Fingernails and toenails, hair, skin, animal fur, animal claws and hooves, and even animal feathers are largely made up of the very same chemical protein called keratin. It’s nature’s own version of plastic!
Your nails grow about an inch every 6 months from a bed at their base. That’s the only part that is alive and growing. That’s why it doesn’t hurt when you cut your nails — because the tips aren’t alive at all!
Answer provided by Discovery.com