Microorganisms are typically and consist of bacteria, viruses, fungi, and protozoa.

Answer;

Single celled.

Microorganisms are typically single-celled and consist of bacteria, viruses, fungi, and protozoa.

Explanation;

-Microorganisms or microbes is an organism that are microscopic and can not be seen with a naked eye. Microorganisms are usually single-celled, or unicellular organisms; however, some unicellular protists are visible to the naked eye, and some multicellular species are microscopic.

Microorganism mainly consist of bacteria, viruses, fungi and protozoa.

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.