23 public questions tagged with this topic.
Keystone species are not necessarily the most abundant, but they play a crucial role in maintaining ecosystem structure.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Predation and Herbivory
Keystone species are not necessarily the most abundant, but their presence significantly affects ecosystem structure and function.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Predation and Herbivory
Keystone species are not necessarily the most abundant but play a critical role in maintaining ecosystem structure.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Predation and Herbivory
Keystone species, such as tigers, play a crucial role in maintaining ecosystem balance by controlling prey populations.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Life History Variations and Population Interactions - Overview
Keystone species play a crucial role in ecosystem structure, and their removal can have cascading effects on the ecosystem.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Attributes - Birth Death Sex Ratio Age Distribution
Keystone species are not necessarily the most abundant but play a crucial role in maintaining ecosystem structure.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Adaptations - Morphological Physiological Behavioural
Tigers regulate prey populations and maintain ecosystem balance, making them keystone species.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
Keystone species are not necessarily the most abundant, but they have a disproportionately large impact on ecosystem structure.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
A keystone species plays a critical role in maintaining ecosystem balance, even if it is not the most abundant.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Organism and Environment - Major Biomes Abiotic Factors
“Keystone species” for a species causing ecosystem changes despite being few in number is classified as a. 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—“Dominant species”, “Invasive species”, “Indicator species”—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. 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: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation
“Keystone predator” for what role does the sea otter play in kelp forest ecosystems. 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—“Primary producer”, “Dominant herbivore”, “Generalist species”—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: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation
“Low biomass, significant ecosystem impact” for keystone species typically have. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. A sound explanation connects the stated pattern to a causal pathway and distinguishes it from alternatives that describe different levels of organization or different ecological processes. The remaining alternatives—“High abundance and biomass”, “Moderate biomass, low ecosystem impact”, “High biomass, no impact”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Ecological interpretation requires separating the immediate process from its broader consequence. A mechanism operating through physiology or behavior can scale up to alter survival, reproduction, abundance, distribution, and community structure. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.
Ref: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation
