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.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

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