Answer: Light and nutrients often limit open-ocean producers.
- A Light and nutrients often limit open-ocean producers
- B Oceans have no producers
- C Decomposition does not occur in water
- D Respiration is completely absent in all marine plants
Correct answer: A. Light and nutrients often limit open-ocean producers
Explanation: Open oceans are often nutrient-poor, so despite their huge area they contribute only a fraction of the biosphere's net primary productivity.
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.