Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R). 

Assertion A: Thalassemia and sickle cell anaemia are caused due to problems in globin molecule synthesis in RBC.

Reason R : Both the diseases are due to qualitative defect in globin chain synthesis. 

In light of the above statements, choose the correct answer from the options given below. 

A is true but R is false. 

Assertion (A) states that thalassemia and sickle cell anemia are caused due to problems in globin molecule synthesis in red blood cells (RBCs), which is true. Both conditions involve abnormalities in the synthesis of globin chains, which are essential components of hemoglobin, the oxygen-carrying molecule in RBCs.

Reason (R) states that both diseases are due to qualitative defects in globin chain synthesis, which is also false. In thalassemia, there is a quantitative defect where there is a reduced production of one or more types of globin chains, leading to an imbalance in the alpha and beta chains. In sickle cell anemia, there is a qualitative defect where a specific amino acid substitution occurs in the beta-globin chain, resulting in the formation of abnormal hemoglobin molecules (hemoglobin S).