question_answer 23)

  Which one of the following statements is incorrect? (a) In cockroaches and prawns excretion of waste material occurs through Malpighian tubules. (b) In ctenophores, locomotion is mediated by comb plates. (c) In Fasciola flame cells take part in excretion (d) Earthworms are hermaphrodites and yet cross fertilization take place among them.

Answer:

                  (a) The statement (a) is incorrect because Malpighian tubules are excretory structures inmost of the insects, including cockroach, but green glands perform excretory functions in crustaceans like prawns, whereas all the other statements are true.