Gene HBB for β-thalassemia is present on which chromosome?

The correct answer is Option (3) → 11

Thalassemia is an autosome-linked recessive blood disease. A mutation or deletion lowers the synthesis of one of the globin chains of haemoglobin, and this causes anaemia. The two kinds are named after the chain affected: α thalassemia (genes HBA1 and HBA2) and β thalassemia (gene HBB). Chromosomes 5, 22 and 9 carry neither of these genes.

NCERT Extract:
Mendelian Disorders – “… Thalassemia can be classified according to which chain of the haemoglobin molecule is affected. In α Thalassemia, production of α globin chain is affected while in β Thalassemia, production of β globin chain is affected. α Thalassemia is controlled by two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent and it is observed due to mutation or deletion of one or more of the four genes. The more genes affected, the less alpha globin molecules produced. While β Thalassemia is controlled by a single gene HBB on chromosome 11 of each parent and occurs due to mutation of one or both the genes.”