Which of the following is not a feature of the tube- within- a- tube body plan in most animals?
A) The inner tube consists of digestive organs.
B) Typically, the mouth and anus form the ends of the inner tube.
C) The two "tubes" are separated by mesoderm tissue.
D) Typically, the outer tube consists of a hard exoskeleton.

Question

Quizplus · Accepted Answer

Typically, the outer tube consists of a hard exoskeleton is not a feature of the tube-within-a-tube body plan in most animals. This is because not all animals have an exoskeleton, and many animals have a soft outer layer that is not a tube.

Which of the Following Is Not a Feature of the Tube-