Biological immortality

Biological immortality means that an organism never dies because it can't age or get sick. Some small creatures like jellyfish, called Turritopsis dohrnii, can do this. The jellyfish can turn back into a younger version of itself when it gets older and it keeps repeating this process over and over again, so it never really dies. Humans can't do this, but some scientists are hoping to one day develop a way for us to become biologically immortal.