Explanation

Fasciola hepatica is a dignetic termatode. It spends its life cycle in two hosts. Sheep (primary host) and the invertebrate host (intermediate host) snail. They have an alternation of generation in their life cycle. This means the egg hatches into a larval form, this larval form reproduces asexually to produce numerous copies of itself. Eventually, these copies change into another larval form, which in time grows into a sexually reproducing adult. This possession of an asexual generation, means that a single egg can produce not just one infectious agent, but may be even tens or hundreds or thousands.