1. A. carbon dioxide B. oxygen C. nitrogen
16. Coral animals survive BEST in warm water. Which material is MOST abundant in warm water?
A. carbon dioxide
B. oxygen
C. nitrogen

2. A. sonar B. robots C. depth gauges D. satellite imaging
17. Which technology is MOST efficient in mapping large areas of the ocean floor?
A. sonar
B. robots
C. depth gauges
D. satellite imaging

3. 18. How does upwelling in the ocean affect algae populations in that area?
A. The algae populations grow slowly and force marine life to move out to sea.
B. The current produced by the upwelling forces the algae population to relocate.
C. The algae population becomes depleted as a result of colder water temperatures.
D. The nutrients supplied as a result of the upwelling causes algae to become abundant.

4. 19. What would MOST LIKELY happen to the entire ocean food web if plankton were not available?
A. All organisms that live in the ocean would not survive.
B. The organisms would adapt and find another source of food.
C. Only whales and other large ocean mammals would be affected.

5. 20. Why are estuaries often valued as the center of human coastal communities?
A. Estuaries create mild habitats for deep sea life.
B. Estuaries enhance marine biology resources for the future.
C. Estuaries are needed to filter pollution out of ocean water.
D. Estuaries provide a place for people to live, fish, and swim.

6. 21. Organisms that live in an intertidal zone must be able to tolerate which changes to survive?
A. changes in temperature but not salinity
B. changes in salinity but not temperature
C. changes in both temperature and salinity
D. changes in neither temperature nor salinity

7. A. algae B. small fish C. photosynthesis D. chemosynthesis
22. Which MOST LIKELY provides energy to tubeworms that live on the deep ocean bottom?
A. algae
B. small fish
C. photosynthesis
D. chemosynthesis

8. 23. Which are the 2 main sources of dissolved oxygen in the ocean?
A. surface air and ocean plants
B. warm water vents and Earth's core
C. underwater volcanoes and earthquakes
D. animal respiration and dead matter decomposition

9. A. bog B. canyon C. estuary D. hydrothermal vent
24. Which natural feature protects inland bodies of water from contamination by salt water?
A. bog
B. canyon
C. estuary
D. hydrothermal vent

10. 25. How do mussels adapt to changing tides near shore?
A. Mussels adapt by burying underground when the tide goes out.
B. Mussels adapt by tightly closing their shells when the tide goes out.
C. Mussels adapt by attaching firmly to rocks on the shore when the tide goes out.

11. 26. Which BEST describes the source of oxygen in ocean water?
A. Oxygen is produced by marine plants in the process of making food.
B. Oxygen is produced through the exhalation of marine animals.
C. Oxygen is produced through precipitation falling into the ocean.
D. Oxygen is produced by nodules on the ocean floor.

12. A. barometer B. satellite C. submersible
27. Which invention allowed individuals to better perform research at ocean depths greater than 100 feet?
A. barometer
B. satellite
C. submersible

13. 28. Which BEST explains why estuaries are an important habitat for many marine organisms in comparison to the open ocean?
A. There is less food in estuaries.
B. There are more predators in estuaries.
C. There is more salt available in estuaries.
D. There are more nutrients available in estuaries.

14. 29. Why is productivity greatest near the ocean's surface?
A. More predators live in the top layers of the ocean.
B. Salinity at all layers of the open ocean is fairly consistent.
C. Sunlight penetrates the top layers of the ocean so photosynthesis occurs there.
D. Nutrients, minerals, and gases are more available to marine life in the bottom layers of the ocean.

15. 30. Which BEST illustrates how aquatic and terrestrial food webs are interconnected?
A. sharks eat smaller fish in the ocean
B. algal blooms feed the fish populations
C. phytoplankton use sunlight to produce food
D. red tide in the sea poisons land plants and animals