all cells die at one time or another and they are all shedded or destroyed. The single most shedded cell layer is the epidermis of the skin which sheds millions of cells a day.

No root. Only crown of tooth.

A US nickel with 1 gram shedded off it.

Not normally, but if you have babies in a tank with adults they might eat them but probably not. Some eat their shedded skin though.

im not joking: camel feces, cactus parts, they pass sand through their body to clean their liver, and they eat there shedded skin.