If you think of the tube- within- a- tube body plan as a pipe with a straw inside, where would you expect to find most of the ectodermal, mesodermal, and endodermal germ layers, respectively?
A) straw; space between pipe and straw; pipe
B) pipe; straw; space inside of straw
C) space inside of straw; straw; space between pipe and straw
D) pipe; space between pipe and straw; straw

Question

Quizplus · Accepted Answer

The outer layer, or ectoderm, would be represented by the pipe, while the inner layer, or endoderm, would be the straw. Mesoderm, which is located between the ectoderm and endoderm, would be represented by the space between the pipe and straw. Therefore, the best choice is D - pipe; space between pipe and straw; straw.

If You Think of the Tube- Within- A- Tube Body