UPSC CSE Prelims
Biodiversity and Conservation Previous Year Questions (PYQs)
Showing solved Previous Year Questions for Chapter: Biodiversity and Conservation
Topic Breakdown: Scroll →
Consider the following:
- Bats
- Bears
- Rodents
The phenomenon of hibernation can be observed in which of the above kinds of animals?
Detailed Explanation:
✅ Statement 1 – Correct: Bats undergo hibernation during winter months when insect prey becomes scarce, entering torpor to conserve energy.
✅ Statement 2 – Correct: Bears (brown bears, black bears, polar bears) are well-known hibernators, though they experience a lighter form of dormancy compared to true hibernators.
✅ Statement 3 – Correct: Many rodent species like groundhogs, chipmunks, ground squirrels are true hibernators with drastically reduced body temperature and metabolic rate.
Among the following organisms, which one does not belong to the class of the other three?
Detailed Explanation:
Crab belongs to class Crustacea, while Mite, Scorpion, and Spider all belong to class Arachnida.
Both are arthropods, but Crustaceans typically have two pairs of antennae and gills, whereas Arachnids have no antennae and possess eight legs.
Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss?
- Hard and waxy leaves
- Tiny leaves or no leaves
- Thorns instead of leaves
Select the correct answer using the codes given below.
Detailed Explanation:
✅ Statement 1 – Correct: Desert plants develop hard, waxy cuticles on leaves to create a waterproof barrier that prevents transpiration and water loss.
✅ Statement 2 – Correct: Reduced leaf size or complete leaf loss minimizes surface area exposed to heat and sunlight, thereby reducing water evaporation.
✅ Statement 3 – Correct: Leaf modification into thorns/spines drastically reduces transpiring surface area while providing protection from herbivores in arid environments.
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Contour bunding is a method of soil conservation used in
Detailed Explanation:
Contour bunding is a soil and water conservation technique used on sloping lands (typically 2-10% gradient) where earthen embankments are constructed along contour lines to reduce water runoff velocity and prevent soil erosion.
It is primarily employed in rainfed agricultural areas on gentle to moderate slopes, not in desert margins (where wind breaks are used), flat plains (where leveling/drainage is needed), or scrublands (where weed control is unrelated to contour structures).
Consider the following fauna of India:
- Gharial
- Leatherback turtle
- Swamp deer
Which of the above is/are endangered?
Detailed Explanation:
✅ Gharial (Gavialis gangeticus) – Listed as Critically Endangered (CR) on IUCN Red List; faces drastic population decline due to habitat loss, prey depletion, and fishing nets.
✅ Leatherback turtle (Dermochelys coriacea) – Categorized as Vulnerable (VU) globally; found in Andaman & Nicobar Islands; protected under Schedule I, Wildlife Protection Act, 1972.
✅ Swamp deer/Barasingha (Rucervus duvaucelii) – Listed as Vulnerable (VU) on IUCN Red List; threatened by habitat fragmentation and grassland conversion.
All three species fall under IUCN 'Threatened' categories (CR/EN/VU) and are considered endangered in broader conservation context.
Consider the following:
- Star tortoise
- Monitor lizard
- Pygmy Hog
- Spider monkey
Which of the above are found in India?
Detailed Explanation:
✅ Star Tortoise – Found in India: Native to dry scrub forests of south and west India, listed as Vulnerable on IUCN Red List.
✅ Monitor Lizard – Found in India: Four species (Bengal Monitor, Water Monitor, Desert Monitor, Yellow Monitor) protected under Schedule I of Wildlife Protection Act, 1972.
✅ Pygmy Hog – Found in India: World's smallest and rarest wild pig, now restricted to Manas National Park, Assam, listed as Critically Endangered.
❌ Spider Monkey – Not Found in India: New World monkey native to Central and South America (southern Mexico to Brazil), absent from Indian wildlife.
Consider the following organisms:
- Agaricus
- Nostoc
- Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers?
Detailed Explanation:
Nostoc is a nitrogen-fixing cyanobacterium (blue-green algae) used as a biofertilizer due to its ability to fix atmospheric nitrogen and enrich soil.
Agaricus is a mushroom (fungus) used for food, not as a biofertilizer.
Spirogyra is a green alga (filamentous) used for research and education, not as a biofertilizer.
In which of the following States is lion-tailed macaque found in its natural habitat?
- Tamil Nadu
- Kerala
- Karnataka
- Andhra Pradesh
Select the correct answer using the codes given below.
Detailed Explanation:
✅ Statement 1 – Correct: Lion-tailed macaque is found in Tamil Nadu's Western Ghats forests, particularly in Anaimalai Hills and surrounding evergreen regions.
✅ Statement 2 – Correct: Kerala hosts significant populations in Silent Valley National Park and other Western Ghats rainforests.
✅ Statement 3 – Correct: Karnataka's Western Ghats regions including Kudremukh and Sirsi-Honnavara ranges form part of the natural habitat.
❌ Statement 4 – Incorrect: Andhra Pradesh lies outside the Western Ghats endemic zone; the species is not found naturally in this state.
Consider the following animals:
- Sea cow
- Sea horse
- Sea lion
Which of the above is/are mammal/mammals?
