Excretory Structures Known as Protonephridia are Present In

Question

Excretory structures known as protonephridia are present in
A) flatworms.
B) earthworms.
C) insects.
D) vertebrates.
E) cnidarians.

Accepted Answer

Protonephridia are present in flatworms, where they function in excretion and osmoregulation. Earthworms have metanephridia, insects have malpighian tubules, vertebrates have kidneys, and cnidarians lack specialized excretory structures.