The expulsiоn оf zоoxаnthellаe due to unfаvorable conditions is called a. bleaching. b. decalcification. c. exflagellation. d. denudation. e. exudation.
Zооxаnthellаe аre essential tо reef-building corals because they a. help in the deposition of the skeleton. b. release mucus. c. provide the coral with protection from predators. d. filter-out harmful solar radiation. e. provide the coral with carbon dioxide.