Which of the following is correct description for thalassemia and sickle cell anaemia?

	Thalassemia	Sickle cell anaemia
1.	Qualitative trait	Quantitative trait
2.	Pleiotropic trait	Point mutation of two linked genes
3.	It is due to recessive mutation of two linked genes of 16th chromosome	$\mathrm{\beta }$-chain of haemoglobin has valine at 6th place
4.	Synthesis of few $\mathrm{\alpha }$ or $\mathrm{\beta }$ chains of  haemoglobin	Deletion of HBB gene of 11th chromosome coding for $\mathrm{\beta }$ chain of haemoglobin

•  Qualitative trait - Sickle cell anemia

Sickle cell anemia is a qualitative trait because it is characterised by a specific and distinct change in the shape of red blood cells due to a mutation in the HBB gene, resulting in the production of abnormal hemoglobin (hemoglobin S). Sickle cell anemia is caused by a point mutation in the HBB gene, leading to the substitution of valine for glutamic acid at the 6th position of the beta-chain of hemoglobin. This mutation is associated with a single gene.

• Quantitative trait - Thalassemia

Thalassemia is a quantitative trait because it involves a spectrum of disorders with varying degrees of severity related to the amount of functional hemoglobin produced. It is not a simple binary trait like sickle cell anemi. Thalassemia, particularly beta-thalassemia, is due to a recessive mutation in the HBB gene on the 11th chromosome, which codes for the beta chain of hemoglobin. It is not located on the 16th chromosome, and it involves a mutation in a single gene rather than two linked genes.