Just for the sake of accuracy I thought I would mention that bacteria also get new DNA through plasmids in addition to internal mutations.

Also, some(or maybe all, I don't remember) viruses contain only RNA and have no DNA. That is why they are able to mutate so quickly.

By the way, the wild horse(Mongolian) has 2 more chromosomes than the modern, domesticated version of itself. If you can change the number of chromosomes then you can make pretty much any changes within a kingdom. I still don't know how plants->animals would work because some plants have a trinity of chromosomes instead of pairs like animals. However, I'm only a high school senior, so I'm sure the answer is out there somewhere.

Creationism can be taught in a humanities class when the religion in question is discussed. It has no place in a science class.