Question

The life cycle of a liver fluke is complex. The fertilised egg containing a ciliated larva, the ______________, is released from humans or other mammals, in their ______________, and may enter a water source where it may be ingested by an aquatic ___________. Within this organism, the ciliated larva transforms into a ________________, that contains embryonic germs cells, each of which develops into a ___________, a non-ciliated larva. Each of these larvae develops into the next larval form, the _______________. These larvae escape into the water and attach to aquatic plants. On these plants the larvae develop into _____________ cysts. When ingested by a mammal, these larva mature into adult __________ and migrate to the ______ ______, where they can live for up to a decade or more. Humans are often infected by eating infected sheep or ____________.

Answer 1

Liver fluke is known as Fasciola hepatica. Fertilized egg containing ciliated larva, unembryonated egg is released from humans and other mammals in their faeces. It may enter water source where it gets ingested by aquatic snails.

Within this organism, the ciliated larva transforms into a metacercariae that contains embryonic germs cells, each of which develops into a rediae, a non-ciliated larva.

Each of these larvae develops into the next larval form, the cercariae. These larvae escape into the water and attach to aquatic plants. On these plants the larvae develop into encysts. When ingested by a mammal, these larva mature into adult fluke and migrate to the intestinal tract and liver, where they can live for up to a decade or more. Humans are often infected by eating infected sheep or undercooked crabs, fish and crayfish.