Bacteria are single celled microorganisms. They are simple, primitive and microscopic prokaryotic organisms. Fungi are non- green organisms. They cannot prepare their own food so they are known as heterotrophs. This note provides information about bacteria and fungi with its general characteristics, harmful effects, disease caused by it and control measures.
The virus was first discovered by a German scientist Adolf Meyer in 1886 A.D. The word virus is derived from the latin word (Latin, venum = poisonous fluid) meaning poison. Protozoans are acellular or unicellular organisms. This note provides information about virus and protozoa.