Which of the following show regressive metamorphosis?
Ans. is 'a' i.e., Hydatid cyst(Ref: D.R. Arora, 3rd/e, p. 141)* Regressive metamorphosis: Sometimes, hydatid cyst (containing protoscolices) may rupture in intermediate host to release its content in the tissue. If such a patient survives, the released protoscolices may revert to hydatid cyst instead of developing into an adult worm (Normally protoscolex give rise to adult worm).
Hydatid cyst
Cysticercoid
Cysticercus bovis
Cysticercus cellulosae
Parasitology