A disease caused due to mutation in DNA resulting in the production of sickle shaped RBCs.

Q.

Statement 1: A blood disease caused by gene mutation is sickle cell anaemia.

Statement 2: It results in the production of sickle-shaped WBCs

Q. Sickle cell anaemia results due to mutation caused by

Q. Two Mark Questions :
A relevant portion of $\beta$-chain of haemoglobin of a normal human is
Val-His-Leu-Thr-Pro-Glu-Glu
1 2 3 4 5 6 7
The codon for the sixth amino acid is GAG. It mutates to GAA due to mutation 'A' and GUG due to mutation 'B'. Haemoglobin structure did not change as a result of mutation 'A' but mutation 'B' led to sickle cell-shaped RBCs. Explain giving reasons how could mutation 'B' change the haemoglobin structure and not mutation 'A'.

Q. Statement 1: Genetic disorder caused by change in the molecular structure of haemoglobin is sickle cell anaemia.

Statement 2: It results in the production of sickle-shaped WBC.

Q. How many of the given statements are incorrect?

I. Thalassemia is caused due to mutation in only chromosome 21
II. Mutation on either chromosome 11 or 16 may cause sickle cell anaemia
III. At the 6${}^{\mathrm{th}}$ position beta globin chain, glycine is replaced by glutamic acid in case of sickle cell anaemia
IV. Phenylketonuria is caused due to lack of enzyme phenylalanine tyrosinase