* Virus: Viruses are the smallest, often measuring just a few nanometers (nm) in diameter. They are so small that they require an electron microscope to be seen.
* Bacteria: Bacteria are much larger than viruses, typically ranging from 0.5 to 10 micrometers (µm) in diameter. This means they are still microscopic but can be seen with a light microscope.
* Yeast Cell: Yeast cells are the largest of the three, generally measuring around 5 to 10 µm in diameter. Like bacteria, they can be seen with a light microscope.
To summarize:
Viruses < Bacteria < Yeast cells
