Microorganisms, also known as microorganisms, are microscopic organisms that can be found in all environments. They include BACTERIA, viruses, fungi, protozoa, and archaea. The crossword solutions for the term microorganism include BUG (3 letters), BACTERIA (8 letters), MICROBE (7 letters), BACTERIUM (9 letters), AEROBE (6 letters), GERM (4 letters), VIRUS (5 letters), and PATHOGEN (8 letters). BACTERIA are single-celled organisms that can be found in soil, water, and air, and can cause disease. Viruses are small infectious agents that can cause a variety of diseases. Fungi are multicellular organisms that can cause infections and allergies. Protozoa are single-celled organisms that can cause diseases such as malaria and amoebic dysentery. Archaea are single-celled organisms that can survive in extreme environments. Pathogens are microorganisms that can cause disease. Finally, germs are microorganisms that can cause infection.