How do you get a 3 gene animal?

[paulh]

... Bps can carry more than 1 gene at a time. ....

This is because it takes many thousands of genes to build a ball python. All ball pythons have the same number of genes. A "one gene" snake has an error in one gene. A "two gene" snake has an error in two different genes. A "three gene" snake has an error in three different genes. And so on. For simplicity, we ignore the huge number of genes that are error-free.