Flatworms possess excretory organs known as nephridia. Specifically as annelids, flatworms possess a variant known as metanephridia.
IN THE LUMEN INSIDE OF THE ENDOPLASMIC RECTICULUM.
<u>Explanation:</u>
The endoplasmic recticulum is the continuous membrane system that forms that forms the more number of flattened within the cytoplasm of eukaryotic cells and performs the multiple process in the cell.
The immportant functions of endoplasmic recticulum is folding, synthesis, modification, ans transport of the protein. The lumen is the protein which is present in the endoplasmic recticulum.
The lumen of the endoplasmic recticulum is the area closed by the endoplasmic recticulum membrane, it is an extensive network of the membrane tubues, visicles, and flattened the cisternae found in the eukaryotic cells.
If realigns the domains of weaker magnet