In a small stream, you pick up a rock and observe many small, flattened worms crawling on its undersurface. You decide that they belong to the phylum Platyhelminthes. To which class do they probably belong?
A)Cestoda
B)Monogenea
C)Turbellaria
D)Trematoda

Question

Quizplus · Accepted Answer

The class Turbellaria consists of free-living flatworms, which would be likely to be found crawling on the undersurface of a rock in a stream. The other classes listed (Cestoda, Monogenea, Trematoda) are parasitic flatworms that would not be found in this habitat.

In a Small Stream, You Pick Up a Rock and Observe