Question

QUESTION 11 What is the reason of the extremely low prevalence of P. vivax in tropical Africa O Buffy coat resistance of black people to this species of malaria parasite Lack of suitable mosquito vectors in Africa that can transmit the paraiste Efficient mosquito control in Africa O High prevalence of sickle cell anemia in West Africa 1 points Save Answer

Answer 1

Option D, due to high prevalence of sickle cell anemia in west Africa.

Tropical region has high no of plasmodium infections. But this kept low by mainting sickle cell heterozygote population.

In sickle cell anemia due to point mutation, shape of RBC change to sickle shape and increase lysis of RBC . So sickle cell anemia in homozygous condition is lethal. But in heterozygous conditions due to presence of both normal as well as disease haemoglobin, individual survive normal. But it provide protection against plasmodium infection. Plasmodium parasite, spend a part of its life cycls in RBC . When it enters in to sickle shape RBC , its promote sickling of RBC ( lysis) thus cause interruption in completing of parasite life cycle and prevent infection.