Answer:
Due to mutation of the HBB gene.
Step-by-step explanation:
This causes a change in amino acids which are the building blocks of proteins. Therefore the proteins stick together and form a fiber that changes the shape of the red blood cell making them more fragile.
Evidence that supports my explanation
People with Sickle cell anemia cannot contract malaria since they have low surface area for hemoglobin retention.
Relationship between the structure of the red blood cell and it’s function
It has a biconcave shape with a large surface area to increase space for parking hemoglobin.
How the shape of the red blood cell affect its function in the case of sickle cell anemia
In the case of sickle cell anemia, the shape of the red blood cell becomes sickle like thus reducing the surface area for packing of hemoglobin.