Back to Directory
NEET BIOLOGYMedium

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:

A

(B), (C) and (D) only

B

(B) and (D) only

C

(A), (B) and (D) only

D

(A) and (C) only

Step-by-Step Solution

:

  • 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.
Practice Mode Available

Master this Topic on Sushrut

Join thousands of students and practice with AI-generated mock tests.

Get Started