Practice question

Fertilization in frogs generally external occurring outside female body in aquatic environment, male grasping female in axillary amplexus stimulates oviposition of several hundred eggs surrounded by gelatinous jelly coats, simultaneously releasing sperms over clutch where hypoosmotic activation enhances motility, syngamy occurs within water film outside parental tissues. Absence of intromittent organ or oviducal sperm storage, lack of shelled amniotic egg, reliance on water prevents desiccation. High fecundity compensates predation losses, internal fertilization seen in few caudates and caecilians not typical anurans, parthenogenesis essentially absent.