Question Detail
Question
Sickle cell anemia is due to the substitution of
Correct Answer
Option B is the correct answer.
Detailed Explanation
Sickle cell anemia is caused by a point mutation in the beta-globin gene, resulting in a single amino acid substitution. Specifically, a hydrophobic amino acid, valine, replaces a hydrophilic one, glutamic acid, at the sixth position of the beta-globin chain. This substitution causes hemoglobin molecules to polymerize under low oxygen conditions, leading to sickle-shaped red blood cells.
Hint
This classic example of a molecular disease involves a single amino acid change in hemoglobin.