Sickle-Cell Anemia:
Healthy red blood cells are shaped like a disc. Each cell contains the protein hemoglobin, which carries oxygen throughout the body. In some people, a crescent-shaped cell forms instead of the normal disc-shaped cell. The crescent-shaped cells contain abnormal hemoglobin. These sickle-shaped cells are fragile and are unable to carry oxygen properly throughout the body.
Sickle-cell anemia is an inherited disease that affects about 72,000 people in the United States. It is more common among people of South American or African descent. The genes for sickle-cell anemia are inherited from both parents. When both parents carry a gene for the trait for sickle-cell, there is a one in four chance that they will pass the disease on to their children.
Symptoms of sickle-cell anemia can include sudden occurrences of extreme abdominal and back pain, bone pain, fever, fatigue, and a rapid heart rate. One patient compared the pain in his back to a jackhammer and said the pain could take over his entire body. Another patient, an eight-year-old girl, described fevers and the feeling of someone squeezing her arms and legs. Cycles of symptoms are often unpredictable and can occur infrequently or almost constantly. Some people who are affected report weekly occurrences of persistent pain, while others report occurrences once a month. Some report that relief comes only by using powerful painkillers. For others, relief comes with bed rest and a hot-water bottle. Most agree that while the challenges of managing sickle-cell anemia are great, with diligent care, it can be managed.
What is the main idea of the passage about Sickle-Cell Anemia?
Correct Answer: D
Rationale: The correct answer is D. The passage focuses on describing sickle-cell anemia as a painful and inherited disease. It details how the abnormal sickle-shaped cells cause symptoms like bone pain, fever, and fatigue. While bone pain is mentioned as a symptom, it is not the main idea of the passage. Choice A is incorrect. Choice B, which mentions oxygen transport, is not the main idea but a general concept. Choice C, stating genetically inherited diseases affect thousands, is too broad and does not focus on the specifics of sickle-cell anemia. Therefore, D is the most precise choice.
Nokea