Match List-I with List-II
| List-I | List-II |
|---|---|
| Genetic disorder | Characteristics |
| (A) Haemophilia | (I) Mutation in HBB gene |
| (B) Thalassemia | (II) Sex-linked recessive disease |
| (C) Phenylketonuria | (III) Aneuploidy |
| (D) Klinefelter's syndrome | (IV) Mental retardation and reduced hair and skin pigmentation |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
(A) Haemophilia — this matches (II) Sex-linked recessive disease. The gene is on the X chromosome. A carrier mother passes it to half her sons, and affected persons are mostly males, because a male has only one X.
(B) Thalassemia — this matches (I) Mutation in HBB gene. β thalassemia is controlled by the single gene HBB on chromosome 11. Its mutation reduces the making of a globin chain, so too little haemoglobin forms.
(C) Phenylketonuria — this matches (IV) Mental retardation and reduced hair and skin pigmentation. The enzyme that converts phenylalanine into tyrosine is missing. Phenylalanine builds up and harms the brain, and less tyrosine means less of the pigment melanin.
(D) Klinefelter’s syndrome — this matches (III) Aneuploidy. The person has one extra X chromosome (47, XXY), a gain of a single chromosome.