Why did the alleles that conferred insecticide resistance in mosquitoes become less frequent in the population when insecticide application was discontinued in the 1960s in Thailand?
A)The mosquitoes experienced a bottleneck and by chance the surviving insects had a low proportion of resistance alleles.
B)The resistance alleles were linked to a body color variation that led to resistant mosquitoes experiencing a higher rate of predation.
C)A mosquito population with a low proportion of resistant alleles migrated to Thailand and interbred with the original population.
D)In the absence of pesticide, mosquitos homozygous for the resistance alleles had lower fitness than the other genotypes.

Question

Quizplus · Accepted Answer

In the absence of the selective pressure provided by insecticides, alleles that confer resistance can sometimes come at a cost to the organism, such as reduced fitness in environments where the insecticide is not present. This can lead to a decrease in the frequency of these alleles when the insecticide application is discontinued.

Why Did the Alleles That Conferred Insecticide Resistance in Mosquitoes