Yawns are more contagious among people with closer relationships.
163
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Every year your body replaces 98% of your atoms.
119
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human body contains over a billion miles of DNA.
147
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18