Final answer:
The inheritance of eye colors in the family described reflects a polygenic trait. Incomplete dominance results in an intermediate phenotype, while codominance allows for both alleles to be expressed fully, as seen in the ABO blood type system.
So, the correct answer is A.
Step-by-step explanation:
Eye colors are a polygenic trait in humans, resulting from multiple genes contributing to the color. Eye color is determined by multiple genes, each contributing to the final color of an individual's eyes. This complexity is why there is such a wide range of eye colors in humans. An example of a polygenic trait is skin color, which like eye color, is the result of the cumulative effect of many genes. To predict the eye color of children from parental eye colors, more than one gene needs to be considered, as it is not controlled by a single gene.
It is also important to note that incomplete dominance is when one allele is not completely dominant over the other, producing an intermediate phenotype. This is seen in the case of black and white true-breeding mice that are mated and produce all gray offspring. Codominance occurs when both alleles in a heterozygous organism are fully expressed, such as in the ABO blood group antigens where both A and B alleles are fully expressed in a type AB individual.
So, the correct answer is A) Polygenic traits