<Li> Hereditary spherocytosis syndromes are a group of inherited disorders characterized by defects in the red blood cell's cell membrane, causing the cells to be small, sphere - shaped, and fragile instead of donut - shaped and flexible . These abnormal red blood cells are destroyed by the spleen . Several other hereditary disorders of the red blood cell membrane are known . </Li> <Dl> <Dd> <Ul> <Li> Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B from food . Vitamin B is needed for the production of hemoglobin . </Li> </Ul> </Dd> </Dl> <Dd> <Ul> <Li> Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B from food . Vitamin B is needed for the production of hemoglobin . </Li> </Ul> </Dd> <Ul> <Li> Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B from food . Vitamin B is needed for the production of hemoglobin . </Li> </Ul>

What is the structure and function of a red blood cell