UPSC Prelims 2021
World Geography Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 2 — 2 and 3 Only

This question tests knowledge about international seabed governance and mineral resources. Statement 1 is incorrect because the International Seabed Authority (ISA), not the Global Ocean Commission, grants licenses for seabed exploration. Statements 2 and 3 are correct as India holds ISA licenses for deep-sea mineral exploration and rare earth minerals are indeed present on the international seabed.

❌ Statement 1 – Incorrect: The International Seabed Authority (ISA) regulates seabed mining in international waters, not the Global Ocean Commission, which was a 2013-2016 advisory initiative focused on ocean degradation and high seas governance.

✅ Statement 2 – Correct: India has received multiple licenses from the International Seabed Authority for seabed mineral exploration in international waters, including areas in the Central Indian Ocean Basin (since 1987, renewed in 2002 and 2017) and for polymetallic sulphides in the Indian Ocean Ridge (2016).

✅ Statement 3 – Correct: Rare earth minerals are found in polymetallic nodules and deep-sea sediments on the ocean floor in international waters, though their commercial extraction remains economically challenging.

📝 Short Notes: International Seabed Authority (ISA) and Deep-Sea Mining

• International Seabed Authority (ISA): Autonomous international organization established under UNCLOS (1994) to regulate mineral-related activities in the international seabed area beyond national jurisdiction (the 'Area').
• Headquarters: Kingston, Jamaica; 167 member states and the European Union.
• India's ISA Licenses: Pioneer Investor status (1987) for polymetallic nodules in Central Indian Ocean Basin; renewed licenses in 2002 and 2017; additional license for polymetallic sulphides exploration in Indian Ocean Ridge (2016).
• Deep-Sea Minerals: Include polymetallic nodules (manganese, nickel, cobalt, copper), polymetallic sulphides (copper, zinc, gold, silver), and cobalt-rich ferromanganese crusts containing rare earth elements.
• Global Ocean Commission: Temporary initiative (2013-2016) led by former heads of state to propose reforms for high seas governance; not a regulatory body.
• India's Deep Ocean Mission: Launched to explore deep-sea resources, develop deep-sea technologies, and enhance understanding of ocean resources including minerals in India's licensed areas.

Detailed Explanation:

Answer: Option 2 — 2 Only

This question tests the understanding of Earth's water distribution. Statement 1 is incorrect because groundwater constitutes a much larger portion of Earth's freshwater compared to the relatively small volumes found in rivers and lakes. Statement 2 is correct as polar ice caps and glaciers store significantly more water than groundwater reservoirs.

❌ Statement 1 – Incorrect: The amount of water in rivers and lakes is much less than groundwater; groundwater accounts for approximately 30% of Earth's freshwater while rivers and lakes contain less than 1%.

✅ Statement 2 – Correct: Polar ice caps and glaciers contain about 68-70% of Earth's freshwater, which is significantly more than the groundwater storage.

📝 Short Notes: Distribution of Earth's Water

Detailed Explanation:

Answer: Option 3 — 2, 3 and 4

Savannah vegetation is characterized by grasslands with scattered small trees. Forest development in these areas is primarily limited by fire, grazing herbivores, and seasonal rainfall. Fire burns young tree saplings preventing forest establishment, grazing herbivores consume tree seedlings before they mature, and the distinct wet-dry seasonal rainfall pattern favors grasses over trees.

✅ Statement 2 (Fire) – Correct: Frequent fires in savannahs burn tree saplings while grasses survive due to their underground root systems and rapid regeneration.

✅ Statement 3 (Grazing herbivores) – Correct: Large herbivores consume young tree seedlings and saplings, preventing trees from establishing and maintaining grassland dominance.

✅ Statement 4 (Seasonal rainfall) – Correct: The pronounced wet and dry seasons create conditions favorable for grasses rather than dense forest growth, as trees require more consistent moisture.

❌ Statement 1 (Burrowing animals and termites) – Incorrect: While these organisms affect the ecosystem, they are not primary factors preventing forest development in savannahs.

❌ Statement 5 (Soil properties) – Incorrect: Soil properties influence vegetation types but are not the primary limiting factors for forest development in savannah regions.

📝 Short Notes: Savannah Ecosystem

• Location: Transitional climate zone between equatorial rainforests and hot deserts, found in tropical regions (Africa, South America, Australia)
• Climate Characteristics: Distinct wet and dry seasons; less rainfall than monsoon climates; temperatures remain high year-round
• Vegetation: Dominated by tall grasses (up to 3-4 meters) with scattered drought-resistant trees (acacia, baobab)
• Fire Ecology: Natural fires occur during dry season; grasses adapted to fire with underground stems; trees susceptible when young
• Herbivore Impact: Home to large grazing animals (zebras, wildebeest, elephants) that prevent tree encroachment through browsing
• Rainfall Pattern: 500-1500mm annually, concentrated in summer months; long dry season (6-8 months) limits tree growth
• Nickname: Called 'Big Game Country' due to abundant wildlife populations

Detailed Explanation:

Answer: Option 3 — Both 1 and 2

Both statements correctly describe the influence of prevailing winds on ocean temperature distribution. Trade winds in tropical zones and westerlies in temperate zones drive warm surface currents in their respective directions, creating distinct temperature patterns across ocean basins.

