TLS Online TPP Program

#Question id: 8908


According to one hypothesis, the jaws of vertebrates were derived by the modification of

#Unit 9. Diversity of Life Forms
  1. scales of the lower lip.
  2. skeletal rods that had supported pharyngeal (gill) slits.
  3. one or more gill slits.
  4. one or more of the bones of the cranium.