Answer: Downstream transport and cycling of nutrients -- nutrients spiral through biotic and abiotic forms while being transported downstream.
- A The circular, rotating water currents that form naturally within flowing streams, a hydrological pattern unrelated to nutrient cycling between organisms and water
- B Downstream transport and cycling of nutrients -- nutrients spiral through biotic and abiotic forms while being transported downstream
- C The cycling of phosphorus specifically, occurring independently of any other nutrient, excluding nitrogen, carbon, and other nutrients that also spiral downstream
- D The natural meandering and lateral movement of a river channel over time, a geomorphological process distinct from nutrient transport and uptake
Correct answer: B. Downstream transport and cycling of nutrients -- nutrients spiral through biotic and abiotic forms while being transported downstream
Explanation: Nutrient spiraling: in streams, nutrients are taken up by organisms, processed, released, transported downstream, and taken up again. The spiraling length is the average distance traveled per uptake cycle.
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.