Q. With reference to coral reefs consider the following statements:
1. The biggest coral reefs are generally found in water of the tropics and subtropics.
2. The Great Barrier Reef in Australia is the largest coral reefs in the world.
3. Barrier reef grows seaward directly from the shore.
Which of the statements given above are correct?

[A] 1 and 3 only

[B] 2 and 3 only

[C] 1 and 2 only

[D] 1, 2 and 3

Answer: C
Notes:

Statement 1: big coral reefs are mostly found in the clear and shallow water of the tropic and sub tropics.

Statement 2: The Great Barrier Reef in Australia is the largest coral reefs in the world.

Statement 3; The statement is incorrect. Barrier reef is separated from mainland by lagoon and they only grow when there is a change in the sea level and where land is sinking faster in water. Source: https://www.thehindu.com/sci-tech/energy-and-environment/heat-resilient-red-sea-reefs-offer-last-stand-for-corals/article65991661.ece