May 17 B

Which of the gases below is found at high levels near the surface of the ocean due to plant photosynthesis?

• oxygen

• neon

• nitrogen

• carbon dioxide

Which of the following is the best example of a food chain in a marine ecosystem?

• orca whale → seals → algae → salmon

• phytoplankton → mussels → otters → tuna fish → octopus

• algae → phytoplankton → shark → crab

• phytoplankton → krill → herring → mackerel → shark

Currents caused by differences in water density are most often the result of

• uniform salinity and wind.

• uniform temperature and salinity.

• differences in temperature and salinity.

• differences in salinity and wind.

Deep ocean technology has allowed scientists to discover and study organisms living near deep-sea vents. Unlike surface organisms, these organisms survive on a food web based on chemosynthesis instead of photosynthesis. Deep-sea vent organisms live in complete darkness under extreme pressure. What are deep-sea vent organisms evidence of?

• a source of light other than sunlight on the ocean floor

• the ability of plants to survive without light

• the rich diversity of marine life

• the harm pollution can do to marine ecosystems

Which of the following is a benefit of the process of upwelling?

• Warm water is brought to the surface of the ocean to increase its coastal air temperature.

• The wind sweeps warm water toward the ocean's shore to increase erosion.

• Pollutants, such as mercury, are circulated from the ocean's bottom to the surface.

• Large amounts of dissolved nutrients are brought to the ocean's surface.

Which of the following best describes why estuaries are important resources?

• They are the world's richest sources of precious metals.

• They are among the most productive types of ecosystems.

• They help stabilize the global climate.

• They prevent weathering of rock from slopes and cliffs.

Which process is diagrammed in the figure below?

• Evaporation

• tidal surge

• continental drift

• upwelling

Which factor best explains why estuaries provide a safe environment for young animals?

• Constant changes in salinity and temperature prevent predators from surviving.

• High pressure, cold temperatures, and lack of light prevent many predators from surviving.

• Pollutants from inflowing rivers provide nutrients that support the development of young animals.

• Estuaries are rich in nutrients and contain roots and grasses that provide shelter for young animals.

The population of photosynthetic organisms is higher in the neritic zone and surface waters than in the deep ocean. Which statement best explains the reason for this?

• There is more space for plants to grow in these areas of the ocean.

• There is more dissolved oxygen for plants in these areas of the ocean.

• The availability of sunlight and nutrients supports photosynthetic organisms.

• The high salinity and cool temperature supports photosynthetic organisms.

What is the most likely result of overfishing in oceans?

• disrupted balance in ocean food webs

• increased reproduction of fish species

• disrupted ocean temperature patterns

• increased ocean food web productivity