Biogeochemical Cycles Quiz

What is a major human activity that impacts the phosphorus cycle?

• Deforestation

• Overfishing

• Industrial emissions

• Burning fossil fuels

Why is phosphorus essential for living organisms?

• It is a component of chlorophyll

• It forms the backbone of DNA

• It is used in photosynthesis

• It is a primary component of proteins

How do seabirds contribute to the phosphorus cycle?

• By consuming oceanic plants

• Through their guano, which returns phosphorus to the soil

• By building nests in phosphorus-rich areas

• By migrating across continents

What is the first step in the nitrogen cycle?

• Ammonification

• Nitrification

• Nitrogen fixation

• Denitrification

Which process converts ammonia into nitrite and then nitrate?

• Nitrogen fixation

• Assimilation

• Nitrification

• Denitrification

What percentage of the Earth's atmosphere is made up of nitrogen?

• 78%

• 33%

• 21%

• 50%

How do human activities contribute to the nitrogen cycle?

• By eliminating nitrogen-fixing bacteria

• By decreasing soil nitrogen levels

• By increasing nitrogen through fertilizers and fossil fuel burning

• By reducing atmospheric nitrogen

What is a major source of sulfur dioxide in the atmosphere?

• Volcanic eruptions

• Combustion of fossil fuels

• Photosynthesis

• Ocean currents

Which sulfur compound is most abundant in the atmosphere?

• Carbonal sulfide

• Hydrogen sulfide

• Sulfur dioxide

• Carbon disulfide

What natural process contributes to the sulfur cycle?

• Photosynthesis

• Sea spray

• Lightning

• Volcanic eruptions