Question

Sickle-cell anemia helps in the prevention of which disease?

• A. Haemophilia
• B. Malaria
• C. Anemia
• D. Thalassemia

Answer 1

The correct option is B Malaria

Persons with sickle cell anemia are mostly found in those areas of tropical Africa where malaria is very common. It was reported that sickle-shaped cells of the heterozygote kill the malaria parasite. So the heterozygotes can resist the malaria infection in a much better way than the homozygous for the normal hemoglobin. The loss of deleterious recessive genes through the death of homozygotes is being balanced by successful reproduction of heterozygotes. Thus, the natural selection has preserved it along with the normal hemoglobin in malaria affected areas. It is an example of balancing or stabilizing selection. So, sickle cell anemia helps to prevent malaria and not hemophilia, anemia and thalassemia.

So, the correct answer is option B.