What is the general term for close interactions between two organisms that include mutualism, commensalism, parasitism, and competition?

• A. Predation
• B. Symbiosis
• C. Competition
• D. Cooperation

Answer: (B)

Symbiosis describes close interactions between two species. It covers mutualism, where both partners benefit; commensalism, where one benefits and the other is unaffected; and parasitism, where one benefits at the expense of the other. Some definitions also include competition under this umbrella because the two species interact and impact each other when sharing resources. Predation focuses on one organism feeding on another, which is a different kind of interaction. Cooperation isn’t the standard term used for these ecological relationships. So the broad term that fits all these examples is symbiosis.