Read the following about sickle cell anaemia.
(A) There is a change in gene for beta haemoglobin.
(B) In the beta haemoglobin, there is valine in the place of Lysine.
(C) It is an example of point mutation.
(D) It is autosomal dominant disorder.
Select the option with the correct statements.

A and C only are correct.
Sickle cell anaemia is a genetic disorder characterised by the presence of abnormal haemoglobin, called haemoglobin S. The disorder is caused by a mutation in the gene that codes for beta globin, a component of
haemoglobin.
A. Gene for beta globin undergoes a point mutation.
B. In the beta globin, there is valine in place of glutamic acid.
C. Sickle cell anaemia is an example of point mutation which is a change of a single base pair in DNA.
D. The base ‘U’ cannot be present in a gene (DNA). Uracil (U) is found in RNA while thymine (T) is found in DNA. The normal beta globin gene has the triplet CTC in the antisense strand. The mutant gene has the triplet CAC. The corresponding mRNA codon transcribed from the normal gene is GAG while the codon transcribed from the mutant gene is GUG.