6 public questions tagged with this topic.
Nutrient cycling is a cyclic process, not unidirectional, ensuring the continuous reuse of essential nutrients in an ecosystem.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Ecosystem - Structure Components Stratification
Bacteria play a key role in the nitrogen cycle by converting atmospheric nitrogen into forms usable by plants.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Organism and Environment - Major Biomes Abiotic Factors
“Sedimentation” for what process describes nutrients settling and locking into ocean sediments. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. 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—“Leaching”, “Respiration”, “Immobilization”—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. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 18
The keyed exception is “Nitrite.” In the context of which component is not part of the sulfur cycle, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. 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. The remaining alternatives—“Sulfate”, “Sulfur dioxide”, “Hydrogen sulfide”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The relevant inference should follow the pathway from resource supply to organismal uptake and then to ecosystem-level flux. Productivity, trophic transfer, decomposition, and nutrient regeneration are connected, but each measures a different part of that pathway. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 18
“Phosphorus” for which element is responsible for eutrophication in freshwater lakes. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. 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. The remaining alternatives—“Carbon”, “Nitrogen”, “Sulfur”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The relevant inference should follow the pathway from resource supply to organismal uptake and then to ecosystem-level flux. Productivity, trophic transfer, decomposition, and nutrient regeneration are connected, but each measures a different part of that pathway. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 18
“Local cycle” for phosphorus cycle is considered a. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. The relevant inference should follow the pathway from resource supply to organismal uptake and then to ecosystem-level flux. Productivity, trophic transfer, decomposition, and nutrient regeneration are connected, but each measures a different part of that pathway. The remaining alternatives—“Global cycle”, “Atmospheric cycle”, “Cyclic respiration”—refer to different states, processes, or scales and therefore do not express the same causal relationship. 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. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 18
