Minimalist IAS
Geography

Prelims · Geography · 16 questions

Oceans

Every UPSC Prelims question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

Oceans questions per year: 2016: 0, 2017: 0, 2018: 1, 2019: 0, 2020: 1, 2021: 3, 2022: 1, 2023: 0, 2024: 1, 2025: 0, 2026: 1 Asked in 6 of 11 years · most in 2021 (3)

Practising Geography? Take it as timed sets of 25 →

UPSC syllabus: “Indian and World Geography-Physical, Social, Economic Geography of India and the World.” Sub-topics in the detailed syllabus →

निम्नलिखित कथनों पर विचार कीजिए :

  1. 1.विश्व की सर्वाधिक प्रवाल भित्तियाँ उष्णकटिबंधीय सागर जलों में मिलती हैं ।
  2. 2.विश्व की एक-तिहाई से अधिक प्रवाल भित्तियाँ ऑस्ट्रेलिया, इंडोनेशिया और फिलीपीन्स के राज्य-क्षेत्रों में स्थित हैं ।
  3. 3.उष्णकटिबंधीय वर्षा वनों की अपेक्षा, प्रवाल भित्तियाँ कहीं अधिक संख्या में जन्तु संघों का परपोषण करती हैं ।

उपर्युक्त कथनों में से कौन-सा/से सही है/हैं ?

Read this question in English

Consider the following statements:

1. Most of the world’s coral reefs are in tropical waters.

2. More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia and Philippines.

3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.

Which of the statements given above is/are correct?

(a) 1 and 2 only · (b) 3 only · (c) 1 and 3 only · (d) 1, 2 and 3

उत्तर और व्याख्या · explanation in English

Answer: (d) 1, 2 और 3

All three statements are taken as correct. NCERT places coral reefs in the tropical oceans; half of all reef area is in just five countries, and Australia, Indonesia and the Philippines alone hold about 42% of it; and reefs host 32 of the 34 recognised animal phyla (UN).

  • ✓ 1. NCERT describes atolls as low islands of coral reefs found in the tropical oceans, so most reefs lie in tropical waters.
  • ✓ 2. Half of the world's reef surface lies in only five countries: Australia, Indonesia, the Philippines, France and Papua New Guinea. The GCRMN ranking gives Australia 16.88%, Indonesia 15.26% and the Philippines 9.74% of reef surface, a cumulative 41.88% for the three, which is more than one-third.
  • ✓ 3. The UN's World Ocean Assessment says reefs host 32 of the 34 recognised phyla, nearly all of them. UPSC's official key treats this statement as correct; we could not confirm the comparison with rainforests from an official source, so we do not explain it here.

Remember · Reefs: mostly tropical, concentrated in a few countries (Australia, Indonesia, Philippines hold about 42%), and home to 32 of 34 animal phyla.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 12 (practise this chapter)

Sources

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

The Syllabus X-Ray of this topic

2 of its 6 sub-topics are High

0 Core · 2 High · 2 Steady · 2 Rare

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The X-Ray ranks all 928 sub-topics of the UPSC syllabus by what UPSC has asked since 2016. The 60 Prelims Core sub-topics are behind 51% of Prelims questions.

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The same topic in Mains

Read it in NCERT