Which relationship benefits both species?

• A. Mutualism
• B. Parasitism
• C. Niche
• D. Random Distribution

Answer: (A)

Mutualism is a relationship in which both species benefit from the interaction. In the ocean, this shows up in partnerships like corals and their symbiotic algae, zooxanthellae: the algae perform photosynthesis and share the sugars with the coral, while the coral provides a protected environment and access to nutrients for the algae. Another example is cleaner fish that remove parasites from larger fish; the cleaner gains food, and the client fish benefits from being parasite-free. This differs from parasitism, where only one partner benefits at the expense of the other. A niche describes the role an organism plays in the ecosystem, not a direct two-species interaction, and random distribution refers to how organisms are spaced in the environment, not the nature of their relationship.