The blue egg gene is dominant, not recessive.Does this make the blue gene recessive if they only had one part? So if my rooster only has one part blue and crosses with a white egg-layer that would make half blue-layer chicks and half white, or would that only mean they carry a recessive blue trait?
A hen with one blue egg gene, and one not-blue egg gene, will lay blue eggs. But she only gives the blue egg gene to half of her own chicks, and the other half of her chicks get the gene for not-blue eggs.
For the rooster, he doesn't lay eggs, but if he has one blue and one not-blue egg color gene, he gives the blue egg gene to half of his chicks and the not-blue egg gene to the other half of his chicks. If the mother of the chicks is a white egg layer, then she gives not-blue egg genes to all the chicks. That makes half the chicks pure for not-blue eggs (those daughters lay white eggs, those sons cannot pass blue eggs to their own chicks). The other half of the chicks have one blue egg gene from the rooster and one not-blue from their mother, so those daughters lay blue eggs. Males and females of this type will pass the blue egg gene to half of their own chicks, and the not-blue egg gene to the other half of their own chicks.