IAS Prelims Geography Q.1–2025 | Andes Mountains & South America

Authentic Classroom Explanation by IAS Monk

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❓ Question

Consider the following countries:

I. Bolivia
II. Brazil
III. Colombia
IV. Ecuador
V. Paraguay
VI. Venezuela

Andes mountains pass through how many of the above countries?

(a) Only two
(b) Only three
(c) Only four
(d) Only five

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✅ Correct Answer

(c) Only four

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🎯 Theme of the Question

Physical Geography | World Geography | Major Mountain Systems | South America

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🧠 Classroom Explanation

The Andes Mountains form the longest continental mountain range in the world and run continuously along the western edge of South America.

UPSC uses such questions to test whether aspirants can:

• Visualise continental-scale physical features,
• Distinguish mountain systems from plateaus, and
• Avoid country-level traps like Brazil and Paraguay.

The Andes stretch for about 7,000 km, created by the subduction of the Nazca Plate beneath the South American Plate.

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🌍 Countries Through Which the Andes Pass

The Andes pass through seven South American countries (north to south):

• Venezuela
• Colombia
• Ecuador
• Peru
• Bolivia
• Chile
• Argentina

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🔍 Applying the Logic to the Given Countries

Country	Andes Pass Through?	Explanation
Bolivia	✅	Contains Altiplano plateau
Brazil	❌	Part of Brazilian Shield
Colombia	✅	Northern Andes present
Ecuador	✅	Andes cross the equator
Paraguay	❌	Flat lowland region
Venezuela	✅	Merida Andes

👉 Correct count = 4

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❌ UPSC Elimination Logic

• Brazil ❌ → Brazilian Highlands, not Andean system
• Paraguay ❌ → Plains, east of Andes

Once these two are eliminated, option (c) is automatically correct.

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🧠 Memory Hook

“V-C-E-P-B → Chile → Argentina”
(Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, Argentina)

👉 Brazil is never part of the Andes chain.

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🧩 Curiosity Corner

Bolivia, despite being landlocked today, still hosts Lake Titicaca, one of the highest navigable lakes in the world, entirely because of Andean uplift.

Mountains shape nations.

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📌 Enrichment Note

The Andes strongly influence:

• Rain shadow effect (Atacama Desert)
• River origins (Amazon headwaters)
• Volcanic and seismic activity
• Human settlement patterns (Altiplano civilisation)

Expect UPSC to connect the Andes with plate tectonics, climate, deserts, and biodiversity.

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🧠 Prelims Strategy Insight

• World Geography questions demand map imagination, not rote memory
• Always ask: “Is this country on the western cordillera?”
• Elimination > counting

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🧠 One-Line Ready Recall

Andes → Western South America → 7 countries → Brazil & Paraguay excluded

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🧭 IAS Monk Whisper

“In Geography, the map is the memory.”