The measles virus, Morbillivirus, has a size of about $150\,\text{nm}$. Mimivirus is about $4.5$ times bigger than Morbillivirus, while Pandoravirus is about $1.5$ times bigger than Mimivirus. Which of these viruses can be observed with a light microscope that has a maximum resolution of $0.25\,\mu\text{m}$, and which can be observed with an electron microscope?
Biology 9700 · AS & A Level · The microscope in cell studies