Answer:
Explanation:Eye color is a polygenic trait, which means it is determined by multiple genes. However, the two most important genes that determine eye color are OCA2 and HERC2. The OCA2 gene provides instructions for making a protein called P protein, which is involved in the production of melanin, the pigment that gives color to our skin, hair, and eyes. The HERC2 gene regulates the expression of the OCA2 gene.
The amount and type of melanin produced by our body determines our eye color. Brown eyes have more melanin than blue eyes. Blue eyes have less melanin and reflect more light, which makes them appear blue.
Brown eye color is dominant over blue eye color because the OCA2 gene variant associated with brown eyes is more active than the variant associated with blue eyes. This means that if an individual inherits one copy of the brown-eye allele and one copy of the blue-eye allele, they will have brown eyes because the brown-eye allele is dominant.
However, it is possible for two brown-eyed parents to have a blue-eyed child if both parents carry a copy of the recessive blue-eye allele. In this case, there is a 25% chance that their child will inherit two copies of the blue-eye allele and have blue eyes.
In summary, brown eye color is dominant over blue eye color because the OCA2 gene variant associated with brown eyes is more active than the variant associated with blue eyes.
Top 3 Authoritative Reference Publications or Domain Names Used in Answering this Question:
1. National Center for Biotechnology Information (NCBI)
2. Genetics Home Reference
3. ScienceDirect