Reefs are formed by calcium carbonate produced by the coral polyps. As a single polyp dies, its soft tissue decays, but the calcium carbonate cup remains.Other polyps build on top of the cup, and when they die, other polyps will build on their cups. Over time, this process creates larger and larger coral reefs.While corals are the chief architects of the reef structure, they are not the only builders. Corallin algae cement various corals together with compounds of calcium, and other organisms such as tube worms andmollusks donate their hard skeletons to the construction.
The answer will mostly likely be D
Answer:
A is answer.
<h3>I don't know this is correct or incorrect.</h3>
<h3>But hope it is helpfully</h3>
The stem cells represent an exciting area in medicine because of their potential to regenerate and repair damaged tissue. Some current therapies, such as bone marrow transplantation, already make use of stem cells and their potential for regeneration of damaged tissues.