Final answer:
Leukemia is not a red blood cell disorder; it affects white blood cells. Disorders such as Pernicious anemia, Aplastic anemia, and Sickle cell anemia directly affect red blood cells, with symptoms related to insufficient or defective RBCs.
Step-by-step explanation:
The red blood cell disorder that is not a type of red blood cell disorder among the given options is B) Leukemia. Leukemia is a type of blood cancer that affects white blood cells (WBCs), not red blood cells (RBCs). Disorders such as A) Pernicious anemia, C) Aplastic anemia, and D) Sickle cell anemia directly affect red blood cells. Pernicious anemia involves a deficiency in vitamin B12 leading to faulty RBC production, while aplastic anemia is characterized by insufficient RBC stem cells due to factors like radiation or medication.
Sickle cell anemia is a genetic disorder where red blood cells assume a sickle or crescent shape due to abnormal hemoglobin, causing a range of health issues due to impaired oxygen delivery and blood flow. In contrast, leukemia entails abnormal and uncontrolled proliferation of white blood cells, which can overshadow and impair the normal production and function of RBCs as well as other blood components.