Recessive gene
A recessive gene was a type of gene that would not manifest unless two copies were present. For example, in Human-Skagaran hybrids, the Skararan cranial genes were recessive, meaning that an hybrid with only 1/4th Skagaran ancestry would look Human. ()

Within the Borg Collective, access to Unimatrix Zero was controlled by a recessive genetic mutation. ()

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de: Rezessive Mutation
Biology