Marine Biogeochemical Cycles

Description: Test your knowledge on Marine Biogeochemical Cycles, the intricate processes that govern the movement and transformation of elements and compounds in the marine environment.
Number of Questions: 15
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Tags: marine biogeochemistry oceanography biogeochemical cycles
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What is the primary driver of the biological pump in the ocean?

  1. Phytoplankton photosynthesis

  2. Zooplankton grazing

  3. Bacterial decomposition

  4. Upwelling of deep waters


Correct Option: A
Explanation:

Phytoplankton photosynthesis is the initial step in the biological pump, where phytoplankton convert inorganic carbon into organic matter through photosynthesis.

Which element is the limiting factor for primary production in vast regions of the ocean?

  1. Nitrogen

  2. Phosphorus

  3. Iron

  4. Silicate


Correct Option: C
Explanation:

Iron is a limiting factor for primary production in many parts of the ocean, particularly in high-nutrient, low-chlorophyll regions.

What is the process by which organic matter produced in the surface ocean sinks to the deep ocean?

  1. Export production

  2. Remineralization

  3. Upwelling

  4. Denitrification


Correct Option: A
Explanation:

Export production refers to the sinking of organic matter from the surface ocean to the deep ocean.

Which marine organism plays a crucial role in the remineralization of organic matter in the deep ocean?

  1. Copepods

  2. Foraminifera

  3. Bacteria

  4. Diatoms


Correct Option: C
Explanation:

Bacteria are responsible for the majority of remineralization of organic matter in the deep ocean.

What is the primary mechanism for the removal of carbon dioxide from the atmosphere and its storage in the ocean?

  1. Photosynthesis

  2. Respiration

  3. Diffusion

  4. Volcanic activity


Correct Option: A
Explanation:

Photosynthesis by marine phytoplankton is the primary mechanism for the removal of carbon dioxide from the atmosphere and its storage in the ocean.

Which marine ecosystem is particularly efficient at sequestering carbon dioxide from the atmosphere?

  1. Coral reefs

  2. Mangrove forests

  3. Kelp forests

  4. Seagrass meadows


Correct Option: B
Explanation:

Mangrove forests are highly efficient at sequestering carbon dioxide from the atmosphere due to their high productivity and the accumulation of organic matter in their sediments.

What is the process by which nitrogen gas in the atmosphere is converted into a form usable by marine organisms?

  1. Nitrogen fixation

  2. Nitrification

  3. Denitrification

  4. Anammox


Correct Option: A
Explanation:

Nitrogen fixation is the process by which nitrogen gas in the atmosphere is converted into a form usable by marine organisms, primarily through the action of certain bacteria.

Which marine organism is primarily responsible for the production of dimethyl sulfide (DMS), a compound that plays a role in cloud formation?

  1. Phytoplankton

  2. Zooplankton

  3. Bacteria

  4. Fish


Correct Option: A
Explanation:

Phytoplankton are the primary producers of dimethyl sulfide (DMS) in the marine environment.

What is the primary mechanism for the removal of excess carbon dioxide from the ocean?

  1. Photosynthesis

  2. Respiration

  3. Calcification

  4. Upwelling


Correct Option: C
Explanation:

Calcification, the process by which marine organisms form calcium carbonate shells or skeletons, is a major mechanism for the removal of excess carbon dioxide from the ocean.

Which marine ecosystem is particularly vulnerable to ocean acidification, a decrease in ocean pH caused by the absorption of carbon dioxide?

  1. Coral reefs

  2. Mangrove forests

  3. Kelp forests

  4. Seagrass meadows


Correct Option: A
Explanation:

Coral reefs are particularly vulnerable to ocean acidification because the decrease in pH makes it more difficult for corals to build their calcium carbonate skeletons.

What is the process by which organic matter is broken down and converted into inorganic compounds?

  1. Photosynthesis

  2. Respiration

  3. Decomposition

  4. Nitrification


Correct Option: C
Explanation:

Decomposition is the process by which organic matter is broken down and converted into inorganic compounds.

Which marine organism plays a crucial role in the cycling of sulfur in the ocean?

  1. Phytoplankton

  2. Zooplankton

  3. Bacteria

  4. Fish


Correct Option: C
Explanation:

Bacteria play a crucial role in the cycling of sulfur in the ocean, particularly through the processes of sulfate reduction and sulfide oxidation.

What is the primary mechanism for the removal of excess nitrogen from the ocean?

  1. Denitrification

  2. Nitrification

  3. Anammox

  4. Nitrogen fixation


Correct Option: A
Explanation:

Denitrification is the primary mechanism for the removal of excess nitrogen from the ocean, converting nitrate and nitrite into nitrogen gas.

Which marine ecosystem is particularly important for the cycling of mercury, a toxic heavy metal?

  1. Coral reefs

  2. Mangrove forests

  3. Kelp forests

  4. Seagrass meadows


Correct Option: B
Explanation:

Mangrove forests are particularly important for the cycling of mercury, as they can accumulate and transform mercury into less toxic forms.

What is the process by which dissolved organic matter (DOM) is converted into particulate organic matter (POM)?

  1. Aggregation

  2. Coagulation

  3. Flocculation

  4. Sedimentation


Correct Option: A
Explanation:

Aggregation is the process by which dissolved organic matter (DOM) is converted into particulate organic matter (POM) through the formation of larger particles.

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