Question

A farmer sprays insecticide on his crops to kill unwanted insects. Most of the insects die, and the chemicals have the effect of damaging the DNA of the insects that are not killed. Which of these has happened?
A. Sexual selection among the insects has changed the gene pool.
B. Genetic equilibrium has been maintained.
C. Mutations have arisen that may have altered allele frequencies.
D. Individuals with new genes have immigrated into the population.

Answer 1

The correct answer is option C, Mutations have arisen that may have altered allele frequencies

There have been several instances where mutation in the gene of an insect is caused due to the harmful external environmental condition which are either created or occurs naturally. Usually, the organisms evolve themselves to sustain in an adverse environment condition. In the process of evolution, they go through the process of positive genetic mutation but sometimes the mutation may also produce negative effect on the DNA of an species through wrong or inefficient pairing/coding.  Here in this case it can be stated that the chemical sprayed on insects might have attacked the gene pool of the insects thereby producing adverse genetic mutation.

Answer 2

Answer – C (Mutations have arisen that may have altered allele frequencies)

If the insecticide sprayed by a farmer on his crops have the effect of killing some insects and damaging the DNA of the insects that are not killed, it shows that due to the effect of the chemicals in the insecticide, mutations have arisen that may have altered allele frequencies of the insects