[Campbell Biology P.484] Based on the text's discussion of Imatinib Gleevec and subsequent d... | Practice Question

Based on the text's discussion of Imatinib Gleevec and subsequent drug resistance, which statement best explains the observed phenomenon of resistance in cancer cells?

  • A: Cancer cells actively develop new genes to specifically counteract the drug's mechanism after exposure.
  • B: Certain tumor cells with pre-existing random mutations that allow survival in the drug's presence are naturally selected and reproduce.
  • C: Imatinib loses its effectiveness over time due to chemical degradation within the patient's body.
  • D: The drug's mechanism of inhibiting tyrosine kinase only works for a limited duration, after which the enzyme becomes immune.

Explanation

The text explicitly states: 'Here, we can see that cancer cells demonstrate the principles of evolution: Certain tumor cells have a random mutation that allows them to survive in the presence of a particular drug, and as a consequence of natural selection in the presence of the drug, these are the cells that survive and reproduce.' This directly supports option B.