Question
Solenocytes are the main excretory structures in
Annelids
Molluscs
Echinodermates
Platyhelminthes
Solution
D.
Platyhelminthes
Solenocytes (also called flame cells) are meant for excretion and osmoregulation in Platyhelminthes. Annelids have metanephridia for excretion, Molluscs have kidneys (although different from vertebrate kidneys) for excretion. In echinodermates, no special excretory organs are found for excretion. In them, excretion takes place through diffusion or osmosis or through active transport.
