Airborne microorganisms can travel on which types of particles?

Airborne microorganisms primarily travel on particles that can remain suspended in the air for extended periods. Dust and water droplets are two significant carriers of these microorganisms.

Dust particles can include a variety of materials, such as soil, skin cells, and other organic matter, which can harbor bacteria, viruses, and spores. When dust is lifted into the air, any pathogens attached to it can become airborne and potentially infect individuals who inhale them.

Water droplets, especially those produced during activities such as coughing, sneezing, or even from aerosol-generating procedures, can also carry microorganisms. These droplets are a common transmission route for various infectious diseases, as they can easily be inhaled or settle on surfaces.

The other options presented do not accurately represent the primary modes of airborne transmission. While gases and moist air might create environments conducive to the spread of certain pathogens, it's the solid and liquid particulates—specifically dust and water droplets—that serve as the actual vehicles for airborne microorganisms.