Question

Map pling Sickle-cell anemia is a disease that affects the type of hemoglobin (Hb) a person makes in his or her red blood cells. Consider the case of Martin and Cindy, who are the parents of Mary. Martin has sickle-cell anemia with abnormal hemoglobin, and his genotype is HbS/HbS. Cindy has normal hemoglobin, and her genotype is HbA/HbA Their child, Mary, carries the sickle-cell trait and produces both normal hemoglobin and abnormal hemoglobin. Mary's genotype is Hbs/HbA. What type of dominance pattern would result in Mary's blood producing both normal and abnormal O incomplete dominance O pseudodominance O complete dominance O codominance

Answer 1

Answer:

The correct answer is codominance.

Explanation:

It is given in the question that the genotype of Martin is HbS/HbS, and is exhibiting sickle cell anemia with unusual hemoglobin. On the other hand, the genotype of Cindy is HbA/HbA, which shows that she possesses normal hemoglobin. Both of them have a child, Mary who as usual is exhibiting genotype HbS/HbA.  

This shows that Mary has acquired both the alleles for sickle cell anemia from her parents, and thus, is demonstrating both unusual and normal form of hemoglobin. Sickle cell is a condition that does not demonstrate the phenomenon of complete dominance, as it is a codominant trait.  

A phenomenon in which the features of both the alleles are expressed in the phenotype is termed as codominance. Hence, Mary is demonstrating a codominance pattern.