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

Question

Quizplus · 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.

Excretory Structures Known as Protonephridia Are Present in