Answer:
coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Explanation:
that is all I can say.
A class of lipids derived from cholesterol are called steroids.
Steroids are important large class of biological molecules which are significant components of cell membrane and signaling molecules.
I would say that active transport is the answer because it's from LOW concentration to HIGH concentrations, so it's going against the concentration gradients.
With the exception of echinoderms, invertebrates are protostomes; chordates, echinoderms and vertebrates are deuterostomes.
