Unlike a dog, how can a turtle be naked?

Well, I am sitting in class, contemplating this topic, and thinking to myself, wow, I can't believe I am contemplating this. 

Technically, a turtle can be totally naked, but then it would be dead.  I mean, it requires a shell to keep its innards safe, so how could you take that away?  It's not like it moves from shell to shell like a hermit crab.  It's not like he can say, "well, I don't really like the rooms in this shell" or "the view is just not as great as the one from that Tudor style shell".  So, you ask, how can a turtle be naked, unlike a dog... how can a dog really be naked?