Question

Match the components in List I with those in the List II.
List I: A. Down's Syndrome, B. Turner Syndrome, C. Phenylketonuria, D. Sickle cell anemia
List II: I. Autosomal recessive trait, II. Point mutation, III. Females only, IV. 21 Trisomy

• A. A-I, B-II, C-III, D-IV
• B. A-IV, B-III, C-I, D-II
• C. A-IV, B-I, C-II, D-I
• D. A-I, B-III, C-II, D-IV

Hint:

Down's = 21, Turner = X0 (Female), Sickle Cell = Point Mutation (Glu to Val).

Answer 1

The Correct Option is B

Step 1: Analysis of Down's Syndrome
Down's Syndrome is caused by the presence of an extra copy of chromosome 21, known as Trisomy 21 (A-IV).

Step 2: Analysis of Turner Syndrome
Turner Syndrome results from a missing X chromosome (45, X) and affects females only (B-III).

Step 3: Analysis of Metabolic Disorders
Phenylketonuria is an autosomal recessive metabolic disorder (C-I).

Step 4: Conclusion
Sickle cell anemia is caused by a point mutation in the beta-globin gene (D-II). The correct sequence is A-IV, B-III, C-I, D-II. Final Answer: (B)