Question

UPSC Prelims 2018 Question:

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?

  1. 1. 1 and 2 only
  2. 2. 3 only
  3. 3. 1 and 3 only
  4. 4. 1, 2 and 3

Answer (Detailed Solution Below)

Option 4: 1, 2 and 3

Detailed Solution

Explanation:

  • Coral reefs can be found in tropical destinations around the world, mostly in areas around the equator where the water is warmer. So, statement 1 is correct.

  • Over half of the world’s coral reefs are found within six countries: Australia, Indonesia, Philippines, Papua New Guinea, Fiji, and the Maldives. The coastal waters of Australia, Indonesia and Philippines are home to more than one third of the world's coral reefs. So, statement 2 is correct.

  • Although they cover less than 0.1% of the earth’s surface, coral reefs are the most biodiverse marine ecosystem in the world. Coral reefs are home to 4,000 species of reef fish, 840 species of corals and over 1 million species of other animals. Coral reefs are also home to 32 of 34 recognized animal Phyla whereas only 9 are found in tropical rainforests. Thus, it has more number of animal phyla than those hosted by tropical rainforests. So, statement 3 is correct.

Therefore, option (4) is the correct answer.

Subject: Environment | Biodiversity and Conservation

Latest UPSC Exam 2026 Updates

Last updated on January, 2026

→ Check out the latest UPSC Syllabus 2026 here.

→ Join Vajiram & Ravi’s Interview Guidance Programme for expert help to crack your final UPSC stage.

UPSC Mains Result 2025 is now out.

UPSC Notification 2026 Postponed for CSE & IFS which was scheduled to be released on 14 January 2026.

UPSC Calendar 2026 has been released.

UPSC Prelims 2026 will be conducted on 24th May, 2026 & UPSC Mains 2026 will be conducted on 21st August 2026.

→ The UPSC Selection Process is of 3 stages-Prelims, Mains and Interview.

→ Prepare effectively with Vajiram & Ravi’s UPSC Prelims Test Series 2026 featuring full-length mock tests, detailed solutions, and performance analysis.

→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2026 for structured answer writing practice, expert evaluation, and exam-oriented feedback.

→ Join Vajiram & Ravi’s Best UPSC Mentorship Program for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

UPSC Result 2024 is released with latest UPSC Marksheet 2024. Check Now!

UPSC Toppers List 2024 is released now. Shakti Dubey is UPSC AIR 1 2024 Topper.

→ Also check Best UPSC Coaching in India

Vajiram Content Team
Vajiram Content Team
UPSC GS Course 2026
UPSC GS Course 2026
₹1,75,000
Enroll Now
GS Foundation Course 2 Yrs
GS Foundation Course 2 Yrs
₹2,45,000
Enroll Now
UPSC Mentorship Program
UPSC Mentorship Program
₹85000
Enroll Now
UPSC Sureshot Mains Test Series
UPSC Sureshot Mains Test Series
₹19000
Enroll Now
Prelims Powerup Test Series
Prelims Powerup Test Series
₹8500
Enroll Now
Enquire Now