Question

During its lifecycle Fasciola hepatica (liver fluke) infects its intermediate host and primary host at the following larval stages respectively are

• A. Redia and meracidium
• B. Cercaria and redia
• C. Metacercaria and cercaria
• D. Miracidium and metacercaria

Answer 1

The correct option is D Miracidium and metacercaria

The Fasciola hepatica belongs to Platyhelminthes these have a flat body. They are bilaterally symmetrical and triploblastic.

Fasciola parasites develop into adult flukes in the bile ducts of infected mammals, which pass immature Fasciola eggs in their feces. The next part of the life cycle occurs in freshwater. After several weeks, the eggs hatch, producing a parasite form known as the miracidium, which then infects a snail, an intermediate host. Cercariae are then shed in the water around the snail. The cercariae lose their tails when they encyst as metacercariae or infective larvae on water plants, which serve as the primary hosts. Metacercariae have a hard outer cyst wall and can survive for prolonged periods.
So, the correct answer is option D.