In the earthworm body plan, the digestive system can be described as a "tube-within-a-tube." Where would you expect to find most of the tissues that developed from endoderm?
A) lining the straw
B) lining the space between the pipe and the straw
C) forming the outside of the pipe
D) forming the outside of the straw

Question

Quizplus · Accepted Answer

The endoderm is the innermost germ layer that develops into the lining of the digestive tract and other internal organs. In the "tube-within-a-tube" body plan, the digestive tract is the "straw," so the endoderm would line the inside of this "straw."

In the Earthworm Body Plan, the Digestive System Can Be