National Geographic Coral Reefs

What are coral reefs made of?

• hard coral polyps

• rocks

• soft coral polyps

• none of the above

Which zone is found on the highest part of the reef?

• the reef flat zone

• the crest zone

• the reef slope zone

• the end zone

Which of these animals does not live along a coral reef?

• eel

• horse

• sea star

• giant clam

Which of these animals can be found along reefs at night?

• cone snail

• octopus

• shark

• all of them

Earth's largest coral reef system is off the coast of what country?

• Australia

• Belize

• Indonesia

• United States

How old are most coral reefs today?

• 5,000 to 10,000 years old

• 50,000 years old

• 500,000 years old

• 500 million years old

What can be harmful to coral reefs?

• fishing and boating

• pollution

• rising water temperatures

• all of them