Coral reefs are primarily formed by

The largest coral reef system in the world is the

The Great Barrier Reef lies off the coast of

Which of the following is not a type of coral reef?

The Lakshadweep Islands are examples of which type of coral reef?

Coral reefs are made of which substance?

Which factor is most essential for coral growth?

Coral reefs thrive best in water depth of

Which Indian Gulf region is known for its coral reefs?

Coral reefs contribute to the global economy mainly through