Bio Engineer Archive

Hi, I'm not a BE but a potential customer thinking long term. I know about how the various creature bodies are now shells for DNA that makes all the difference, so here's my question:

Does the quality of the DNA affect the size of the creature? In other words, is a rancor-strength durni the same size as a wild durni, or larger?

And does anything else affect the size, besides growth from babyhood? Not that I have this in mind, but is there a way to make giant bunnies?

Thanks!