In geophysics the refraction or reflection of seismic waves is used for research into the structure of the Earth's interior, and man-made vibrations are often generated to investigate shallow, subsurface structures.
Flatworms are considered acoelomate, since they have no body cavity, and roundworms are pseudocoelomate because they have a body cavity, but it is not derived from the splittiâ¦ng of the mesoderm tissue. Also, flatworms only have one opening in their digestive system unlike roundworms with two.
Body Cavity. Flatworms are acoelomate, which means they do not have a body cavity. Roundworms are psuedocoelomate, which means they have a body cavity between their mesoderm and endoderm layers.he flatworm Planaria and the roundworm Caenorhabditis elegans are both lab organisms that are called worms. However, they are not closely related. Flatworms (phylum Platyhelminthes) and roundworms (phylum Nematoda) are both called worms, but there are many differences between these two types of organisms.