Question

Match List I with List II.

	List I		List II
A.	Down’s syndrome	I.	11th chromosome
B.	α-Thalassemia	II.	‘X’ chromosome
C.	β-Thalassemia	III.	21st chromosome
D.	Klinefelter’s syndrome	IV.	16th chromosome

Choose the correct answer from the options given below:

Options

• A - III, B - IV, C - I, D - II

• A - IV, B - I, C - II, D - III

• A - I, B - II, C - III, D - IV

• A - II, B - III, C - IV, D - I

Answer 1

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

Explanation:

List I		List II
Down’s syndrome	III.	21st chromosome
α-Thalassemia	IV.	16th chromosome
β-Thalassemia	I.	11th chromosome
Klinefelter’s syndrome	II.	‘X’ chromosome

An extra copy of chromosomal number 21 is the cause of Down syndrome. Klinefelter’s syndrome is caused by an extra copy of the X chromosome, which results in a karyotype of 47, XXY. Two closely related genes on each parent’s chromosome 16, HBA1 and HBA2, govern α-thalassaemia. The single gene HBB on each parent’s chromosome 11 regulates β-thalassaemia.