Question

the foundation of a coral reef is made of calcium carbonate (or limestone) that was created by
1)ancient coral polyps
2)volcanic eruptions
3)sea level change

Answer 1

The foundation of a coral reef is primarily made of calcium carbonate (or limestone) that was created by **1) ancient coral polyps**. Coral polyps are small marine animals that secrete calcium carbonate to form their hard skeletons. As these polyps live, grow, and die, their skeletons accumulate, forming the structure of the reef. Volcanic eruptions and sea level changes can influence the development and environment of reefs, but the primary construction material comes from the corals themselves.