Wouldn’t it be wonderful if people who lost an arm or a leg or even a finger in an accident could simply grow another one in its place? Human beings can’t do this, but there are living creatures who can! The process by which such organisms can replace structures or organs is called regeneration.

Regeneration varies quite a bit among these creatures. For example, in certain types of worms and in starfish, a tiny part of the body can restore the whole organism. If only a small piece is left, a whole new body will grow!