Basics
Structure
Conditions
Nutrition
Threats
100

What phylum do corals belong to?

Cnidaria

100

What are the stinging cells used by corals?

Cnidocytes

100

What temperature range do coral reefs require?

16-35C (around 23-28C)

100

What algae live inside coral tissue?

Zooxanthellae
100

What is it called when coral turns white due to stress?

Coral bleaching

200

What is the adult form of a coral called?

Polyp

200
What are the toxin-injecting structures inside those cells?

Nematocysts

200

Up to what depth do reef-building corals grow?

About 20 meters

200

What type of relationship do corals have with these algae?

Mutualism

200

What is the decrease in ocean pH from CO2 called?

Ocean acidification

300

What is the free-swimming stage of coral called?

Planktonic larval stage

300

What substance forms the coral skeleton?

Calcium carbonate (CaCO3)

300

What must be low in water for light to penetrate?

Turbidity

300

What process do the algae use to make food?

Photosynthesis

300

Name one organism that eats coral 

Crown-of-thorns starfish/parrotfish/butterfly fish

400

What is the asexual reproduction method in corals?

Budding

400

What is the cup-like structure a coral polyp lives in?

Calyx

400

What types of surface do coral larvae attach to?

Hard substrate

400

What is it called when corals catch zooplankton?

Predation

400

What does sediment block that harms coral?

Light

500

What is the sexual reproduction method where corals release gametes?

Broadcast spawning

500

What are the walls of the calyx called?

Theca

500
What type of water is required for tropical reef formation?

Saltwater

500

What process allows corals to absorb dissolved organic matter?

Diffusion
500

What is it called when coral loses more calcium carbonate than it gains?

Reef erosion

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