Detailed Explanation:
Sea Cow (Dugong): A herbivorous marine mammal found in coastal waters of the Indian and Pacific Oceans; classified under class Mammalia.
Sea Horse: A carnivorous fish (not a mammal) belonging to class Osteichthyes; found in shallow tropical and temperate waters.
Sea Lion: A carnivorous marine mammal of family Otariidae; breeds on Pacific and Atlantic coasts; classified under class Mammalia.
Therefore, only Sea Cow (1) and Sea Lion (3) are mammals.
Government of India encourages the cultivation of ‘sea buckthorn’. What is the importance of this plant?
- It helps in controlling soil erosion and preventing desertification.
- It is a rich source of biodiesel.
- It has nutritional value and is well-adapted to live in cold areas of high altitudes.
- Its timber is of great commercial value.
Detailed Explanation:
✅ Statement 1 – Correct: Sea buckthorn is a soil-binding plant with extensive root systems that effectively control soil erosion and prevent desertification, particularly in fragile Himalayan ecosystems.
❌ Statement 2 – Incorrect: Sea buckthorn is not a source of biodiesel; it is cultivated for its berries, leaves, and medicinal/nutritional products, not biofuel production.
✅ Statement 3 – Correct: The plant has high nutritional value with berries rich in vitamins C, E, carotenoids, and omega fatty acids, and thrives in cold, high-altitude regions like Ladakh and Spiti (-40°C to +40°C tolerance).
❌ Statement 4 – Incorrect: Sea buckthorn is a shrub, not a timber tree; its commercial value lies in fruits, cosmetics, pharmaceuticals, not timber.
What is the difference between the antelopes Oryx and Chiru?
Detailed Explanation:
✅ Statement 1 – Correct: Oryx is a genus of four large antelope species adapted to hot and arid areas of Africa and Arabia, whereas Chiru (Tibetan antelope) is adapted to steppes and semi-desert areas of cold high mountains on the Tibetan Plateau.
❌ Statement 2 – Incorrect: Oryx has horns (not antlers) but is not primarily poached for them; Chiru is poached for its fine underfur (shahtoosh), not musk.
❌ Statement 3 – Incorrect: Oryx does not exist in western India naturally (found in Africa/Arabia); Chiru is found in Ladakh and high-altitude regions, not north-east India.
Consider the following:
- Black-necked crane
- Cheetah
- Flying squirrel
- Snow leopard
Which of the above are naturally found in India?
Detailed Explanation:
✅ Black-necked crane – Correct: Naturally found in Ladakh and Arunachal Pradesh (trans-Himalayan regions); migrates to India during winter.
❌ Cheetah – Incorrect: Declared extinct in India since 1952; the last three cheetahs were shot in Chhattisgarh (then part of Madhya Pradesh) in 1947. Recent reintroductions in Kuno National Park (2022) are not naturally found populations.
✅ Flying squirrel – Correct: Several species naturally occur in India, including Indian Giant Flying Squirrel (Western Ghats) and Red Giant Flying Squirrel (Northeast forests).
✅ Snow leopard – Correct: Found in high-altitude Himalayan and trans-Himalayan regions (Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh) at elevations above 3,000–5,500 meters.
Consider the following kinds of organisms :
- Bat
- Bee
- Bird
Which of the above is/are pollinating agent/agents?
Detailed Explanation:
Pollinating agents are organisms that transfer pollen from male to female parts of flowers, enabling fertilization and seed production.
Bats (especially frugivorous and nectar-feeding species) pollinate tropical and desert plants while feeding on nectar, with pollen sticking to their fur.
Bees are the most efficient pollinators, collecting nectar and pollen for food and transferring pollen between flowers during foraging.
Birds (like hummingbirds, sunbirds, and honeyeaters) pollinate brightly colored, tubular flowers while feeding on nectar, with pollen adhering to their beaks and feathers.
All three organisms — bats, bees, and birds — are important pollinating agents in various ecosystems.
Vultures which used to be very common in the Indian countryside some years ago are rarely seen nowadays. This is attributed to
Detailed Explanation:
Diclofenac, a non-steroidal anti-inflammatory drug (NSAID) used by cattle owners to treat livestock, caused the catastrophic decline of vulture populations in India.
Vultures feeding on carcasses of diclofenac-treated cattle suffered acute kidney failure, leading to a 99% population crash of three species (White-rumped, Indian, and Slender-billed vultures) between the 1990s and early 2000s. India banned veterinary diclofenac in 2006.
Which one of the following groups of animals belongs to the category of endangered species?
Detailed Explanation:
Great Indian Bustard is Critically Endangered (IUCN), found in Rajasthan and Gujarat; Musk Deer is Endangered, hunted for musk pods in Himalayas; Red Panda is Endangered, native to eastern Himalayas; Asiatic Wild Ass (Khur) is Near Threatened (IUCN) but Schedule I species under Wildlife Protection Act, 1972.
Options 2, 3, and 4 are incorrect because they include Least Concern species: Cheetal, Blue Bull (Nilgai), Rhesus Monkey, and Hanuman Langur. Additionally, Saras Crane and Swamp Deer are Vulnerable, not Endangered.