[Campbell Biology P.567] Given the information that the r allele confers insecticide resista... | Practice Question

Given the information that the r allele confers insecticide resistance and that hybridization can facilitate the transfer of adaptive alleles, what is the most likely consequence of the observed increase of the r allele in Anopheles coluzzii populations on malaria cases in the years immediately following the transfer?

  • A: The number of malaria cases would likely increase because Anopheles coluzzii mosquitoes would become more resistant to insecticides, reducing the effectiveness of control measures.
  • B: The number of malaria cases would likely decrease as the spread of the r allele would make Anopheles coluzzii less fit, reducing their population size.
  • C: The number of malaria cases would remain unchanged, as the r allele only affects mosquito survival, not their ability to transmit malaria.
  • D: The number of malaria cases would fluctuate unpredictably due to complex ecological interactions unrelated to the r allele transfer.

Explanation

The r allele confers resistance to insecticides. If this allele spreads within Anopheles coluzzii populations, these mosquitoes will become more resistant to the control measures like treated bed nets designed to kill them. An increase in resistant mosquito populations would lead to a reduced effectiveness of malaria control efforts, subsequently resulting in an increase in malaria cases.