NEETZoologyPrinciples of Inheritance and Variation
In sickle cell anaemia, the defect is caused by the substitution of a specific amino acid at the sixth position of the beta globin chain of the haemoglobin molecule. Which of the following represents the correct substitution?
Options
- AValine by Glutamic acid
- BGlutamine by Valine
- CValine by Glutamine
- DGlutamic acid by Valine
Correct answer
D. Glutamic acid by Valine
Step-by-step solution
Sickle cell anaemia is a genetic disorder caused by a point mutation in the beta globin gene. The defect is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position of the beta globin chain of the haemoglobin molecule. This substitution occurs due to a single base change at the sixth codon of the beta globin gene from GAG (which codes for Glutamic acid) to GUG (which codes for Valine). Options suggesting Glutamine are incorrect as the original amino acid is Glutamic acid. Options sugg