[Campbell Biology P.729] Which of the following statements accurately distinguishes between ... | Practice Question

Which of the following statements accurately distinguishes between diploblastic and triploblastic animals based on the provided text?

  • A: Diploblastic animals have two germ layers (ectoderm and endoderm), while triploblastic animals have three germ layers, including mesoderm.
  • B: Cnidarians are examples of triploblastic animals due to their complex body plans.
  • C: All diploblastic animals eventually develop a mesoderm, making them triploblastic later in development.
  • D: The mesoderm in triploblastic animals primarily forms the digestive tract lining and central nervous system.

Explanation

The text states that 'Cnidarians and a few other animal groups that have only these two germ layers are said to be diploblastic' ectoderm and endoderm . It then clarifies, 'All bilaterally symmetrical animals have a third germ layer, called the mesoderm... animals with bilateral symmetry are also said to be triploblastic having three germ layers '. This directly supports option A.