Final answer:
Sickle cell disease is incorrectly said to be caused by a parasite transferred to humans by a mosquito; it is actually a genetic disorder with mutations causing abnormally shaped hemoglobin. It does provide some resistance to malaria and is characterized by sickle-shaped red blood cells.
Step-by-step explanation:
All the following statements about sickle cell disease are true, except that it:
- is caused by a parasite transferred to humans by a mosquito. This statement is incorrect because sickle cell disease is not caused by a parasite, but rather a genetic mutation.
- provides resistance to malaria by limiting its ability to replicate. Individuals who are heterozygous for the sickle cell trait have some resistance to malaria.
- is characterized by an abnormality in the shape of the hemoglobin. Specifically, the disease is caused by a single base change in the gene for human hemoglobin, leading to hemoglobin S.
- leads to high childhood mortality rates in low-income countries where advanced medical care is scarce. This high mortality rate is due, in part, to complications from blocked blood vessels and inadequate oxygen delivery to tissues.
Sickle cell anemia is particularly prevalent among individuals of African descent. The abnormal, sickle-shaped red blood cells can clog blood vessels, leading to pain and other serious health issues.