Ocean Carbon and Nutrient Cycles

The video discusses the chemistry of the ocean, highlighting its role in Earth's productivity and oxygen supply. It explains biogeochemical cycles, the movement of elements, and the importance of various elements for marine life. The video also covers nutrient limitations, carbon cycling, and the mechanisms of physical and biological carbon pumps.

What percentage of Earth's primary productivity is contributed by the ocean?

• 10%

• 25%

• 75%

• 50%

Which cycle involves the movement of elements among the lithosphere, atmosphere, and hydrosphere?

• Hydrological cycle

• Carbon cycle

• Biogeochemical cycle

• Nitrogen cycle

What is the approximate percentage of oxygen in seawater compared to the atmosphere?

• 21%

• 0.4% to 0.6%

• 5% to 10%

• 15% to 20%

Which organism is primarily responsible for nitrogen fixation in the ocean?

• Zooplankton

• Diatoms

• Phytoplankton

• Cyanobacteria

What is the main form of phosphorus found in aquatic habitats?

• Carbonate

• Nitrate

• Sulfate

• Phosphate

What is the second most abundant element in the ocean that limits diatom populations?

• Silicon

• Iron

• Nitrogen

• Carbon

What process involves the transfer of carbon from the ocean surface to the deep ocean?

• Carbon cycling

• Carbon sequestration

• Photosynthesis

• Carbon fixation

Which type of carbon pump involves the movement of currents and upwelling?

• Chemical pump

• Physical pump

• Thermal pump

• Biological pump

What role do photosynthetic plankton play in the carbon cycle?

• They store carbon

• They release carbon

• They fix carbon

• They decompose carbon

What happens to carbon when phytoplankton die and decompose?

• It evaporates

• It settles in the deep ocean

• It is released into the atmosphere

• It is absorbed by fish