The excretory system of flatworms is composed of:

Explanation

The excretory system of flatworms is composed of specialized structures called flame cells, also known as protonephridia. Flame cells are the primary excretory organs in flatworms, and they play a crucial role in removing metabolic waste and excess water from the body.Flame cells are found in the parenchyma (the tissue filling the space between organs) of flatworms. They consist of a tubule with a single flame-shaped cluster of cilia (hair-like structures) at their open end. The beating cilia create a flickering or flame-like appearance, giving these cells their name.