The reason a bp can't be "25% normal and 75% pastel"
Based on gene ineritance, an offpsring gets a single copy of a given gene from the sire, and the other given gene from the dam. In the case of the pastel gene, lets say the sire is a pastel and the dam is a normal. The sire's two genes are Pastel and Normal (P and N). The females two genes are Normal and Normal (N and N). The sire can pass on either the P or the N gene, the female will pass on just one of the N genes.
IF the offspring inherits the P gene from the father, that overrides the normal gene and the animal expresses as a pastel since the pastel gene is a co dominant gene. If the offspring inherites the pastel gene, it expresses as a pastel. The reason that animal can still produce normals when bred to another normal is because at the gene location there is a second gene, the Normal gene (N).
Super Pastels have two copies of the P gene, so no matter what ONE of those P genes is getting passed onto the babies.
I hope my oversimplified version of gene inheritance helped!
Reply With Quote