EMT Module 4 Practice Exam

Sickle cell disease is a genetic disorder characterized by the production of abnormal hemoglobin, known as hemoglobin S. This abnormal hemoglobin causes red blood cells to take on a distinctive sickle, or crescent shape, especially when oxygen levels are low. These sickle-shaped cells can lead to various complications, including pain crises, increased risk of infection, and organ damage because they can block blood flow through small vessels.

The disorder's genetic basis means it is inherited in an autosomal recessive pattern, which means a person must inherit two copies of the sickle cell gene (one from each parent) to have the disease. Those who inherit only one copy typically are carriers (sickle cell trait) and may not exhibit symptoms.

In contrast, other options presented are related to different types of anemia or blood disorders. Thalassemia involves the production of abnormal hemoglobin but does not result in the sickle-shaped cells seen in sickle cell disease. Iron deficiency anemia is typically related to a lack of iron, leading to smaller and paler red blood cells. Pernicious anemia is caused by the inability to absorb vitamin B12 and results in larger, immature red blood cells called megaloblasts, not sickle-shaped cells.