Question

Malaria is a blood disease caused by a parasite carried by mosquitoes. Some populations of mosquitoes have become resistant to two insecticides often used to kill them. Scientists have discovered that these mosquitoes have a gene mutation that makes them able to break down the insecticides into a harmless substance.

Which statement about the effect of the mutation on the mosquito populations best explains the relationship between natural selection and this mutation?

A
Mosquitoes are able to adapt by mutating to resist the insecticides.
B
Mosquitoes with the mutation are more likely to carry the parasite that causes malaria.
C
Mosquitoes without the mutation are able to move to other locations to avoid the effects of the insecticides.
D
Mosquitoes with the mutation are better able to survive and produce offspring.

Answer 1

D

The mutation allows mosquitoes to survive exposure to the insecticides, so those individuals are more likely to live long enough to reproduce and pass the resistant allele to offspring. Over time the resistant allele becomes more common by natural selection.