Question

name mackenzie
coral reefs are some of the most diverse and productive ecosystems on earth, often called the
ainforests of the sea.\ they are built by tiny animals called coral polyps. each polyp secretes a hard calcium carbonate skeleton, and over thousands of years these skeletons accumulate to form massive reef structures. corals have a special partnership with microscopic algae called zooxanthellae. these algae live inside the corals tissues, performing photosynthesis and providing the coral with most of its energy. in return, the coral provides the algae with a protected home and nutrients.
coral reefs thrive in clear, warm, shallow water where sunlight can penetrate, because both the corals and their algae depend on light. reefs support an incredible array of life, including fish, crustaceans, mollusks, sea turtles, and many more. they provide food, coastal protection, and billions of dollars in tourism and fisheries revenue.
despite their importance, coral reefs are under serious threat. climate change is causing ocean temperatures to rise. when water gets too warm, the relationship between the coral and its algae breaks down—a process known as coral bleaching. without their algae, corals turn white and can starve. pollution, overfishing, destructive fishing practices, and ocean acidification also weaken reefs.
scientists and conservationists are working to protect reefs through marine protected areas, reef restoration projects, and reductions in carbon emissions. while reefs face many challenges, they can recover if conditions improve. understanding how they function and why they are at risk is an essential first step in protecting these unique ecosystems for the future.

1. what tiny animals are responsible for building coral reefs?

a. sea anemones
b. coral polyps
c. plankton
d. marine worms

1. the hard structure of a reef is formed from:

a. calcium carbonate
b. silica
c. iron deposits
d. crushed shells only

1. zooxanthellae provide corals with energy by:

a. breaking down minerals
b. performing photosynthesis
c. filtering seawater
d. producing heat

1. why do corals provide nutrients to zooxanthellae?

a. to keep algae from leaving
b. to support their mutualistic relationship
c. to attract fish
d. to absorb more sunlight

1. coral reefs thrive in shallow water mainly because:

a. they need strong waves
b. they rely on sunlight
c. they grow faster in cold water
d. they require high pressure

1. based on the passage, coral reefs are compared to rainforests because:

a. both are hot
b. both are diverse ecosystems
c. both are made of trees
d. both are growing on land

1. which organism is least likely to depend on a coral reef habitat?

a. clownfish
b. parrotfish
c. sea turtles
d. penguins

1. coral bleaching occurs when:

a. corals eject their zooxanthellae
b. corals become overfed
c. corals expand too quickly
d. corals lack calcium

Explanation:

For question 1: The passage says "They are built by tiny animals called coral polyps", so the answer is B.
For question 2: "Each polyp secretes a hard calcium carbonate skeleton", so the answer is A.
For question 3: "These algae live inside the corals’ tissues, performing photosynthesis and providing the coral with most of its energy", so the answer is B.
For question 4: The relationship between coral and zooxanthellae is mutualistic (coral provides home and nutrients, algae provides energy), so coral provides nutrients to support this relationship, answer is B.
For question 5: "Coral reefs thrive in clear, warm, shallow water where sunlight can penetrate, because both the corals and their algae depend on light", so answer is B.
For question 6: "Coral reefs are some of the most diverse and productive ecosystems on Earth, often called the 'rainforests of the sea'", rainforests are also diverse ecosystems, so answer is B.
For question 7: Penguins live in cold, Antarctic - like environments, not coral reef habitats (which are warm, shallow marine environments), while clownfish, parrotfish, and sea turtles are associated with coral reefs. So answer is D.
For question 8: "When water gets too warm, the relationship between the coral and its algae breaks down - a process known as coral bleaching" (implies corals eject their zooxanthellae), so answer is A.

Answer:

1. B. Coral polyps
2. A. Calcium carbonate
3. B. Performing photosynthesis
4. B. To support their mutualistic relationship
5. B. They rely on sunlight
6. B. Both are diverse ecosystems
7. D. Penguins
8. A. Corals eject their zooxanthellae