Which term refers to a close, long-term interaction between two different species?

• A. Symbosis
• B. Symbiosis
• C. Mutualism
• D. Parasitism

Answer: (A)

Two different species living together in a long-term association is called symbiosis. This term serves as the broad category for any close, ongoing relationship between species, shaping each partner’s life over time. Within symbiosis, different outcomes exist: mutualism is when both partners benefit, and parasitism is when one benefits at the other’s expense. There’s also commensalism, where one benefits and the other is largely unaffected, though that’s not the focus here.

Symbiosis is the correct term because it covers all these long-term interactions, not just one specific type. The first option is a misspelling of symbiosis, which is not the recognized scientific term. The other choices describe particular kinds of symbiotic relationships, not the general umbrella term itself.