An illustration titled Coral Anatomy shows three coral polyps affixed to a base labeled D. The long, thin arms extending from each coral are labeled C. A blow up of the tissue of a long, thin arm identifies a row of cells containing small darts labeled A. Another row of algae cells is labeled B.

Question

Which is the part of the coral that is built up over thousands of years into a reef?
a
b
c
d

Answer 1

The part of the coral that is built up over thousands of years into a reef is labeled d. This refers to the base of the coral polyps, where the skeleton and structures are formed over time, contributing to the growth of the reef.