A coral reef is made of thin layers of calcium carbonate. Coral polyps form a living mat over a calcium carbonate skeleton. Stony corals (or scleractinians) are the corals primarily responsible for laying the foundations of, and building up, reef structures.
Its called central vacuole
The greenhouse effect occurs when rays enter our atmosphere and are reflected from the ground up. They get changed during their voyage through our atmosphere and they change in such a way that they can't leave the atmosphere anymore. Then they stay inside and heat up the planet which causes thing like global warming. That's what the greenhouse effect is.
It would disrupt the CO2 cycle, since plants would no longer absorb carbon dioxixde, nor let out oxygen meaning it would also provide animals with little oxygen, and they can’t produce CO2 then either