Radio 4 in Four - How does hair know how long to grow? - ÃÛÑ¿´«Ã½ Sounds

Radio 4 in Four - How does hair know how long to grow? - ÃÛÑ¿´«Ã½ Sounds
How does hair know how long to grow?
Explore why the hairs on your legs don't grow as long as the hairs on your head.