✅ Statement 1 – Correct: Trade winds (blowing east to west) in tropical zones push warm surface waters westward, making western sections of tropical oceans warmer than eastern sections (e.g., warm Western Pacific versus cool Eastern Pacific).

✅ Statement 2 – Correct: Westerlies (blowing west to east) in temperate zones drive warm waters eastward, making eastern sections warmer than western sections (e.g., warm North Atlantic Drift warming Western Europe).

📝 Short Notes: Ocean Temperature Distribution and Wind Patterns

• Trade Winds mechanism: Push warm equatorial waters westward, causing warm water accumulation on western ocean boundaries and upwelling of cold water on eastern boundaries
• Westerlies mechanism: Drive warm currents from west to east, transferring heat from lower latitudes to higher latitudes on eastern ocean sides
• Western boundary currents: In tropical zones (e.g., Gulf Stream, Kuroshio) are warm, narrow, and fast-flowing
• Eastern boundary currents: In tropical zones (e.g., California Current, Peru Current) are cold, wide, and slow-flowing
• Climate impact: These patterns significantly influence coastal climates, with western tropical coasts being warmer and wetter, while eastern tropical coasts are cooler and drier

Detailed Explanation:

Answer: Option 4 — tropical rain forest

The description perfectly characterizes tropical rain forests, where high temperature and humidity year-round create optimal conditions for rapid microbial decomposition of leaf litter, leaving the soil surface almost bare. The dense multi-layered canopy blocks sunlight to the forest floor, forcing many plants to adapt by climbing trees (lianas) or growing as epiphytes on upper branches to access light. These unique features—rapid nutrient cycling, bare soil surface, and abundant epiphytes—are hallmarks of tropical rain forests, distinguishing them from coniferous, deciduous, or mangrove ecosystems.

📝 Short Notes: Forest Biomes - Comparative Features

• Epiphytes in Tropical Rain Forests: Non-parasitic plants (orchids, bromeliads, ferns) that grow on tree branches to access sunlight without competing for soil nutrients.
• Rapid Nutrient Cycling: Despite lush vegetation, tropical rain forest soils are often nutrient-poor because nutrients are quickly absorbed by plants rather than accumulating in soil.
• Indian Distribution: Tropical rain forests in India are found in Western Ghats, Northeast states (Assam, Arunachal Pradesh), and Andaman & Nicobar Islands.
• Key Species: Mahogany, Rosewood, Ebony, Rubber, Cinchona in tropical rain forests.

Detailed Explanation:

Answer: Option 3 — Phosphorus Cycle

The Phosphorus Cycle is unique among biogeochemical cycles as it lacks a gaseous phase and primarily relies on the weathering of phosphate-rich rocks as its main source. Geological weathering processes break down these rocks over time, releasing phosphate ions (PO₄³⁻) into the soil and water, which are then absorbed by plants and move through the food chain.

Why other options are incorrect:
• Carbon Cycle: Primarily driven by atmospheric CO₂ from respiration, combustion, and volcanic activity, not rock weathering.
• Nitrogen Cycle: Relies on atmospheric nitrogen with fixation by bacteria as the key process, not weathering of rocks.
• Sulphur Cycle: Main sources include volcanic eruptions, decaying organic matter, and fossil fuel combustion, not primarily rock weathering.

📝 Short Notes: Biogeochemical Cycles

Detailed Explanation:

Answer: Option 2 — 2 and 3 Only

This question tests knowledge about palm oil's origin, industrial applications, and use as biofuel. Statement 1 is incorrect as the oil palm tree is native to West Africa, not Southeast Asia, though major production now occurs in Indonesia and Malaysia. Statements 2 and 3 are correct regarding palm oil's use in cosmetics and biodiesel production.

❌ Statement 1 – Incorrect: The oil palm tree (Elaeis guineensis) is native to West Africa, not Southeast Asia. However, it was introduced to Southeast Asia in the 19th century, and today Indonesia and Malaysia account for about 85% of global palm oil production.

✅ Statement 2 – Correct: Palm oil and its derivatives are extensively used in cosmetic industries for manufacturing lipsticks, perfumes, soaps, and lotions due to their moisturizing properties and texture-enhancing qualities.

✅ Statement 3 – Correct: Palm oil is a major feedstock for biodiesel production. Countries like Indonesia and Malaysia use Palm Methyl Ester (PME) as a renewable fuel alternative, and it is blended with conventional diesel.

📝 Short Notes: Palm Oil

• Botanical Origin: Oil palm (Elaeis guineensis) is native to West and Central Africa, particularly the coastal regions of Angola, Benin, Cameroon, and Nigeria.
• Major Producers: Indonesia (58% of global production) and Malaysia (27%) are the world's largest producers, contributing about 85% of total global output.
• Industrial Uses: Food industry (cooking oil, margarine), cosmetics (soaps, lipsticks, creams), pharmaceuticals, and biofuel (biodiesel).
• Biodiesel Production: Palm oil has high oil yield (4-5 tonnes/hectare), making it economically viable for biodiesel. It is converted to Palm Methyl Ester (PME) through transesterification.
• India's Context: India is the world's largest importer of palm oil (about 8-9 million tonnes annually), primarily from Indonesia and Malaysia, meeting nearly 40% of its edible oil requirements.
• Environmental Concerns: Large-scale palm oil plantations have led to deforestation, habitat loss (especially for orangutans), and greenhouse gas emissions in Southeast Asia.