. . . . . . is an example of a trematode parasite.

The excretory structure in flatworms/Taenia is ........

"Triploblastic, unsegmented, acoelomate exhibiting bilateral symmetry and reproducing both asexually and sexually, with some parasitic forms". The above description is the characteristic of phylum:

In which phylum do animals have a digestive tract that opens at only one end?

Given below are two statements.
Statement $I$: Cephalic ganglion appears like $U$ shaped structure in Hydra.
Statement $II$: Ventral nerve cords are connected to each other by commissure in a ladder like manner in Planarian.
In the light of above statements,choose the most appropriate answer from the options given below:

Parenchymal circulation is found in . . . . . . .