in their body. The protozoans digest the cellulose in the wood eaten by termites and convert it into carbohydrates that the termites can use.

Harmful protozoans:

1.Some protozoans cause diseases. The protozoan Endamoeba histolytica causes amoebiasis (amoebic dysentery) in human beings, Giardia causes giardiasis (dysentery), while Plasmodium causes malaria. trypanosome, a parasitic protozoan which lives in the bloodstream of human beings, cattle and other animals, causes a dangerous disease called sleeping sickness.

Answer 2

Answer:

Explanation:

usefulness of protozoa is they are th ebest decomposers in nature they feed on bacteria and fungi which decomposes the dead matter. they are useful in sewage treatment

harmfulness is they can cause diseases like one protozoa parasite living in the bloodstrems of human beings and animals and other living organisms can cause a disease named as sleep sickness