UGC NET Questions (Paper – 1)

Biodiversity encompasses variation at three main levels: genetic diversity within species,species diversity within communities and ecosystem diversity across landscapes. The stem explicitly mentions diversity within species,between species and of ecosystems. This threefold description is the standard way of defining biodiversity,so the correct term is biodiversity.

Option A:
Biomagnification refers to increasing concentration of certain pollutants as they move up food chains. It is a process affecting organisms but is not a measure of variety of life. Hence it does not fit the definition in the question.

Option B:
Bioaccumulation denotes the progressive build up of substances,such as pesticides,in an organism over time. While related to ecological health,it does not capture the multiple levels of diversity specified in the stem.

Option C:
Biodiversity is the umbrella term for the total variety and variability of living organisms and the ecological complexes they form. It directly corresponds to the three dimensions of diversity mentioned,so this option correctly names the concept.

Option D:
Biodegradation is the breakdown of substances by microorganisms. It relates to waste management and nutrient cycling rather than to variation in living forms. Therefore it is not the intended concept here.

Statements A, B, C, D and F are correct and collectively describe ecological, functional, cultural, climate and economic dimensions of biodiversity. Biodiversity supports key services, loss harms livelihoods, cultural meanings are important, conservation aids mitigation and adaptation, and payment schemes reward service provision. Statement E is wrong because biodiversity clearly remains essential for food, health, materials and cultural identity even in modern societies. Therefore, the combination that includes all true statements and excludes E is correct.

Option A:
Option A is incorrect as it omits F, which correctly notes the role of payment for ecosystem services in incentivising conservation. Without F, the answer misses an important policy mechanism linked to ecosystem services.

Option B:
Option B is incorrect because it leaves out C while including F. Cultural services are a standard category in ecosystem service frameworks, so excluding C gives an incomplete view of biodiversity’s contributions.

Option C:
Option C is incorrect as it includes E, a statement that denies the relevance of biodiversity to modern human well-being. Since E is clearly false, this combination mixes correct and incorrect statements.

Option D:
Option D is correct because it aggregates all the accurate statements—ecological, livelihood, cultural, climate and economic—and excludes only the claim that biodiversity has no relevance. It thus reflects the integrated role of biodiversity in people, development and environment.

Statements A, B, C, D and F are correct because they show how biodiversity underpins services, provides livelihoods, is conserved through protected areas, is threatened by invasives and must be used sustainably. Statement E is wrong since biodiversity loss affects health and cultural values. Thus, the correct combination excludes E.

Option A:
Option A is correct as it includes all true statements and excludes E.

Option B:
Option B is incorrect because it includes E (false).

Option C:
Option C is incorrect because it omits A and includes E (false).

Option D:
Option D is incorrect because it includes E and omits C.

Project Tiger is a centrally sponsored scheme started in 1973 to ensure a viable population of tigers in India and protect them from extinction. It created and strengthened a network of tiger reserves across the country. The stem mentions conservation as the central aim,which directly points to tigers. Therefore “tiger populations” correctly completes the statement.

Option A:
Tiger populations serve as flagship species whose protection also conserves entire forest ecosystems. Project Tiger focuses on habitat improvement,anti-poaching and community involvement. These goals match the conservation emphasis of the question.

Option B:
Asian elephants are conserved through different programmes and elephant reserves. They are not the primary focus of Project Tiger,so Option B is incorrect here.

Option C:
The one horned rhinoceros has its own specialised conservation efforts,especially in Assam. It is not the species named in the title of Project Tiger.

Option D:
Blackbuck conservation is handled through protected areas and specific regional initiatives. This antelope species is not the target of Project Tiger,so Option D does not fit the stem.

Ecological succession describes the gradual change in species composition and community structure over time after disturbances. Human actions such as clearing forests, burning grasslands or building infrastructure can interrupt or restart this process by removing existing vegetation and altering soil conditions. Frequent or intense disturbances may prevent ecosystems from reaching later successional stages, or they may send succession along a different trajectory altogether.

