UGC NET — Environmental Sciences (subject code 89) · India · National Testing Agency for the University Grants Commission
Original practice questions written to the published syllabus · not past papersWhat biodiversity is, how it is measured, why it is being lost and how it is conserved, from IUCN Red List categories and protected areas to the Kunming-Montreal Global Biodiversity Framework.
In the exams: ICAR AICE subject 71 Unit 2 (whole unit); GATE ES Section 8 (biodiversity); UGC NET Unit 3; UPSC CSE Prelims environment (heavily asked)
UGC NET Environmental Sciences (Unit 3) and professional ecologists (ESA Certified Ecologist)
Biodiversity measurement, conservation biology concepts (MVP, PVA, SLOSS, extinction vortex), drivers of loss, invasive species management and conservation planning.
How our questions for UGC NET spread across the units of Biodiversity Science & Conservation. Difficulty: 16 easy, 34 medium, 21 hard.
| Drivers of biodiversity loss: land-use change, overexploitation, climate, pollution, invasive species | 8 | |
| IUCN Red List categories and criteria | 8 | |
| Measuring biodiversity: alpha, beta, gamma diversity and indices | 7 | |
| Convention on Biological Diversity and the Kunming-Montreal Global Biodiversity Framework | 7 | |
| Values of biodiversity: use, non-use, intrinsic | 6 | |
| In-situ conservation: protected areas, biosphere reserves | 6 | |
| Biogeographic realms and biodiversity hotspots | 5 | |
| Island biogeography and species-area relationships | 5 | |
| Invasive alien species management | 5 | |
| National biodiversity laws and access and benefit-sharing | 5 | |
| Levels of biodiversity: genetic, species, ecosystem | 4 | |
| Population viability and minimum viable population | 3 | |
| Ex-situ conservation: zoos, botanic gardens, seed and gene banks | 2 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Approximately how many species have been formally described by science?
C. About 2 million
Around 2.1 million species are described; estimates of total eukaryotic species are several times higher (one estimate is about 8.7 million). 20000 and 200000 are far too low; 200 million far exceeds described species.
Further reading: Mora et al. 2011; IUCN
What does environmental DNA (eDNA) metabarcoding allow ecologists to do?
C. Detect species from DNA traces in water or soil samples
eDNA metabarcoding sequences DNA shed into the environment to detect which species are present, aiding surveys of fish, amphibians and soil biota. It does not date trees, clone extinct species or edit genomes.
Further reading: Biodiversity monitoring literature
According to Myers and colleagues (2000), the original 25 hotspots covered what share of the land surface?
D. 1.4 %
The 25 hotspots covered 1.4 % of land yet held 44 % of vascular plants and 35 % of terrestrial vertebrates as endemics. 44 % is the plant share, not area.
Further reading: Myers et al. 2000
According to IPBES (2019), which is the largest direct driver of biodiversity loss on land globally?
B. Changes in land use
IPBES ranked land- and sea-use change first, then direct exploitation, climate change, pollution and invasive species. On land, agricultural expansion dominates.
Further reading: IPBES Global Assessment 2019
Roughly how many species did the IPBES Global Assessment (2019) estimate to be threatened with extinction?
D. About 1 million
IPBES estimated around one million animal and plant species threatened with extinction, many within decades.
Further reading: IPBES Global Assessment 2019
Which of the five past mass extinctions was the largest?
C. The end-Permian extinction
The end-Permian event (about 252 million years ago) eliminated the largest share of marine and terrestrial species. The end-Cretaceous, which ended the non-avian dinosaurs, is the most famous but not the largest.
Further reading: Primack, Essentials of Conservation Biology
Why does acting only on direct drivers often fail to halt biodiversity loss?
C. Indirect drivers keep creating pressures
Land conversion, exploitation and pollution are driven by demand, trade, technology, governance and values; without addressing these, pressures shift elsewhere. Direct drivers clearly matter, indirect drivers are policy-sensitive, and no threshold of protection stops loss automatically.
Further reading: IPBES Global Assessment 2019
Which agricultural change is most linked to declines in farmland birds and insects in Europe?
B. Agricultural intensification
Studies link declines to simplified landscapes, loss of non-crop habitat and pesticide and fertiliser use. Organic schemes, legume rotations and fallows generally support farmland biodiversity.
Further reading: Farmland biodiversity studies
What was the 'SLOSS' debate about?
D. Whether a single large or several small reserves of equal total area conserve more species
SLOSS asked whether one large reserve or several small ones of the same total area are better; the answer depends on species, habitats and threats. The other expansions are invented.
Further reading: Diamond 1975; Simberloff and Abele 1976
Why can a species be globally Least Concern yet legally protected in India?
C. They are separate: global science versus national law
IUCN assessments are scientific and global; Wildlife (Protection) Act schedules reflect national status, trade and cultural considerations. The Red List is not law, India does not copy it into schedules, and national law can protect any species.
Further reading: IUCN; Wildlife (Protection) Act
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