What is the average length of a single cell in micrometers (um)?

How many cells are our body made of ? ♡

Amniocentesis is a process in which amniotic fluid is taken from the mother's womb to identify any genetic abnormalities in the fetus. how would the discovery of the human genome contribute to this process?

Some tools have graduations to show multiple measurements. for example, a ruler may have graduations for both millimeters and centimeters. when measuring the length of an earthworm, which graduations would allow for the most accurate measurement? millimeters centimeters decimeters meters