Snails Typically Avoid Sunlit Areas, but Some Snails Infected with Certain

question 21

Multiple Choice

Snails typically avoid sunlit areas, but some snails infected with certain parasites become attracted to light and prefer sunlit areas. Which of the following is the most likely hypothesis given the life cycles of many parasites?

• A) The parasite must exit the snail in a sunlit area in order to move and find its next host.
• B) The snail is dying from the parasite and is therefore looking for the light.
• C) The parasite itself must be exposed to light in order to survive in the snail.
• D) The parasite manipulates the behaviour of the snail so that it gets eaten more readily, which allows the parasite to complete its life cycle.
• E) The snail is behaving differently in order to rid itself of the parasite.

---

Definitions:

New Toy

A recently acquired or unveiled item intended for play or amusement.

Grimaces

Facial expressions often conveying disapproval, pain, or discomfort.

Screams

High-pitched, loud vocalizations that are typically a response to fear, excitement, or surprise.

Temperament

A person's natural temperament or way of behaving and typical emotional reaction.