Option A:
Option A is incorrect because it suggests humans alter succession by never disturbing ecosystems, which is unrealistic and does not describe the main way people influence successional dynamics.

Option B:
Option B is incorrect because humans cannot and do not completely stop all natural disturbances such as fires, storms and grazing everywhere.

Option C:
Option C is correct because repeated disturbances like deforestation, overgrazing and construction repeatedly push ecosystems back to earlier successional stages or redirect them into novel states.

Option D:
Option D is incorrect because ecological theory recognises multiple potential stable states and ongoing dynamics; it is unrealistic to expect all ecosystems to quickly reach and remain in a single climax state, especially under strong human influence.

The Silent Valley movement opposed the construction of a hydroelectric dam that would have submerged unique tropical rainforest in the Western Ghats. Activists argued that the ecological loss would outweigh power gains. The stem refers to a project on the Kuntipuzha river,which was specifically a hydroelectric project. Therefore Option A is correct.

Option A:
Hydroelectric projects can provide renewable electricity but may also cause serious ecological and social impacts. In Silent Valley the concern was protecting an undisturbed rainforest ecosystem. This context aligns with the question.

Option B:
Mining was not the central issue in Silent Valley,although mining threatens other forest areas. The campaign here focused on stopping a dam,rather than extraction of minerals.

Option C:
An expressway affects land and traffic patterns,but Silent Valley’s controversy did not involve road construction. Thus Option C is not relevant.

Option D:
An airport project was not proposed in this forested area. The key threat was flooding from a reservoir,so Option D does not match the historical facts.

Statements A, B and C are correct: biodiversity provides a range of products to communities, supports resilience to shocks and can be conserved in ways that recognise rights and livelihoods. Statement D is incorrect because biodiversity underpins economic activities and cultural traditions as well as ecological processes. The correct combination is therefore A, B and C only.

Option A:
Option A is incomplete as it leaves out C, which accurately notes that conservation policies can and should consider customary rights and livelihoods. Without C, the social-justice dimension is missing.

Option B:
Option B is incorrect because it includes D along with A and B. By treating D as correct, it denies the economic and cultural significance of biodiversity, which is inconsistent with the syllabus.

Option C:
Option C is correct since it gathers the three true statements and excludes the false one, presenting a holistic view of biodiversity’s ecological, economic and social importance.

Option D:
Option D is incorrect because it includes D, which is wrong, and omits A, thereby downplaying direct livelihood dependence on biodiversity.

Statements B, C and D are correct descriptions of biodiversity conservation concepts. Statement B identifies in-situ conservation through national parks and sanctuaries, C explains ex-situ conservation through gene banks and botanical gardens and D notes that biodiversity loss undermines ecosystem stability and livelihoods. Statement A is incorrect because biodiversity covers the diversity of genes, species and ecosystems, not only animals. Thus the correct combination is the one that includes B, C and D only.

Option A:
Option A is incorrect because it includes B and C but leaves out D. While B and C are correct, D is also a true statement since biodiversity loss clearly affects ecosystem services and human well-being. By omitting a correct statement, this option fails to capture the full set of correct statements.

Option B:
Option B is correct because it brings together all three correct statements B, C and D and excludes the incorrect statement A. It recognises both in-situ and ex-situ approaches and the link between biodiversity and ecosystem stability. Hence this combination matches the conceptual understanding required in the unit.

Option C:
Option C is incorrect because it includes statement A along with B and C. Statement A narrows biodiversity to animals only, ignoring plants, microorganisms and ecosystem diversity, which is conceptually wrong. Presence of this incorrect statement makes the whole combination unacceptable.

Option D:
Option D is incorrect because it asserts that all four statements A, B, C and D are correct. Since A is an incorrect definition of biodiversity, selecting all four means accepting a wrong idea. A correct option must exclude statement A while retaining B, C and D.