Oceans #1

Which is the main source of dissolved oxygen in the ocean?

• underwater earthquakes

• decay of living organisms

• animals that live near the surface

• plants and algae that live near the surface

Which is able to give the most detailed information about the topography of a large area on the ocean floor?

• Sonar

• Submersibles

• satellite imagery

• teams of scuba divers

Which contributes most in supporting life on the deep ocean floor?

• cold water temperatures

• extreme water pressure

• hydrothermal vents

• lack of predators

Which hazard must submersible vehicles overcome while exploring and studying the deep ocean zone?

• high waves

• increased salinity

• high water pressure

• underwater mountain ranges

Why do large numbers of ocean life­forms live near areas of upwelling?

• Upwelling brings nutrients to the surface.

• Upwelling brings warm water to the surface.

• Upwelling helps push small fish up toward the surface.

• Upwelling keeps large predator fish away from the surface.

Why are many fishing boats found near ocean upwellings?

• There is less vegetation there.

• The water is less turbulent there.

• Many marine species gather there to eat the nutrients brought to the surface.

• Upwellings are found in more shallow waters, so boats do not need deep anchorage.

Which causes cold ocean water to rise during an upwelling event?

• motion of organisms

• deep water currents

• mass of nutrients

• surface winds

The diagram shows the surface winds and water in a coastal area.

• density currents

• downwelling

• spring tide

• upwelling

Deep ocean technology has discovered organisms in hydrothermal vents that do not rely on sunlight to survive. What do these organisms use as their energy source?

• chemosynthesis

• electrical charge

• hydropower

• thermal heat

Which is most likely to be the energy source for organisms living in hydrothermal vents?

• oxygen

• sunlight

• methane

• carbon dioxide