Use the Following Information to Answer the Question

question 42

Multiple Choice

Use the following information to answer the question.
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways:
(1) if kept in darkness, the algae will die; and
(2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae.
Which term best describes the symbiotic relationship of well-fed P. bursaria to their zoochlorellae?

• A) mutualistic
• B) parasitic
• C) predatory
• D) pathogenic

---

Definitions:

Mental Representation

The mental imagery of things that are not currently seen or sensed by the sense organs.

Novel Situation

An unfamiliar or new circumstance that an individual encounters, which may require adaptation or new responses.

Concepts

Abstract ideas or general notions that exist in the mind as representations of categories of objects, events, or qualities.

Mental Representation

An internal image or symbol of external reality, representing aspects of the world or one's own mental processes or concepts.