Understanding the Life Cycle of a Parasitic Flatworm

In a serene setting near California Peaks, children play by a watering hole, unaware of a hidden drama involving a parasitic flatworm. This flatworm undergoes a complex life cycle involving three hosts: a snail, a tadpole, and a heron. The flatworm first invades a snail, turning it into a parasite-producing machine. The larvae then infect tadpoles, causing deformities as they grow into frogs. These crippled frogs are easy prey for herons, which then spread the parasite to new locations, continuing the cycle.

What is the initial host for the parasitic flatworm?

• A fish

• A bird

• A snail

• A frog

How do the flatworm larvae affect the tadpoles?

• They help them swim better

• They make them immune to predators

• They cause deformities in their limbs

• They make them grow faster

Why are the deformed frogs more vulnerable to predators?

• They are slower and less able to escape

• They attract more predators

• They make loud noises

• They are more visible to predators

Which animal helps spread the flatworm to new locations?

• Fish

• Tadpoles

• Snails

• Birds

What happens to the flatworm when the infected frog is eaten by a bird?

• It becomes dormant

• It dies

• It is spread to new ponds

• It infects the bird

What role do birds play in the life cycle of the flatworm?

• They are immune to the parasite

• They help spread the parasite

• They destroy the parasite

• They are the primary host