[Campbell Biology P.626] Based on the provided text, which of the following best describes t... | Practice Question

Based on the provided text, which of the following best describes the concept of exaptation in the context of bacterial flagellum evolution?

  • A: The process where existing structures are modified to perform new functions, as seen in the flagellum's components evolving from an ancestral secretory system.
  • B: The development of entirely new structures from scratch to adapt to new environmental pressures.
  • C: The loss of a function in a structure due to disuse over evolutionary time.
  • D: The rapid genetic mutation leading to immediate and drastic changes in cell morphology.

Explanation

The text defines exaptation as 'the process in which structures originally adapted for one function take on new functions through descent with modification,' specifically linking it to the bacterial flagellum's evolution from an ancestral secretory system. Option A directly reflects this definition and example.