Test: Microorganisms Friend & Foe- 3 - Class 8 MCQ

Both options (A) and (B) are correct.

• Option A: Malaria is caused by the protozoan Plasmodium and symptoms include fever and chills.
• Option B: Hepatitis B is caused by a virus and can lead to symptoms such as a swollen liver.

Option C is incorrect because cholera is caused by a bacterium, not a virus. Symptoms of cholera include vomiting and diarrhea.

Fermentation takes place when yeast is added to grape juice and left for a week.

A virus is in the average smaller than a bacteria and unicellular algae are more or less in the same size domain as bacteria but more commonly algae are multicellular and hence larger.

The release of carbon dioxide gas causes dough to rise when yeast is added to it. (Fermentation)

In the given figure W - virus, X - fungus and Y - protozoan.

If a piece of bread is kept in a container in a moist place for two to three days, some light type of hairy growth may happen on the surface. It is generally referred to as the bread mold. It is a kind of fungus. The absence of light and moist temperature favour the growth of the fungus.