Question

In humans, an X-linked disorder called coloboma iridia (a fissure in the iris) is a recessive trait. A normal couple has an afflicted daughter. What would be the most plausible scenario for this situation?

A. Both parents are heterozygous for the trait.

B. The mother carries two recessive alleles.

C. The female is not the biological mother, but the male is the biological father.

D. The male is not the biological father, but the female is the biological mother.

E. The father carries one recessive allele, and the mother carries one recessive allele.

Answer 1

Answer: A.) Both parents are heterozygous for the trait.

Explanation: It says that both parents are normal but they gave birth to an afflicted daughter. This means both parents have a recessive trait. That will conclude that both parents are heterozygous. I hope this helps!

Friendly reminder: The dominant trait always takes over the recessive trait. Have a good day!