Select the correct statements about sickle cell anemia:
A: There is a change in the gene for beta-globin
B: In

Question

Select the correct statements about sickle cell anemia:
A: There is a change in the gene for beta-globin
B: In beta-globin, there is a valine in place of Lysine
C: It is an example of point mutation
D: In the normal gene, U is replaced by A

Choose the correct answer from the options given below:

Accepted Answer

:
- Statement A is Correct: Sickle-cell anaemia is caused by a defect in the gene coding for the beta globin chain of haemoglobin .
- Statement B is Incorrect: The defect causes the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position, not Lysine .
- Statement C is Correct: It is a classic example of a point mutation (change of a single base pair) .
- Statement D is Incorrect: The mutation results from a single base substitution at the sixth codon of the beta globin gene from GAG to GUG . Genes (DNA) do not contain Uracil (U); they contain Thymine. Furthermore, the substitution is A to U in mRNA (or A to T in DNA), not U replaced by A.

Step-by-Step Solution

Practice All BIOLOGY Questions