The Prokaryotic Flagellum Is a Complex Structure Consisting of Several

Multiple Choice

The prokaryotic flagellum is a complex structure consisting of several dozen different proteins. Which of the following statements best describes the origin of flagella in prokaryotes?

A) Natural selection cannot account for the evolution of the prokaryotic flagellum.
B) Ancestral versions of this protein assemblage were either less functional or had different functions than modern prokaryotic flagella.
C) Flagella could not have arisen by evolution because the structure is too complex to have evolved gradually.
D) The need for more complex structure must have driven evolution.