Imagine that you are studying stripe formation in a species related to zebras. Gene Z controls stripe development, where only individuals with at least one copy of allele Z₁ form stripes. Among those that have stripes, homozygotes for allele B₁ form black stripes on a silver background while individuals of other genotypes form grey stripes on a white background. Answer the following:
1. How can you explain the genetics of this trait? Give a term from lecture and explain how the term applies to this scenario.
2. Then, give the phenotypic ratio expected of the offspring from a cross between two individuals who are heterozygous for both genes (Z₁Z₂B₁B₂). Be sure to include all relevant phenotypes in your ratio. Assume that these genes each only have two possible alleles (Z₁ and Z₂, B₁ and B₂).