Question

Clark's eyes are blue in color. However, both his parents have eyes that are brown in color. According to the dominant-recessive genes principle, the most likely reason for Clark's eyes being blue in color is that

Answer 1

Both parents are heterozygous for the trait. They must be carriers of the recessive gene that codes for blue eyes.

Step-by-step explanation:

Let us assume that the dominant gene codes for brown eyes while the recessive gene codes for blue eyes. We can suggest that both parents are carriers of the recessive gene. They both express brown eyes because they also have a dominant gene that codes for brown. Clark inherited one recessive allele from each parent, so he expresses blue eyes. The couple has a 75% probability of getting a brown-eyed child, while the probability of getting a blue-eyed child is 25%.