Question. Which of the following amino acid substitution is responsible for causing sickle cell anemia?
A. Valine is substituted by Glutamic acid in the α globin chain at the sixth position
B. Valine is substituted by Glutamic acid in the β globin chain at seventh position
C. Glutamic acid is substituted by Valine in the α globin chain at the sixth position
D. Glutamic acid is substituted by Valine in the β globin chain at the sixth position
Answer: D. Glutamic acid is substituted by Valine in the β globin chain at the sixth position