Practice question

The keyed exception is “Herbivore efficiency higher in oceans.” In the context of which is not correct about food web energy flow, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. Rates depend on temperature, moisture, substrate quality, consumer physiology, and the elemental balance between organisms and their food. These controls explain why the same process can differ among terrestrial, freshwater, and marine systems without changing its definition. The remaining alternatives—“Herbivores enhance productivity in productive ecosystems”, “Detritus chains longer in productive systems”, “Carnivore production efficiency > herbivores”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Ecosystem processes are constrained by energy conservation and by the cycling of matter. Energy enters mainly through primary production, is lost as metabolic heat at every transfer, and therefore cannot be recycled in the way that carbon, nitrogen, phosphorus, or water can.