Which of the following is a feature of the tube-within-a-tube body plan in most animals?
A)The outer tube consists of a hard exoskeleton.
B)The outer tube consists of digestive organs.
C)The mouth and anus form the ends of the inner tube.
D)The two "tubes" are separated by endoderm tissue.

Question

Quizplus · Accepted Answer

In the tube-within-a-tube body plan, the inner tube includes the digestive tract, and the mouth and anus form its ends. This allows for a unidirectional flow of food and waste. The outer tube includes other organs and tissues, such as muscles and nerves. It is not typically a hard exoskeleton (A) or made entirely of digestive organs (B). While endoderm tissue is involved in the development of the inner tube, it is not a specific feature of the body plan itself (D).

Which of the Following Is a Feature of the Tube-Within-A-Tube