Question

Why are human sickle-cell heterozygotes less likely to die of malaria?

Answer 1

People with sickle cell disease can get malaria just like anyone else. However, people with sickle cell trait are less likely to get malaria. The trait doesn't completely protect a person from infection, but it makes death from malaria less likely.

It so happens that in areas where there is a high incidence of the sickle cell anaemia allele, there is also a high incidence of malaria. The parasite that causes malaria infects the red blood cells and multiplies within them.

People who are heterozygous for sickle cell anaemia are much less likely to get the potentially lethal malaria than those who have 2 copies of the normal allele.

There is a strong selection pressure against homozygous sicklers because they can become seriously anaemic.

There is a strong selection pressure against homozygous normal haemoglobin alleles in malarial areas because these individuals are more likely to contract malaria.

Therefore, in malarial areas, there is a strong advantage to be a carrier for the sickle cell disease.

Answer 2

hope that helped

Answer 3

http://www.funtrivia.com/askft/Question94252.html

Answer 4

@warood @Azureilai
Thank you so much!