Final answer:
Mutations in hemoglobin genes can alter the primary structure of hemoglobin, leading to conditions like sickle cell anemia.
Step-by-step explanation:
The primary structure of a protein is determined by the gene encoding the protein. Mutations in the hemoglobin genes can result in changes to the primary structure of hemoglobin. An example of this is sickle cell anemia, where a single amino acid substitution in the hemoglobin β chain causes a change in protein structure and function. Specifically, the substitution of valine for glutamic acid leads to the formation of sickled red blood cells and the development of sickle cell anemia.