Coral Reefs & Bleaching: 10 Explained Questions

Check your knowledge of coral polyps, reef skeletons, symbiotic algae and what NOAA means by coral bleaching.

Choose one answer per question. There’s no timer. You can skip a question; unanswered questions count as incorrect.

QUESTION 01Are corals animals, plants, or rocks?

AnimalsPlantsRocksFungi

QUESTION 02What is the soft-bodied animal unit in a coral colony called?

KelpPolypKrillBarnacle

QUESTION 03Which mineral forms the hard skeleton of reef-building stony corals?

GranitePure ironCalcium carbonateRock salt

QUESTION 04What does the term zooxanthellae commonly refer to in coral reefs?

The coral’s tentaclesA type of sea urchinFragments of beach sandPhotosynthetic symbiotic algae

QUESTION 05What best describes the coral–zooxanthellae relationship?

Mutualistic symbiosisPredation without benefitCompetition for sunlightA connection between two rocks

QUESTION 06What does coral bleaching usually indicate?

Instant and certain death of all coralLoss of symbiotic algae during environmental stressA coral changing into a plantNormal yearly shedding of its skeleton

QUESTION 07Is a bleached coral always already dead?

Yes, bleaching proves deathOnly if it is a soft coralNo, some bleached corals can recoverOnly during a new moon

QUESTION 08What environmental condition is a major trigger for coral bleaching?

A normal sunriseLow tides in all casesThe presence of dolphinsUnusually warm seawater

QUESTION 09Which describes many reef-building corals?

Colonies of animals depositing hard skeletonsSubmerged terrestrial treesMineral formations with no organismsLarge fish resting on the seafloor

QUESTION 10Why is sunlight important to many shallow coral reefs?

It turns seawater into fresh waterIt fuels photosynthesis in symbiotic algaeIt eliminates the need for coral polypsIt makes every reef identical in color

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Coral Reefs & Bleaching: 10 Explained Questions

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