[Campbell Biology P.768] Based on Figure 34.2 and the accompanying text, which of the follow... | Practice Question

Based on Figure 34.2 and the accompanying text, which of the following statements about the classification and characteristics of certain groups is correct?

  • A: Hagfishes (Myxini) and lampreys (Petromyzontida) are classified as Gnathostomes because they possess jaws.
  • B: All animals within the Osteichthyans clade possess lungs or lung derivatives.
  • C: Mammals are the only Amniotes that produce milk.
  • D: The common ancestor of chordates is characterized by the presence of vertebrae.

Explanation

The phylogenetic tree shows 'Milk' as a derived character that appears on the branch leading specifically to Mammalia, which is a sub-clade of Amniotes. This indicates that among the Amniotes shown, only Mammals possess milk production as a defining trait at this evolutionary stage.