What term describes an earthworm's body plan?

Answer 1

If you look at an anellida you will have to admit that it kind of looks like a tube, from the outside, right. Well inside the worm has a gut that is just as long and as straight as it is on the outside. And between the outer-skin and the inner gut there is the body medium, a mostly fluid filled series of chambers. This makes for a tube within a tube.

Answer 2

The body is built on the plan of "a tube within a tube." The inner tube is the straight-line digestive tract, extending from the slit-like mouth on the first segment to the anal slit on the last segment. The outer tube, forming the body wall, consists of two layers of muscle, the moist skin, a cuticle, and a secretion of slimy mucus. The fluid-filled cavity between the two tubes contains a well-developed circulatory system, a nervous system, numerous thread-like kidneys, and the reproductive organs. In fact, the worm is exceptionally well organized, more so than one would imagine from its lowly position in the animal world.

here:

http://www.tvdsb.on.ca/Westmin/science/snc2g1/worm.htm

Answer 3

All higher animals have the same structure. We have an external tube-like form from head to toe. Inside this, starting at our mouth, we have a digestive system that goes all the way through our body and ends at the anus. This is a tube inside of a tube.

Answer 4

tube within a tube plan.(body coelom present)