Answer: Both organisms benefit.
- A One benefits, one is harmed
- B Both organisms benefit
- C One benefits, other is unaffected
- D Neither benefits
Correct answer: B. Both organisms benefit
Explanation: Mutualism: both species benefit (e.g., bees and flowers, cleaner fish and sharks, Rhizobium and legumes).
Energy pyramid showing a simple food chain (producer to herbivore to carnivore) with energy decreasing roughly tenfold at each trophic level.
Concept context
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation.