What condition is characterized by a lack of intrinsic factor that affects red blood cell production?

The condition characterized by a lack of intrinsic factor affecting red blood cell production is pernicious anemia. Intrinsic factor is a protein produced by the stomach that is essential for the absorption of vitamin B12 in the intestines. Vitamin B12 is crucial for the production of red blood cells, and when intrinsic factor is deficient, it leads to impaired absorption of this vitamin. This results in the development of pernicious anemia, which is marked by the production of abnormally large and dysfunctional red blood cells (megaloblastic anemia) due to the insufficient vitamin B12.

In contrast, sickle cell anemia is a genetic disorder that affects the shape and function of hemoglobin but is not related to intrinsic factor or vitamin B12 absorption. Iron deficiency anemia occurs due to inadequate iron levels, resulting in reduced hemoglobin production. Aplastic anemia is a condition where the bone marrow fails to produce enough blood cells, leading to a deficiency of all types of blood cells, not specifically linked to intrinsic factor or vitamin B12. Therefore, the specific lack of intrinsic factor directly connects to pernicious anemia as the correct answer.