Explain how zooxanthellae have a symbiotic relationship with coral.

There is a symbiotic relationship between algae called zooxanthellae and coral. Coral provides a place to live protecting these microscopic algae from direct ultraviolet light and giving them nutrients such as ammonium and phosphate. Algae provide coral with substances necessary for growth, calcification, nutrition and development, because they transfer the products of photosynthesis.

"a.) well–developed vascular system."