Ecology Biogeochemical Nutrient Cycles 2

Question 1

Which process converts dissolved nitrate (NO₃⁻) back into atmospheric nitrogen gas (N₂)?

Accepted Answer

Denitrification

Answer

Nitrification

Answer

Ammonification

Answer

Nitrogen fixation

Question 2

In the phosphorus cycle, which reservoir holds the largest long-term store of phosphorus?

Accepted Answer

Sedimentary rocks

Answer

Ocean water

Answer

Living biomass

Answer

Soil organic matter

Question 3

What is the term for the release of nutrients from decomposing organic matter back into inorganic form?

Accepted Answer

Mineralization

Answer

Immobilization

Answer

Assimilation

Answer

Volatilization

Question 4

Which gas released from wetlands and rice paddies is a significant product of the carbon cycle and a potent greenhouse gas?

Accepted Answer

Methane (CH₄)

Answer

Carbon dioxide (CO₂)

Answer

Nitrous oxide (N₂O)

Answer

Hydrogen sulfide (H₂S)

Question 5

Sulfur enters the atmosphere naturally in large quantities primarily through which process?

Accepted Answer

Volcanic eruptions

Answer

Forest fires

Answer

Ocean evaporation

Answer

Animal respiration

Question 6

Which type of symbiosis is responsible for the majority of biological nitrogen fixation in terrestrial ecosystems?

Accepted Answer

Mutualism between Rhizobium and legumes

Answer

Parasitism between fungi and roots

Answer

Commensalism between algae and mosses

Answer

Competition between soil bacteria

Question 7

When a nutrient is taken up by microorganisms and incorporated into their biomass, making it temporarily unavailable to plants, this is called:

Accepted Answer

Immobilization

Answer

Leaching

Answer

Mineralization

Answer

Adsorption