Question

Fringing reefs note. Class 11th bio

Answer 1

Coral reefs are built by and made up of thousands of tiny animals—coral “polyps”—that are related to anemones and jellyfish.Polyps are shallow water organisms which have a soft body covered by a calcareous skeleton. The polyps extract calcium salts from sea water to form these hard skeletons.The polyps live in colonies fastened to the rocky sea floor.The tubular skeletons grow upwards and outwards as a cemented calcareous rocky mass, collectively called corals.When the coral polyps die, they shed their skeleton [coral] on which new polyps grow.The cycle is repeated for over millions of years leading to accumulation of layers of corals [shallow rock created by these depositions is called reef].These layers at different stages give rise to various marine landforms. One such important landform is called coral reef.Coral reefs over a period of time transform or evolve into coral islands (Lakshadweep).The corals occur in different forms and colours, depending upon the nature of saltsor constituents they are made of.Small marine plants (algae) also deposit calcium carbonate contributing to coral growth.