This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Sickle cell anemia is a - 
Select and explain. 
A. Gene deletion, B. Gene modification, C. Point mutation, D. Frame shift mutation
C: Point mutation
Answer: C: Point mutation 
Explanation: Answer- c- point mutation.Sickle-cell anemia is caused by a point mutation in the b-globin chain of hemoglobin, causing the hydrophilic amino acid glutamic acid to be replaced with the hydrophobic amino acid valine at the sixth position.It is caused by a point mutation (Base substitution mutation) at the sixth position of the b-globin chain leading to subsitution of a valine residue for a glutamic acid residue resulting in sickle hemoglobin (HbS).Sickle cell anemia is an autosomal recessive disorder.