Having a double set of the ww allele causes the dragon to die. In real life, there are many mutations which are lethal. This is another case of trying to bridge the gap between the model and the real world. Write it in the space below. Mutations are usually, but not always recessive.
Some mutations can be lethal if the allele is present as a double dose.
The most difficult task for almost everyone, adult or student, is to take data and make a generalization from them. By leading the kids through this exercise, we hope that they will get some much needed practice. In this way, they should be able to make the jump from modeling to real life. There are more mutations. See if you can find them.