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Liver fluke (Fasciola hepatica) is an endoparasite that occurs in the liver of some farm animals - Leaving Cert Agricultural Science - Question b - 2014
Question b
Liver fluke (Fasciola hepatica) is an endoparasite that occurs in the liver of some farm animals. (i) To what phylum does F. hepatica belong? (ii) Give two charact... show full transcript
Worked Solution & Example Answer:Liver fluke (Fasciola hepatica) is an endoparasite that occurs in the liver of some farm animals - Leaving Cert Agricultural Science - Question b - 2014
Step 1
Step 2
Step 3
iii) Draw a diagram of an adult fluke, labelling any three structures.
Answer
A diagram of an adult fluke should include the following labelled structures:
- Oral Sucker: Used for attachment to the host.
- Ventral Sucker: Assists in attachment and feeding.
- Testes: The reproductive organs that produce sperm.
Step 4
c) Describe in detail, with the aid of a labelled diagram, the life cycle of the liver fluke.
Answer
The life cycle of Fasciola hepatica is as follows:
- The adult liver fluke is attached to the bile duct of a primary host, typically a cow or sheep.
- It lays fertilised eggs, which pass out of the host in the faeces.
- In water, the eggs hatch into miracidia, which then penetrate a snail (the secondary host).
- Inside the snail, the miracidia develop into cercariae, which are then released back into the water.
- The cercariae attach to grass, forming cysts (metacercariae).
- The primary host ingests these cysts while grazing, continuing the cycle.
A labelled diagram should include the primary and secondary hosts, as well as the stages of the fluke's lifecycle.