Question

Brown-eyed Alma has a blue-eyed mother and a brown-eyed father. In this case, her brown eyes were determined by a _____ allele. A. dominant–recessive B. recessive C. dominant D. dizygotic

Answer 1

Answer: Option B) recessive

Brown-eyed Alma has a blue-eyed mother and a brown-eyed father. In this case, her brown eyes were determined by a recessive allele.

Explanation:

The recessive allele for brown-eyed colour was masked in Alma's mother (that is why she had blue-eyed colour), but expressed in Alma's father (reason for his brown-eyed colour)

Thus, Alma's brown-eye colour means she possess a homozygous allelic pair for the sex-linked character, since her both parents contributed X-chromosome each.