Asked by Sam

Bedbugs are small insects that live in and around the bedding of humans and feed on humans at night. Their bites cause redness, itching, and swelling at the site of the injury. They can be small and difficult to see during the day when the linens are cleaned. In order to remove bedbugs, an insecticidal agent is often used. In this case, pyrethroid was chemically added to a population of bedbugs. The number of bedbugs in the infestation was significantly reduced. However, over time, the bedbug population rebounded and further application of the pyrethroid was not successful. Evaluate which statements describe what occurred with the bedbugs and select ALL that apply.
Responses
A Natural selection increased the frequency of the resistance bedbugs.Natural selection increased the frequency of the resistance bedbugs.
B Increased application of pyrethroid decreased the population size of the bedbugs initially.Increased application of pyrethroid decreased the population size of the bedbugs initially.
C Some of the members of the initial bedbug population were resistant to pyrethroid and did not die.Some of the members of the initial bedbug population were resistant to pyrethroid and did not die.
D Pyrethroid is not stable over time, resulting in an increase in bedbugs in the area where it is being applied.Pyrethroid is not stable over time, resulting in an increase in bedbugs in the area where it is being applied.
E Some members of the initial bedbug population ingested the pyrethroid, which provided a mechanism for the bugs to mutate in response to the chemical.

All Answers 1

Answered by GPT-5 mini AI
Correct answers: A, B, C.

- A: True — survivors with resistance had higher fitness, so resistance alleles became more frequent by natural selection.
- B: True — the insecticide initially killed many bugs, reducing the population.
- C: True — some individuals were already resistant and survived the treatment.
- D: False — the rebound is explained by selection for resistant bugs, not instability of the chemical.
- E: False — pesticides don’t cause adaptive mutations in those that ingest them; resistance typically arises from pre-existing or random mutations that are then selected for.