Microbiology
Microbiology (from Greek , "mīkros", "small"; , "bios", "life"; and , "-logia") is the study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, parasitology, mycology and bacteriology.
Transmission (medicine)
The mode of transmission is also an important aspect of the biology of beneficial microbial symbionts, such as coral-associated dinoflagellates or human microbiota. Organisms can form symbioses with microbes transmitted from their parents, from the environment or unrelated individuals, or both.