[ There's just a moment there where Erik stares, closes his eyes, then takes a deep breath. Something tells him he'll only frustrate himself further if he keeps trying to correct her without some (much needed) knowledge on the basis of that word, so he lets it go for now. ]

Not really, no. Every living creature is made of cells. They're these very small things, so small that you can't even see them with your eyes, but many of them come together to shape us. Our bodies are made up of all these cells, and inside them there is something called DNA. It's like... a code, that makes us look the way we do. If we're tall or short, if we have dark or light hair, the color of our skin. And among my kind, that code has something else that's different. A mutation, which is the change of something in that code, and that's what gives us our abilities.