Most dissolved carbon in the ocean is used to form which structure in marine organisms?

The skeletons of coral polyps

Explanation:

A coral is a colony of many individual animals called polyps, originating from the replication of an initial polyp. The coral reef is made up of “zillions” of coral colonies and other limestone-depositing organisms, growing amidst the skeletons of their predecessors and the sand and sediment derived from them. Most of the dissolved carbon in the ocean is used to form the skeletons of coral polyps.

every el niño cycle is different. every year.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.