Memory and multiple animations for a sprite

I was wondering how are multiple animation for a sprite treated.

Let's say that I have one sprite with 20 different animations (each with just one frame), at the start of the layout one of these 20 animations gets shown and stays the same for the whole layout, are the other 20 animations still loaded into memory?

Thanks

Yep - sprites are loaded all at once. Either all their animations are in memory, or none of them are.