The color of the human eye is controlled by two gene loci. T…

The color of the human eye is controlled by two gene loci. The first locus determines whether the iris will be brown, green, or hazel (brown and green). The second locus determines whether the brown or green color will be expressed. If the gene inhibits the expression of color, the eye is blue. Which of the following best explains the equal, but separate expression of the brown and green pigment in hazel eyes?