GENERAL KNOWLEDGE

Detailed explanation-1: -Coral reefs are massive structures made of limestone deposited by coral polyps . Often referred to as the “rainforests of the sea, ‘’ coral reefs support approximately 25 percent of all known marine species.

Detailed explanation-2: -Many of these corals possess chemical properties that give them value as a source of lime. A need for rather large quantities of lime is also present.

Detailed explanation-3: -As corals grow, they produce limestone–calcium carbonate–skeletons which build up over time into vast reefs.