Question

$\alpha$-thalassemia is controlled by:
[0.7 mark]

• A. Single gene HBB located on chromosome 11
• B. Single gene HBA located on chromosome 18
• C. Two closely linked genes on chromosome 16
• D. Two genes located on two different chromosomes 16 and 11

Answer 1

The correct option is C Two closely linked genes on chromosome 16

$\alpha$-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 genes.

$\beta$-thalassemia is controlled by a single gene HBB on chromosome 11.