What genetic principle governs the blue coloration arising from the dilution gene acting on black plumage?

Answer

Incomplete dominance (or co-dominance)

The blue coloration arises from a dilution gene operating under the rules of incomplete dominance, meaning the intermediate phenotype (blue) is expressed when only one copy of the gene is present.

What genetic principle governs the blue coloration arising from the dilution gene acting on black plumage?
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