UPSC CSE Prelims
Keystone and Flagship Species Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 4 — 1, 2, 3 and 4

All four statements are factually correct as they accurately describe the dietary habits and reproductive characteristics of various animal species. Each statement can be verified through well-documented examples from the animal kingdom.

✅ Statement 1 – Correct: Many turtle species like green sea turtles and Galapagos tortoises are herbivores, feeding primarily on plants, leaves, and fruits.
✅ Statement 2 – Correct: Numerous fish species such as surgeonfish, parrotfish, and tangs are herbivorous, feeding on algae and seaweed in marine ecosystems.
✅ Statement 3 – Correct: Some marine mammals like manatees and dugongs (sea cows) are herbivores, feeding exclusively on seagrasses and aquatic vegetation.
✅ Statement 4 – Correct: Several snake species including boas, vipers, and sea snakes are viviparous, giving birth to live young instead of laying eggs.

📝 Short Notes: Biodiversity - Feeding Types and Reproductive Modes

• Herbivory in Marine Ecosystems: Herbivorous species play crucial roles in maintaining ecosystem balance by controlling algal growth and vegetation.
• Viviparity vs Oviparity: While most reptiles are oviparous (egg-laying), viviparity has evolved in several snake families as an adaptation to specific environmental conditions.
• Green Sea Turtle: Adults are almost exclusively herbivorous, feeding on seagrasses and algae, though juveniles may be omnivorous.
• Ecological Importance: Herbivorous fish are essential for coral reef health as they prevent algal overgrowth that can smother corals.

Detailed Explanation:

✅ Statement 1 – Correct: Neem oil contains azadirachtin, a natural compound that effectively controls the proliferation of insects and mites by disrupting their growth and feeding patterns, making it a widely used biopesticide.

❌ Statement 2 – Incorrect: While neem seeds have been explored for various applications, they are not commercially used for manufacturing biofuels or hospital detergents. Hospital detergents require regulated chemical formulations with specific disinfectant properties.

✅ Statement 3 – Correct: Neem oil has significant applications in the pharmaceutical industry, including anti-bacterial, anti-fungal, anti-inflammatory, and anti-diabetic properties, and is used in various medicinal formulations and traditional Ayurvedic preparations.

Detailed Explanation:

✅ Statement 1 – Incorrect: Painted Storks are wading birds that feed on fish, frogs, and aquatic insects in shallow water bodies; they do not follow cattle through grasslands.

✅ Statement 2 – Correct: Common Mynas are insectivorous birds commonly seen following cattle and grazing animals to catch insects disturbed by their movement through grasses.

✅ Statement 3 – Incorrect: Black-necked Cranes are primarily herbivorous, feeding on grains, tubers, and aquatic plants; they are not known for insect-hunting behavior alongside cattle.

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.

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.

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.

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.