EVERYDAY SCIENCE

Detailed explanation-1: -Generally, the size range of cells like egg cells, unusually large bacteria, some amoebas and squid nerve cells are of the range of 100 microns and these are visible to the naked eye. So, the correct answer is ‘100 micron’.

Detailed explanation-2: -So microns are small. It is interesting, however, that a particle that is just 10 microns in size can actually be seen by a human being with 20/20 vision without optical aid!

Detailed explanation-3: -Mycoplasma gallicepticum is the smallest cell. Mycoplasma’s size is 0.2–0.3 m. Mycoplasma are the smallest living organisms on the earth.

Detailed explanation-4: -They are typically 40–50 µm long, and their diameter varies from 0.5 to 4.0 µm, being smallest and most tightly packed at the center of the eye at the fovea.