Question

1. bleached corals appear white because:

a. their skeletons become exposed
b. they produce white pigments
c. their algae turn silver
d. fish clean off their color

1. which of the following is a human activity that harms coral reefs?

a. reducing carbon emissions
b. sustainable fishing
c. destructive fishing
d. creating marine protected areas

1. ocean acidification makes it harder for corals to:

a. absorb heat
b. build skeletons
c. reproduce
d. produce light

1. which reason best explains why coral reefs help protect coastlines?

a. they reflect sunlight
b. their structures reduce the energy of waves
c. they increase marine mammal populations
d. they produce freshwater

1. based on the passage, a major economic benefit of coral reefs is:

a. providing freshwater resources
b. offering space for wind farms
c. supporting tourism and fisheries
d. increasing rainfall

1. if sunlight could no longer reach shallow waters, what would likely happen to most coral reefs?

a. they would produce more algae
b. they would stop receiving enough energy
c. they would grow faster
d. they would move to deeper water

1. why might overfishing harm coral reef ecosystems?

a. it removes predators that protect coral
b. it reduces species that help keep algae in balance
c. it creates more sunlight for corals
d. it increases calcium in seawater

1. a reef that has lost many of its corals will probably:

a. gain more fish species
b. lose biodiversity
c. grow taller
d. produce more energy

1. which best describes the coral - zooxanthellae relationship?

a. mutualistic
b. parasitic
c. competitive
d. predatory

1. marine protected areas are designed to:

a. limit harmful human activities
b. remove all algae
c. add chemicals to reefs
d. increase coastal construction

1. restoration projects often involve:

a. planting coral fragments
b. building artificial islands
c. lowering sea level
d. removing all fish species

1. rising ocean temperatures are dangerous to corals because:

a. corals prefer freezing water
b. heat can force out their algae
c. heat expands coral skeletons
d. warm water dissolves sand

1. the passage suggests that coral reefs are productive ecosystems because they:

a. require no energy to survive
b. support many species
c. form in deep dark water
d. move across the ocean

1. why is clear water important for coral reefs?

a. sediments block sunlight needed for photosynthesis
b. predators hide in clear water
c. clear water is colder
d. clear water contains more nutrients

Explanation:

Question 9

Coral bleaching occurs when corals expel the symbiotic algae (zooxanthellae) living in their tissues, which exposes their white calcium carbonate skeletons. Option A matches this process. Option B is incorrect as corals don't produce white pigments during bleaching. Option C is wrong because algae don't turn silver. Option D is incorrect as fish don't clean off coral color.

Destructive fishing (e.g., using dynamite or cyanide) damages coral reefs. Reducing carbon emissions (A), sustainable fishing (B), and creating marine protected areas (D) are activities that help or protect coral reefs, not harm them.

Ocean acidification increases the concentration of hydrogen ions in seawater, which reduces the availability of carbonate ions. Corals use carbonate ions to build their calcium carbonate skeletons, so acidification makes it harder for them to build skeletons. Option A is incorrect (corals don't absorb heat for structure), C (reproduction isn't directly hindered by acidification in this way), D (corals don't produce light).

Answer:

A. Their skeletons become exposed

Question 10