Question

why are mosquitoes now found to be a DDT resistant although DDT was known to be highly effective incectiside in the pest ?

Answer 1

DDT has been continuously used by humans as mosquitoes killer.Earlier it was very effective against mosquitoes but because of continuous use,new strains of DDT resistant mosquitoes developed,which after continued reproduction, replaced the DDT sensitive strains(now are no more survived). Survival of FITTEST theory is the reason that mosquitoes are now DDT resistant.

Answer 2

Explanation:

X-ray crystallography of the protein coded by the gene illustrated exactly how the mutation conferred resistance, by opening up the 'active site' where DDT molecules bind to the protein, so more can be broken down. This means that the mosquito can survive by breaking down the poison into non-toxic substances.