Which of the following show regressive metamorphosis -: (A) Hydatid cyst, (B) Cysticercoid, (C) Cysticercus bovis, (D) Cysticercus cellulosae
Answer is A. Retrogressive metamorphosis is when an organism changes from a more advanced form to a primitive one.the ruptured hydatid cyst releases protoscolices into tissues which do not develop into adult forms according to law of migration of cestodes.... but they form a new hydatid tissue against the law.... this is called regressive metamorphosis.