[Campbell Biology P.434] Edward B. Lewis's research on Drosophila led to the discovery of ho... | Practice Question

Edward B. Lewis's research on Drosophila led to the discovery of homeotic genes. Based on the description and Figure 18.20, which of the following best describes the consequence of a homeotic gene mutation?

  • A: Homeotic gene mutations lead to a complete absence of body segments in the adult fly.
  • B: These mutations cause the development of extra wings or legs at their normal anatomical locations.
  • C: Homeotic gene mutations result in the misplacement of body parts, such as legs developing in place of antennae.
  • D: The primary role of homeotic genes is to regulate the formation of the eggshell during early development.

Explanation

The text explicitly states that Lewis 'studied bizarre mutant flies with developmental defects that led to extra wings or legs in the wrong place Figure 18.20 .' Furthermore, it defines homeotic genes as 'regulatory genes that control pattern formation in the fly.' Figure 18.20 clearly illustrates this with 'Leg instead of antenna' in a mutant fly, which is a classic example of homeotic transformation or misplacement of body parts.