Final answer:
Flame cells are primitive excretory organs found in flatworms, specifically freshwater planaria. These organs help propel waste matter for excretion and maintain the organism's osmotic balance.
Step-by-step explanation:
Flame cells are primitive excretory organs found in flatworms. These excretory organs, also known as protonephridia, are present in planaria, which are freshwater flatworms. The flame cells have a cluster of cilia that look like a flickering flame and help propel waste matter down the tubules for excretion. They also regulate the osmotic balance of the organism.