Bacteria

which of these cells are you?

a drop of you under the microscope, counted on a lab tally: press you or bacteria for each cell, then weigh them

Counted the way Sender, Fuchs and Milo did in 2016, a 70 kg adult carries about 38 trillion bacteria and 30 trillion human cells, about 1.3 to 1, not the 10 to 1 still quoted from one 1972 estimate. 25 trillion of those human cells are red blood cells. By weight it is the other way round: all the bacteria together weigh about 0.2 kg, against about 46 kg of human cells. Nearly all of them live in the colon, and one trip to the toilet empties a quarter to a third of it, which can tip the count back to human. Each cell on the slide stands for 2 trillion.

Concepts: biology, scale.

An interactive you play with one thumb, on Wundr.