Final answer:
The CB and CW alleles in Andalusian chickens are co-dominant, leading to a phenotype that expresses the characteristics of both alleles when they are both present.
Step-by-step explanation:
In Andalusian chickens, the relationship between the CB and CW alleles is that they are co-dominant. This means that both alleles are expressed equally and neither allele is dominant over the other. When both alleles are present in an individual, a combination of both traits is seen. For example, if a chicken has the CB allele and the CW allele, its feathers may have patches of both colored and white feathers.
The relationship between the CB and CW alleles in Andalusian chickens is that they are co-dominant. This means that when an organism has one of each allele, both alleles are expressed in the phenotype. This is similar to the multiple allele system seen in rabbit coat color where the wild-type allele is dominant over all others, and where various degrees of dominance exist among other alleles. In the case of Andalusian chickens, a bird with one CB allele and one CW allele will have a mixed or 'blue' phenotype, displaying characteristics of both alleles.